# Where does width come from?



## pionkej (Feb 29, 2008)

Ok, so this may seem like a "newb" question, but it's one I can't seem to find a good answer to...WHERE DOES WIDTH COME FROM?

I'm going to "clif note" some other points for now just to quantify where I'm coming from. Height cues come from around 3khz+ and it's why you can get good height by just putting tweeters up high (I understand shallow slopes to midbass/midrange down low can "rainbow" height, but I'm trying to keep this basic for now). Depth cues are generally from a lack of early reflections and hearing some late reflections, in my experience (which is why MS8 rear-fill helps with depth).* A good center image comes from solid balance between left and right and is primarily affected by midbass/midrange (ITD). I understand that head-shadowing in tweeters can also affect balance (ILD), but it's not the primary focus (i.e. it's easier to get a "center" with good MB spacing and poor tweeter placement than the other way around).

So, WHERE DOES WIDTH COME FROM? I ask because it seems there are two arguements commonly seen as I search.

-If you put your tweeters at the widest point, you will have good width (most people suggest sails).
-If you put MB/MR as wide as possible, you will have good width (most people say doors, but moving to kicks is worth the small width "sacrifice" for improved imaging).

I wouldn't think that width could be fixed by wide tweeters OR wide speakers, so I'm curious which actually DOES affect it. Is there a specific frequency that width comes from? Does phyical placement affect "acoustic" width? Do we need to be as 'wide as possible'? 

I would think that width, like depth, is mostly a function of reflections. Thinking that, I would argue that since it is nearly impossible to avoid reflections anywhere below 3khz or so because of wavelegnth AND because crosstalk is hard to also avoid in this range...treble frequencies are the answer to good width. I believe that the reason people have good luck with sail panels and width ISN'T because they are physically wider, but IS because it's generally the best place for avoiding early reflections. 

For the sake of making this short enough that people don't "give up" on this thread before even starting, I'll stop there and open up discussion. I'll make one last comment on my reflection theory first though: if you put a speaker in an anechoic chamber where no reflections where present to give you a "physical boundry"...how wide would the image be?



*Intensity differences can affect depth too (imagine your eyes closed and a speaker being moved closer towards you--increased intensity CAN lead to preceived depth or shallowness).


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## ErinH (Feb 14, 2007)

Physical boundaries and physical location. Like you've said, reflections due to the environment seem to be the driving factor. this effects the arrival time, yes, but IMO moreso the amplitude which helps to give a sense of breadth in the system. 
If we base it around time then ITD (below 1khz or so) would take precedent. If we say it's amplitude driven then ILD takes over and we focus on above 2khz. 
I'm going to go with ILD here but based in reflection. The further the reflection, the less amplitude impact it imparts. At least... That's how I'm seeing it. 

/weak reply from iPhone.


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## pionkej (Feb 29, 2008)

bikinpunk said:


> Physical boundaries and physical location. Like you've said, reflections due to the environment seem to be the driving factor. this effects the arrival time, yes, but IMO moreso the amplitude which helps to give a sense of breadth in the system.
> If we base it around time then ITD (below 1khz or so) would take precedent. If we say it's amplitude driven then ILD takes over and we focus on above 2khz.
> I'm going to go with ILD here but based in reflection. The further the reflection, the less amplitude impact it imparts. At least... That's how I'm seeing it.
> 
> /weak reply from iPhone.


Nice ninja edit.  That reply isn't as "weak" as your first one.

What gets me about physical boundaries is that some people can get a system to have apparent width outside the vehicle. If I'm reading your reply correctly, it also seems you mostly agree with my logic. If so, it still makes since why tweeters off-axis in the sails work so well for width. It isn't so much they are literally wide, but that they minimize (or delay and reduce the amplitude) reflections off the dash, windshield, and side glass.


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## minbari (Mar 3, 2011)

I liked the first reply better


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## GavGT (Sep 5, 2011)

I've also wondered about this, and i am going to be rebuilding my kicks soon so it will be interesting to see the responses. 

I have always thought having the speakers on axis helps, but unsure wether this is because of lack of reflections or a better FR. I plan on getting some metal baffles made up and tilting the edges of the midbass into the a frame, to get them more on axis AND wider at the same time.

Gav


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## highly (Jan 30, 2007)

Primary width cues are in the midrange. Primary stage width will be dictated by placement of whichever drivers are responsible for midrange frequencies. Ambient width can be augmented with treble placement. I've heard this called 'stage boundary' width. It is possible* to have primary width at or outside the pillars by placing the midranges far outboard and the tweeters in a central location designed to reduce early reflection. This can lead to a split image and other problems, however. 'Phantom' ambient width can be created with late reflection in the treble creating a heightened sense of LEV (Listener envelopment), and although it may be considered more pleasant it is also less accurate. Generating primary width outside the confines of the vehicle requires both physical width of the midrange-carrier and reflection control. I have not yet found a 'magic ratio' of direct to reflected sound in the midrange that guarantees that effect, but I feel it probable that one exists.

I'll go back to my references and try to pick out quotes (from Toole's Sound Reproduction) that reinforce the statements above. Until then, they are my opinions based on what I've determined experimentally in my car combined with information gleaned from hundreds of hours of reading. That should not be considered in any way conclusive.

Excellent subject , and I hope to hear people with experience chime in! I also look forward to the backing arguments as well. This is one of those subjects that deals with many interactions that I think challenge the installer to really understand what's happening. It's also an area that I think could use a bit of demystification. I'm not trying to say I have the knowledge to do that concisely, but I look forward to seeing other's thoughts on the matter!


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## pionkej (Feb 29, 2008)

I want to add another caveat. I think keeping directivity the same at crossover points is also important in helping width. If one speaker is beaming and the other has wide dispersion, you can localize the one that's beaming. I would think the key to width is not actually knowing where the soundfield ends. If you can localize by reflections at the physical boundry or by a speaker beaming, the effect is ruined and your stage stops WHEREVER that localization is.

That means either using a wideband setup, 3-way setup, or waveguides (like the JBL 660GTi) to avoid problem #2.


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## ErinH (Feb 14, 2007)

highly said:


> Primary width cues are in the midrange. Primary stage width will be dictated by placement of whichever drivers are responsible for midrange frequencies. Ambient width can be augmented with treble placement. I've heard this called 'stage boundary' width. It is possible* to have primary width at or outside the pillars by placing the midranges far outboard and the tweeters in a central location designed to reduce early reflection. This can lead to a split image and other problems, however. 'Phantom' ambient width can be created with late reflection in the treble creating a heightened sense of LEV (Listener envelopment), and although it may be considered more pleasant it is also less accurate. Generating primary width outside the confines of the vehicle requires both physical width of the midrange-carrier and reflection control. I have not yet found a 'magic ratio' of direct to reflected sound in the midrange that guarantees that effect, but I feel it probable that one exists.
> 
> I'll go back to my references and try to pick out quotes (from Toole's Sound Reproduction) that reinforce the statements above. Until then, they are my opinions based on what I've determined experimentally in my car combined with information gleaned from hundreds of hours of reading. That should not be considered in any way conclusive.
> 
> Excellent subject , and I hope to hear people with experience chime in! I also look forward to the backing arguments as well. This is one of those subjects that deals with many interactions that I think challenge the installer to really understand what's happening. It's also an area that I think could use a bit of demystification. I'm not trying to say I have the knowledge to do that concisely, but I look forward to seeing other's thoughts on the matter!


I think you and I are pretty much in agreeable. Hopefully I can get some computer time later and provide some sources as well.


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## Mic10is (Aug 20, 2007)

IMO you cannot get width to exceed the the boundaries of the speaker locations.
As Todd mentioned and We've had some great discussions on this-width cues are primarily in the midrange. There are some ambient cues above 4khz.

But the easiest way for me to explain this would be, its very difficult to be wider than the center of the speakers location and proximity to the outer boundary of the vehicle (apillar)
So if you have a speaker mounted somewhere and the center is 3" inside the pillar then your width will be primarily about that far inside.
There may be some ambient cues that pull the width out at certain freqs, but the primary stage width will be narrower.

also, note that some of this will have to do with how the media is mixed. Where the recording engineer "placed" images in the final mix etc...

also, when evaluating any aspect, either use a track especially designed to determine that aspect like the IASCA,EMMA disc or even the Chesky Disc with the tracks used for judging width.
Or
use multiple tracks, with your eyes closed or in the dark with an Open Mind.
Its amazing what people can make themselves hear.

also, practice and hear other reference systems.
Different people cue in on different frequencies. Its very interesting to note how people hear differently.
So knowing what you are using also helps.

Most inexperienced listeners tend to pick up on ambient cues 1st, so to them the car may seem wider than it really is. some pay attention to the "base" of the sound. some are able to process the entire spectrum together to determine a location. etc.. etc...


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## highly (Jan 30, 2007)

bikinpunk said:


> I think you and I are pretty much in agreeable.


In that case I meant something completely different.


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## pionkej (Feb 29, 2008)

Mic10is said:


> IMO you cannot get width to exceed the the boundaries of the speaker locations.
> As Todd mentioned and We've had some great discussions on this-width cues are primarily in the midrange. There are some ambient cues above 4khz.
> 
> But the easiest way for me to explain this would be, its very difficult to be wider than the center of the speakers location and proximity to the outer boundary of the vehicle (apillar)
> ...


Ok, I like this point. If you are correct, then shouldn't we aim for our width to be located however far outward we can get our midrange? Anything beyond that would not be actual "width" if that's the case but actually inaccurate ambient affects. 

I do also agree about inexperienced listeners to a degree. When I first started, I liked reflections from the tweeter because it made things sound "fuller". Now I pretty much hate them because you realize how fatiguing they can be and how that "fuller" adjective is actually "diffuse center image". 

What are your thought's on nailing down an actually frequency for "midrange". Is that 350-3khz? 80-1.5khz? Can you have a midbass in your door playing 60-200hz and "fix" the width of a midrange in the kicks or pillars (if not, didn't you just kill PLD's to try and help "width" when it really doesn't change anything)? 

This is the type of info I think we can get out there to help people. It is already there for height and depth IMHO, so I think we can at least work on some general ideas for getting good width...or at least something better than "XXX worked for me" type subjectivity.


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## chad (Jun 30, 2005)

In recording width can and does come from L-R information....

Sleep on that one for a bit


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## highly (Jan 30, 2007)

chad said:


> In recording width can and does come from L-R information....
> 
> Sleep on that one for a bit


Chad, you have been spending WAY too much time reading Lycan's posts. 

Dropping a bomb and leaving is just wrong.


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## sqshoestring (Jun 19, 2007)

I've had rears with no processing that with the right FR and right fading the car nearly sounded like headphones. I shoot for that with most of my personal installs, but sometimes don't have the time to get all the way there via trial and error.

I think spikes in the response destroy the illusion, this is worse when integrating rears. Note most rears are similar distance with less treble to make it work best. Not wanting to discuss 'rears' here, just saying it can work to pull the left out to the left, thus give a wide stage similar to headphones. I can't say exactly what makes it work or not, I often swap drivers in the rear and change the install until it works. Install meaning depth/angle of the driver, attenuating the tweeter mechanically or with install, etc. T/A gives a similar effect with the fronts alone but its not the same, at least in this car.


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## chad (Jun 30, 2005)

highly said:


> Chad, you have been spending WAY too much time reading Lycan's posts.
> 
> Dropping a bomb and leaving is just wrong.


I do it on the other side for a living 

Ever look at how old skool "dolby surround" worked?

they put that L-R somewhere.

you can get width AND depth from L-R and depending on where you place that information you can move, in reason, anything anywhere you want (within reason) it as long as you are recording anywhere outside an anechoic chamber. the 'ol M-S mic technique is a cool way to do this with few channels live.


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## Mic10is (Aug 20, 2007)

pionkej said:


> Ok, I like this point. If you are correct, then shouldn't we aim for our width to be located however far outward we can get our midrange? Anything beyond that would not be actual "width" if that's the case but actually inaccurate ambient affects.
> 
> I do also agree about inexperienced listeners to a degree. When I first started, I liked reflections from the tweeter because it made things sound "fuller". Now I pretty much hate them because you realize how fatiguing they can be and how that "fuller" adjective is actually "diffuse center image".
> 
> ...


Imaging localization typically start around 150hz or so. One of the very few things I ever agree with someone like Scott Buwalda with is I prefer to have a midrange that can cleanly play up as high as possible, preferably to at least 4 or 5khz.

So YES, IMO the goal is always to get the speakers as far away and as wide as possible and away from as many direct reflecting surfaces as possible.

The ability to do that at least gets you in very good neighborhood. after that the ability to control individual phase response, eq, time etc...can come into play to move things around.
I still donot fully understand How Mark Elderidge is able to do with his phased arrays--but from what I hear its amazing.
and I know after talking to him at Finals he is working on the ability to move the left side out physically much wider than the boundaries while keeping the right side at the pillar so in the driver seat -you are truley in the acoustic center listening position.

for the rest of us stick with the basics above.
If you can use acoustic treatments, they can help alot as well when used in the right places.


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## Mic10is (Aug 20, 2007)

Additional Info
CARSOUND.COM Forum - View Single Post - Pathlengths...Help Mark E.

Image Width - CARSOUND.COM Forum
The widest sound stage you've ever heard - CARSOUND.COM Forum
Im having a hard time finding... - CARSOUND.COM Forum

Great Thread and whats even better is this is from 2005 and we were discussing Harman (JBL) "new" processor which eventually 5 years later became the MS8
SQ Tuning 101? - CARSOUND.COM Forum


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## pionkej (Feb 29, 2008)

I can't tell everybody how much I appreciate this thread staying in a positive direction. The information has been good as have the links that Mic provided. I'm looking forward to seeing what Bikin and Highly can dig up as well. 

That being said, the comments below are a bit frustrating. I'm not trying to be a dick, but you can't really have one or the other. I understand Mark E. has more experience, resources, and processing power than most of us, but if it can be done...it CAN be done. If Mark can manipulate the sound to appear to come from beyond the driver's physical location, it means there is a "science" to width just as their is to height and depth. 

That is the purpose of this thread, to see how to get good width, what frequencies primarily control it, and if we can "width" to exceed the physical boundaries of the speakers themselves (without simply being inaccurate ambiance). I think we've got some solid stuff on #1, and a good idea of #2, so can we/how do we get to #3 in the car?



Mic10is said:


> IMO you cannot get width to exceed the the boundaries of the speaker locations.





Mic10is said:


> I still donot fully understand How Mark Elderidge is able to do with his phased arrays--but from what I hear its amazing.
> and I know after talking to him at Finals he is working on the ability to move the left side out physically much wider than the boundaries while keeping the right side at the pillar so in the driver seat -you are truley in the acoustic center listening position.


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## chad (Jun 30, 2005)

It's an undeniable fact that even in a closed environment you can get the stage to extend.... Headphones do it.

Ambio rigs do it.


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## 60ndown (Feb 8, 2007)

vacuum pumps.


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## 60ndown (Feb 8, 2007)

chad said:


> It's an undeniable fact that even in a closed environment you can get the stage to extend.... Headphones do it.


yup, every now and again even in my van a song comes on and the speakers disappear !!

f#ck knows how that happens?


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## Mic10is (Aug 20, 2007)

pionkej said:


> I can't tell everybody how much I appreciate this thread staying in a positive direction. The information has been good as have the links that Mic provided. I'm looking forward to seeing what Bikin and Highly can dig up as well.
> 
> That being said, the comments below are a bit frustrating. I'm not trying to be a dick, but you can't really have one or the other. I understand Mark E. has more experience, resources, and processing power than most of us, but if it can be done...it CAN be done. If Mark can manipulate the sound to appear to come from beyond the driver's physical location, it means there is a "science" to width just as their is to height and depth.
> 
> That is the purpose of this thread, to see how to get good width, what frequencies primarily control it, and if we can "width" to exceed the physical boundaries of the speakers themselves (without simply being inaccurate ambiance). I think we've got some solid stuff on #1, and a good idea of #2, so can we/how do we get to #3 in the car?


Todd can explain more about Mark's set up or maybe even Mark will come on here
1st of all, his car is purpose built for sound. the speakers as far forward as he can get them and as physically wide as possible-the car was basically built around the locations.

How many people are willing to go to these lengths?

Next, he is using arrays and has the ability to control the phase of each speaker in the array to align them to be a single source...

So Im not saying it CANT be done--more of--to what limits are you willing to go to attain it? both, in physical labor cutting and removing/relocating things, money for the processing to augment things etc...


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## pionkej (Feb 29, 2008)

Mic10is said:


> Todd can explain more about Mark's set up or maybe even Mark will come on here
> 1st of all, his car is purpose built for sound. the speakers as far forward as he can get them and as physically wide as possible-the car was basically built around the locations.
> 
> How many people are willing to go to these lengths?
> ...


I hear ya man, and I'm not willing/able to go to that length. What I'm getting at is that if he thinks he can do it with everything he's got, it means he knows what frequencies to manipulate to do it. THAT is what I'm getting at. 

We may not be able, or care, to do what Mark's car can, but knowing which frequencies primarily effect width MUST be known since Mark is planning to manipulate them.


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## Mic10is (Aug 20, 2007)

read thru the 1st carsound post--lots of hints there

or cliff notes version--reread Todds post


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## pionkej (Feb 29, 2008)

Mic10is said:


> read thru the 1st carsound post--lots of hints there
> 
> or cliff notes version--reread Todds post


OK. Two people who are reported to have the widest soundstages in MECA, that you asked me to re-read comments from, have essentially suggested the opposite of each other? Todd's car IS the widest I've personally heard for the record. 

Maybe Mark is talking about "ambient" width because it's much easier to get than a "primary" width Todd speaks of? That WOULD make sense because most people would be happy with "ambient" width, and then Mark can tell people to just place the tweeters high and wide and you're set. I have no idea if that's true, if one is right and the other is wrong, or if both approaches are right and can work. 

I'm not sure if your intention was to exemplify what I said in my first post (that there are various open-ended/differing comments on how to get width) or to try and tell me to "check again kiddo, you've already got the answer" (and if so, I did and I still don't see it).



highly said:


> *Primary width cues are in the midrange.* Primary stage width will be dictated by placement of whichever drivers are responsible for midrange frequencies. *Ambient width can be augmented with treble placement.* I've heard this called 'stage boundary' width. It is possible* to have primary width at or outside the pillars by placing the midranges far outboard and the tweeters in a central location designed to reduce early reflection. This can lead to a split image and other problems, however. 'Phantom' ambient width can be created with late reflection in the treble creating a heightened sense of LEV (Listener envelopment), and although it may be considered more pleasant it is also less accurate. Generating primary width outside the confines of the vehicle requires both physical width of the midrange-carrier and reflection control. I have not yet found a 'magic ratio' of direct to reflected sound in the midrange that guarantees that effect, but I feel it probable that one exists.
> 
> I'll go back to my references and try to pick out quotes (from Toole's Sound Reproduction) that reinforce the statements above. Until then, they are my opinions based on what I've determined experimentally in my car combined with information gleaned from hundreds of hours of reading. That should not be considered in any way conclusive.
> 
> Excellent subject , and I hope to hear people with experience chime in! I also look forward to the backing arguments as well. This is one of those subjects that deals with many interactions that I think challenge the installer to really understand what's happening. It's also an area that I think could use a bit of demystification. I'm not trying to say I have the knowledge to do that concisely, but I look forward to seeing other's thoughts on the matter!





CarSound said:


> Hmmm... path length differences... You might as well get that signal alignment device cause I'm not going to help you...
> 
> 
> 
> ...


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## thehatedguy (May 4, 2007)

It's a bit odd hearing a 12' wide stage coming from speakers 12" apart. But I have heard it with my own two ears.




chad said:


> Ambio rigs do it.


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## Mic10is (Aug 20, 2007)

Thanks for keeping a level head through all of this and wanting a true "understanding" of how some of this works.

Todd and Mark actually agree on the biggest point in that the most crucial component is the midrange. If you get that right then the rest becomes easier.

I am no expert by any means, there are many more qualified people to answer. majority of what I know is from years building competition cars and a ton more from doing exactly what you are doing and picking others brains who may have more scientific knowledge of how things work.


also, note that Mark highly recommends keeping the Mid and Tweets as close together as possible. If additional CUES for height are needed you can add an additional set.
So we're talking about drivers that can reproduce from around 150-5khz or so

also, I will apologize bc the the thread I referenced, Mark is more talking about the importance of pathlengths for imaging.

also there is a possibility that some of Mark's views have changed since that post and he has gone in a slightly different direction since he was using custom horns etc...
id be curious to know if they have indeed changed


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## chad (Jun 30, 2005)

Sometimes guessing TA by ear does not work and good test equipment helps a lot.... just sayin.....


Says he who scores a regular 5/6 out of stage width by looking at a computer sceen and punching in numbers in stock class.

Has world class conductors look outside the window to look for that extra string section.. etc. In fact I suffer a bit more on my center image to go big. My center is actually in front of ME.... because that's where I prefer it... I'm driving the damn car, not the e-brake.

Been saying this since I came here.. you CANNOT do TA by ear alone, it's impossible, some try, and get close, but not that close.

As for frequency dependencies, I disagree from THAT standpoint, it comes with overall engineering and thinking outside the box a bit. It's the whole shebang.


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## chad (Jun 30, 2005)

thehatedguy said:


> It's a bit odd hearing a 12' wide stage coming from speakers 12" apart. But I have heard it with my own two ears.


yup!


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## Mic10is (Aug 20, 2007)

chad said:


> Sometimes guessing TA by ear does not work and good test equipment helps a lot.... just sayin.....
> 
> 
> Says he who scores a regular 5/6 out of stage width by looking at a computer sceen and punching in numbers in stock class.
> ...


what freq range would you say plays the largest point in Width?I think thats what John is after?
or are you saying its an all encompassing effort that cant be put into a Box and say -this is how you do it??

But Chad does bring up a good point that I dont think anyone else mentioned.
To get one thing, you may sacrifice another.
There have been people who have had extraordinary width but their imaging was diffuse.


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## chad (Jun 30, 2005)

Width IMHO is NEVER EVER defined by a frequency band.


Go see a good classical performance in an even somewhat famous concert hall, you owe it to yourself.


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## cvjoint (Mar 10, 2006)

A lot of good info has already been given. I will add one point and some comments. 

This hasn't been mentioned yet. A lot of the SPL gets absorbed in the air itself. There is a differential impact depending on the frequency range. Highs should get absorbed quicker than lows. If your brain processes something with relatively low high frequency content it's probably likely to interpret the source as being farther. Not sure anybody would sacrifice linear response for it but anywho. 

If I had to pick the two most important aspects I would say:
1. Midranges far apart, 200hz-1,600hz 
2. Steering algorithm that works (MS8)




pionkej said:


> I want to add another caveat. I think keeping directivity the same at crossover points is also important in helping width. If one speaker is beaming and the other has wide dispersion, you can localize the one that's beaming. I would think the key to width is not actually knowing where the soundfield ends. If you can localize by reflections at the physical boundry or by a speaker beaming, the effect is ruined and your stage stops WHEREVER that localization is.
> 
> That means either using a wideband setup, 3-way setup, or waveguides (like the JBL 660GTi) to avoid problem #2.


However, on the other hand more dispersion should give you a harder time reducing early reflections. So which is it? I tend to think you want an omnidirectional source and no early reflections. In a home you just place speakers that have good dispersion far from a wall. 

In a car you can't just move your dash for example or your top (well I can ). That's when I find it crucial to have limited dispersion where reflections are most problematic. I think line arrays, planars or other vertical speakers, like ovals work great in a car in the pillars. You limit dispersion where it can hurt, dash and top, and give it free reign where it helps most and hurts least, horizontally. Aiming the pods equally far away from the windshield and windows probably works best. 

Then there is the path length difference by Carsound. With dispersion characteristics that match the car interior path length differences are not as important. It helps with the early reflections that would give away the speaker placement and TA does the rest. With a vertical rectangular speaker mounted up high you can also mount a tweeter close to get a better point source, have the stage high (1khz and up is high) and cross high 5khz or so like highly says. I presume the high crosspoint is good for transient response, phase distortion, and especially THD.


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## sqnut (Dec 24, 2009)

highly said:


> Primary width cues are in the midrange. Primary stage width will be dictated by placement of whichever drivers are responsible for midrange frequencies.





