# Tweeters crossed no lower that 4 KHz?



## jimbno1 (Apr 14, 2008)

This reference came up in another thread. I thought it merits discussion on its own. Can you smart guys comment on this? 

It is basically recommending that no tweeter in car audio application is crossed over no lower that 4 KHz. The arguments appear to be pretty sound to me but I am not that smart  

Buwalda Hybrids International Bulletin Board • View topic - My views on tweeters and crossovers

I understand that some 6.5 mids perform better than others off axis but still aren't they governed by beaming starting ~2.2K due to the diameter of the cone?

Does this preclude 2-way unless the mid is pretty much on axis?

Please comment and educate me. Or as we say down south "learn me something". 

Regards,
Jim


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## ErinH (Feb 14, 2007)

edit: Looks like you already found the original thread it came from.

My take: do what you need to do to get the best sound you can. There is no real 'right' or 'wrong' in car audio. There are a whole lot of variables (driver used and install to name a few). Some will find that crossing X tweeter lower than X frequency sounds bad in their car while another may find it works well.


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## jpswanberg (Jan 14, 2009)

Dynaudio crosses their tweeters over at 2.5k hz with a 2nd order slope. I love their sound and have thrown major wattage at them without problem. I believe my ID Chameleons are also crossed over at a similar frequency. Both however have large (1"+) diaphragms on their tweeters. I think the crossover frequecy and slope are very much driver specific, as opposed to a rule written in stone.


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## marko (Jul 10, 2006)

the same idiots will say it's wrong as the ones that claim active is better than passive! each to their own, there is no wrong or right in car audio just like bikinpunk says!


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## t3sn4f2 (Jan 3, 2007)

bikinpunk said:


> *edit: Looks like you already found the original thread it came from.*
> 
> My take: do what you need to do to get the best sound you can. There is no real 'right' or 'wrong' in car audio. There are a whole lot of variables (driver used and install to name a few). Some will find that crossing X tweeter lower than X frequency sounds bad in their car while another may find it works well.


And here's the original original thread that inspired it........

Starting from post #50

http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/32824-how-good-these-hybrid-speakers-5.html


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## raamaudio (May 4, 2005)

Quote:

"the same idiots will say it's wrong as the ones that claim active is better than passive!"

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

1) passives are built to a generic all purpose fitment, except the rare few that happen to have enough adjustment to fit the vehicle and location installed, few do. I have only done one install ever with the component set passives that I have not had to modify them. 

2) custom passives can be incredible but they are not easy to get right, I have done it, at considerable effort, not something I care do to any longer. The first ones I made were with hand wound inductors, exactly matched resistors and caps, back in 1979 I believe. 

3) Active if you have a variable slope/freq crossover can be very easy to dial in, it takes me little time compared to a huge effort to make custom passives. I switched from the most expensive all time component passives(Rainbow Reference) to active and had better results, immediately, and that was with fixed 24db slopes. 

4) Having your amps separated between drivers when you are really getting it on does not drain the power supply feeding the tweeters than can be quite obvious when lacking, I have experienced this as well. 

Calling anybody an idiot is a bit rude


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

ON TOPIC:

What works in your particular install is what works, if not clipping, the sound stage is right, then it is setup the way it needs to be, period. 

Tuning: You can use any sort of test gear, hours upon hours tweaking, etc but in the end you might be close, might be way off track. A very good set of ears will always be better, I know as have been there, done that, way to many times. Any of you guys that have had the ID guru's tune your systems know exactly what I am talking about

Rick


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## Scott Buwalda (Apr 7, 2006)

I see a 20-page thread about to happen.


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## marko (Jul 10, 2006)

raamaudio said:


> Quote:
> 
> "Calling anybody an idiot is a bit rude
> 
> ...


this is what i'm getting at, there is no right or wrong, what works works! so when somene comes along and says "this is better than that" JUST because it worked in their car then it's just wrong to quote that, i've made more mistakes then i can think f just by following the rest of the clan instead of experimenting with my car, my stereo, my setting, my insta... you get the picture!

Mark.


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## ErinH (Feb 14, 2007)

tuning:
it's not that crossing below 4khz is 'bad'. it's that your ear is most sensitive to the 2-4k range, which happens to be about where most 6.5's roll off naturally on the top end (2k) and where most tweeters are less taxed on their low end (4khz). 

So, do you really have to cross down to 2khz or 3khz to match your mid and tweeter's crossover points? Not necessarily. You can take advantage of this knowledge and possibly leave a gap in your crossover points. Many people do this. I do this. I find it's worked well for me and I don't have to also worry about EQ'ing the 2-4khz range down. 

But, like I said, it's all dependent upon you, your gear, and your install. There is no absolute for any of us.

Good reads:
Equal Loudness Curves
&
Interactive Ear Sensitivity Chart - Independent Recording Network

Let's not also forget crossover slope, as well. That's just as important as the crossover point.


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## t3sn4f2 (Jan 3, 2007)

Scott Buwalda said:


> I see a 20-page thread about to happen.


Those days are long gone here.