Mic10is said:


> So YES, IMO the goal is always to get the speakers as far away and as wide as possible and away from as many direct reflecting surfaces as possible.
> 
> I still donot fully understand How Mark Elderidge is able to do with his phased arrays--but from what I hear its amazing.
> and I know after talking to him at Finals he is working on the ability to move the left side out physically much wider than the boundaries while keeping the right side at the pillar so in the driver seat -you are truley in the acoustic center listening position.





bikinpunk said:


> reflections due to the environment seem to be the driving factor. this effects the arrival time, yes, but IMO moreso the amplitude which helps to give a sense of breadth in the system.
> I'm going to go with ILD here but based in reflection. The further the reflection, the less amplitude impact it imparts. At least... That's how I'm seeing it.


The concept of placing the drivers as far apart and as far forward as possible makes a lot of sense. That reflections play a part in defining the physical boundries, vis a vis width is also logical. There's one more issue that I'd like to raise and I'd be interested to know what folks think. I think width is also defined partly by IAC. 



> In stereophonics, the reproduced sound is distorted by crosstalk, where signals from either speaker reach not only the intended ear, but the opposite ear, causing comb filtering that distorts timbre of central voices, and creating false “early reflections” due to the delay of sound reaching the opposite ear. In addition, auditory images are bounded between left (L) and right (R) speakers, usually positioned at ±30° with respect to the listener, thereby including 60°, only 1/6 of the horizontal circle, with the listener at the center. Human hearing can locate sound from directions not only in a 360° circle, but a full sphere.
> 
> Ambiophonics eliminates speaker crosstalk and its deleterious effects. Using ambiophonics, auditory images can extend in theory all the way to the sides, at ±90° left and right and including the front hemi-circle of 180°, depending on listening acoustics and to what degree the recording has captured the interaural level differences (ILD) and the interaural time differences (ITD) that characterize two-eared human hearing. Most existing two channel discs (LPs as well as CDs) include ILD and ITD data that cannot be reproduced by the stereo loudspeaker “triangle” due to inherent crosstalk. When reproduced using ambiophonics, such existing recordings’ true qualities are revealed, with natural solo voices and wider images, up to 150° in practice.


Assume a 3 way setup with say mids and tweets on the pillars. The information from your right mid is reaching your right ear and part of it is also reching your left ear. Both by difracting around your face and by reflecting off the drivers side window. This is causing both comb filtering and it's limiting your width. As a simple exercise, roll down the front windows and chances are you'll hear a 'wider' stage. 

Now suppose you add an additional midrage on on both sides (hence array) with the extra mid on the drivers side (left) carrying right channel info in a narrow bandpass, say ~1-5khz, in reverse polarity and attenuated 10-12db's. If you could time this drivers arrival time to coincide with the diffracted / reflected of the R midrange, you would in effect cancel out the crosstalk. That's the theory. 

Polk used this in their SDA line back in the 70's/80's and these speakers project amazing width. IAC to my mind is much more relevant in a near field environment like a car than a far field, typical home setup. Polk tried this for the car using passive xovers but it didn't work. To my mind it failed because with passives you cannot manage arrival times which is critical to achieve the cancellation. 

I really believe this could be made to work in a car, I'm wondering if anyone has tried this.


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## 14642 (May 19, 2008)

I just can't resist this one, despite having too much to do to spend the time I'm about to spend.

The big fat hint here, isn't in the carsound post, which is a bunch of basic audio supplemented by some wishful thinking and writing about that wishful thinking. 

Here's the hint:

"Ambio rigs do it"

Now, think about what that means and how that setup is the OPPOSITE of a car. In-between a car and an ambio rig is a big room. Read the section in Floyd's book about image spread due to reflections from side walls. I don't have my copy here, but I'll find one at work and edit this to add a page number. 

Here are some rules for this topic:

1. Acoustic crosstalk is the enemy of "width"
2. Cars are acoustic crosstalk nightmares because all of the boundaries are so close that the reflections are heard as part of the primary signal and the reflections that kill width most effectively are the ones off the near side glass (from the far side speaker) and the ones off the front windshield. Basically, you have a right speaker mounted on the right and you hear it in your left ear too (off the near side glass) and you hear the speakers off the windshield too.. 
3. Ambio rigs have one main objective--eliminating acoustic crosstalk. 
4. Headphones have no acoustic crosstalk, but the setup eliminates our ability to determine the location of sound in any plane except one--left and right--because it doesn't allow the shapes of our heads or ears to be used as location cues for front or rear and doesn't allow us to move our heads to change ITD to determine location either. For 3-D headphones, a head tracker and a serious DSP that imparts binaural filters and room reflections fix this. 

So, Floyd's book illustrates perfectly what makes apparent width in a room--the primary reflection from a side wall. A perfect reflection from a side wall would be like having an additional speaker located outside that wall at a distance that corresponds to the length of the reflection. If the reflection was the same amplitude and the same frequency response and in phase with the sound of the speaker, the image would appear at a midpoint between the speaker and the apparent location of the "phantom" speaker, just as a center image is formed between the left and right speakers for a mono signal. There's an illustration in the book that makes this really easy to understand. 

I've read plenty of posts here and in other forums about people attempting to exploit this using the side glass. Does it work? Well, sort of. There isn't much width enhancement because the side glass is so close, but you can get a little. The big problem with this is that it's difficult to reflect the ENTIRE spectrum off the glass because of the location of the midrange and tweeters. 

So, while the reflection off the side glass can be helpful, the reflection off the windshield does the opposite--it narrows the stage. Hanging mids and tweeters in the a-pillars works at really high frequencies because the high frequencies are radiated into forward angles and less into rearward angles. At lower frequencies where the speaker radiates into all angles the reflection off the windshield and the side glass basically cancel each other and the left and right images in the midrange frequencies are just big. Floyd writes about this too and the term he uses is 'image spread", I think. The BS widebander in the a-pillar approach is effective at high frequencies only, makes the situation much worse in the midrange and lower frequencies and has other serious drawbacks that, in my opinion, make them a sham. I heard a car in Jakarta one day where the tweeters and mids in the a-pillars were mounted on some BIG baffles. This was pretty effective, but I couldn't have driven the car safely and especially not in Jakarta traffic!

So, if we know that we can exploit the reflection off the side glass (sort of) and no matter what we do, every source on the right will also be heard on the left because of acoustic crosstalk in our little reflective car interior, this all seems like a game of whack-a-mole and that's apparent in listening to cars whose owners claim to have "a stage that extends outside the boundaries of the car". I always find that there are one or two tracks that these guys play to prove this. Usually, those tracks include some sound or event that really does seem to happen outside the car. The stupid pink panther track on the IASCA disc is perfect for this. It's really easy to get the triangle to sound like it comes from outside the car. I use the track from the EMEA disc where the guy walks across the stage. It works perfectly in my car because I have a DSP algorithm that synthesizes a room and with the settings just right, I can make it seem to synthesize the room in the recording. With that track, I can get the guy to sound like he's 10 feet to the right and left of the car and 10 feet in front of the hood. Does it work on all tracks? Of course not. It's way more impressive than the Pink Panther's triangle, though. For many recordings, I have a car that makes it seem that the room is bigger than the car. 

The second hint is Chad's suggestion about L-R. An old recording technique is to maximize width by recording left sounds out of phase and at a lower level in the right, and vice versa. Upmixers like L7 and DolbyPL2 steer these sounds to the rear. In L7, the rears and sides are stereo and also steer left and right based on relative level. So...

Carefully placed left and right rear speakers will place these sounds in another pair of locations which, properly delayed and at the right level, can create a phantom image for those sounds in a location that is "between" the left front and left rear speakers (and the same for the right). Since the shape of our ears and our heads are primarily how we determine the front to rear locations of sounds, we can make the sound of the rear speakers more difficult to locate by attenuating the frequencies at which we do that--high frequencies. Then, if we close our eyes and make a wish, we can convince ourselves a little more easily that sounds come from outside the car.

The effects of all of these are seriously diminished in a car because of the acoustic crosstalk. You can eliminate a bunch of reflections (as Mark E. did in his 4-runner) to improve this a little bit, but the killer reflections are the ones from the side windows and the door glass and can't be eliminated in cars that are driven on the street. We have to be able to see. However, the rear speakers are far away from the windshield..that's good and in my experience, this is the place to start. 

OK...there are some more hints.


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## ErinH (Feb 14, 2007)

Andy, I think I'm right where you're at in your post. In my first reply I mentioned width possibly being linked to reflection amplitude over the span of a band. I was driving in this morning and thinking about what Chad (and Darrin) talked about regarding ambio and how that might work with what I was saying. I was thinking, if you were to put the drivers in the center of your car you spread out the first reflection off the side glass to a MUCH greater degree, therefore diminishing the first reflection amplitude much more than it is when it's coming off a driver right next to the reflection point. I could see this being a way to increase the sense of width. Again, I guess my main point/thought is that width is driven by amplitude over a spectrum which is driven by the time of the the first reflection.
Werewolf (Jeff) said something a _while_ back regarding point sources. Each reflection is a point source. We don't have 2 tweeters in a car; we have 8 (or more) which is a resultant of each reflection point. You could use this in your favor to "create" a pointsource 'outside' the physical boundary. This is where my idea then takes over... the pointsource seems further away because it has a reduced amplitude. This would really only be possible, IMO, with drivers aimed at the _opposite_ window. 
Not sure how exactly you could do this, but, it's worth thinking further about.*

*again, I am not saying this is the answer. It's just me trying to correlate some various ideas in a manner that make sense to me.



I don't have anymore time to commit, but I will say that I also don't think width is going to be attributed to one band like we often do with height. We say height cues are in the band of 2-3khz (or something around there, right?) and this is because and the reason is based on ear geometry. This has been discussed here to some degree and I honestly don't have time to search for it right now. I'll leave it up to one of you guys to dig that up.
But, my thought is simply that ear geometry doesn't influence width like it does height. Wish I had time to try to give sources and rationalize this further...

I'll be back later!

Great stuff!


- Erin


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## BowDown (Sep 24, 2009)

I am curious Chad. How do you go about setting TA without using your ears? We're not talking about auto-tune with an MS8 right.. What equipment can you use for this?


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## ErinH (Feb 14, 2007)

BowDown said:


> I am curious Chad. How do you go about setting TA without using your ears? We're not talking about auto-tune with an MS8 right.. What equipment can you use for this?


Npdang has a tutorial on this in the tutorials section. It's all about lining up Impulse response.


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## 14642 (May 19, 2008)

bikinpunk said:


> Werewolf (Jeff) said something a _while_ back regarding point sources. Each reflection is a point source. We don't have 2 tweeters in a car; we have 8 (or more) which is a resultant of each reflection point. You could use this in your favor to "create" a pointsource 'outside' the physical boundary. This is where my idea then takes over... the pointsource seems further away because it has a reduced amplitude. This would really only be possible, IMO, with drivers aimed at the _opposite_ window.
> 
> 
> 
> ...


Mount your midranges and tweeters in HUGE baffles on top of the dashboard and point them at the side windows. Maybe if the baffles were made of clear plastic, you could see through them and still drive the car. I think that might qualify as "Ambisonic lite".


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## highly (Jan 30, 2007)

I agree with everything stated here, and thank you Andy for taking the time to post here. 

Floyd does get into this and I was looking over the book lightly last night, but he doesnt actively say it in a concise manner (that I found) in a couple of sentences; he devotes _chapters _to it instead. 

His book uses a lot of statistical evidence to indicate what 'most listeners' like or percieve. I think that our use case from a competition standpoint tends to fall to the fringe of his statistical evidence of what 'sounds good' and leans more towards what 'sounds correct'. 

His discussions on reflections and acoustic mirrors lean to being helpful, but much of his discussion is in (large) rooms in far field listening situations. _Our_ best case is a highly reflective nearfield environment where, as you say, acoustic crosstalk is inevitable. At the same time, however, I can't say that I recall a farfield experience (listening in the home for instance) where the apparent source width exceeded the listening space. Sure, it exceeded the physical speaker placement, but it stayed inside the physical confines of the listening area. (I do not feel I have an exhaustive catalog of experience in this environment, either..)The physical boundary of the listening space dominated and the image width remained inside the physical space. Mind you, I am speaking specifically to a L/R stereo image and not to a surround environment. 

Crosstalk reduction through (digital) manipulation of out of phase information can be used to help negate the effects of the environment... if you have your head in a vice and the listener's pinnae and head shape is part of the correction factor (using HRTF data with binaural reproduction or ambisonic manipulation, for instance), but for a mobile real-world environment that seems to lack the robustness to make it a feasable realtime solution. You'd need to implement precision head tracking and some sort of realtime head/ear measurement system to expand the sweet spot such a system could provide into a meaningful listening space. 

Before we get into all sorts of side conversations about what can be done to mitigate the problems we encounter with electronic wizardry I'd be interested to focus on the problem acoustically. Specifically:

1) What can be done at installation time to maximize the apparent source width of a given system such that it is natively capable of meeting or exceeding the physical boundaries of the vehicle? 

2) What are the primary factors that lead to successful implementation? Thus far we have mentioned that source width is determined primarily in the midrange, and have qualified that highly reflective environments contribute to a degradation of ASW due to crosstalk and acoustic mirrors. What other factors are involved?

3) What are the relative influences amongst those factors? Is crosstalk the number one factor? Image smearing caused by acoustic mirrors creating multiple sources that are 'integrated' poorly?

4) What could be done to help maximize those factors in a practical implementation? Is this another area that favors kick panel installation and the natural acoustic absorbtion it provides?

Just some thoughts... not necessarily aimed at Andy and/or Chad. 

-Todd


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## 14642 (May 19, 2008)

bikinpunk said:


> Npdang has a tutorial on this in the tutorials section. It's all about lining up Impulse response.


 
It's tricky, though, especially for midbass and woofers.


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## 14642 (May 19, 2008)

Todd, eliminating DSP tools from this exercise is like asking someone to make great red sauce using only tomatoes--no onions, no crushed red peppers, no oregano, no basil and no garlic!

Crush the tomatoes by hand would be my only suggestion.

Oh, and in my opinion, accuracy isn't attractive because it unattainable, but believability is. Dude, Jessica Rabbit is HOT!


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## highly (Jan 30, 2007)

Andy Wehmeyer said:


> Todd, eliminating DSP tools from this exercise is like asking someone to make great red sauce using only tomatoes--no onions, no crushed red peppers, no oregano, no basil and no garlic!
> 
> Crush the tomatoes by hand would be my only suggestion.


My point is not to eliminate DSP in practice - I agree, that would be an exercise in pointlessness. I am looking instead from the 'everything begins at install' perspective. What installation practices lead to the best possibility of expanding the stage beyond the confines of the vehicle? 

I'm following my own rabbithole where DSP is concerned - I've been working on a WFS-based implementation for the last year and a half in my Fortress of Solitude. Transitioning that system into a functional in-car system is not an insignificant endeavor as I am certain you are aware (having followed your intrest there through your posts). Nevertheless, installation practices can make or break what DSP can correct. Where should we place our focus when making those initial decisions to give us the best leg up, so to speak?


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## ErinH (Feb 14, 2007)

I agree. Get a good baseline to the best of your ability.


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## ErinH (Feb 14, 2007)

Andy Wehmeyer said:


> It's tricky, though, especially for midbass and woofers.


Open up the low pass. Basically make it full range so the wavelength can be measured a bit more accurately. But I agree, it's still not quite that simple due to the cause itself.


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## highly (Jan 30, 2007)

bikinpunk said:


> I agree. Get a good baseline to the best of your ability.


So with that thought in mind, what factors can we optimize wrt ASW? 

1) Minimize reflection of the primary source as much as possible
2) Locate the primary and secondary sources (mirror sources) as close to each other as possible 
3) ???
4) Profit

...


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## pionkej (Feb 29, 2008)

highly said:


> So with that thought in mind, what factors can we optimize wrt ASW?
> 
> 1) Minimize reflection of the primary source as much as possible
> 2) Locate the primary and secondary sources (mirror sources) as close to each other as possible
> ...


I really wish I had a keyboard and not an iPhone right now. I'm still following and love the discussion. I will jump in as soon as typing isn't such a chore.


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## michaelsil1 (May 24, 2007)

chad said:


> In recording width can and does come from L-R information....
> 
> Sleep on that one for a bit


A very talented recording engineer told me the same thing.


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## pionkej (Feb 29, 2008)

I'm a bit hesitant to throw an example into the mix (because my intent was to discuss theory and experience), but I honestly think dissecting it may help anchor some of what has been covered. 

My goal is 2-seat. I have DSP/TA at my disposal. I am running a 3-way setup. Midbass will cover approximately 80-350hz. Midrange and tweeter take over from there. 

My midrange and tweeter will be on a baffle/pod in the corner of the dash (far back as possible). It will transition smoothly to the dash below, windshield above, and pillar. On the inboard side, it will extend around 6" past the speaker and has a roundover at the edge (to reduce baffle-step/diffraction). 

I have the ability to put the midbass in the door or on the dash, up firing, before the pods (no kicks). I will get better PLD's on the dash, and my entire front stage will approximate a point-source. It will also be about 8" further inbound (center of cone) if I use the dash. I can align either location with the "deep" pods via DSP. The ONLY thing keeping me from going dash is width. Can 80-350hz help widen the entire stage or will width be determined by the pods and the reflections they encounter?

EDIT: Since Andy is contributing here, I'll state that I'm planning to use a center (100hz+) and rear-fill with L7 processing. I only mention it because I think it would be cool to hear "without center and rears, you can expect XYZ" vs "with center and rears". I didn't originally post it because I wanted to keep the topic open enough that it could apply to most people.


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## michaelsil1 (May 24, 2007)

chad said:


> Width IMHO is NEVER EVER defined by a frequency band.
> 
> 
> Go see a good classical performance in an even somewhat famous concert hall, you owe it to yourself.


Good advice!
I don't think a lot of people realize just how dynamic a Orchestra is.


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## chad (Jun 30, 2005)

BowDown said:


> I am curious Chad. How do you go about setting TA without using your ears? We're not talking about auto-tune with an MS8 right.. What equipment can you use for this?


Smaart_Software

That, a dual channel sound card, some cabling, and a microphone.


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## michaelsil1 (May 24, 2007)

60ndown said:


> fixored


That's why people spend millions of dollars trying to recreate a orchestra in there home because it's so boring. Thank you for enlightening me.


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## 60ndown (Feb 8, 2007)

michaelsil1 said:


> That's why people spend millions of dollars trying to recreate a orchestra in there home because it's so boring. Thank you for enlightening me.


id prefer to listen to Hendrix on that system.


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## pionkej (Feb 29, 2008)

highly said:


> So with that thought in mind, what factors can we optimize wrt ASW?
> 
> 1) Minimize reflection of the primary source as much as possible
> 2) Locate the primary and secondary sources (mirror sources) as close to each other as possible
> ...


Added #3. Trying to bring this thread back to where it was this morning... before being so kindly derailed by the semantics of how entertaining the orchestra is.


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## denetnz (Jul 31, 2009)

The interactions of early reflections with the direct radiation from the drivers is a significant problem in a car that is impossible to completely escape.

If we can't get away from the reflections in a car, perhaps it would be easier to utilise the reflections and get away from the direct radiation? Has anyone tried pointing tweeters directly at the side windows, such that only the reflected sound can be heard?


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## pionkej (Feb 29, 2008)

denetnz said:


> The interactions of early reflections with the direct radiation from the drivers is a significant problem in a car that is impossible to completely escape.
> 
> If we can't get away from the reflections in a car, perhaps it would be easier to utilise the reflections and get away from the direct radiation? Has anyone tried pointing tweeters directly at the side windows, such that only the reflected sound can be heard?


Look up polar response, dispersion, and beaming. A 1" tweeter doesn't start to beam (remains omnidirectional) until around 10khz. Anything below that point and it won't matter too much where the tweeter is aimed. There are things you can do to help (absorption), but that is something that would have to be considered. 

The other thing is that if you pull that off, you're only fixing around 3500hz+. You still have the midrange/midbass you have to worry about trying to stop having crosstalk.


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## cvjoint (Mar 10, 2006)

If you can see the tweeter pointed at the windshield you can hear the direct sound as well. Based on what Andy posted the actual image would be somewhere between the direct sound and the one reflected off the windshield. We are talking about a very minor shift in the image. 

Time for me to listen to some more L7 cars, not much I can do moving speakers around.


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## AAAAAAA (Oct 5, 2007)

^ It's not just one reflection..there are actually many and this creates a blur and not just moving it in between the 2 to create a new "source".


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## Patrick Bateman (Sep 11, 2006)

pionkej said:


> Ok, so this may seem like a "newb" question, but it's one I can't seem to find a good answer to...WHERE DOES WIDTH COME FROM?


I think the easiest way to answer that is to imagine a Viewmaster. Remember those red things, that would show you an image in 3D?

Stereo is like that. If you're in exactly the right spot, you can have an image that is deeper and wider than the physical location of the loudspeakers.

After screwing around with ambio for a while, I am thoroughly convinced that trying to create an authentic soundstage with conventional locations is just a waste of time. *I'm not saying that you can't create a soundstage with a conventional triangle - you CAN.* But that soundstage has nearly nothing to do with what's on the recording. You are basically creating a soundstage out of thin air, and the speaker locations and the room will dictate what the soundstage is like, *not the recording.*

This is especially apparent with arrays. I can setup an array to create a huge, tall and wide soundstage *with a mono recording!* (This is one of the reasons I hate most arrays BTW.) The stage is fake.

















The other end of this spectrum would probably be an ambio setup in a super super heavily treated room. They're doing this at Stanford, using the same loudspeakers that I own. Great minds think alike lol

The first pic is Stanford. Second pic is my house. I now have the speakers in a different location, and in a configuration which I think eliminates the need for most acoustic treatment. This setup is documented in the link at the bottom of this post.

If you REALLY want to hear the recording, this is probably 'the hot ticket.' Be prepared to get disappointed though - there really isn't much of a soundstage on your recordings. A lot of the 'tricks' we've been hearing in our car are our own creation. It's fake soundstaging.

I posted a brain dump on this here, and I think there's some good info in the thread if you have some time to sift through my ramblings

Audio Psychosis • View topic - A Soundstage with Width and Depth.


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## cvjoint (Mar 10, 2006)

AAAAAAA said:


> ^ It's not just one reflection..there are actually many and this creates a blur and not just moving it in between the 2 to create a new "source".


I believe that's accurate. The reflection manipulative approach is very dubious imo. I see speakers mounted in very odd locations then the owner would say sound starts here, reflects off x, then Y and lands exactly in my left ear drum. Questionable. I call it the "arrow" properties of sound, where you can trace an arrow coming out of the diaphragm. 

The most compelling aim for me is on axis. That gives nice even dispersion from both L and R, but I could be wrong.


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## pionkej (Feb 29, 2008)

My personal opinion so far...width should be a last concern. This doesn't mean good width *can't* be achieved and it doesn't mean it isn't worth *trying* to achieve. What it does mean, to me, is that height, depth, staging (within whatever the stage's width is), and tonality should come first. 

The good news is that to get good staging and tonality, you need to minimize localization (be it from the speaker, resonances, fr imbalances, etc.) and reflections that smear the image (reflections that aren't early enough to appear to be part of the source or late enough to meet HAAS requirements), and if you can do that, you will likely have the best width achievable anyway.

I literally hate typing that because it sounds defeatest, but I also think it's being realistic. Others may consider width a more important factor than some I mentioned above, but if car audio truly must have trade-offs, I'll take any/all of the above for a stage that is a bit narrower. Just my .02


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## strakele (Mar 2, 2009)

Patrick Bateman said:


> If you REALLY want to hear the recording, this is probably 'the hot ticket.' Be prepared to get disappointed though - there really isn't much of a soundstage on your recordings. A lot of the 'tricks' we've been hearing in our car are our own creation. It's fake soundstaging.
> 
> 
> Audio Psychosis • View topic - A Soundstage with Width and Depth.



This cracks me up, yet to me really isn't surprising either. 

This is one of the best threads I've read in a while. Awesome info.


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## thehatedguy (May 4, 2007)

Which is why on the center channel post I mentioned having the center midbass to equal the output of BOTH fronts...cause it's almost always going to be coming from the center, especially when you start to cross it over lowish.




Patrick Bateman said:


> Be prepared to get disappointed though - there really isn't much of a soundstage on your recordings.


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## DiMora (Nov 14, 2011)

Mic10is said:


> IMO you cannot get width to exceed the the boundaries of the speaker locations.
> As Todd mentioned and We've had some great discussions on this-width cues are primarily in the midrange. There are some ambient cues above 4khz.
> 
> But the easiest way for me to explain this would be, its very difficult to be wider than the center of the speakers location and proximity to the outer boundary of the vehicle (apillar)
> ...


You can get width - much wider than the car - but it requires time alignment, or a product such as AudioControl's ESP3 with an actual center-channel speaker...or a 5.1 system.

Kick panel mounted speakers also do a good job of delivering the perception of width (vs. door mounted drivers), but without time alignment it is still not that great.

I agree that the recording is key - because even on a real home stereo system, if there is not width and instrument placement in the recording, you won;t reproduce it on any system.


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## Mic10is (Aug 20, 2007)

DiMora said:


> You can get width - much wider than the car - but it requires time alignment, or a product such as AudioControl's ESP3 with an actual center-channel speaker...or a 5.1 system.
> 
> Kick panel mounted speakers also do a good job of delivering the perception of width (vs. door mounted drivers), but without time alignment it is still not that great.
> 
> I agree that the recording is key - because even on a real home stereo system, if there is not width and instrument placement in the recording, you won;t reproduce it on any system.


Use all the TA you want, you will not increase width. if anything you can start creating a tunnel like effect as you move the speakers farther away in time/distance.

and Depending on how the Kick panel speakers are mounted will determine the stage width versus Door mounted. You just cant make a blanket statement that Kick panels give you more width over Door mounted.
Actually the way most people build Kicks and attempt to move the drivers really far on axis and push them closer to the middle to accommodate the size of the driver will decrease the width.


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## Mic10is (Aug 20, 2007)

pionkej said:


> My personal opinion so far...width should be a last concern. This doesn't mean good width *can't* be achieved and it doesn't mean it isn't worth *trying* to achieve. What it does mean, to me, is that height, depth, staging (within whatever the stage's width is), and tonality should come first.
> 
> The good news is that to get good staging and tonality, you need to minimize localization (be it from the speaker, resonances, fr imbalances, etc.) and reflections that smear the image (reflections that aren't early enough to appear to be part of the source or late enough to meet HAAS requirements), and if you can do that, you will likely have the best width achievable anyway.
> 
> I literally hate typing that because it sounds defeatest, but I also think it's being realistic. Others may consider width a more important factor than some I mentioned above, but if car audio truly must have trade-offs, I'll take any/all of the above for a stage that is a bit narrower. Just my .02


Just a quick FYI--I know you plan to compete and many of your questions may be in regards to competing or how everything will pan out once you start competing based on what you can do w your install.

When judging staging. Width is one of the VERY 1st categories we judge.
The 1st thing is to determine the size and location of the apparent stage. So We determine stage Width, Height and Depth and Location of Listener in relation to Soundstage (IASCA).
Once we determine the boundaries, then we move on to imaging.

Imaging should be in correct location based on the stage dimensions. etc.. etc...

and perceptually, as a listener and a judge it irks me to have a narrow stage. Im already in a car, sometimes listening to systems with speakers at awkward positions so I may have to sit differently than usual to not interfere with their operation. so Im already feeling enclosed, then hoping to sit back and have the stage be open and expansive to at least the physical boundaries and have it be well inside the pillars...not fun.

also keep in mind that MECA scores based on vehicle boundaries not acoustic boundaries. so youll likely take a hit in multiple areas. width, and imaging.


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## sqnut (Dec 24, 2009)

Based on what's been said till now,

1. Width is one of the three dimensions of staging. The three dimensions have to be in proportion to create accurate staging. So eye level height, depth midway to the hood but a 3' width is not going to cut it. At least not in competitions. Even as a hobbyist, I am finicky about having the staging right and it bugs me no end if something is out of whack. Of course, if the cd is an average/poor recording, theres no point fretting about this. 

2. Patrick makes this point


> Be prepared to get disappointed though - there really isn't much of a soundstage on your recordings. A lot of the 'tricks' we've been hearing in our car are our own creation. It's fake soundstaging.


 I'm not sure I agree. While a lot of commercial recording are not made for great staging, but thats more to do with the way the music was recorded. I have lots of cd's that sound ok, but there's practically no staging / imaging, everythings squished at the centre. Then there are cd's where the artist and the engineer are focused on making a good recording and you end up with stuff like Donald Fagans Nightfly, Diana Kralls Live in Paris, Floyd, Dire Straits a lot of Jazz and classical recordings and many, many others, that have great staging and imaging. Both with a home 2ch and in the car.

3. Driver placement is important. I'm with the school that says width would be from VC to VC. Generally, doors will give you better width, but kicks will be better for depth. Getting the speakers wider and deeper will help with width and depth. Venting drivers by cutting metal either on the pillars or kicks will give better depth/width. Mounting tweeters higher (A pillars) will help with height. If you're mounting mids and tweets on pillars then baffles and angling will help with reflections off the windscreen. Crossing the tweets higher will let it play frequencies that have a more linear dispersion and hence lesser reflections off the windscreen. Pillar to pillar width or just a bit beyond is achievable and a good target to shoot for as a start. Even here, not all cd's will give you this width. Only the well recorded ones. Some cd's have some tricks recorded in, e.g. Roger Waters Amused to Death. There is a sound of a dog barking and on one of the tracks this images up out on the hood and on another it is to my right outside the car. However this does not mean my normal width/depth is there. 

4. The car is a nearfield and highly reflective environment. You can never _eliminate _the reflections, but you can _minimise_ them. You will hear that difference for sure. You can spend a ton of time and resources here and look at stuff like dashmats, using foam / carpeting on obvious places, using baffles on pillar mounted drivers and the sound will get better but you will hit the brickwall at some point.

5. Reflections and crosstalk are key factors that limit your stage dimensions and impact your imaging as well. Since you cannot eliminate these reflections, focus on minimising them specially the early reflections. Andy and Chad cited Ambiophonics to manage reflections and crosstalk. The only issue here is that speakers would have to be really close to each other to create a stereo dipole. Not sure how practical this would be in a car. Not sure if this has even been tried in a car. If I had the equipment, the time and the diy skills (I'm lacking all three), I would still give my idea of active SDA drivers a shot. Even if it solves 20% of the problem, the sound would be atleast 10% better if not more. 

So it seems we're back to square one. Get the driver placement right and work towards reducing the reflections. You will never eliminate them. If you're in this hobby, accept that . That's my take from this thread. Open to corrections if I have misunderstood anything.

Arun


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## sqnut (Dec 24, 2009)

To the OP, if you're planning to compete, get the basic placement and install right and spend tons of time on tuning the setup. While there is a lot of good information in this thread, it will have greater relevance when the rest of your sound tonality, staging, imaging is at a point where the extra 6" of width will make a difference vis a vis points scored.


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## pionkej (Feb 29, 2008)

I appreciate people chiming in with how things are viewed from a competition standpoint. This thread is somewhat selfish in nature (that I want it to help my build), but my main intention was to try and get a good/informative thread on width going. In searching, TONS came up on height and depth, but tips for width was much more ambiguous. I want this to be a reference thread for anyone trying to get good width. 

Since this thread is tracking in a productive direction again (away from 60ndown's thoughts on orchesta), I'll ask a pointed question again (I do know it will still be a best guess for anyone). 

My midrange/tweeter location is set. It will be in the corner of the dash by the pillar. My midbass will play 80-350hz. It can go in the doors or on the dash. In the doors they will be approximately 6" wider than the midrange, dash would be 3" narrower. Based on the range they are playing, is it likely they could "widen" the stage beyond the midrange location if in the door. As an inverse, if placed on the dash, will they "widen" to the midrange location...OR will the midrange possibly "narrow" to the stage to the midbass?

NOTE: My question assumes nothing else would pinpoint location (ie-proper level matching, T/A, and no resonances to give away location).


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## Wesayso (Jul 20, 2010)

The woofers won't stop playing above 350hz depending on crossover slope. I'd go doors.
But a question, what air space do they need and can both locations mentioned give you that?
I found this thread a good read on the subject and it got me a better wider stage with good tonality and imaging by just trying some of the things mentioned there:
http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/107269-tuning-judging-question.html


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## 14642 (May 19, 2008)

Patrick Bateman said:


> If you REALLY want to hear the recording, this is probably 'the hot ticket.' Be prepared to get disappointed though - there really isn't much of a soundstage on your recordings. A lot of the 'tricks' we've been hearing in our car are our own creation. It's fake soundstaging.


This is absolutely true and the reason I'll take believability over accuracy any day. My DSP includes room synthesis. Does it recreate a room? Well, no, because I'm in a car and my experience is subject to all of those reflections that define the space in which I listen. Does it make listening much more fun and does it sound more natural and less bound by the car. Yes. Do I give two ****s about what's on the CD? Well...no. Have I won and IASCA contest or two by duping the judges into thinking that the ambience created by my DSP is really on the recording and not reproduced by other cars? Yes. Does that matter? Not to them, I didn't tell them that the ambience they loved was "fake". It mattered to me because it made me laugh.

Thanks Patrick


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## michaelsil1 (May 24, 2007)

Andy Wehmeyer said:


> This is absolutely true and the reason I'll take believability over accuracy any day. My DSP includes room synthesis. Does it recreate a room? Well, no, because I'm in a car and my experience is subject to all of those reflections that define the space in which I listen. Does it make listening much more fun and does it sound more natural and less bound by the car. Yes. Do I give two ****s about what's on the CD? Well...no. Have I won and IASCA contest or two by duping the judges into thinking that the ambience created by my DSP is really on the recording and not reproduced by other cars? Yes. Does that matter? Not to them, I didn't tell them that the ambience they loved was "fake". It mattered to me because it made me laugh.
> 
> Thanks Patrick


Thanks Andy,

We hope you can make it Dec. 10th. for our little get together in Anaheim.


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## DiMora (Nov 14, 2011)

Andy Wehmeyer said:


> This is absolutely true and the reason I'll take believability over accuracy any day. My DSP includes room synthesis. Does it recreate a room? Well, no, because I'm in a car and my experience is subject to all of those reflections that define the space in which I listen. Does it make listening much more fun and does it sound more natural and less bound by the car. Yes. Do I give two ****s about what's on the CD? Well...no. Have I won and IASCA contest or two by duping the judges into thinking that the ambience created by my DSP is really on the recording and not reproduced by other cars? Yes. Does that matter? Not to them, I didn't tell them that the ambience they loved was "fake". It mattered to me because it made me laugh.
> 
> Thanks Patrick


That is precisely my point.

Modern signal processing can create ambiance and fake width that exceeds the boundaries of the car.

The vehicle environment is harsh...not like a dedicated listening room where we can control first-order reflections, add corner traps, etc...plus there are those highly reflective windows...and the limitations of driver placement.

Until DSP and time alignment came out, hands down the best systems I heard (sound quality) were using high-powered co-located drivers and compression loaded horn drivers that were set up to minimize the path-length differences between left and right front drivers. I also heard many systems that used the AudioControl ESP-3...it is a noisy piece, but was one of my favorites and I added a center channel to my last car and ran that piece for 17 years.

In today's world, the modern DSP powered equipment with time alignment and surround-like modes does wonders. 

My simple Eclipse CD7100 coupled with door-mounted cheap Boston Acoustics speakers (with time alignment, parametric EQ, and "Circle-Surround") has a far better soundstage than vehicles I have heard with much more expensive drivers in custom kick panels. It has depth, width, and images nicely.


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## sqnut (Dec 24, 2009)

Andy Wehmeyer said:


> This is absolutely true and the reason *I'll take believability over accuracy any day.* My DSP includes room synthesis. Does it recreate a room? Well, no, because I'm in a car and my experience is subject to all of those reflections that define the space in which I listen. Does it make listening much more fun and does it sound more natural and less bound by the car. Yes. Do I give two ****s about what's on the CD? Well...no. Have I won and IASCA contest or two by duping the judges into thinking that the ambience created by my DSP is really on the recording and not reproduced by other cars? Yes. Does that matter? Not to them, I didn't tell them that the ambience they loved was "fake". It mattered to me because it made me laugh.
> 
> Thanks Patrick


To my mind they go hand in hand. More accurate = more believable. The ears and mind under the right circumstances will believe practically anything. I've had way too many tuning sessions when I've walked away thinking wow I nailed it, only to be confronted with a WTF moment the next day. So for me believabilty has to be linked to accuracy. 

I'm not aware of the software you used, so I can't comment. Maybe if it was different enough from the rest of the cars, it generated a wow moment. I'm sure you won beacuse a lot of the other things were great too. The only things I compete against are the Totems at home. I already know that I will never have that accuracy in the car. The idea is to see how close I can get.


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## Darth SQ (Sep 17, 2010)

Lately, width for me has been coming from too many Little Caesar's $5.00 pizzas. :mean:

Sorry.....
Please continue.

Bret
PPI-ART COLLECTOR


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## garysummers (Oct 25, 2010)

_"But that soundstage has nearly nothing to do with what's on the recording. You are basically creating a soundstage out of thin air, and the speaker locations and the room will dictate what the soundstage is like, not the recording."
_
I have to strongly disagree! The "real" soundstage is in the original recording, whether wide, narrow, deep or shallow. Everything else is faked, synthesized and not natural!


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## ErinH (Feb 14, 2007)

This just got interesting again..


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## durwood (Mar 7, 2007)

When I read things like "stage width is confined to the speakers", or you define a set static stage width, all you have done is acheived panned monophonic. Space is defined in 3 dimensions, you need to at least think in 2D. Looking at only time or distance = 1D thinking. If you are not thinking in azimuth angles or X and Y dimensions, then you are not discussing width.

There will always be one side that claims that 3D sound is in the recording, and the other side will claim 3D sound is defined by the playback space AND playback system.

Both are correct, but only together, not separately.

The recording attempts to capture the original space whether it be artificially done with signal manipulation or real space. Note, how many different microphone setups there are available, let alone recording spaces (i.e. not just studios where everything is multi-tracked and mixed back together with fancy effects applied).
The playback system then tries to recreate this space on the recording medium overlaying it into a new space.
If you cannot grasp this concept you will fail at trying to achieve a satisfying result.

If your playback system cannot expand and contract in width and depth to coincide with what our brains have learned real life events sound like, but instead have a static stage width and depth, you either have a faulty recording or a panned monophonic playback system, or both. A solo singer/instrument should sound as such, whereas a chorus or 70 ft wide organ should also sound just as wide and deep to achieve a sense of realism.

A wise man once said, _Maybe one day, enough lemmings will fill the trench, and people can cross over to the promised Nirvana_


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## highly (Jan 30, 2007)

I agree with your definition of width and your assertion that width is just one aspect of the soundstage. I have only ever heard this reproduced in a way that completely disregards the vehicle one time, and only very recently. The first time you truly hear a system vastly exceed the boundaries of the vehicle it takes the brain time to process what you are hearing as you have to 'let go' of the boundaries. The result is awesome. I know how it was achieved in that instance, and it wasn't through any steering algorithms. It was done without a center channel. No ambi-anything was used. Cathedrals were every bit as large as they should be, and a standup bass had vertical components in the soundstage that were clearly represented and completely realistic. Small rooms collapsed as they should, and large spaces expanded. Depth followed, as did height and 'ambiance'.

It wasn't without artifacts and is still far from perfect, but it was the best representation of reality I have ever experienced in a car. It was Mark E's latest tune that debuted at MECA Finals this year, and it is far and away better than anything his car has _ever _done.

What are your recommendations for achieving a stage that is not limited by the vehicle's boundaries? Your last sentence infers that you don't think the commonly pursued methods are the way to go. I would very much like to read your take on things - and I type this from a place of respect; I am not trying to push buttons or poke with a stick! I am honestly asking for your perspective... that is what this thread is all about!

Thanks
-Todd


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## ErinH (Feb 14, 2007)

durwood said:


> When I read things like "stage width is confined to the speakers"


I'd actually like to retract my statement of this. I was posting that under the pretense that most people put the speakers right next to the boundary. However, that's a generalization that might not always be true.

I do still believe, though, the boundary is what is the limiting factor. Over the past few days I've played with tweeter positioning. So far, I've found the _best_ location to place them is above the dash a few inches and few inches inside the pillars on each side. The width is beyond the physical location in most recordings but still limited to roughly where the side glass is.

Of course, I think there's still a lot of room here in this discussion for _how _people listen.


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## durwood (Mar 7, 2007)

highly said:


> I know how it was achieved in that instance, and it wasn't through any steering algorithms. It was done without a center channel. No ambi-anything was used.





> It was Mark E's latest tune that debuted at MECA Finals this year, and it is far and away better than anything his car has _ever _done.


These are conflicting statements. Any manipulation is a steering algorithm. An EQ is a steering algorithm.

My recommendations-gain an understanding of how our hearing works, and how the space works.
Then experiment.
First grasp in real life that the environment gives you a sense a space, your ears and brain only try to navigate it.
The Room is the single biggest manipulation. Learn to work with it, or minimize it's effects by paying attention to boundaries and how your speakers interact with it.

Vague enough?


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## AAAAAAA (Oct 5, 2007)

From what I have read, the feeling of space and ambiance is due to reflections.
In a car when we get "early" reflextions due to windows and other elements that are close it has the oposit effect of narrowing and confining the space.

That explains andy's recomendations in part.

I wonder if his set up creates the equivalent of delayed reflextions to enhance the feeling of "ambiance" or "space".


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## highly (Jan 30, 2007)

AAAAAAA said:


> From what I have read, the feeling of space and ambiance is due to reflections.
> In a car when we get "early" reflextions due to windows and other elements that are close it has the oposit effect of narrowing and confining the space.
> 
> That explains andy's recomendations in part.
> ...


If you are looking for a false sense of space and are content with Andy's admonition that a true space cannot be recreated in a car, then this is one way out. Override the recording and create your own acoustical space. It can be quite enjoyable even if it isn't accurate to the recording.

'there are a lot of decaffeinated brands on the market today that are just as tasty as the real thing. ' - Chris Knight


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## highly (Jan 30, 2007)

durwood said:


> These are conflicting statements. Any manipulation is a steering algorithm. An EQ is a steering algorithm.


That is an oversimplification of my statement and the common definition of a steering algorithm, and you know it. <chuckles> I am sure that was your 'learning point' - to expand one's thinking and definition. If you'd like to be vague and avoid the point of the thread so be it. I am looking forward to it if you change your mind, however. I've spent a lot of time over the last two years trying to learn exactly the things you mention (and to put them into practice) and though I will not attempt to imply that I am a master or even know what I am talking about... I AM trying.

Thus my interest in this post. It has the potential and participants to make it an interesting treatise on the subject if they'd stop acting secretive  (and I say this jokingly and in good natured fun, so don't get all upset about it)

-Todd

Off to smoke some Salmon!


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## sqnut (Dec 24, 2009)

Hell Freezes Over is probably recorded on what looks like a 40ft wide stage. That width and sense of space, is on the recording. To recreate it, you would need somewhat similar space for a start. You'd also need huge speakers and tons of power .

The physical boundaries will always limit your sense of space. If the recorded space is larger than that for reproduction, you are technically losing accuracy, vis a vis that recording. Smaller space, fewer watts and you've scaled down the stage in all three dimensions. While maintaining accuracy within the scaled down version. Going the other way and presenting a size way beyond the boundaries or the recording, is not making it more accurate.

That same album would sound very different when played back in a concert hall, a large room, your living room and lastly the best and most accurate car.


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## pionkej (Feb 29, 2008)

highly said:


> If you are looking for a false sense of space and are content with Andy's admonition that a true space cannot be recreated in a car, then this is one way out. Override the recording and create your own acoustical space. It can be quite enjoyable even if it isn't accurate to the recording.
> 
> 'there are a lot of decaffeinated brands on the market today that are just as tasty as the real thing. ' - Chris Knight


I would argue that the first part of AAAAA's post is relevant for ALL cars (though I would use the term "medium delay" reflections). Reflections early enough to trick the brain into thinking its part of the orignal signal would not reduce width IMHO (though it makes the reproduction less accurate). Late reflections (beyond the HAAS precident) can add to the depth and width by tricking the brain into thinking the space is larger/wider than it really is. I would consider "medium reflections" anything between those two points. Side glass, opposite side glass, and dashboard/windshield reflections ALL play a part in killing the illusion. The brain knows these reflections are not part of the original signal and therefore deems them to be boundaries instead (HAAS reflections do the same thing, it's just that they trick us into thinking the boundaries of the room are much larger than they are). I *believe* Mark E. has done a lot of work in controlling and reducing the amplitude of these offending reflections. 

I do also agree with your point 100%. Andy W. prefers to use L7 steering to increase width and depth. At the most basic level, it is doing the same thing as natural late reflections would achieve above. It seems there is more than one way to skin a cat when it comes to width in the car. 

People have mentioned that no specific frequency is responsible for width in the car but it is more a function of reflections and acoustic crosstalk. If this is true, I would think the "meat" of our problems happen between 200-3khz. 

I say this because:

Anything below 200hz is going to have a wavelength over 4'-0" correct? If so, there isn't much we can do about crosstalk in the car since that is nearly as wide as left to right dimensions and as you go lower it also encompasses front to back.

Anything above 3khz can be avoided with directivity control or a 1" piece of foam (1/4 wave). 

So were back to the 200-3khz range. This area would need up to 9" of foam (1/4 wave) to stop reflections...not easy. So what can we do? Is this maybe why Andy W recommends door mounted midbass and midrange? You do have the "advantage" of a center console to help reduce crosstalk. The majority of reflections do also then stop in the center. The problem with that is: terrible PLD's, typically terrible comb-filtering, and it's probably the hardest location to stop rattles/resonances (which I think also localizes a speaker and "tells" the brain it's a boundary).

I'm just thinking out loud here, so I encourage people to pick this apart or contribute to it for the sake of moving this great thread forward.


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## durwood (Mar 7, 2007)

I am not trying to hide anything or be secretive. I have my reasons, one of which is to minimize my support for this forum owner so as to not add to his monetary valuation of his forum empire and his past (and or future) unethical behavior via post contribution.

Arrays are another steering mechanism...it's an acoustic steering mechanism for dealing with the room and dispersion patterns.

You can either make the room become part of the baffle minimizing direct to reflected path lengths, or you can place your speakers farther away from reflecting surfaces to increase direct to reflected path lengths. You also need to pay attention to matching your playback azimuth requirements to your recording signal/medium azimuth requirements.

I choose not to discuss any further here, feel free to move this topic of discussion elsewhere at any of the other various forums not in this empire, and maybe we can have a conversation.


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## pionkej (Feb 29, 2008)

durwood said:


> There will always be one side that claims that 3D sound is in the recording, and the other side will claim 3D sound is defined by the playback space AND playback system.
> 
> Both are correct, but only together, not separately.





sqnut said:


> Hell Freezes Over is probably recorded on what looks like a 40ft wide stage. That width and sense of space, is on the recording. To recreate it, you would need somewhat similar space for a start. You'd also need huge speakers and tons of power .
> 
> The physical boundaries will always limit your sense of space. If the recorded space is larger than that for reproduction, you are technically losing accuracy, vis a vis that recording. Smaller space, fewer watts and you've scaled down the stage in all three dimensions. While maintaining accuracy within the scaled down version. Going the other way and presenting a size way beyond the boundaries, is not making it more accurate.
> 
> That same album would sound very different when played back in a concert hall, a large room, your living room and lastly the best and most accurate car.


So what do you think would happen to the width if the speakers were placed 10ft. apart in the concert hall instead of 40ft. apart? Would the concert hall only appear to be 10ft. wide? Could you tell if you were blindfolded before entering and had no idea where the speakers were?

I'm honestly not picking at you because I don't know the answer to my questions either. BUT I'm not entirely convinced there would be a 30ft. difference between the two and width would still end up having more to do with the reflections. If that is correct, then it seems plausible/possible to make a smaller environment not be the limiting factor to the width, but let the recording itself be the limiting factor, by controlling those reflections.


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## pionkej (Feb 29, 2008)

durwood said:


> I am not trying to hide anything or be secretive. I have my reasons, one of which is to minimize my support for this forum owner so as to not add to his monetary valuation of his forum empire and his past unethical behavior via post contribution.
> 
> Arrays are another steering mechanism...it's an acoustic steering mechanism for dealing with the room and dispersion patterns.
> 
> ...


Gave you a thanks for that post (though I know you could care less) and I can't fault your logic for not wanting to contribute more (though I don't 100% agree with it either). I think that there is plenty of potential in what I highlighted above. I am actually trying to work with this theory in my next install. I haven't made much of it to this point because, frankly, I don't know if it works yet. But after seeing this post and one Andy W. made earlier about large baffles...it is enough to keep me encouraged and optimistic. So again, thank you.


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## AAAAAAA (Oct 5, 2007)

highly said:


> If Override the recording and create your own acoustical space. It can be quite enjoyable even if it isn't accurate to the recording.


I think this is what logic7 (and other multichannel suround sound systems for music) does. "Forcing" the sound of a different environment into the car (or home theather). The more speakers (with logic behind what they are playing a la logic 7), the less reliance we have on placement and pathlenghts and we end up with less of a listening sweet spot like with plain old 2.1 stereo.

Multichannel "smart" systems is where it's at.




pionkej said:


> ...The problem with that is:* terrible PLD's*, typically terrible comb-filtering, and it's probably the hardest location to stop rattles/resonances (which I think also localizes a speaker and "tells" the brain it's a boundary)...


This is where the beauty of more speakers is more better. PLD and "sweet" spots are no longer as important.

To put it into perspective with an extreme example. If the car had 100 independ channels for suround sound where a circle of speakers line the interior of the car, --litteraly every speaker is touching-- then it doesn't matter where you sit within the circle. If a sound seems to be comming where the wiper blade is sitting, then since it is phisically coming from that spot, everyone in the car will be able to recognise that the sound is coming from that location, instead of relying on PLD's between two speaker locations to determine a *relative* location, more speakers actually make it come from there.

Realistically though, you probably need way less speakers and channels to get the same affect but definitly more then 2.1 are required.


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## sqnut (Dec 24, 2009)

pionkej said:


> So what do you think would happen to the width if the speakers were placed 10ft. apart in the concert hall instead of 40ft. apart? Would the concert hall only appear to be 10ft. wide? Could you tell if you were blindfolded before entering and had no idea where the speakers were?


If you were in the concert hall with a blindfold and you heard the speakers 10' apart and then 15' apart or vice versa, would you be able to say 'further apart' or 'closer'? Yes, not an issue. Could you tell exactly by how much? Perhaps, with a lot of practice.


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## pionkej (Feb 29, 2008)

sqnut said:


> If you were in the concert hall with a blindfold and you heard the speakers 10' apart and then 15' apart or vice versa, would you be able to say 'further apart' or 'closer'? Yes, not an issue. Could you tell exactly by how much? Perhaps, with a lot of practice.


I call ********. The directivity of speakers large enough to fill a concert would SURELY be wide enough to make pinpointing a 5' change nearly impossible (as being "further apart" or "closer"...let alone accurately predict *WHAT* the change was).

Unfortunately, I don't have access to a concert hall so we can't dispute the point any further than that.

That being said, I would LOVE it if you could let me know how your posts are contributing to this thread. If the only point you want to make is that it's "impossible" to make a listening environment seem larger than it is while maintaining accuracy...consider your point made. So please feel free to move along.


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## Wesayso (Jul 20, 2010)

highly said:


> I have only ever heard this reproduced in a way that completely disregards the vehicle one time, and only very recently. The first time you truly hear a system vastly exceed the boundaries of the vehicle it takes the brain time to process what you are hearing as you have to 'let go' of the boundaries. The result is awesome. *I know how it was achieved in that instance, and it wasn't through any steering algorithms.* It was done without a center channel. No ambi-anything was used. Cathedrals were every bit as large as they should be, and a standup bass had vertical components in the soundstage that were clearly represented and completely realistic. Small rooms collapsed as they should, and large spaces expanded. Depth followed, as did height and 'ambiance'.
> 
> It wasn't without artifacts and is still far from perfect, but it was the best representation of reality I have ever experienced in a car. It was Mark E's latest tune that debuted at MECA Finals this year, and it is far and away better than anything his car has _ever _done.


So you know how Mark E did that? We would like to know as well .
This is probably not going to happen though but what do you guys know about that car that you can share with the rest of us? All I know about it is reading how great it sounds. I've seen the pictures on here but there isn't much to see. I can understand the reasons for the secrecy but for example, does it sound better than the big Sprinter Van known as the Magic Bus?
That last one obviously has a bigger space to work with and a lot of acoustic treatments.
I'm just curious as to what works and why...


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## thehatedguy (May 4, 2007)

Todd, isn't Mark using an array of sorts across the dash?


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## ErinH (Feb 14, 2007)

No. Unless he lied when we talked about it.


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## thehatedguy (May 4, 2007)

I was under the impression that there was more to that car than just a "regular" stereo set upfront...an array of sorts that he and Dr. Doug had worked on.

But like the 4-Runner, who really knows what is behind the grills.


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## ErinH (Feb 14, 2007)

It's not conventional but it's not across the dash.


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## thehatedguy (May 4, 2007)

Spill the beans buster...PM me if you want, I won't tell anyone.


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## highly (Jan 30, 2007)

He has exactly what he has told everyone that he has. L, R, and C are MTM with individual control over each driver. Components are off-the-shelf C5s.

When I said that he doesn't use a steering algorithm, I meant that there is nothing in his system besides crossovers steering the audio to individual drivers. He is not using Logic 7 or Pro Logic or ambio or WFS or bass management or... any of those things. He's using the processing provided by the DBX. That's it.


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## highly (Jan 30, 2007)

I'm not telling you anything he wouldn't happily discuss with you (or anyone else) face to face, either. Mark's more than happy to engage in discussion about his car and how it does what it does, so I am not letting any cats out of any bags here.


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## Wesayso (Jul 20, 2010)

highly said:


> He has exactly what he has told everyone that he has. L, R, and C are MTM with individual control over each driver. Components are off-the-shelf C5s.
> 
> When I said that he doesn't use a steering algorithm, I meant that there is nothing in his system besides crossovers steering the audio to individual drivers. He is not using Logic 7 or Pro Logic or ambio or WFS or bass management or... any of those things. He's using the processing provided by the DBX. That's it.


So what does the C stand for in your "L,R, and C" use above? Not trying to be smart here, just wondering about this:


highly said:


> It was done without a center channel. No ambi-anything was used.


Just curious, that's all


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## michaelsil1 (May 24, 2007)

Center


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## highly (Jan 30, 2007)

Wesayso said:


> So what does the C stand for in your "L,R, and C" use above? Not trying to be smart here, just wondering about this:
> 
> Just curious, that's all


Center channel for 2-seat mode. It is bypassed (as far as I am aware) in single seat mode. One setup per event. He also does RTA. I don't know what he uses there but it also works extremely well.


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## thehatedguy (May 4, 2007)

Light right center.

I see why someone could mistake it for an array.

Does he not have the Alpine H990 in the car anymore? I haven't seen pictures of the back of the car in a while.


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## highly (Jan 30, 2007)

thehatedguy said:


> *Left* right center.
> 
> I see why someone could mistake it for an array.
> 
> Does he not have the Alpine H990 in the car anymore? I haven't seen pictures of the back of the car in a while.


Fixored.
He is in effect running 3 arrays 
No H990 that I am aware of; just the DBX (482 I believe).


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## michaelsil1 (May 24, 2007)

Someone told me that Mark E. car imaged very very well, but didn't really sound that great. Does he have more than one?


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## BigRed (Aug 12, 2007)

I talked to Mark about a week ago, and he was pretty open about his setup. maybe he can chime in on this discussion? Todd is right though, all his processing is from the driverack, NO logic 7 or steering algorithms.


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## ErinH (Feb 14, 2007)

thehatedguy said:


> Spill the beans buster...PM me if you want, I won't tell anyone.


I wasn't trying to be secretive. I was on my phone replying. Had to keep it short.


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## thehatedguy (May 4, 2007)

I wonder why I was thinking it had a H990 in it?


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## BigRed (Aug 12, 2007)

^^ thats Gary...he has two of them


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## sqnut (Dec 24, 2009)

pionkej said:


> I call ********. The directivity of speakers large enough to fill a concert would SURELY be wide enough to make pinpointing a 5' change nearly impossible (as being "further apart" or "closer"...let alone accurately predict *WHAT* the change was).
> 
> Unfortunately, I don't have access to a concert hall so we can't dispute the point any further than that.
> 
> That being said, I would LOVE it if you could let me know how your posts are contributing to this thread. If the only point you want to make is that it's "impossible" to make a listening environment seem larger than it is while maintaining accuracy...consider your point made. So please feel free to move along.


You're calling BS? The guy who wants to know where width comes from? That really is funny. Forget a concert hall. In you living room if you move the speakers 2' further apart or closer and you don't hear the difference, you're in the wrong hobby bud. 

My posts in this thread are part of the general discussion on the topic. If a straight answer to your dumb question got you riled, that's your issue. For the record, I'm not saying that its 'impossible' to make the listening environment larger than the physical environment or the recording, just that it would be more 'inaccurate'. Big difference. 

If you're serious about competing, know that you will have to unlearn to relearn and that you can't learn with mindsets.


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## ErinH (Feb 14, 2007)

sqnut said:


> your dumb question


LOL @ "dumb". I don't know if you've been reading this thread, but there's quite a lot of 'heavyweights' in this thread discussing the topic and the answer isn't so clear cut as you infer.
Since it's such a dumb question, please, tell us the answer. You'll save Andy, Chad, myself, Todd, and Darrin a lot of time.


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## michaelsil1 (May 24, 2007)

bikinpunk said:


> LOL @ "dumb". I don't know if you've been reading this thread, but there's quite a lot of 'heavyweights' in this thread discussing the topic and the answer isn't so clear cut as you infer.
> Since it's such a dumb question, please, tell us the answer. You'll save Andy, Chad, myself, Todd, and Darrin a lot of time.


You forgot to mention Gary Summers!


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## sqnut (Dec 24, 2009)

bikinpunk said:


> LOL @ "dumb". I don't know if you've been reading this thread, but there's quite a lot of 'heavyweights' in this thread discussing the topic and the answer isn't so clear cut as you infer.
> Since it's such a dumb question, please, tell us the answer. You'll save Andy, Chad, myself, Todd, and Darrin a lot of time.


LOL!! I think this is a great thread. "Dumb' was not with ref to OP's original question. On page 4 he wanted to know if one would hear the difference if you changed the distance between the speakers and when I said you would, he called my 'BS' . 

There are a lot of folks in this thread way ahead of me in experience and knowledge and I'm not running anyone down. Yes I agree that there are no clear cut answers. But its interesting to see how people are stacked up in two camps. One that believes that the recording or physical space (whichever is smaller) will determine width and the other that believes you can use dsp to go beyond the recording / physical space. 

I'm firmly in the former camp as I believe that gives better accuracy. But it's a really interesting discussion. Back on topic.......


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## garysummers (Oct 25, 2010)

"I have only ever heard this reproduced in a way that completely disregards the vehicle one time, and only very recently. The first time you truly hear a system vastly exceed the boundaries of the vehicle it takes the brain time to process what you are hearing as you have to 'let go' of the boundaries. The result is awesome."

How did Mark do it guys?


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## 14642 (May 19, 2008)

pionkej said:


> I
> 
> Anything above 3khz can be avoided with directivity control or a 1" piece of foam (1/4 wave).
> 
> ...


What makes you think that foam will stop reflections at low frequencies? Damping material (like the stuff you stuff inside a subwoofer box) works because it turns acoustic energy into heat and motion by causing the whole bunch of little fibers in wool or dacron to move, not because it's "springy". It also stops reflections at really high frequencies, but that's useless inside a box. Putting one of those heavy "deflex" pads behind your speaker doesn't reduce the reflection at low frequencies, it adds mass to the panel to reduce it's resonance frequency. It's a little square because that's easy to apply through the hole in the baffle without taking the entire door panel apart. Covering everything in Dynamat reduces the resonance of the panel too.


----------



## 14642 (May 19, 2008)

garysummers said:


> "I have only ever heard this reproduced in a way that completely disregards the vehicle one time, and only very recently. The first time you truly hear a system vastly exceed the boundaries of the vehicle it takes the brain time to process what you are hearing as you have to 'let go' of the boundaries. The result is awesome."
> 
> How did Mark do it guys?


For awhile, there was an MS-8 in that car, carefully hidden somewhere,(or so I heard). I've heard that he has since "removed it", but who knows. Mark is very secretive about what's in his cars. The 4-runner used to include some rear speakers and a digital delay in a lexicon processor that he used to add some decorrelated stuff to the back, similar to what PL2 and L7 do. This I know, because he was a consultant for JBL at the time.


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## Boostedrex (Apr 4, 2007)

Wesayso said:


> So you know how Mark E did that? We would like to know as well .
> This is probably not going to happen though but what do you guys know about that car that you can share with the rest of us? All I know about it is reading how great it sounds. I've seen the pictures on here but there isn't much to see. I can understand the reasons for the secrecy but for example, does it sound better than the big Sprinter Van known as the Magic Bus?
> That last one obviously has a bigger space to work with and a lot of acoustic treatments.
> I'm just curious as to what works and why...


I have listened to Mr. Whitledge's "Magic Bus" and I was one of the judges at the MECA Finals this year. So I have spent time in Mark E's car. To me there is a large difference in which vehicle sounds better. Mark's car is head and shoulders above the "Magic Bus."




michaelsil1 said:


> Someone told me that Mark E. car imaged very very well, but didn't really sound that great. Does he have more than one?


You heard wrong I'm afraid. At least speaking about the tune that was on Mark's car at Finals this year. It takes a LOT for me to really be blown away. In fact, there is only 1 other car in history that has left me in awe after listening to it. Marks' car deserves the hype it's given IMHO.


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## ErinH (Feb 14, 2007)

Boostedrex said:


> You heard wrong I'm afraid. At least speaking about the tune that was on Mark's car at Finals this year.


Agreed.


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## thehatedguy (May 4, 2007)

Ok, I will admit my ignorance here...how does one gain THAT much more width from re-tuning the system? I can't really wrap that around my head.


----------



## AAAAAAA (Oct 5, 2007)

thehatedguy said:


> Ok, I will admit my ignorance here...how does one gain THAT much more width from re-tuning the system? I can't really wrap that around my head.


Whats up with you and not getting back to me in PM's.

---------------------------

It's interesting how people can hide things in their install and gain an upper hand somehow during competitions.

----------------------------

Something else along the same lines but about depth.
The ear has no way to calculate how far away a sound is, it relies only on past experiences to best guess if the sound is close or far. How neet is that?


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## michaelsil1 (May 24, 2007)

Boostedrex said:


> It takes a LOT for me to really be blown away. In fact, there is only 1 other car in history that has left me in awe after listening to it. Marks' car deserves the hype it's given IMHO.


I would like to know which car that was.


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## ErinH (Feb 14, 2007)

mine. 



I kid, I kid....


----------



## thehatedguy (May 4, 2007)

I hardly check my PMs.

Just checked, and I could, but the price couldn't compete with other online vendors.



AAAAAAA said:


> Whats up with you and not getting back to me in PM's.
> 
> ---------------------------
> 
> ...


----------



## thehatedguy (May 4, 2007)

So Mark is using regular off the shelf JL ZR or C5 components?


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## cvjoint (Mar 10, 2006)

I would be interested to know if there is a tool (other than ear) based method of improving the soundstage. I can share the few ways I've learned to improve staging and hopefully someone else can add on some new methods. The big problem as I see it is that we have to rely heavily on what we hear. If we can quantify the results for evaluation somehow we won't have to talk about x's car and how it sounded in various stages of disguise. This is why I hardly engage in soundstaging talk, there's not a lot of ways to evaluate performance.

1. Left and Right target curves can be matched so that they are nearly replicas of each other. This can be achieved with any 1/3 octave tool that can take averages. I don't find noise vs. sweep or less smoothing adds in considerable benefits but my preference is for the sweep with 1/6 octave smoothing. I take 30+ averages around the head adding more weight to areas around the ears.

2. Aligning impulse responses to fine tune arrival times.


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## ErinH (Feb 14, 2007)

IF my idea of achieving width by minimizing the reflective amplitude at some given delay is remotely valid, then one idea might be able to do the following:
Take an impulse response. Look at the initial amplitude in impulse. Achieve a lower amplitude at x msec after the initial response.

Of course, you'd have to experiment (or know from some source) what is the optimal delay and respective amplitude.


Again, I'm not saying this is right. It's just one man's idea.


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## sqnut (Dec 24, 2009)

cvjoint said:


> 1. Left and Right target curves can be matched so that they are nearly replicas of each other. This can be achieved with any 1/3 octave tool that can take averages. I don't find noise vs. sweep or less smoothing adds in considerable benefits but my preference is for the sweep with 1/6 octave smoothing. I take 30+ averages around the head adding more weight to areas around the ears.
> 
> 2. Aligning impulse responses to fine tune arrival times.


I have a slightly different take on this.

1. If you want L/R balance, the L/R target curves will not be replicas. I think this should be Andys 10th rule.

2. How you set the relative delay between the drivers will impact the connectivity of drivers and help with the stage height. You want the drivers in acoustic phase which may be a bit different from mechanical phase that you're shooting for with the impulse response. 

While there are a lot of useful tools at the end of the day, if you're tuning you're going to use your ears.


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## cvjoint (Mar 10, 2006)

bikinpunk said:


> IF my idea of achieving width by minimizing the reflective amplitude at some given delay is remotely valid, then one idea might be able to do the following:
> Take an impulse response. Look at the initial amplitude in impulse. *Achieve a lower amplitude at x msec after the initial response.*
> 
> Of course, you'd have to experiment (or know from some source) what is the optimal delay and respective amplitude.
> ...


The bolded part is the tough one as far as I can tell. You would need an absorbent material that does not change its coefficient depending on the frequency. Secondly, since we are in the car environment it would have to be see through I imagine.

I forget who mentioned this in the thread, but instead of dealing with reflections it may be more tractable to smooth the transition from the speaker to the nearby reflective panels. The easiest way to achieve this would be to use a BG planar to take advantage of it's depth and built a pod that makes a smooth transition to the door window and windshield. The pod would have little room behind the planar but gives the idea of smooth transitions great potential.


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## Wesayso (Jul 20, 2010)

Boostedrex said:


> I have listened to Mr. Whitledge's "Magic Bus" and I was one of the judges at the MECA Finals this year. So I have spent time in Mark E's car. To me there is a large difference in which vehicle sounds better. Mark's car is head and shoulders above the "Magic Bus."


That's the answer I expected somehow without hearing them but just from reading the posts from people who did hear one or the other.
And a sign that the size of the vehicle isn't THE determining factor. That's why I asked about these two cars. One is obviously bigger than the other.


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## 14642 (May 19, 2008)

bikinpunk said:


> IF my idea of achieving width by minimizing the reflective amplitude at some given delay is remotely valid, then one idea might be able to do the following:
> Take an impulse response. Look at the initial amplitude in impulse. Achieve a lower amplitude at x msec after the initial response.
> 
> Of course, you'd have to experiment (or know from some source) what is the optimal delay and respective amplitude.
> ...


That IS a reflection. In a room, this is precisely what an inpulse response measurement looks like. It's pretty simple to determine WHICH surface corresponds to the reflectoin with a tape measure and a calculator. 

Try that in a car. Seriously. Make an impulse response measurement in a car and then in a room. This is an excellent way to see just how difficult this whole idea of eliminating reflections really is. 

Sure, if you could remove all the reflections in the car and then REPLACE them with those from another room by using some additional speakers placed around the car, that would work. Hey, wait. That's called Multichannel. So, if you can't eliminate the near field reflections and those are what defines the listening space (besides what we see when we sit in the car-our ears are designed to help our eyes), then what's the next best thing? Add the other reflections anyway. Hmmm...what happens then? Hmmm...we get a stage-sort-of-sounding-thing about as big as the car and the sense that the rest of the space is bigger than the car.


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## Wesayso (Jul 20, 2010)

Just for fun I downloaded this wma file made with the Ambiophonic DSP plugin from this site:
FilmakerTechnology Systems & Products - Ambiophonic DSP stereo enhancer Halfway the page look for For a demonstration, save the wma. (not great quality)
I have a 2 way in the doors but noticed the sound comming more from the sides with this saved example from the plugin. I bet it would work with convervative settings with a kickpanel/a-pillar install to hear more width. 
Not how it's ment to be used but it tries to eliminate crosstalk between the channels to enhance the width. It might give some ideas to use DSP to enhance the width in a car.


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## asawendo (Nov 22, 2009)

Andy Wehmeyer said:


> That IS a reflection. In a room, this is precisely what an inpulse response measurement looks like. It's pretty simple to determine WHICH surface corresponds to the reflectoin with a tape measure and a calculator.
> 
> Try that in a car. Seriously. Make an impulse response measurement in a car and then in a room. This is an excellent way to see just how difficult this whole idea of eliminating reflections really is.
> 
> Sure, if you could remove all the reflections in the car and then REPLACE them with those from another room by using some additional speakers placed around the car, that would work. Hey, wait. That's called Multichannel. So, if you can't eliminate the near field reflections and those are what defines the listening space (besides what we see when we sit in the car-our ears are designed to help our eyes), then what's the next best thing? Add the other reflections anyway. Hmmm...what happens then? Hmmm...we get a stage-sort-of-sounding-thing about as big as the car and the sense that the rest of the space is bigger than the car.



Couldn't agree more!

The conventional stereo system IMHO simply could not beat multi channel system in terms of big and spacious sound. So I already using multiple speakers and multiple processor in order to reproduce music in my car


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## ErinH (Feb 14, 2007)

Andy Wehmeyer said:


> That IS a reflection. In a room, this is precisely what an inpulse response measurement looks like. It's pretty simple to determine WHICH surface corresponds to the reflectoin with a tape measure and a calculator.
> 
> Try that in a car. Seriously. Make an impulse response measurement in a car and then in a room. This is an excellent way to see just how difficult this whole idea of eliminating reflections really is.
> 
> Sure, if you could remove all the reflections in the car and then REPLACE them with those from another room by using some additional speakers placed around the car, that would work. Hey, wait. That's called Multichannel. So, if you can't eliminate the near field reflections and those are what defines the listening space (besides what we see when we sit in the car-our ears are designed to help our eyes), then what's the next best thing? Add the other reflections anyway. Hmmm...what happens then? Hmmm...we get a stage-sort-of-sounding-thing about as big as the car and the sense that the rest of the space is bigger than the car.



Yes I understand what a reflection is. My post was gear towards determining IF amplitude and/or arrival time of a reflection has any bearing on the sense of width.


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## thehatedguy (May 4, 2007)

It's pretty easy to do that... cut a couple of strips of wood the length of the planar to space the speaker off of the door and to meet the back of the door panel. Screw them to the door, silicone the big holes. Measure where the planar sits and cut the plastic door panel. If you are careful, you can cut the plastic without cutting the vinyl or fabric. Pull the plastic out, wrap the fabric around the opening and superglue it to the door panel. Put the door panel back on...and now the planar is pretty flush with the door panel.




cvjoint said:


> The easiest way to achieve this would be to use a BG planar to take advantage of it's depth and built a pod that makes a smooth transition to the door window and windshield.


----------



## ErinH (Feb 14, 2007)

sqnut said:


> 2. How you set the relative delay between the drivers will impact the connectivity of drivers and help with the stage height. You want the drivers in acoustic phase which may be a bit different from mechanical phase that you're shooting for with the impulse response.


Impulse response is a measure of acoustical delay but can also be used to show polarity. 


I disagree. Matching L/R is a means of balancing your stage via amplitude; the same as you do with gains for level matching. The same notion that using t/a is used to balance your stage via phase.


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## Boostedrex (Apr 4, 2007)

michaelsil1 said:


> I would like to know which car that was.


It was Kevin K's Accord. And it was at the 2007 Marv's BBQ to be exact. In fact, I spent time in the "Magic Bus" that same day. Kevin had the best sounding car there that day BY FAR. I wish I could've heard it again now since I have learned a lot more about what to listen for. But the window has closed for that.


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## michaelsil1 (May 24, 2007)

Boostedrex said:


> It was Kevin K's Accord. And it was at the 2007 Marv's BBQ to be exact. In fact, I spent time in the "Magic Bus" that same day. Kevin had the best sounding car there that day BY FAR. I wish I could've heard it again now since I have learned a lot more about what to listen for. But the window has closed for that.


Kevin K. did have an amazing car before he got a bright idea.


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## garysummers (Oct 25, 2010)

"I have only ever heard this reproduced in a way that completely disregards the vehicle one time, and only very recently. The first time you truly hear a system vastly exceed the boundaries of the vehicle it takes the brain time to process what you are hearing as you have to 'let go' of the boundaries. The result is awesome."

Maybe in order to understand what Mark did to make his car sound this good, we have to think about and understand what he did not do! Any ideas?


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## thehatedguy (May 4, 2007)

I am kind of curious as to how a re-tune could change the width that dramatically...using only the front speakers.

Rears and sides I can understand.

Which I think there is more processing going on in Mark's car than just a single DBX482. How is the center derived when it was being used? I think Mark is smart enough to know that just an ordinary mono signal to the center wouldn't get the world class results he is after.

Then again I do believe in UFOs.


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## BigRed (Aug 12, 2007)

He uses rears and a center. All mono. One drive rack.


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## thehatedguy (May 4, 2007)

So there are passives between the midbasses and tweeters? Cause there are an awful lot of speaker wires from his 4 channel amps going somewhere...unless he is biamping the passives.


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## BigRed (Aug 12, 2007)

8 channels. 

2 channels stereo subs
2 channels Midbass
2 channels mids/tweets (using amp crossover)
1 channel rear fill mono. L-R
1 channel center

That is what he told me which he seemed very open about discussing it. I wish he came on here more


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## thehatedguy (May 4, 2007)

But the JL crossovers only go to a touch over 500 hertz, so there has to be passives in the system between something.

Then why all of the speaker wire on the outputs unless biamping? And even then it doesn't add up.

And how is he deriving a center? L+R? That's the only way unless something else is in the car.


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## Mic10is (Aug 20, 2007)

thehatedguy said:


> But the JL crossovers only go to a touch over 500 hertz, so there has to be passives in the system between something.
> 
> Then why all of the speaker wire on the outputs unless biamping? And even then it doesn't add up.
> 
> And how is he deriving a center? L+R? That's the only way unless something else is in the car.


L+R band limited something like 300 to 3000


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## garysummers (Oct 25, 2010)

I had the chance to meet Mark Eldridge two times, the CES Show in 2009 and the Mecca Finals 2010. I only heard his car at the CES. Our meetings were brief but very interesting for me. I could see immediately that this man number one, loves music, number two is passionate about its "accurate" reproduction. He is an established audio engineer and you all know his accolades in car audio. I attempted once to attend his MSE seminar in California but due to work was not able. I have however read and watched everything I could find on the web that Mark has written or demonstrated, multiple times. His solid knowledge of the basics of audio theory are clear in all he says and does. IMHO this is how Mark has achieved the remarkable sound in his car! The laws of Audio Physics have not changed nor will they! Any audio system must be phase, time, timbre and level correct or it will not reproduce audio "accurately". Mark knows this! This may sound real basic but we can never get away from it. How we each apply this knowledge in our respective audio environments whether it be studio, home, or automotive will determine our success. 
Just as an example I have posted a few articles Mark wrote in the past. Many of you will read these and say you already know all this! I say read them again. They have helped me a lot!

Thanks for letting me talk!

What is Sound Quality and How to Achieve It - Features - Car Audio and Electronics
Techniques for Tuning - Guides - Car Audio and Electronics
How to Select and Adjust Crossovers - Guides - Car Audio and Electronics


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## thehatedguy (May 4, 2007)

How does the dBX create a L-R for the rears? Last time I looked at the software you could do L+R, but not a L-R. Aside from a decoder, the only way I knew to do it was speaker level with a stereo input signal.


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## 14642 (May 19, 2008)

Get a line output convertor that includes transformers. Invert the polarity of one of the output channels. Connect them together with a Y adapter. there's L-R. Or, plug them both into the two channels of your amplifier and bridge the two channels into a single speaker. There, L-R.

L+R as a center doesn't give you a wide stage. It narrows the stage. Mono information is basically L+R-lL-Rl (or everything minus pure stereo). Good lock processing that without an active matrix.


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## Patrick Bateman (Sep 11, 2006)

My new setup for ambiophonic seems to work really nicely. The first time around, I had the speakers flat against the wall. This time, they're corner loaded. Both of them are crammed into a corner, similar to what Klipsch does with the Klipschorn.

Seems to work really good. Have been listening this way for a few weeks now.

The reason that I bring this up, is that it's very car-friendly, because there are lots of corners in a car. For instance, you could do a stereo ambio setup under the driver's side of the car.

My speakers are literally touching each other, take up 36" of real estate in the corner, and the soundstage sounds about 180" wide on the right track.

Sure, there are lots of tracks that don't have much width, but that's a problem with the recording, not the speakers.

On a side note, one nice thing about having the speakers so close together is that articulation is really good. (IE, it's easier to understand what singers are singing.) This is because the speakers are so close together. In a conventional set up, due to the distance of between the speakers, one speaker is significantly out-of-sync with the other unless you're exactly in between the two. (Which is impossible in a car.)


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## 14642 (May 19, 2008)

Patrick Bateman said:


> On a side note, one nice thing about having the speakers so close together is that articulation is really good. (IE, it's easier to understand what singers are singing.) This is because the speakers are so close together. In a conventional set up, due to the distance of between the speakers, one speaker is significantly out-of-sync with the other unless you're exactly in between the two. (Which is impossible in a car.)


 
Cool. No better way to minimize phase errors caused by pathlength differences than to put the speakers in the "same" place.


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## pionkej (Feb 29, 2008)

Andy Wehmeyer said:


> Cool. No better way to minimize phase errors caused by pathlength differences than to put the speakers in the "same" place.


Andy, is there any chance of you laying out a bit more detail on how the MS8/L7 does what it does in the car? It seems to fall right in the middle between traditional 2.1 stereo and an ambio setup in term of what it can do with the soundfield (for those of us running center and rears of course).

I'm not trying to put you on the spot, but I've already been looking. Most descriptions you give say it does, "XYZ plus a lot of other stuff". I can only assume you say "a lot of other stuff" because that "stuff" would be over 99% of the people's heads (you still get 20 posts a week about how to level-match in the MS8 thread )...I'm hoping you can see this thread is a bit beyond that level of knowledge and wouldn't mind sharing.


----------



## pionkej (Feb 29, 2008)

garysummers said:


> What is Sound Quality and How to Achieve It - Features - Car Audio and Electronics
> Techniques for Tuning - Guides - Car Audio and Electronics
> How to Select and Adjust Crossovers - Guides - Car Audio and Electronics


Thanks for the links Gary. I'm about to starting reading them since I'm not good for much else with all the food I ate yesterday. Hopefully the tryptophan from the turkey doesn't put me to sleep while I'm pouring over the details.


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## 14642 (May 19, 2008)

pionkej said:


> Andy, is there any chance of you laying out a bit more detail on how the MS8/L7 does what it does in the car? It seems to fall right in the middle between traditional 2.1 stereo and an ambio setup in term of what it can do with the soundfield (for those of us running center and rears of course).
> 
> I'm not trying to put you on the spot, but I've already been looking. Most descriptions you give say it does, "XYZ plus a lot of other stuff". I can only assume you say "a lot of other stuff" because that "stuff" would be over 99% of the people's heads (you still get 20 posts a week about how to level-match in the MS8 thread )...I'm hoping you can see this thread is a bit beyond that level of knowledge and wouldn't mind sharing.


It's all in the big thread, complete with diagrams of the steering. I think it's also been excerpted into the MS-8 FAQ thread.


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## pionkej (Feb 29, 2008)

Andy Wehmeyer said:


> It's all in the big thread, complete with diagrams of the steering. I think it's also been excerpted into the MS-8 FAQ thread.


Cool. I must have missed it in the the "big" thread. I'll check the FAQ thread first since it seems a bit more manageable.


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## sqnut (Dec 24, 2009)

bikinpunk said:


> I disagree. Matching L/R is a means of balancing your stage via amplitude; the same as you do with gains for level matching. *The same notion that using t/a is used to balance your stage via phase.*


Yes,agreed.

I'm talking about setting the t/a a fraction of ms different from measured distance. So you're not getting simultaneous arrival times from the drivers, while still hearing the L&R mids together and highs together. I'm not sure I'm explaining this well.....


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## 14642 (May 19, 2008)

sqnut said:


> Yes,agreed.
> 
> I'm talking about setting the t/a a fraction of ms different from measured distance. So you're not getting simultaneous arrival times from the drivers, while still hearing the L&R mids together and highs together. I'm not sure I'm explaining this well.....


If you mean preserving some phase errors at high frequencies by slightly mis-aligining them also helps to preserve width, then...well...sort of. We don't hear phase errors at high frequencies very easily so it's pretty subtle.


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## pionkej (Feb 29, 2008)

Here is what I found on the MS8 and L7 so far. It doesn't openly state "this is how depth and width is created with L7", but I think where Andy covers that certain information from the front is also sent to the rears but phase-reversed and delayed IS how the MS8/L7 creates a sense of depth and width.

I'm including it here because I think it is the only current midpoint between trying to create width with a 2.1 setup and going ambio (which needs a car-pc to do). I think it's important because it is the only "black box" available right now that can do this. If others think it's pulling things off track, let me know and I'll strike it from the thread.



Andy Wehmeyer said:


> OK, now that my butt has recovered from 15 hours in the same chair yesterday, here goes.
> 
> Every few milliseconds, Logic 7 computes a steering angle by determining a couple of things about the stereo signal. Left, right and center steering is determined by level differences between left and right signals. Mono information--the information that's common to left and right--is steered to the center. Don't confuse mono as L+R for what's actually going on here. Although this isn't how it's done, you could think of the mono info as (L+R)-lL-Rl. It's all of the sound minus the sound that appears only in the left or the right. That mono information is also attenuated in the left and the right. The amount of that information that appears in left and right is an important part of making this thing sound great in cars. If the information is completely removed from left and right, then I don't think it works very well in cars. The images are spot on, but they're really small and don't sound believable, to me. If the mono information isn't attenuated at all, then the stage is narrowed a bit and the images are big and kind of nebulous. Left of center and right of center aren't very accurate. Attenuating the mono signal in left and right by 6dB works great and that's what MS-8's L7 does.
> 
> ...


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## sqnut (Dec 24, 2009)

Andy Wehmeyer said:


> If you mean preserving some phase errors at high frequencies by slightly mis-aligining them also helps to preserve width, then...well...sort of. We don't hear phase errors at high frequencies very easily so it's pretty subtle.


Yes that's the idea. Plus for some reason it gives better height too. Seems to pull everything else up a bit.


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## sqnut (Dec 24, 2009)

Just wanted to say that this is a really great thread. Thanks to everyone who posted in it, with a special thanks to AW.


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## Tendean17 (Feb 23, 2009)

This is great thread .. and here's another very good big threads to read for references from my collections ...

Lycan / Werewolf and Andy Wehmeyer and many others wrote something like this in http://www.diymobileaudio.com/forum/system-design-help-me-choose-equipment-my-car/9806-rear-fill-do-you-use.html

_Big difference between a concert hall and car: size of the acoustic space!

And it's NOT just a relative difference ... there's a real, tangible threshold involved, as defined by the Haas Effect. In a car, there's a real good chance that the natural reflections will not exceed the precedence effect (about 20msec, if memory serves) ... meaning that natural reflections will only tend to smear and confuse the front stage. In a concert hall, there's a real good chance that the natural reflections will exceed the precedence threshold.

So if you delay the rear fill by ~20msec or slightly more, you can create an apparent acoustic space that is much larger ... without confusing or ruining the front stage. This is a good thing Yes, we face the orchestra in a concert hall ... a classic argument against dumb rear fill ... but we also sense that the concert hall is bigger than about 25 cubic feet ... a very good argument in favor of smart rear fill

How to best accomplish it, is perhaps a discussion for another thread. You need a processor with time alignment, and the ability to bandlimit the rears. The difference signal can be formed either actively before the amp (trivial with balanced signals, not even hard with transformers and single-ended signals), or speaker-level after the amp (the classic Hafler matrix was the old, dumb example ... with no time delay, and even only crude attenuation and bandlimiting). But here's an interesting link for further reading:

http://www.mlssa.com/surround/surround3.htm

Of course, you may want to consider the options mentioned above ... Dolby Pro Logic II (invented by Fosgate with an automotive acoustic space in mind), DTS Neo:6, and the new Harman Logic7 processor for the car (which, by the way, is starting to get some very encouraging reviews). All of these options create a multi-channel signal from a 2-channel source, and make very intelligent use of speakers behind your head

I guess my main point is this : all "rear-fill" is not created equal It's important to distinguish what type, before we summarily embrace or dismiss the entire category_

---

Lycan / Werewolf and Andy Wehmeyer and many others wrote something like this in http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/81244-space-final-frontier.html#post1032418

_Ahhh...the right questions. Because these reflections all happen very soon after the initial sound, they sound like frequency response anomalies--peaks and dips in the response. The early ones spread the apparent source and the ones toward the end help us determine that we're in a small space. The reflection from the left speaker off a boundary on the right that arrives at our right ear and vice versa is crosstalk. That crosstalk narrows the image and degrades the stereo reproduction a little bit.

In a big room or a concert hall, the walls are farther away and the reflections arrive at our ears much later and with reduced intensity. many of them sound like separate events--that's reverberation. We can make the space in the car seem larger by ADDING late reflections and some additional early ones. Trying to get rid of the ones that are there is a waste of time. As Patrick has discovered, the size of horns that are required to narrow the dispersion enough to make a difference is prohibitive in a car.

Reflections are how we determine the size of the space we're in. Listening to speakers in an anechoic chamber is horrible--the most unnatural sounding thing you've ever heard. _

---

_I largely agree, but a few points are worth emphasizing :

1. Very near, close-in-time reflections will NOT be distinguished from the original sound (the Haas limit determines how close is "close"). They will impact frequency response (via comb filtering) and localize-ability ... mostly, never in a "good" way: stereo reproduction, from recording through expected playback, does not "depend on" nor "anticipate" these reflections in any way. There are a few exceptions, where near reflections aren't a terrible thing, including : ultra-close reflections, such that the first comb null is outside the driver's pass band (categories include corner-loading subs, and midranges on dash very close to windshield), and deliberately depending, primarily, on a tweeter reflection, while minimizing that tweeter's primary radiation to the ear.

2. Later-in-time reflections do indeed give us a sense of "space". The mind can distinguish these (even if just barely) from the original event. This category was the whole basis for "intelligent rear fill" ... bandlimited, delayed, L-R difference signal. Done properly, this technique will give you a larger sense of space, sounding like you're listening in a larger-than-shoebox venue.

3. Very late reflections sound like reverb or echo ... mostly to be avoided. _

---

_Avoiding these in a car isn't too difficult. there's no possbility thatyou could mount a speaker far enough away to generate these and no reflective surface is far enough away to provide them.

I find, though, that adding some that are synthesized by a DSP can have a really pleasant effect and can dramatically increase the sense of space, but they don't extend the width of the instrument placement. Early reflections (like ones you'd hear from the wall behind and beside the musicians) can also be added in the same way and also have a pleasing effect.

If you're in LA, I'd be happy to give you a demo, but I think this may be the only place to hear this. My car includes some custom DSP that does this, but I've never heard another car that includes it_

Next .. in MS-8 FAQ.


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## Tendean17 (Feb 23, 2009)

Andy Wehmeyer and may others wrote something like this and how MS-8 / L7 works using Rear Channel in http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/98699-jbl-ms-8-faq.html

_Rear speakers should be full range, above 100Hz. The high frequencies are helpful in recreating ambience, so they should play to 10kHz. I recommend that the don't play much of anything below 100Hz, because Logic7 reverses the phase of one side of the rear during front-steered sounds to anchor the image in the front. When sounds steer rear, the phase of the sides and rears is corrected to make the steering more appraent. THe reverse phase for front steered images mucks up the impaact a bit, so cross the sides and rears over at 100 Hz or higher with a steep slope. This reversal happens very quickly each time L7 samples the music. I don't remember the interval but it's short--too quick for you to hear. One thing that L7 cannot do is steer a transient signal rear, if a steady state signal is steered front at the same time. I have a recording that makes this easy to hear. Mono pink noise that steers center and a voice that rotates around the car doesn't work. Fortunately, there are very few recordings that are made this way. L7 doesn't work on every recording and recordings that have little stereo or reverse-phase info won't place much info in the back of the car. Live recordings and direct to 2-track will be awesome. 

---

The out of phase information will steer rear. If you have no rear speakers, it'll disappear. 
L7 works great with stereo recordings and recordings designed to reproduce a space. If the mixologist used a bunch of processing because he fancies himself an artiste and wanted to create some cool effect, then that cool effect will be made even cooler by L7. 
If you want to test this for yourself, download audacity and make a pink noise track. Then, reverse the phase of one channel in the track, burn it onto a CD or load it onto your iPod and play it back. The noise will steer rear. 
Then, record your own voice (or someone else's) and switch the phase of one channel. The voice will appear in the back. You can build a track where the voice will rotate around the car. You have enough info to do that. 
Or, if someone has a place i can upload a track like that, I'd be happy to.

---

Out of phase information in the recording will be steered to the rear. In acoustic or direct to 2-track recordings or recordings designed to recreate a live event, this information will mostly be room reflections. Steering those to the rear works pretty well in terms of creating good ambience. The algorithm is similar to PL2 in the steering of signals to the rear, but L7 has some other goodies that make it possible to resolve rear left and right (something not done very well by other algorithms) and another feature that helps to plant front steered images in front. The difference between rears and sides is an additional few milliseconds of delay.

---

The rear isn't critical, but it's really helpful to have something back there. The level that the rears will play with Logic7 will depend entirely on the amount of out-of-phase information in the recording. -180 degrees between left and right steers rear. It's great at steering room ambience in direct to 2-track recordings. Most pop recordings mixed using simple panning won't produce much rear information. Spacey sounding stuff, live recordings and anything you play back as a 2-channel downmix from a discreet multichannel recording may have lots of rear information. If you plan to do much of that, pay at least some attention to getting a decent pair of speakers back there and mount the tweeters at ear level.

The rear speakers should always have a high pass filter to keep them from playing anything below 100Hz. I usually use a 100Hz 4th order filter. So long as the rears can play between 100Hz and about 15kHz, MS-8 will correct the response well enough

---

If you don't have rears or a center, don't use L7. If you have rears and no center, try L7. If you have a center and no rears, add rears and use L7

---

Yes, she is hot.

The last time I competed in an IASCA/MECA show a couple of the judges told me, "Man, that's incredible. I've never heard a car reproduce the ambience and the sound of the room as accurately as your car does."

I said, "Thanks", but I couldn't bring myself to tell them that none of those sounds were actually in the recording and that they were generated by my DSP. 

I love music--almost all kinds--and refuse to constrain my ability to enjoy it to the few times I listen to really great recordings. The fact is that in many cases, the artists are the ones who insist on mountains of dynamic range compression because they can't abide the thought that someone else's recording will sound louder when a listener hears it on some tabletop system with woofers the size of quarters on on a 99-cent pair of earbuds. Or they say, "We want that '70s sound", (which means no bass and sounds panned hard left and hard right). 

The fact is that I am an audophile and am not well served by recording engineers. If I have to dramatically change the sound to have an experience worthy of the amount of time and money I've spent on my system when I listen to popular music, then so be it. Unlike some others, I can tolerate HUGE errors in frequency response so long as spatial qualities are good. What spatial cues exist in a Black Eyed Peas recording? None. So what's fun about listening to that stuff? Dre has the frequency response thing down. Listen to any hit that he's ever recorded and run a frequency response measurement on the duration of the track. They're all similar and they sound great--so long as one doesn't care about the "room". I care about the room so I have to create one or it isn't fun enough to satisfy me. 

I think the point is that the artist intends the "event" to be engaging, but sometimes he doesn't know what that means in terms of audio reproduction for different kinds of listeners. Here's an example:

I once had a conversation with a VERY well-known and VERY successful record producer who told me, "Man, most audio companies just don't get it. You guys always talk about flat response and accuracy. We want you to reproduce what we experience in the studio, and that experience can't be put on a disc. These guys mix records on an $800,000 system that plays crazy loud with tons of really tight bass. Reproducing that experience is your job--we can't put that on a disc. That's why we're making gear. Why am I telling you this? Because you seem to get it." 

When I demo'ed their tracks for them in the car we were demonstrating, they wanted to know why it sounded "mono" when the DSP was off. I said, because that's what's on the disc and the inside of a car decreases the "stereo" effect anyway". When I turned the DSP on, they said, "Wow. That's what it's supposed to sound like, but it needs more bass." 

Making recordings sound different doesn't have to be smoke and mirrors and a bunch of techno-babble. We can, in fact, figure out what we need to do to playback systems to make the experience more engaging and if the audio industry is to survive, we have to do it._

Next .. Mark Eldrige Post in other forum (Ref to Mic10s links).


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## ErinH (Feb 14, 2007)

Just wanted to jump back in here and add some thoughts...

I started a new build. Blah, blah, blah. However, this time I put the tweeter in front of the midrange with the bottom of the tweeter covering about a third of the top of the mids' cone. The tweeter is physically the furthest away from any reflective surface as has been in any of my previous installs. However, it's also the closest it's been to the listener, too. I was curious if my posts here regarding distance from reflection would hold up. 

I did a make shift install last night and today I roughly dialed in some gains and t/a to see what issues I might have with the midrange response if any due to the tweeter being in its way a bit before I went ahead with the install. 
To my sheer surprise and utter happiness the width of my Mark Knopfler track "Boom, like that" jumped a solid foot outside the window in the guitar riff between verses. I about **** a brick. I literally said OMG and repeatedly played those few seconds over and over again. I actually got goosebumps. 

Moral? I don't know yet, but if it's all psychoacoustics, keep it comin. I'm going back in to hiding a bit on this one.


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## Tendean17 (Feb 23, 2009)

As Mic10s Links ..

Mark Eldridge :

_Congratulations on the wins in Texas. There are some really good cars that compete in that area. 

Speaker placement, along with controling reflections and the speakers' dispersion patterns are definitely critical aspects of ataining good stage width. If your high frequency drivers are on top of the dash, they are likely mounted inside the A-pillars. You're also likely getting a very strong early reflection off the windshield that arrives within a millisecond of the direct sound from the speakers. These two conditions will make it very difficult to create an aural illusion of the stage being much wider than where the speakers are placed, regardless of how much signal processing you throw in the mix. 

Barring a pretty substantial rebuild of the front stage configuration, you can try placing a thick piece of foam just above the speakers on the windshield to reduce the reflection energy. Other than that, there aren't too many techniques that will be very effective. 

Good luck! If it gets to a point that you can't get the system working better with what you've got, and you want to look at some reconfiguration ideas, let us know_

---

Mark Eldridge :

_Speaker placement is always the first,and most important part of designing a great sounding system. If you want to (or have to because of time/financial requirements) you can use factory locations. But even if you only care about the driver's seat listening location, I'd bet you can make a significant improvement in the system SQ by working on the speaker placement.

Andy's car is one of the best sounding systems I've ever heard using almost factory locations. He has spent a ton of time with the Harman processor to make it sound as good as it does. IT does some things like no other system I've heard, and other things that are average, and many in between. He didn't want to spend the time and money, not to mention he didn't want to tear up the Mini, to place the speakers other than in the doors. That's great, and I whole-heartedly agree. I wouldn't cut that car either.

But, it is limited in some areas that could be improved by mechanically relocating the speakers. That's the trade off. Cut the car, and make it better, or don't cut it, and accept the trade offs. Sometimes, only a little modification work can go a long way to improving the acoustical properties of the car. 

Making a car sound good from only one seat is really easy compared to making it sound equally good from both seats. For one seat, the signal delay can help, but you sacrifice the other seat every time. 

The real challenge is in taking the time to learn about sound, how to control it, and make it sound great from both seats. 

BTW, if you get the chance, listen to the room effect in Andy's car... Unbelievable!!!
_

Mark Eldridge :

_Do you have any room for a midbass enclosure in the bottom of the dash assembly, above your feet? 

Midbass is not very critical for stage width or height, but is essential for depth. Also, if the pathlength difference is too large, say over 6 inches for the midbass range from 100 to 400 Hz, the imaging will be shifted to the close side. 

Mounting them under the dash will help with equalizing path lengths, and leave the kick panel area for the mids, which will have a strong influence on width.

Tweeters mounted only in the pillars... I'd put them next to the mids, maybe mounted just above, or in front of them, or where ever you get the best staging properties. Mounting them so far away from the mid up in the pillar can cause problems with creating a coherent wave front, and possibly comb filtering. The results can be phase related problems causing depth, height, and imaging problems. 

In every case I have worked on in a serious SQ competition car, I have found that placing the primary tweeter as close to the mid as possible yields the best results. With them close together, it is much easier to achieve a coherent wave front from both channels, and minimize comb filtering. The staging and imaging will be much more stable, and easier to tune. If after tweaking the system with this configuration you find that height and width might be improved, you can add a secondary tweeter in the pillar, turned down, and crossed over somewhere above 8,000 Hz, only enough to bring up the corners of the stage, and add some width.

Not necessarily. Sure, if your feet feel the air movement, your perception of the stage will be affected. But in many cases, when done well, midbass drivers mounted in that area work great.

If you have a solid midrange and high frequency stage with good perceived stage height, locating the midbass lower will not affect it. 

Comb filtering is a result of the same sound arriving at a point like your ear or a microphone tip, but at two different times. For example, a midrange and tweeter mounted on the dash top pointed at the windshield will result in your ears hearing the direct sound from the speaker, followed a fraction of a milisecond by the reflection of the sound off of the windshield. You get essentially the same sound twice at two different times. The phase differences in the arrival sounds will combine either destructively, or constructively, depending on the frequency and the additional distance/time the reflected sound incurs before arriving at your ear. The result can be some very wildly variating frequency response. 

Try sitting in front of a single home seaker with no hard surfaces near you or the speaker. Listen to a song you are familiar with. Then have someone hold a board, large mirror, or some other hard surface so that it creates a reflection that arrives at your ear also. That is comb filtering.
_


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## pionkej (Feb 29, 2008)

Tendean17 said:


> Lycan / Werewolf and Andy Wehmeyer and many others wrote something like this in http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/81244-space-final-frontier.html#post1032418
> 
> _Ahhh...the right questions. Because these reflections all happen very soon after the initial sound, they sound like frequency response anomalies--peaks and dips in the response. The early ones spread the apparent source and the ones toward the end help us determine that we're in a small space. *The reflection from the left speaker off a boundary on the right that arrives at our right ear and vice versa is crosstalk. That crosstalk narrows the image and degrades the stereo reproduction a little bit.*
> 
> ...


_

Thanks for the great links Tendean17. I read through all of them, and I think they summerize everything pretty well. I hightlighted what I personally found most relevant to our width discussion.

That is that acoustic crosstalk and localization are the two primary culprits for killing perceived width. Localization can come from rattles/resonances or reflections from what I'm reading and have experienced. Early reflections are NOT the "devil" if treated properly and the brain processess them as one sound (this may be why the large baffle Andy W. mentioned earlier worked so well)._


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## pionkej (Feb 29, 2008)

bikinpunk said:


> Just wanted to jump back in here and add some thoughts...
> 
> I started a new build. Blah, blah, blah. However, this time I put the tweeter in front of the midrange with the bottom of the tweeter covering about a third of the top of the mids' cone. The tweeter is physically the furthest away from any reflective surface as has been in any of my previous installs. However, it's also the closest it's been to the listener, too. I was curious if my posts here regarding distance from reflection would hold up.
> 
> ...


That's awesome you had some good initial results. It tracks with what we had been discussing about reflections from tweeters and I'm glad it seems to hold some validity. Eagerly awaiting more listening impressions.


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## Patrick Bateman (Sep 11, 2006)

Putting a tweeter in FRONT of a midrange, instead of coaxial seems a little silly. *It just looks wrong.* But due to the frequencies involved, it can actually work better. For instance, if the upper end of your midrange goes to 2khz, that's a waveform that's nearly seven inches in length. Not large by any means, but not tiny either.

So due to the size of the waveform, you can get away with a tweeter pod in FRONT of the woofer.

OTOH, if you use a higher crossover point, that wavelength will get shorter and shorter, and problems will become more and more audible. And of course, you're creating some timing issues, but those issues are nowhere near as severe as having the tweeter two feet away, in the A Pillar.

If you REALLY drop that xover point, you can go crazy with the size of the tweeter pod. For instance, if you use a small full range as a 'tweeter' and drop the xover point to 500hz, that's TWENTY SEVEN inches in length. So with a fullrange as a 'tweeter', you can really go nuts with the mounting scheme that you're describing, where the tweeter is located in front of the woofer in a pod.

Basically the lower that xover point is to the 'tweeter', the more distance you can get away with while still being nearly in phase. And obvisouly digital delay would allow you even more leeway.


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## ErinH (Feb 14, 2007)

Yes, Patrick, I am aware of all the things you mentioned. It, indeed, looks HIDEOUS. 

My concern was how the tweeter may affect the midrange output. In theory, I knew the issue would be up higher and some math told me that it would be at the higher end of the nominal bandpass for the driver I'm using (scanspeak 12mu). To see just what affect the tweeter had, however, I decided to do some testing outside of the car. Below is a quote from my build thread, located here:
http://www.diymobileaudio.com/forum...1873-2006-civic-lx-sedan-build-thread-35.html



bikinpunk said:


> On to something else. Back to scan. I ordered up the illuminator 12mu and the discovery 10f to test. The Illuminator is a BEAST in all regards. For a 4" midrange it's hugemongous. Large underhung motor. Large surround. The sucker has 5.1mm linear xmax. No other 4" midrange I've seen can do this. The problem is simply size.
> The 10f has 2.2mm xmax (I haven't posted data yet). It's a good deal smaller than the 12mu and can fit in the pillars with much less effort.
> Enter my diimma...
> 
> ...





Going a bit further, I did some tweeter analysis.



bikinpunk said:


> out of curiosity I did some testing using a small square of 3/8" Roxul on the pillars about 1" forward of the tweeter, with *only the tweeter playing*. My goal was to see what kind of tamed response I might get using this absorptive material to help minimize some reflections. The results were opposite of what I expected, though, they do make sense.
> 
> You'll see below that the response without roxul (in black) has a bump around 4.2khz and then starts rolling downward.
> The response with roxul minmizes this bump but lowering the overall response below 6.6khz.
> ...





bikinpunk said:


> iphone pictures...
> 
> Here's what I'm toying with as of now. It's uuuuuuuggggglllllllyyyyyyyy.
> 
> ...






The thing I found, after I actually installed the pillars, is that the results from the out of car testing were pretty much the same in regards to the larger deviations in response. The pillar itself has a huge effect on the frequency response; even without the tweeter there's some interferance (decon and con). Luckily, it's not terribly severe and the EQ can fix it. The point, though, is that I was able to pinpoint the cause without having to do a whole lot of in-car analysis. THis is one reason I'm a proponent of out-of-car testing, when possible.

The more I listen to the system, the more I realize I just fell in to something that works better than any setup I've ever had. When I move the tweeters to the dash locations the width falls part as does the depth. When I put the tweeters back in the cups on the pillar, it's all there again. And, to go back to what Durwood said in one of his posts: my boundaries are no longer as severely "fixed" for any given recording. I now notice the stage changes with the recording, which I've never experienced before and I've listened quite intently for (a reason I have considered numerous times to go ambio). The width with the tweeters in the pillars as shown above is the best I've ever experienced in my car. In the opening of "Thriller" the stair stepping is outside the far right window a noticeable amount. What's even better is the height of the stage has gotten better as well with the tweeters at ear level.

In summary: it looks like ****, but damn... it sounds phenomenal (in my own biased opinion).


- Erin


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## cvjoint (Mar 10, 2006)

I'm really confused about one thing. Patrick, you are really big on not having any sort of deflection near the speaker. There was that thread you had about rounding over the box too, tear drop enclosures and what not. I don't see you are that much against placing a decent size tweeter right in the middle of a midrange. How do you reconcile?


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## SSSnake (Mar 8, 2007)

Size of the obstruction vs high freq cutoff freq of the mid. remember the whole round over discussion started about tweets and readers extrapolated to mids.


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## SSSnake (Mar 8, 2007)

Early reflections are the primary cause of comb filtering in an automotive environment. These cannot be equalized effectively. So unless someone can show some evidence to the contrary I will stand by my devil comment.


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## SSSnake (Mar 8, 2007)

BTW - the text you quoted also discussed the negative effects of early reflections. The only exception is when the first null is outside the passband which rarely occurs in mid and tweeter drivers in a car.


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## cvjoint (Mar 10, 2006)

So you are saying the readers incorrectly extrapolated. I would think the tweeter sitting on top of the mid would have a hard time getting flush mounted or cast in a teardrop shape still. You would basically have to cover the whole mid to pull it off. 

As for comb filtering I did play around a bit with my line array. Till this day I don't have any evidence that it is a reality. I tried weaker smoothing algorithms, nada. I have serious doubts that at 1/3 octave or anywhere around it's much of a problem. At least not in the "comb" pattern that it suggests.


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## SSSnake (Mar 8, 2007)

Sorry CV I thought you were referring the the effect of the tweet obstructing the mid. The roundover for the tweets really display the most prominent effects if the xover freq on the tweet is sufficinetly low that the baffle on the tweet is less than one wavelength. If Erin crosses the tweets at 5500hz or above he should be in good shape. Lower and he will likely start noticing some difraction artifacts.


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## SSSnake (Mar 8, 2007)

> I have serious doubts that at 1/3 octave or anywhere around it's much of a problem. At least not in the "comb" pattern that it suggests.


Not sure what you mean by this statement. Crank the resolution on the measurement system and you should seem to the comb resolve.


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## cvjoint (Mar 10, 2006)

SSSnake said:


> Sorry CV I thought you were referring the the effect of the tweet obstructing the mid. The roundover for the tweets really display the most prominent effects if the xover freq on the tweet is sufficinetly low that the baffle on the tweet is less than one wavelength. If Erin crosses the tweets at 5500hz or above he should be in good shape. Lower and he will likely start noticing some difraction artifacts.


So 2000hz to 5500hz would need the roundover? I was referring to both since there are countless designs with mids and tweeters in a teardrop enclosure on Patrick's thread. 

I forget how unsmoothed I went, I think 1/24 octave and I still couldn't see comb filtering forming on the plots. That's with two 4.5" cones. It may be that I averaged plots, I'll have to run the tests again now that I think about it, the averaging might hide the comb filtering.

This is what I got in the mail today(magazine):


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## ErinH (Feb 14, 2007)

SSSnake said:


> Sorry CV I thought you were referring the the effect of the tweet obstructing the mid. The roundover for the tweets really display the most prominent effects if the xover freq on the tweet is sufficinetly low that the baffle on the tweet is less than one wavelength. If Erin crosses the tweets at 5500hz or above he should be in good shape. Lower and he will likely start noticing some difraction artifacts.



Just wanted to make sure that you realize the testing I did with the tweeter in front of the mid was done with only the mid playing. There was no response from the tweeter because it was not playing for those measurements.


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## SSSnake (Mar 8, 2007)

I was and that's why I jumped to the discussion about the masking of the midrange. Thanks for keeping me straight though.


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## SSSnake (Mar 8, 2007)

From my understanding, and I welcome any clarification from Patrick, if the tweet were crossed below 5500 you would start seeing a lot of diffraction artifacts in the tweets output. Above 5500 the artifacts would be greatly lessened. With the current mounting scheme I would expect diffraction artifacts from the mid, as a result of the tweet, as you approach and exceed 5500. I would expect the overall design and output to be smoothed in this area if Erin implemented a teardrop enclosure on the tweet.


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## pionkej (Feb 29, 2008)

SSSnake said:


> From my understanding, and I welcome any clarification from Patrick, if the tweet were crossed below 5500 you would start seeing a lot of diffraction artifacts in the tweets output. Above 5500 the artifacts would be greatly lessened. With the current mounting scheme I would expect diffraction artifacts from the mid, as a result of the tweet, as you approach and exceed 5500. I would expect the overall design and output to be smoothed in this area if Erin implemented a teardrop enclosure on the tweet.


I agree with this thought, but it also brings up a good question. I feel comfortable saying that Erin has a great sounding car and has listened to and tuned many other good to great sounding cars. If an experienced person such as he feels that width is already better than it's even been and doesn't hear any offensive frequency response issues...is there a benefit to adding a teardrop shaped enclosure?

I know that reducing diffraction is a good thing (I'm doing everything I can to control/reduce it in my upcoming install), but where is the "audible boundry"? Can more be gained from going to a teardrop? I DON'T want to put the burden on Erin, but I believe he is the only one who could tell us, and it would require making a teardop shaped enclosure. It would be interesting to see if an A/B comparison made an audible difference though.


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## pionkej (Feb 29, 2008)

cvjoint said:


> As for comb filtering I did play around a bit with my line array. Till this day I don't have any evidence that it is a reality. I tried weaker smoothing algorithms, nada. I have serious doubts that at 1/3 octave or anywhere around it's much of a problem. At least not in the "comb" pattern that it suggests.


I don't think you will ever see a true "comb" pattern because of how omni-directional the sound is (and how it spreads out the combs to where "nulls" are filled by "peaks). You can however see some big nulls that can't be boosted with EQ and, to me, that's about the most we'll see of comb-filtering.

You can get a better picture of it in the home however. Take a speaker, face it towards the wall, play a tone (say 1000hz), move the speaker close enough to where the primary reflection creats comb-filtering (say 3 1/3"), place the mic between the speaker and the wall, measure the frequency response. You can do the same thing with pink noise and see the "combs" move as you move the speaker closer or further from the wall. It STILL won't be a perfect "comb", but will show you better that it does exist and should be avoided if possible.


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## SSSnake (Mar 8, 2007)

Your comments about a true comb in the car are definitely correct. You have so many reflective surfaces contributing to the summed response that a textbook comb is unlikely. The comb issue can cause issues in the imaging with greater diffusion and a wandering placement being the issues that I have noticed. 

On Erin's car

Erin is an engineer and very familiar with trade offs. The gains of this mounting scheme may greatly outweigh any diffraction issues. With the diffraction occurring so closely to the drivers I am sure the results are less offensive than they might otherwise be. All of this is about trade offs and I am sure he will make decisions that support his goals. I need to get back over to his house for some more seat time.


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## SSSnake (Mar 8, 2007)

CV

On your choice of mounting location and comb filtering. I really think that you have chosen an excellent location to reduce these effects. Your drivers on the a pillars should reduce problems by getting the speakers away from the dash. This is exactly why I like putting the tweets in the sail panels.


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## pionkej (Feb 29, 2008)

SSSnake said:


> Your comments about a true comb in the car are definitely correct. You have so many reflective surfaces contributing to the summed response that a textbook comb is unlikely. The comb issue can cause issues in the imaging with greater diffusion and a wandering placement being the issues that I have noticed.
> 
> On Erin's car
> 
> *Erin is an engineer and very familiar with trade offs. The gains of this mounting scheme may greatly outweigh any diffraction issues. With the diffraction occurring so closely to the drivers I am sure the results are less offensive than they might otherwise be. All of this is about trade offs and I am sure he will make decisions that support his goals. I need to get back over to his house for some more seat time.*


I hope you didn't take my post as being an attack on what you said. It's, in fact, completely the opposite and I agree with what you said. I just wonder how audible the difference would be and basically pondered that question "aloud".

I wish I new all this when I started my build a couple of years ago. I was aware of beaming and did my best (at the time) with driver aiming. However, I still saw huge benefits in my install with the addition of a dashmat for pillar mounted tweeters. The problem is that I can't show it. I assume it's because the wavelengths that are affected are so short, but the RTA shows no appreciable difference between dashmat vs. no dashmat. However, when listening, perceived amplitude is reduced (enough to the point of adjusting gains and retuning) and images are more solid. Without the dashmat I had a "lively" sound that was somewhat diffuse and EXTREMELY fatiguing with long listening sessions. All the end user is left with, however, is my subjective opinion that things did improve. 

This experience, and listening time in other great sounding cars, has led me to personally believe that while all reflections and diffractions are bad, the ones that our tweeters create are the most offensive.

I've left my install as "well enough" since I only drive the car a handful of times a year, but I'm approaching the build in my wife's car with all that I've learned. So far it involves, baffles to reduce diffraction, waveguides to help with directivity, placing drivers in locations that will "tell" me when the primary combs should occur and crossing outside of that, and using enclosures that either reduce impedance spikes (resonance) or place them outside the passband. Nothing that I'm doing is "reinventing the wheel", but I am trying to bring everything I have learned together and start with the best possible plan I can. I have held the details of what I'm trying to do "close to the chest" so far since I don't know if my plan will work. If it does, I'll report my experiences. If it doesn't, I'll report my experiences. I just want to know WHAT it does before I share anything.


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## ErinH (Feb 14, 2007)

I have plans to try to do some shaping and transitioning of the tweeter pods. For now, here are some more pictures of the way things are now.


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## Mic10is (Aug 20, 2007)

bikinpunk said:


> I have plans to try to do some shaping and transitioning of the tweeter pods. For now, here are some more pictures of the way things are now.


im normally a pretty creative guy when it comes to figuring out some install solutions, but I have no idea how you can make that look good..lol


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## ErinH (Feb 14, 2007)

I wasn't talk if about making it look good. Lol. 

Moreso in making a transition so there aren't as abrupt surfaces.


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## BigRed (Aug 12, 2007)

this is an interesting read about reflections

The Murphy Corner-Line-Array Design Concepts


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## 14642 (May 19, 2008)

Guys,
the audibility of comb filtering isn't even decided among acousticians. there are as many opinions as there are acousticians. In my experience, the lowest frequency part of the comb is the only one that reliably causes issues for midbass/midranges mounted in the doors and not adjusted using delay. Over the years there have been several "tricks" used to "fix" this, the most revolting of which was the "yo, just throw one of those mids out of phase". While that may help to locate female vocals in the center when you listen to the spoken tracks on the IASCA disc, it blows A$$ when you listen to music that isn't a female vocal. 

The basic issue is that a comb filter is created anytime there are two or more apparent sources of sound from which the sound arrives at the microphone at different times. Cna it be measured? Yes. Does that mean it's objectionable? Not under all circumstances. As someone has suggested here, the biggest drawback of comb filtering in a car is lilkely to be image spread and image location shift at various frequencies. It shouldn't take a rocket scientist to see that mounting speakers a few inches from the apex of the three primary reflective surfaces in the front of a car could creat more problems than it solves (it solves the image height issue nicely). MAXIMIZING the size of the baffle to MINIMIZE the reflections off the windshield will HELP. Minimizing the size of the baffle will allow the spherical radiation from the drivers at low frequencies to reflect off of all the nearby surfaces.


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## trojan fan (Nov 4, 2007)

bikinpunk said:


> I have plans to try to do some shaping and transitioning of the tweeter pods. For now, here are some more pictures of the way things are now.


Wow!... Do you drive around with your car looking like that


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## ErinH (Feb 14, 2007)

I do right now. It's under construction. Thus the torn off cloth and painters tape.

Rather than throw speakers in a car and hope it works, I spend some time listening to various install methods. And when I say time, I mean more than 2 minutes... Something along the line of days. It's easy to be impressed for a few minutes. It takes time to figure out how it really sounds.


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## ErinH (Feb 14, 2007)

Andy Wehmeyer said:


> Guys,
> the audibility of comb filtering isn't even decided among acousticians. there are as many opinions as there are acousticians. In my experience, the lowest frequency part of the comb is the only one that reliably causes issues for midbass/midranges mounted in the doors and not adjusted using delay. Over the years there have been several "tricks" used to "fix" this, the most revolting of which was the "yo, just throw one of those mids out of phase". While that may help to locate female vocals in the center when you listen to the spoken tracks on the IASCA disc, it blows A$$ when you listen to music that isn't a female vocal.
> 
> The basic issue is that a comb filter is created anytime there are two or more apparent sources of sound from which the sound arrives at the microphone at different times. Cna it be measured? Yes. Does that mean it's objectionable? Not under all circumstances. As someone has suggested here, the biggest drawback of comb filtering in a car is lilkely to be image spread and image location shift at various frequencies. It shouldn't take a rocket scientist to see that mounting speakers a few inches from the apex of the three primary reflective surfaces in the front of a car could creat more problems than it solves (it solves the image height issue nicely). MAXIMIZING the size of the baffle to MINIMIZE the reflections off the windshield will HELP. Minimizing the size of the baffle will allow the spherical radiation from the drivers at low frequencies to reflect off of all the nearby surfaces.


Agreed. But doing this in a car is something I consider a trade off. It's not exactly easy to build a baffle to compensate for baffle rolloff without it consuming a ton of real estate. 
However, I'm hoping I can do some s oohing with my own install to see how it will help the response. The troubling part is the tradeoff of baffle size vs "out the box" nominal response. Not only "baffle" but enclosure geometry itself. 

As has been said numerous times in every thread about car audio: we make choices and sacrifices we can live with. I've spent a lot of time lately measuring, building and listening. Wish I had saved the in car response of my setup so I could discuss my own tradeoffs so the saying could be given some merit. 

PS: that rocket scientist comment hurt.


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## michaelsil1 (May 24, 2007)

trojan fan said:


> Wow!... Do you drive around with your car looking like that


I drive my car looking like that it has kept thieves away, I live in the ghetto.


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## cvjoint (Mar 10, 2006)

Andy Wehmeyer said:


> Guys,
> the audibility of comb filtering isn't even decided among acousticians. there are as many opinions as there are acousticians. In my experience, the lowest frequency part of the comb is the only one that reliably causes issues for midbass/midranges mounted in the doors and not adjusted using delay. Over the years there have been several "tricks" used to "fix" this, the most revolting of which was the "yo, just throw one of those mids out of phase". While that may help to locate female vocals in the center when you listen to the spoken tracks on the IASCA disc, it blows A$$ when you listen to music that isn't a female vocal.
> 
> The basic issue is that a comb filter is created anytime there are two or more apparent sources of sound from which the sound arrives at the microphone at different times. Cna it be measured? Yes. Does that mean it's objectionable? Not under all circumstances. As someone has suggested here, the biggest drawback of comb filtering in a car is lilkely to be image spread and image location shift at various frequencies. It shouldn't take a rocket scientist to see that mounting speakers a few inches from the apex of the three primary reflective surfaces in the front of a car could creat more problems than it solves (it solves the image height issue nicely). MAXIMIZING the size of the baffle to MINIMIZE the reflections off the windshield will HELP. Minimizing the size of the baffle will allow the spherical radiation from the drivers at low frequencies to reflect off of all the nearby surfaces.


When you say it can be measured what test do you have in mind? I've seen tests of frequency response with very little smoothing pick up some comb patterns in line arrays. The cancellations are extended narrow dips, unlikely to be filtered out by any potent eq. machine but at the same time also not obvious they would be audible. Are you thinking more along the lines of time arrival tests like CSD and burst response? CSDs look awful in a car, so much so that I posted a few plots and sort of ran after that. 

If the comb filtering due to reflections manifests as wide dips in the frequency response we can eq. them out. I suppose the EQ. itself would induce some phase distortion. Shucks.


I would rocks Illuminators in a crater of a pillar as long as it sounds good. Every top project looks like a mess in the early stages. No shame in that.


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## thehatedguy (May 4, 2007)

I don't know if EQ could fix the dips.


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## asota (Feb 7, 2011)

How much do visual clues play into the inception of stage width, height, and depth? This past summer I experimented with a second set of tweeters (dialed down of course) in the a-pillar, mains being in the kicks. This seemed to give me a great since of height but a bit narrower stage and overall I didn't like the sound and disconnected them. Even after being disconnected it still seemed the sound was coming from the intrusive tweeters in the a-pillars and the stage had good height. After finally getting around to removing the dead tweeters the only visual clue I had were the large intrusive kick-panels. It seemed like the stage height dropped a foot just seeing the tweeters at your feet. Even closing your eyes you still had the image knowing the speakers were at your feet. Most of the cars at Meca finals that did very good seemed to have very stealth speaker placement or they blacked interior so as to not give away any visual clues. Do visual clues screw with your preception of stage height, width, and depth? How important is this? The brain is a funny thing.


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## highly (Jan 30, 2007)

For many listeners - experienced or otherwise- this is often a significant factor. There may have even been one or more cars at Finals showing speakers they weren't using for this very reason, and similarly not talking about speakers you didn't see.


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## ErinH (Feb 14, 2007)

Actually, I intended to bring this up with my own install in mind. My concern is that many people will see the drivers and immediately be misled in to hearing something that's not there. I have heard numerous times where someone made a comment on someone's car based on the location of the drivers and I didn't feel the same way at all. Even from the big wigs of car audio and it's aggravating. (A pet peeve of mine, to be honest).
It's the damn mindset of regurgitating something you read or heard one time and using that to base your claims on for everything you hear/see in the future. 

Listen with your ears and not your eyes. Easier said than done. That's why many do what I call "pseudo installs" where they'll place a driver at X location to use the common thoughts to their advantage. I've actually sneaked a few things by some folks and then listened to them tell me something they would have otherwise not said. Hell, I've had judges sit in my car and tell me it did X very well, then a bit later say that the same X is affected negatively by Y... and Y is exactly what I had.


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## highly (Jan 30, 2007)

bikinpunk said:


> Listen with your ears and not your eyes. Easier said than done.



^^ QFT


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## Boostedrex (Apr 4, 2007)

Todd and Erin are right. I can't tell you how many times I've heard people mention how speaker placement in a particular install would affect the sound before ever listening. It's a shame really. There's a reason I try to look at NOTHING aside from the head unit until after I finish judging. That way I don't form any opinions about how the car "should" sound.

There is also a lot of merit in hiding the drivers as much as possible as to overcome the phsyco acoustic factor. I ran into those issues with my own install during the 2010 MECA season. That's why I'll have pretty much every driver out of view this time around. Nothing like "gaining width" by clever placement of diversion speakers...


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## ErinH (Feb 14, 2007)

I'm going to throw a speaker on the center of my dash and affix some holders to my sideview mirrors to support speakers a foot outside my windows.


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## Boostedrex (Apr 4, 2007)

I forgot to mention, the visual issue is also why I spend 98% of my judging time in a car with my eyes closed. I don't need to see what I'm listening to in order to score how it sounds.


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## pionkej (Feb 29, 2008)

Looks like I'm 4th to agree here. My new build will have some pods on the dash, so no way of getting around knowing SOMETHING is there. However, I plan to cover said pods with grill cloth so you don't know what that something is. Is it midrange, tweeter, mid and tweeter, midbass...who knows.


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## Lorin (May 5, 2011)

I am curious based on a few responses here:
Cool. No better way to minimize phase errors caused by pathlength differences than to put the speakers in the "same" place.
I wonder what would happen if L and R were mounted in the center of the dash and positioned into a reflective surface(windshield) that would reflect sound the same for both - would that work? Am I over simplifying in that all we would be hearing would be the reflections and that we could work to that end? Similar to the older Bose 901 speakers that fired into a (flat) wall to provide the appearance of width? Not sure if this makes sense? I see Home theater speakers attempting to replicate an array of speakers with a single speaker under the tv.


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## ErinH (Feb 14, 2007)

Patrick has a thread about that here somewhere. I tried it and didn't have much luck. In fact, John was there with me and I think we agreed the width suffered too much but the focus was better.


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## pionkej (Feb 29, 2008)

Lorin said:


> I am curious based on a few responses here:
> Cool. No better way to minimize phase errors caused by pathlength differences than to put the speakers in the "same" place.
> I wonder what would happen if L and R were mounted in the center of the dash and positioned into a reflective surface(windshield) that would reflect sound the same for both - would that work? Am I over simplifying in that all we would be hearing would be the reflections and that we could work to that end? Similar to the older Bose 901 speakers that fired into a (flat) wall to provide the appearance of width? Not sure if this makes sense? I see Home theater speakers attempting to replicate an array of speakers with a single speaker under the tv.


Ok, my take on this is that it wouldn't create good results. It would probably create a very solid center image, but anything panned hard left or right would image as being extremely narrow (since the "left" sound would actually be coming from the right side of the driver seat). The MS8 (and some other center-based systems)does work to create a solid image with a dedicated center and keep ambiance and hard panned info to the left and right with traditionally located speakers.



bikinpunk said:


> Patrick has a thread about that here somewhere. I tried it and didn't have much luck. In fact, John was there with me and I think we agreed the width suffered too much but the focus was better.


Patrick's thread was centered around tweeters...and I agree with you, it didn't work that great when we tried it. I do believe it had the opposite affect though, the stage actually widened but the focus was worse. I thought we decided this occured since you were running midranges in the pillars, and the tweeters were carrying just enough signal in the vocal range that it "split" the image. I'm not 100% sure of that, but I know that it didn't sound ideal in your install and the tweeters went back to the sides.


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## Lorin (May 5, 2011)

I hear what you are saying above, I was actually thinking that if the speakers were "aggressively" angled (from middle of dash angled off windshield toward a-pillar), than the first "heard" sound would (theoretically) be coming from left of the driver (and right of the passenger). I realize that then one would have to work through a myriad of issues as a result of reflections, etc...). Just thinking aloud, no practical experience in trying this (yet).


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## pionkej (Feb 29, 2008)

Lorin said:


> I hear what you are saying above, *I was actually thinking that if the speakers were "aggressively" angled* (from middle of dash angled off windshield toward a-pillar), *than the first "heard" sound would *(theoretically) *be coming from left of the driver (and right of the passenger).* I realize that then one would have to work through a myriad of issues as a result of reflections, etc...). Just thinking aloud, no practical experience in trying this (yet).


In order to pull this off, you would need the driver to be beaming. Essentially, when a speaker is playing within it's pistonic range, it outputs sound in all directions (omni-directional) and outside of that dispersion narrows (straight beam). A 6.5" driver starts beaming around 2200hz, so anything below that would not only be heard via reflection (no matter how agressive the angle). If you can fit a 12" speaker up there you would get down to 1,100hz (so you would need a HUGE driver to cover the vocal range which starts around 200hz). You could also use a waveguide to create a beam from a smaller driver, but this would also be very large and nearly impossible to fit.

It is a good idea in theory like you said, but nearly impossible to implement in real-world scenarios.


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## Boostedrex (Apr 4, 2007)

Yeah, I would think waveguides would be the only way to do it. But I would think that they'd be pretty sizeable even then.


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## ErinH (Feb 14, 2007)

Wrong thread. Doh!


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## Neil_J (Mar 2, 2011)

bikinpunk said:


> My concern is that many people will see the drivers and immediately be misled in to hearing something that's not there. I have heard numerous times where someone made a comment on someone's car based on the location of the drivers and I didn't feel the same way at all.


The first part of the Audio Myths Workshop linked below explains this pretty well. Basically, one's expectations of what they are hearing gets "added in" to what is really there. This is true of both casual and experienced listeners. Ethan's tube amp vs transistor amp test was a clever way of demonstrating the phenomenon. 

Is it still a real issue? Yes. So should IASCA judges be required to wear blindfolds for the scoring to be completely fair? Probably wouldn't go over very well. Could a judge hear excellent stage width from a crappy install after being fed a load of BS? Absolutely.

http://www.youtube.com/watch?v=BYTlN6wjcvQ

P.S., this thread is awesome


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## SSSnake (Mar 8, 2007)

On the audibility of combs...

When the nulls/peaks are narrow i believe the audibility to be limited. However when you have a couple combine to form broad peaks and nulls the audibility and apparent accuracy are definitely adversely affected. Unfortunately this is not that uncommon in a car. The number and spacing of the reflective surfaces makes it fairly common. That is why my goal is to limit comb effects as much as possible. How much is practical? Not a lot. The space is just too small but any gains typically make the system more stable (more consistent FR - reduced head in the vice syndrome) and IMO more musical/accurate.


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## highly (Jan 30, 2007)

SSSnake said:


> On the audibility of combs...
> 
> When the nulls/peaks are narrow i believe the audibility to be limited. However when you have a couple combine to form broad peaks and nulls the audibility and apparent accuracy are definitely adversely affected. Unfortunately this is not that uncommon in a car. The number and spacing of the reflective surfaces makes it fairly common. That is why my goal is to limit comb effects as much as possible. How much is practical? Not a lot. The space is just too small but any gains typically make the system more stable (more consistent FR - reduced head in the vice syndrome) and IMO more musical/accurate.


^ This was a _significant_ intent of last season's build and paid dividends. This went hand in hand with reducing boundary reflections as much as possible and attempting to get both real and virtual sources as close to each other as practical to reduce smearing. The results far exceeded my expectations. Install setup time was considerable, but the results more than made up for it in my opinion. 

I have done a lot of playing around with other drivers (midranges) with different dispersion patterns. Each one made significant changes to the stage. This leads me to surmise that I have selected the optimal location and aiming for the intended driver in the intended passband in the intended vehicle. Changing the driver or the passband dramatically alters the result. Take that for what it's worth...


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## Lorin (May 5, 2011)

Todd, I remember you mentioning comb filtering on a few occasions when we met, and I assumed it was incorporated into your install. I have wondered quite a few times how your speakers are angled under your cover? Would love to take a peek sometime when next we meet. Im curious if you used any foam, etc., to block \ absorb reflections before they hit the windshield, and at what angle you stayed with. No need to give up anything here, just wondering aloud.


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## highly (Jan 30, 2007)

Lorin said:


> Todd, I remember you mentioning comb filtering on a few occasions when we met, and I assumed it was incorporated into your install. I have wondered quite a few times how your speakers are angled under your cover? Would love to take a peek sometime when next we meet. Im curious if you used any foam, etc., to block \ absorb reflections before they hit the windshield, and at what angle you stayed with. No need to give up anything here, just wondering aloud.


Lorin-
I don't want to stray too far off topic, but much of the specifics are covered in my build log. If you have any other questions after checking things out there I would be more than happy to answer them in that thread. Many of the solutions that worked for me were unique to individual problems that I ran into that are probably too specific to translate to other installs readily. A hunk of foam here because it helped with this reflection. A couple extra layers of grille cloth there because it pushed that reflection out. That kind of thing I can't see trying to document...

-Todd


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## vitvit (May 3, 2011)

SSSnake said:


> On the audibility of combs...
> 
> When the nulls/peaks are narrow i believe the audibility to be limited. However when you have a couple combine to form broad peaks and nulls the audibility and apparent accuracy are definitely adversely affected.


I think you've mixed comb-filtering with reflection/diffraction.

Comb filtering doesn't create peaks. But latters do. And narrow peaks distracting me more than wide ones. Just listen to Santana guitar and while everything seems to be OK, suddenly one note just drills in your head. Vzh-zh-zh-ik!


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## highly (Jan 30, 2007)

Do what?


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## ErinH (Feb 14, 2007)

vitvit said:


> I think you've mixed comb-filtering with reflection/diffraction.
> 
> Comb filtering doesn't create peaks. But latters do. And narrow peaks distracting me more than wide ones. Just listen to Santana guitar and while everything seems to be OK, suddenly one note just drills in your head. Vzh-zh-zh-ik!


That's incorrect. Comb filtering results in peaks just as it does dips. It's called constructive interference.


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## SSSnake (Mar 8, 2007)

Can't have the destructive interference without the constructive. Revisit your wave theory.


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## strakele (Mar 2, 2009)

bikinpunk said:


> Actually, I intended to bring this up with my own install in mind. My concern is that many people will see the drivers and immediately be misled in to hearing something that's not there. I have heard numerous times where someone made a comment on someone's car based on the location of the drivers and I didn't feel the same way at all. Even from the big wigs of car audio and it's aggravating. (A pet peeve of mine, to be honest).
> It's the damn mindset of regurgitating something you read or heard one time and using that to base your claims on for everything you hear/see in the future.
> 
> Listen with your ears and not your eyes. Easier said than done. That's why many do what I call "pseudo installs" where they'll place a driver at X location to use the common thoughts to their advantage. I've actually sneaked a few things by some folks and then listened to them tell me something they would have otherwise not said. Hell, I've had judges sit in my car and tell me it did X very well, then a bit later say that the same X is affected negatively by Y... and Y is exactly what I had.



I have seen MANY people say something similar to this. My question is..

WHY don't you guys (after the trophies are awarded  ) go back to the judge and tell them that what they "heard" was wrong? 

If they told you to turn down your center channel and you don't have a center.... 
....if they said your ambiance was great when it was created out of thin air by your DSP....
....if they said your A-pillar tweets really gave you nice stage height when your real tweets are in the kicks....

Why do you let them go on with their incorrect thoughts? Why wouldn't you say something to make him realize he may have been listening a bit too much with his eyes? Obviously I wouldn't say it in a rude/condescending/you're an idiot kind of way, but I'd think it important to not have the same old conventional thoughts perpetuated if they aren't correct.

At one of the only shows I've been to, one of the judges commented on how much he liked my "tweeters." I graciously thanked him for his thoughts and politely informed him that I wasn't actually running any tweeters and they were in fact wideband midranges. He was impressed. He learned something, and I felt good about my system. Win-win.

I understand the "lol I fooled you!" thought that you can have when hearing a judge comment about something that isn't there, but I can't see why you let them go on thinking that.


/Rant.


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## ErinH (Feb 14, 2007)

strakele said:


> I have seen MANY people say something similar to this. My question is..
> 
> WHY don't you guys (after the trophies are awarded  ) go back to the judge and tell them that what they "heard" was wrong?
> 
> ...


I don't know why you think I have the mindset of "I fooled you" at all... 
I'm pretty sure you know that my goal is to further the hobby through learning, so fooling someone isn't ever my goal. In fact, the reason my build log still continues being updated is so people can understand what I'm doing. The cases where I sneaked something by folks were cases where I had a friend listen... try to trick him a bit and then tell him what I did. Of course it's never with the intention of trying to make them look dumb. I just wanted to clarify that. 

I've set people straight a couple times if needed but for the most part, everyone knows what I run before they even see my car in person (thanks to my build log). This correction is typically only done at GTGs. The times that I haven't tried to correct someone... well, they were probably because it was just something I didn't feel necessary to pursue. Choose your battles sort of thing. To be honest, the most poignant example I can provide was a case where a judge told me something good about my system. Later on I was in a conversation of a group of dudes in which at one point he commented that Class D amps didn't do that same something good. I chimed in and said I ran all Class D JL amps and left it at that. I think he went on to say something about home audio Class D amps but I tuned back out. 

In conversations I'm happy to tell anyone they want to know. If someone says something about my system that's not right then I'll let them know. Otherwise, I just let it slide. I don't get bent out of shape. 
My comments were regarding the fact there is no way around some people's preconceived notions on a system. If they see a big honkin' driver up front, telling them after they've judged me isn't going to help. So, I just hide the stuff. Some people will see pictures of my setup and all of a sudden know everything about it without taking the chance to listen to it and not pre-judge it. Look at comments in build threads where someone does X and they get replies to the tune of "wow, that's gonna say great" or "you're going to have issues here and here". For the most part, you can indeed predict what issues there will be; the car itself is hell on wheels. But, there are instances where someone does something a bit different... but close to what's already been done... and people default back to the latter portion. Patrick presents new ideas carried over from diyaudio.com (such as the mono tweeter and diffraction threads, IIRC) that haven't really gained ground in car audio (at least in the US; those European guys are ahead of us it seems in some cases). My new install is something I didn't think would work well but surprisingly, it works very well. I even had doubts myself. 

Besides, I think asota made an astute observation: sometimes we do it to ourselves. I can say that I've sat in car, including my own, and seen a speaker and had trouble moving past it. You sometimes have to make an effort to ignore what you see. Like I said above, it's easier said than done. Subjectivity and psychoacoustics is a b1tch! 


Edit: Really, though, you're right. We should do a better job of correcting people when we can. Sometimes I just don't care to get in to it. Especially after shows where I'm just ready to get the eff out of there. Though, my post wasn't so much about steering them right as it was keeping them from getting ahead of themselves.


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## Mic10is (Aug 20, 2007)

strakele said:


> I have seen MANY people say something similar to this. My question is..
> 
> WHY don't you guys (after the trophies are awarded  ) go back to the judge and tell them that what they "heard" was wrong?
> 
> ...


I'll attempt to answer from both sides
As a Judge I do my best to not make specific references to equipment or locations or perceived locations of speakers when I give notations or feedback.
Im not sure why certain judges do continue to do this, but it is bad business in my book.
Tonal Accuracy is about Frequency response--it shouldnt matter if its produced by cone,a ribbon,a dome, or a horn etc...subbass is subbass. Midbass is midbass. Midrange is midrange. Highs are Highs.
Highs are not "your tweeters".

If after the fact, judging is done, show is over, someone pulls me to the side and we walk over to the car and discuss the install and what I heard--I may discuss what I heard and give possible explanations-but thats really about it.

and also bc I have played that "game" of is this speaker really playing--I do majority of judging with my eyes closed, outside of when I need to open them to write down a score or get a visual reference for boundaries.


as a Competitor

I know how people think, and perceive. its been well documented that people can hear and believe things they see. remember the ole saying "seeing is believing"

and honestly, unfortunately there are some judges in some sections , who for whatever reasons, have their own biases and beliefs about speaker locations and how they function. typically its the result of personal triumph or failure using them or simply a lack of understanding.

so knowing this-you have to remember, its a competition. You have to know your audience (judges) and know your competition. Some judges just want certain things and if you give that to them--then youre golden.


but as far as calling someone out on anything...without specifically knowing someone, its a risky proposition. Their initial reaction which seems calm and polite, may really mask something the complete opposite.


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## strakele (Mar 2, 2009)

bikinpunk said:


> I don't know why you think I have the mindset of "I fooled you" at all...
> I'm pretty sure you know that my goal is to further the hobby through learning, so fooling someone isn't ever my goal. In fact, the reason my build log still continues being updated is so people can understand what I'm doing. The cases where I sneaked something by folks were cases where I had a friend listen... try to trick him a bit and then tell him what I did. Of course it's never with the intention of trying to make them look dumb. I just wanted to clarify that.


Erin, I didn't mean to accuse you of doing what I wrote about, and I'm sorry if it came off that way. You of all people are fantastic about sharing what you learn. I just quoted your post to give a bit of context for what I wrote, since what I was 'responding to' was on the previous page. I share your pet peeve.




Mic10is said:


> but as far as calling someone out on anything...without specifically knowing someone, its a risky proposition. Their initial reaction which seems calm and polite, may really mask something the complete opposite.


Good point, and makes sense. I did when I did because I had met the individual on a few occasions before. I can see how this is definitely a pick your battles kind of thing, and would only do so in the future if I thought it was a pretty egregious error, i.e. "I can tell your bass is coming from the back" when you have a sub in the dash, and no rear subs except strictly for SPL competition.


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## Mic10is (Aug 20, 2007)

strakele said:


> Erin, I didn't mean to accuse you of doing what I wrote about, and I'm sorry if it came off that way. You of all people are fantastic about sharing what you learn. I just quoted your post to give a bit of context for what I wrote, since what I was 'responding to' was on the previous page. I share your pet peeve.
> 
> 
> 
> ...


bass in the back can be a function of the car tho. Ask Todd-Highly- about it. I think he even detailed in at the beginning of his install log

some cars just have a node or something weird where no matter where the sub is located. it always feels likes its in the back.

at the end of the day, what I have had to learn over the years and what I now help the guys I mentor, and the guys on our team and new competitors is that---on the day of a show--whatever a Judge hears is what he hears.
No amount of arguing , presentation of facts to the contrary, other opinions will matter--bc the Judge heard what he heard when he was listening for that part of the score sheet.

and sometimes it sucks. sometimes you realize that they were really right (this is often the case with good judges) when you are relaxed and sitting alone in your car listening and sometimes you are just left bewildered as to WTF they are talking about.


I have countless stories about Judges hearing or telling me things about my different cars that were completely false. Ive had Judges tell me I love the way your tweeters sound, when I was using horns--and then when I say I am using horns, Ive had judged argue with me that there was no way that I could be running horns and then ramble off 20 reasons why I cant have horns--and then they even leave my car scratching their heads when I showed them the horns....
and Ive also exhausted myself arguing with judges about their scores and what they heard , only to realize a few days later that I was actually wrong and just needed to settle down to listen for what they were hearing.


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## ErinH (Feb 14, 2007)

Mic10is said:


> bass in the back can be a function of the car tho. Ask Todd-Highly- about it. I think he even detailed in at the beginning of his install log
> 
> some cars just have a node or something weird where no matter where the sub is located. it always feels likes its in the back.


I have a few threads floating around here about the topic myself. For the longest time - I'm talking _years_ here - I had issues with my midbasses punching me in the back, feeling like they were behind me (subs turned off). Took me a while to get it resolved and it was all mechanical.


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## strakele (Mar 2, 2009)

Haha well yeah, I'm definitely not saying get into an argument with them. If they're convinced they're right, then so be it. I also am not recommending arguing with them about scores or anything. If the guy's a decent judge though, I'd figure he'd be interested in improving his own ability to hear and judge without bias, so a little correction after the show is over wouldn't be a bad thing. Guess it depends on the situation.

That story about the horns is pretty hilarious.


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## strakele (Mar 2, 2009)

Mic10is said:


> bass in the back can be a function of the car tho. Ask Todd-Highly- about it. I think he even detailed in at the beginning of his install log
> 
> some cars just have a node or something weird where no matter where the sub is located. it always feels likes its in the back.





bikinpunk said:


> I have a few threads floating around here about the topic myself. For the longest time - I'm talking _years_ here - I had issues with my midbasses punching me in the back, feeling like they were behind me (subs turned off). Took me a while to get it resolved and it was all mechanical.



Only reason I used the bass example is because I had read it in another thread, on this forum I think. Someone said that because the judge was familiar with his car, he told the competitor that the bass was coming from the back, when in fact it was up front, and the rear subs were only for SPL. May have been Scott Buwalda, I don't remember. The gist of it was though, the judge heard what he "knew/thought" was there, not what was there. Maybe he had an issue like you guys were talking about. It was just an example.


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## ErinH (Feb 14, 2007)

My issue was so bad that I often had to disconnect the subs so I knew they weren't playing at all while I tried to hunt the cause down. Car audio sucks. Lol.


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## Mic10is (Aug 20, 2007)

strakele said:


> Only reason I used the bass example is because I had read it in another thread, on this forum I think. Someone said that because the judge was familiar with his car, he told the competitor that the bass was coming from the back, when in fact it was up front, and the rear subs were only for SPL. May have been Scott Buwalda, I don't remember. The gist of it was though, the judge heard what he "knew/thought" was there, not what was there. Maybe he had an issue like you guys were talking about. It was just an example.


I dont think Ive ever posted about it , but at least once I had a judge tell me subass wandered toward the back in my BMW.

I highlighted the 4 10s in the rear deck bc its 4 ****in 10s in a rear deck of a bmw!!!
and few people knew I had a 10" sub up front that was the only sub I ever used.

but still, its one of those things, u just say " OooooooooooKay....thanks for your time" and go about your business


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## vitvit (May 3, 2011)

SSSnake said:


> Can't have the destructive interference without the constructive. Revisit your wave theory.


I stay corrected.


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## BigRed (Aug 12, 2007)

Ummm.....I thought this was about width and where it comes from?


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## Mic10is (Aug 20, 2007)

BigRed said:


> Ummm.....*I thought* this was about width and where it comes from?


theres the problem


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## sqnut (Dec 24, 2009)

Maybe another thing that needs to be factored in, is that one doesn't hear at the same level everyday. Some days are just better hearing days than others. A good nights sleep and a calm mind seems to help here .

Mic made a good point, it's not about how good the setup sounds to you, nor even how good it actually is. What matters is, how good it sounds to the judge on that given day. Finals will be judged by the best. Just like the competitors would like to present their A sound, the experienced judges would also like to get their A game to the table. At the end of the day however it is a subjective game. Fair, but subjective.


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## cvjoint (Mar 10, 2006)

BigRed said:


> Ummm.....I thought this was about width and where it comes from?


Me three. I don't want to go through 2 pages of judging this or that to get an ounce of information.


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## sqnut (Dec 24, 2009)

cvjoint said:


> Me three. I don't want to go through 2 pages of judging this or that to get an ounce of information.


Ah, but the discussion is about more than just judging. Subjective issues yes, but stuff that is pertinent to 'how it sounds'.


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## subwoofery (Nov 9, 2008)

Boostedrex said:


> Todd and Erin are right. I can't tell you how many times I've heard people mention how speaker placement in a particular install would affect the sound before ever listening. It's a shame really. There's a reason I try to look at NOTHING aside from the head unit until after I finish judging. That way I don't form any opinions about how the car "should" sound.
> 
> There is also a lot of merit in hiding the drivers as much as possible as to overcome the phsyco acoustic factor. I ran into those issues with my own install during the 2010 MECA season. That's why I'll have pretty much every driver out of view this time around. Nothing like "gaining width" by clever placement of diversion speakers...


It's in the nature of human kind. I saw a documentary that showed how powerful the perception (eyes) really is and how it can fool the brain. 
They took a couple of kids and made them drink different kind of juices while changing its based color: 
Purple orange juice 
Red pineapple juice 
Green cranberry juice 
Orange blueberry juice 
Results? 
Purple is grape juice 
Red is water+grenadine sirup 
Green is peas juice  
Orange is, well, orange juice 
How great is that to see kids being fooled by what they see? Priceless 

In Tahiti, Focal is really popular... even amongs SPL based cars. 

On the forum? Not so much... Why? Because it's too "bright"  
I don't know how many times I've heard/read that Focal or MB Quart tweeters are too bright and that many wouldn't install them in the car even if given to them for free... 
My install is not stealth and the tweeters in the sails aren't hidden - if I could make it to those GTG, I'm pretty sure that more than 50% of the listeners would make the assumption that it's gonna sound fatiguing without even the first note playing... 

Kelvin


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## subwoofery (Nov 9, 2008)

bikinpunk said:


> I have plans to try to do some shaping and transitioning of the tweeter pods. For now, here are some more pictures of the way things are now.


Earl Zausmer did that in his BMW v.1: 








Not sure how it sounded in this coaxial mode but the tweeter is also quite far from glass... maybe he was already onto something :surprised:

Which I was born 10 years earlier in order to have a chance to hear that "legendary" car... 

I'm not suggesting to do some motorized pods but it's just an idea on how you could mount the tweeter. 

Kelvin


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## BigRed (Aug 12, 2007)

Mic10is said:


> theres the problem


and you *thought* it was about you getting hosed during competitions I guess 

the title is pretty clear. maybe the moderators should "clean" it up like they did the other thread that went down the "judging" lanes?


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## pionkej (Feb 29, 2008)

Ok, so we have calls to get back on topic. Maybe a summary? If anybody has something to add that I've missed, please jump in.

-Reflections at boundary points, that are not close enough to the fundamental in time and high enough in amplitude, reduce width.
-Acoustic crosstalk will reduce width.
-Any issue that pinpoints a drivers location (rattles, resonances, sound-waves against legs, reflections, uneven FR, etc.) will limit width to that drivers location.
-Seeing speaker locations can lead to reduced width via experience/ignorance/bias.
-Extremely delayed reflections, surround processing, L-R rear-fill, and ambio setups can all help give the impression of increased width.


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## ErinH (Feb 14, 2007)

BigRed said:


> and you *thought* it was about you getting hosed during competitions I guess
> 
> the title is pretty clear. maybe the moderators should "clean" it up like they did the other thread that went down the "judging" lanes?



Some of it is off topic but most of the discussion regarding speaker location is absolutely relative to width and perceived width. I'll let them stand because cleaning some of it out and leaving other posts is confusing. Besides, we're heading back on track now anyway.


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## ErinH (Feb 14, 2007)

pionkej said:


> Ok, so we have calls to get back on topic. Maybe a summary? If anybody has something to add that I've missed, please jump in.
> 
> -Reflections at boundary points, that are not close enough to the fundamental in time and high enough in amplitude, reduce width.


I don't think I really agree with this. It seems you can still get excellent stage width by placing a speaker further away from a boundary point because the reduced amplitude correlated with the delay give the appearance of more width. 

I started reading more about apparent source width last night and will delve in to it further tonight.


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## pionkej (Feb 29, 2008)

bikinpunk said:


> I don't think I really agree with this. It seems you can still get excellent stage width by placing a speaker further away from a boundary point because the reduced amplitude correlated with the delay give the appearance of more width.
> 
> I started reading more about apparent source width last night and will delve in to it further tonight.


And I don't have any way to dispute you.  It was just one of the points that had been brought up several times. The part to me (about my own statement) that is ambiguous is that nobody can really pinpoint a delay amount or amplitude so far that causes the problem. Maybe it's a moving target? Like if a reflected sound is 3ms behind the fundamental, at 3db down width would suffer but at 9db down it isn't audible. Or if a reflected sound is 3db down in amplitude, at 3ms behind the fundamental width would suffer, at 10ms it has no affect, and at 20ms it increases width.

I don't have any idea really. I think it is what makes increasing width both more fun and challenging than something like height in a build.

EDIT: Also excited to see what you find in your "research".


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## ErinH (Feb 14, 2007)

This is interesting:
http://www.ingentaconnect.com/content/dav/aaua/1997/00000083/00000004/art00018


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## highly (Jan 30, 2007)

pionkej said:


> And I don't have any way to dispute you.  It was just one of the points that had been brought up several times. The part to me (about my own statement) that is ambiguous is that nobody can really pinpoint a delay amount or amplitude so far that causes the problem. Maybe it's a moving target? Like if a reflected sound is 3ms behind the fundamental, at 3db down width would suffer but at 9db down it isn't audible. Or if a reflected sound is 3db down in amplitude, at 3ms behind the fundamental width would suffer, at 10ms it has no affect, and at 20ms it increases width.
> 
> I don't have any idea really. I think it is what makes increasing width both more fun and challenging than something like height in a build.
> 
> EDIT: Also excited to see what you find in your "research".



I think this is along the lines of what is going on myself. I would suspect that it is also frequency dependent. I would expect the results to plot like a waterfall chart with amplitude, frequency, and time as the axes. Add frequency anomalies and the individual differences of the listener's ears and aptitudes to play along with that so that, at best, something like the FM curves could be generated for 'most' listeners based on listener responses to subjective width evaluations. I don't see how it could be measured empiricallyto draw a line in the sand, so to speak.

-T


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## SQ Audi (Dec 21, 2010)

In my extensive experience, width comes from over eating! And mostly in the Mid-range!


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## BigRed (Aug 12, 2007)

bikinpunk said:


> Some of it is off topic but most of the discussion regarding speaker location is absolutely relative to width and perceived width. I'll let them stand because cleaning some of it out and leaving other posts is confusing. Besides, we're heading back on track now anyway.


I wasn't trying to give anybody a hard time  Maybe Mic took it that way...was not my intention. 

carry on guys, this has been a great thread thus far 

I'm reading Floyd Toole's book right now and it really gives some valuable info in relationship to this topic.


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## Mic10is (Aug 20, 2007)

BigRed said:


> I wasn't trying to give anybody a hard time  Maybe Mic took it that way...was not my intention.
> 
> carry on guys, this has been a great thread thus far
> 
> I'm reading Floyd Toole's book right now and it really gives some valuable info in relationship to this topic.


not in the least, I hit submit before i added the smilie:
but not this time


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## sqnut (Dec 24, 2009)

I think one vehicle that has the potential to sound really nice, is the one Lloyd and Harry drove in D&D....


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## Patrick Bateman (Sep 11, 2006)

sqnut said:


> Maybe another thing that needs to be factored in, is that one doesn't hear at the same level everyday. Some days are just better hearing days than others. A good nights sleep and a calm mind seems to help here .


psilocybin works pretty good too


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## michaelsil1 (May 24, 2007)

Patrick Bateman said:


> psilocybin works pretty good too


Yes it gives the illusion of no glass and you can't visually pinpoint driver location.


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## ErinH (Feb 14, 2007)

It seems I'm finding the biggest helper is getting the time alignment dialed *DEAD RIGHT*. I decided to ditch the ears method and went all PC. Measured the arrival time of each driver, got the deltas, punched the numbers in to my DSP and voila: kickass soundstage.

You guys who hate on measurement gear can chew on that a bit. I'll go ahead and go out on a limb and say there's no way that you can get every driver lined up exactly right only by ear. Sure, you can probably get close, and getting L/R balance is farily easy. But anyone who has really tried to align (in the time domain) all drivers to the same time knows how iterative a process it can be. Line up your L/R sides... then align the drivers on the same sides (ie: line up your midbass with your tweeter on the left side, then do the right side drivers). Then you're back to an offset with your L/R so you have to tweak that a bit... then another round of same side alignments, then another round of L/R alignments, etc, etc. 

Doing this with a simple loopback system is painless and is MUCH more accurate than anything you'll be able to accomplish by ear. I don't give a flying fart if you tell me your center is great, I bet money I can measure what you have, tweak it a bit, and you'll obtain better results without me using my ears at all. 


*flame suit on*


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## pionkej (Feb 29, 2008)

bikinpunk said:


> It seems I'm finding the biggest helper is getting the time alignment dialed *DEAD RIGHT*. I decided to ditch the ears method and went all PC. Measured the arrival time of each driver, got the deltas, punched the numbers in to my DSP and voila: kickass soundstage.
> 
> You guys who hate on measurement gear can chew on that a bit. I'll go ahead and go out on a limb and say there's no way that you can get every driver lined up exactly right only by ear. Sure, you can probably get close, and getting L/R balance is farily easy. But anyone who has really tried to align (in the time domain) all drivers to the same time knows how iterative a process it can be. Line up your L/R sides... then align the drivers on the same sides (ie: line up your midbass with your tweeter on the left side, then do the right side drivers). Then you're back to an offset with your L/R so you have to tweak that a bit... then another round of same side alignments, then another round of L/R alignments, etc, etc.
> 
> ...


Does that mean you're pleased with the results?


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## BigRed (Aug 12, 2007)

bikinpunk said:


> It seems I'm finding the biggest helper is getting the time alignment dialed *DEAD RIGHT*. I decided to ditch the ears method and went all PC. Measured the arrival time of each driver, got the deltas, punched the numbers in to my DSP and voila: kickass soundstage.
> 
> You guys who hate on measurement gear can chew on that a bit. I'll go ahead and go out on a limb and say there's no way that you can get every driver lined up exactly right only by ear. Sure, you can probably get close, and getting L/R balance is farily easy. But anyone who has really tried to align (in the time domain) all drivers to the same time knows how iterative a process it can be. Line up your L/R sides... then align the drivers on the same sides (ie: line up your midbass with your tweeter on the left side, then do the right side drivers). Then you're back to an offset with your L/R so you have to tweak that a bit... then another round of same side alignments, then another round of L/R alignments, etc, etc.
> 
> ...


did you use omnimic? and if so, how did you do it? pm so we can stay on topic


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## redgst97 (Mar 12, 2008)

Mic10is said:


> I dont think Ive ever posted about it , but at least once I had a judge tell me subass wandered toward the back in my BMW.
> 
> I highlighted the 4 10s in the rear deck bc its 4 ****in 10s in a rear deck of a bmw!!!
> and few people knew I had a 10" sub up front that was the only sub I ever used.
> ...


Sounds VERY familiar (and similar)....


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## thehatedguy (May 4, 2007)

Well if you don't have the coils of the rear subs shorted out, the front sub could make the rears vibrate like passive radiators...and pull everything to the rear. I found that out the hard way when I had the sub in front of the Accord and the 3 12s on the rear deck.


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## asawendo (Nov 22, 2009)

thehatedguy said:


> Well if you don't have the coils of the rear subs shorted out, the front sub could make the rears vibrate like passive radiators...and pull everything to the rear. I found that out the hard way when I had the sub in front of the Accord and the 3 12s on the rear deck.


That would be the case,

IMHO the subs from the back works as passive radiators like thehatedguy aforementioned above.


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## cvjoint (Mar 10, 2006)

I have some doubts about the localization with rear mounted subs as pr's. Pr's of that size and number would most likely have a very low resonant frequency. I doubt any output they produce will be high enough to be localized.

If localization is not due to frequency produced but rather suspension noise or related vibration as a concept, I doubt this is strong enough to matter. Again, a single driver up front is not likely to excite the pr's in a very meaningful way. The cabin is really large, the pr's are really large, but the active driver is really small in comparison to both. If you manage to compress the cabin enough to matter your eardrums are compressed as well and not likely picking up any action in the back whatsoever.


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## thehatedguy (May 4, 2007)

When I had my subs on the rear deck and the front sub, it would pull to the back unless the rear coils were shorted or there was a barrier placed on top of the rears.


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## thehatedguy (May 4, 2007)

Small panel resonances can cause rear mounted subs to loose the illusion of being in front, and there you have a lot of freely moving panels back there doing there own thing.

I remember Elridge in his 4 Runner had 3 subs for demoing, but for critical listening 2 of them were shorted out and had heavy panels on top of them to keep them from moving.


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## ErinH (Feb 14, 2007)

BigRed said:


> did you use omnimic? and if so, how did you do it? pm so we can stay on topic


Nope. OM doesn't allow for this (not unless you trick it) because it makes all the initial impulse measurements go to the 0 ms mark. A PITA, but it's also what makes the program simple to use. 

Nyugen did a tutorial on how to do this a long time ago. I did it a long time ago but got the big head and thought I could do better. I finally gave it a true shot this week and realized I've been wrong for a couple years now. 


If you really want me to write up a how to, I'll try to but the nutshell response is this:
You'll need a mic and a way to power it
You'll need measurement software (arta, holmimpulse, rew are all free)
You'll need a way to loop the sound from the soundcard output - to your system's aux input - back to your soundcard input. IOW, you need a loopback cable. 

That's really all you need.

I'm sure John doesn't mind me going OT a bit. Further discussion can be held elsewhere if you guys would like.


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## sqnut (Dec 24, 2009)

Patrick Bateman said:


> psilocybin works pretty good too


can't comment on that, but I'm guessing that it would be a THC like effect. Alcohol though is the absolute worst .


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## thehatedguy (May 4, 2007)

More like LSD than THC.


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## sqnut (Dec 24, 2009)

bikinpunk said:


> It seems I'm finding the biggest helper is getting the time alignment dialed *DEAD RIGHT*. I decided to ditch the ears method and went all PC. Measured the arrival time of each driver, got the deltas, punched the numbers in to my DSP and voila: kickass soundstage.
> 
> You guys who hate on measurement gear can chew on that a bit. I'll go ahead and go out on a limb and say there's no way that you can get every driver lined up exactly right only by ear. Sure, you can probably get close, and getting L/R balance is farily easy. But anyone who has really tried to align (in the time domain) all drivers to the same time knows how iterative a process it can be. Line up your L/R sides... then align the drivers on the same sides (ie: line up your midbass with your tweeter on the left side, then do the right side drivers). Then you're back to an offset with your L/R so you have to tweak that a bit... then another round of same side alignments, then another round of L/R alignments, etc, etc.
> 
> ...


You're probably right, more so when you're this animated . I agree 100% that dialing in the TA is critical for good width. I love your by ear process cause it's spot on, on how tedious and frustrating it can be. 

I'm a by ear guy, partly cause I'm a technical idiot and partly cause every instrument I've used, has given some good results and some that are so-so. I have to come back and tweak a bit by ear in anycase. I use an spl meter for L/R response, but even there the meter is very accurate in the 60-500 zone but 1-5khz sounds best slightly different from what it measures, maybe the ears and mic treat reflections differently. The mic on the meter isn't very accurate above ~5-6khz. 

I agree that measuring stuff can help a lot. But this is car audio and you're never going to measure your way to great sound. It's got to be a balance of measuring and using your ears. I'm oppen to trying the TA your way if you'll give a tutorial.


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## masswork (Feb 23, 2009)

bikinpunk said:


> Nope. OM doesn't allow for this (not unless you trick it) because it makes all the initial impulse measurements go to the 0 ms mark. A PITA, but it's also what makes the program simple to use.
> 
> Nyugen did a tutorial on how to do this a long time ago. I did it a long time ago but got the big head and thought I could do better. I finally gave it a true shot this week and realized I've been wrong for a couple years now.
> 
> ...


Erin, 
quick question: Do you align the knee or the peak?
Or do you align the ETC?


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## pionkej (Feb 29, 2008)

bikinpunk said:


> I'm sure John doesn't mind me going OT a bit. Further discussion can be held elsewhere if you guys would like.


Doesn't bother me at all since you're impressions show it to be important/relavent to the topic at hand...even though you have limited tuning experience to base your listening impressions on.


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## ErinH (Feb 14, 2007)

masswork said:


> Erin,
> quick question: Do you align the knee or the peak?
> Or do you align the ETC?


First impulse spike. This should be the largest and positive. If its not, something's up and you need to flip polarity to make it positive. That's another reason the mic is so good to use. Takes the guesswork out of polarity.


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## garysummers (Oct 25, 2010)

Erin, I would be very interested in a tutorial of your impulse response measurements procedure. I have been trying to align my 5.1 system with a total of 16 separate drivers by ear. I have some very good test discs which provide some excellent tone burst and stuff, but your are correct that the computer measurements are the way to go. I know I am very close but I need to get it EXACT! My one problem is the Alpine F1 processors do not allow input to all of the 5.1 channels. I can input to L and R via the aux input but center, rears and sub are not accessible. Can it be done by inputting the impulse signal directly to the input of each amplifier channel ie; tweeter center, mid center. Then analyze the impulse response chart to get the TA settings. This way I can measure every driver in the car individually, then dial in the exact setting. If I am way off let me know. I have never made this type of measurement although I have looked at the data graphs. Thanks!


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## masswork (Feb 23, 2009)

garysummers said:


> Erin, I would be very interested in a tutorial of your impulse response measurements procedure. I have been trying to align my 5.1 system with a total of 16 separate drivers by ear. I have some very good test discs which provide some excellent tone burst and stuff, but your are correct that the computer measurements are the way to go. I know I am very close but I need to get it EXACT! My one problem is the Alpine F1 processors do not allow input to all of the 5.1 channels. I can input to L and R via the aux input but center, rears and sub are not accessible. Can it be done by inputting the impulse signal directly to the input of each amplifier channel ie; tweeter center, mid center. Then analyze the impulse response chart to get the TA settings. This way I can measure every driver in the car individually, then dial in the exact setting. If I am way off let me know. I have never made this type of measurement although I have looked at the data graphs. Thanks!


You can directly to amp, but you need to do this all to all channel.
You can't for example calculate IR for front by feeding to the aux of the HU/Proc, and then measure IR for other channel by feeding directly to amp. Every digital processing has a latency.

As for measuring sub IR (if you're interested) you can try highpassing to 400Hz ++. Then zoom the "gain" in the software to actually see the hill. ARTA and REW has this capability.


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## masswork (Feb 23, 2009)

bikinpunk said:


> First impulse spike. This should be the largest and positive. If its not, something's up and you need to flip polarity to make it positive. That's another reason the mic is so good to use. Takes the guesswork out of polarity.


I assume it's the peak then, not the knee.
The knee is point where impulse is about to go up.


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## ErinH (Feb 14, 2007)

Yes. The peak.


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## ErinH (Feb 14, 2007)

garysummers said:


> Erin, I would be very interested in a tutorial of your impulse response measurements procedure. I have been trying to align my 5.1 system with a total of 16 separate drivers by ear. I have some very good test discs which provide some excellent tone burst and stuff, but your are correct that the computer measurements are the way to go. I know I am very close but I need to get it EXACT! My one problem is the Alpine F1 processors do not allow input to all of the 5.1 channels. I can input to L and R via the aux input but center, rears and sub are not accessible. Can it be done by inputting the impulse signal directly to the input of each amplifier channel ie; tweeter center, mid center. Then analyze the impulse response chart to get the TA settings. This way I can measure every driver in the car individually, then dial in the exact setting. If I am way off let me know. I have never made this type of measurement although I have looked at the data graphs. Thanks!


Gary,
See if this thread helps:
http://www.diymobileaudio.com/forum...-pc-based-loudspeaker-measurement-system.html

http://www.diymobileaudio.com/forum...based-measurement-setup.html?highlight=winmls


IMO, if you can run an input to your headunit and disable channels from your procesor, that's the best/easiest way to go.


If the above still isn't too clear or helpful, LMK and I'll try to throw something additional together.


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## BigRed (Aug 12, 2007)

REW is free and works good  beat you to it Gary!! ha!


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## ErinH (Feb 14, 2007)

masswork said:


> You can directly to amp, but you need to do this all to all channel.
> You can't for example calculate IR for front by feeding to the aux of the HU/Proc, and then measure IR for other channel by feeding directly to amp. Every digital processing has a latency.
> 
> As for measuring sub IR (if you're interested) you can try highpassing to 400Hz ++. Then zoom the "gain" in the software to actually see the hill. ARTA and REW has this capability.


I ran my sub and midbasses up to 2khz for my measurements. I'd recommend going pretty high to get a more absolute peak due to wavelength at lower frequencies.


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## garysummers (Oct 25, 2010)

The PXH-990 will not allow an input signal directly to center, rear right, rear left, or sub, only to left and right via the aux input. Hence I need to input the signal post DSP or directly to the amplifier inputs. No X-overs, no EQ, no TA. Any thoughts about this method? I realize I should measure all drivers the same way. Can I band pass the impulse signal in the software or will it not be an issue! Thanks!


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## thehatedguy (May 4, 2007)

Gary, wouldn't you need to go active on the rears to do what you want? Your layout shows you are passive on the 3 way rears.


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## ErinH (Feb 14, 2007)

I tell you what Gary... You get me a job as a Disney Imagineer and help me find a deal on an f1 setup like you have and I'll write a tutorial just for you! Lol. 

I kid (sort of). I'll try to answer tonight when I have more time.


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## garysummers (Oct 25, 2010)

You are correct the rears are run with the Morel passive bi-powered. I would still like to take the impulse measurement for those drivers. The left, center, right are the main issues for me at this point.

Erin, do you know anybody at WDI? Worked a some of the theme park attractions in the past.


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## vitvit (May 3, 2011)

bikinpunk said:


> Yes. The peak.


But is it correct?

When I use REW I do time delay based on phase: for example: if crossing sub and mids at 100 I play with time delay that phase "matches" in cross region (60-180, or wider if possible).

It's really hard to get an exact time of "peak" for lower frequencies.


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## ErinH (Feb 14, 2007)

Read the post about 5-6 up...


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## 14642 (May 19, 2008)

Erin,
What part of the peak are you using to determine the arrival of the subwoofer and have you measured the sub through a low pass filter? The slope of the initial impulse depends on high frequency content, so picking the peak will be accurte for drivers that have plenty of high frequency content, but not accurate for low-passed drivers. We've found that some content at or above 1k is suffuicient to get an accurate measurement. There's a trick that works for determinint the actual arrival time (or for getting MUCH closer) using a low-passed impulse for the measurement: Just back up toward the left until the peak has been reduced by 12dB for all th measurements.


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## sqnut (Dec 24, 2009)

Of all the tuning functions, TA is actually the easiest to set by ear. The real toughie is level matching on the eq. For L/R and then across the 10 octaves, while integrating 3-4 sets of drivers. Dialing in that elusive balance between tonality and imaging, one that gives the impact. Wish there was a way to measure your way there, but it doesn't seem likely. 

Erin linked npdang's thread on the previous page. A couple of quick questions:

1. The way the mic is setup, it's way ahead and offset towards the centre, from where the drivers head would be. Is this being done for a 2 seat setup? Not sure I agree with a two seat concept, cause it will be a compromise for both sides.

2. When measuring, wouldn't a binaural setup work better than one mic?

If you're measuring to get in the ballpark, that's fine. But you eventually have to tweak it by ear as well.


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## ecbmxer (Dec 1, 2010)

I'm currently trying to get set up to do impulse measurements just like you described Erin. I need to download REW, but I have an input/output module that should work well for it.

Does anything change phase-wise when you take your measurements running sub/midbass up to 1kHz+ and then putting them back to normal? I assume you keep the slope the same (I guess that keeps the phase the same even though the LP freq changes).


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## 14642 (May 19, 2008)

The point is that the peak is NOT the arrival time, but if the signal includes enough high frequency, the peak is close enough. If the signal doesn't include high frequency, then the peak is not an acceptable approximation of the arrival of the signal.


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## ErinH (Feb 14, 2007)

Yea, I wasn't 100% sure just how well kicking up the LPF to 2khz was going to work. I actually just set that frequency as the point to which all drivers would play. Figured by doing that it would at least give me a good reference point. 

Trying to set the LPF too low is a nightmare when trying to pick the peak out a wavelength 20ft long... as you already know. I know the ms-8 bypasses a LPF when doing the sweeps for the sub channel and I know that's the reason you guys say to remove the LPF on the amp if there is one. Out of curiosity, does it do any filtering at all (crossover or slope) to the sub or just let it roll off? If you've answered this in the ms-8 thread just ignore me... I'm curious, but not curious enough to read 15,000 pages of posts. lol.


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## cvjoint (Mar 10, 2006)

Erin, what's the trick with the Omnimic?


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## 14642 (May 19, 2008)

bikinpunk said:


> Yea, I wasn't 100% sure just how well kicking up the LPF to 2khz was going to work. I actually just set that frequency as the point to which all drivers would play. Figured by doing that it would at least give me a good reference point.
> 
> Trying to set the LPF too low is a nightmare when trying to pick the peak out a wavelength 20ft long... as you already know. I know the ms-8 bypasses a LPF when doing the sweeps for the sub channel and I know that's the reason you guys say to remove the LPF on the amp if there is one. Out of curiosity, does it do any filtering at all (crossover or slope) to the sub or just let it roll off? If you've answered this in the ms-8 thread just ignore me... I'm curious, but not curious enough to read 15,000 pages of posts. lol.


 
Actually, MS-8 doesn't time align the sub--delaying the speakers by a few inches to match a "20 foot long wave" is unnecessary. For all other lowpassed channels, MS-8 looks for a point in the inpulse to the left of the peak where the output has dropped by 12dB. This is a much better approximation of the arrival of the signal and nearly eliminates the effect of the LPF. It's more difficult to do that with most impulse response measurement tools, because they all normalize the peak to a value of and often don't include the resolution necessary to back up to that precise value. Nevertheless, you can still use your measurements to get really close (which is usually close enough).


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## bbfoto (Aug 28, 2005)

Yeah, I'm bumping this old thread. It's a good one and should be continued. Here's a few videos that I thought were interesting to start the commentary.

Note: Keep an eye out for Pete's notes/text labels at the top of the video.

My Humble Listening Room - YouTube

Start at about the 1m:12s mark...

Chad Visits Pete (Demo) - YouTube

As food for thought and discussion, what aspects of this setup can we NOT achieve due to the "room" that we are forced listen to our system in?

You also might want to watch the following video and Pete's other "Listening Room Update" videos on his YouTube channel.

http://www.youtube.com/watch?feature=fvwp&NR=1&v=qCDR_PKk8FY


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