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## mdechgan (Dec 16, 2010)

It really depends.
Dynaudios are crossed at 2.2 or 2.4 I forgot. Some of the best components on the market.
a/d/s (the famous ones) were like 2.5
In common are that they are rather large silk dome tweeters that sound really smooth.
If it they were the titanium Mb Quart RTC 19mm tweeters 4khz is as low as practically possible otherwise they will get blown or sound rather harsh if any lower.
I've seen some networks cross the mids at 2khz and tweeters at 4khz which theoretically would leave a gap, but the slight gap in the midrange actually makes some components sound really good to the ear.
Car audio is mostly subjective on what sounds good, not solely on performance curves alone.


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## ErinH (Feb 14, 2007)

mdechgan said:


> Car audio is mostly subjective on what sounds good, *not solely on performance curves alone*.


which are also approaching meaninglessness once in the car.

I see a whole lot of talk about a speaker's FR, but I see very little about how someone has been able to figure out the effect the car has FIRST and then try to find a nominal speaker FR to work best in the car with that effect.


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## vrdublu (Apr 13, 2009)

jimbno1 said:


> This reference came up in another thread. I thought it merits discussion on its own. Can you smart guys comment on this?
> 
> It is basically recommending that no tweeter in car audio application is crossed over no lower that 4 KHz. The arguments appear to be pretty sound to me but I am not that smart
> 
> ...


Basically everything he says is true. To make it a little more basic, the higher you set your tweeter frequency the higher your stage will appear to be, I have witnessed this on several different tweeter mounting locations. To add to this, the space between the mid and tweeter can increase without the front sound stage sounding "off". In short everything he just said there is right on the money, he knows what he's talking about. I do not know the reason why people insist on playing their tweeters low, more than likely to compensate for poor mids I suppose, or a preconceived notion that the sound stage sounds better with tweeters crossed low?


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## raamaudio (May 4, 2005)

Marko,
I may of misunderstood your comment, sorry if I did. 

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

I have worked for hours and hours using an RTA to get this sweet looking curve all figured out, did not like the sound, tweaked it here and there by ear and headed out to a competition. I beat a world champion with my tune and then went to ID and Eric spent maybe 20 minutes on it and it absolutely blew away what I had accomplished. 

I ran the RTA again to copy the tune the best I could, took pictures of the EQ's, wrote notes, etc...the RTA curve was nothing even close to what I had setup before, really looked like hell and I had the current Audio Control system, calibrated mic, etc........

I have seen Eric use an RTA many times, to get a baseline, look for dropouts, etc.....or add some(as mentioned a gap between crossover points can be needed). Then he tunes by ear. The RTA is a fast way to fix something, when in the right hands cut to the chase very quickly, ears, the right ears, are better for the fine tuning. 

Over a long time I have learned to tune by ear pretty well now, good enough for my tastes so I sold the RTA as can dial in a starting point pretty well without it, finally. But if competing ever again, I am going to get help even if I have to drive the 700 miles for it. 

Rick


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## ErinH (Feb 14, 2007)

raamaudio said:


> I ran the RTA again to copy the tune the best I could,


I've said this a few times in past threads, and I really think it needs to be mentioned again for those who don't realize it or know:
You can have the EXACT same FR curves from a system response and still have them sound COMPLETELY different. One may sound like ass while the other sounds good, or one may sound great while the other is mediocore. 
There are MANY, MANY, MANY ways to skin this particular cat.
A simple example would be to take two of the same cars, use the same drivers, but use different crossover points; make one setup have a HPF on the tweeters set to 1khz instead of the 4khz you have on the other one. Then tune so that the 1khz tweeter version matches the response of the other. You'll get the same response but they won't sound the same. 

I learned a long time ago not to use the rta to get the same tune. The RTA is best used as a tool to help you find flaws or verify what you're hearing or to help you figure out what is wrong (through trial and error) but it should never replace your ears and should not be used to duplicate a pre-determined response curve.
Took me too long to figure that out.


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## mdechgan (Dec 16, 2010)

The article does have a point, but there are so many variables.
I have yet to see a high quality component crossover network not crossed over between 2-4khz
Dynaudios in the 2khz range, focals 4khz, MB quarts 3khz 
And these are some the best sounding speakers on the market.


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## marko (Jul 10, 2006)

i havn't used an rta for a few years now (actually own one but it's at a friends), found with an rta at disposal it was far too easy to get carried away eq-ing in persuit of the ultimate eq curve and proper screw things up!! rta's do have their place but not the be all and end all to tuning a system.


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## marko (Jul 10, 2006)

mdechgan said:


> The article does have a point, but there are so many variables.
> I have yet to see a high quality component crossover network not crossed over between 2-4khz
> Dynaudios in the 2khz range, focals 4khz, MB quarts 3khz
> And these are some the best sounding speakers on the market.


what does that tell you  you listed some of the worlds best sounding speakers and they do ok without a 4k cross over point. it's just a shame not every install/interior is the same..


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## ErinH (Feb 14, 2007)

marko said:


> what does that tell you  you listed some of the worlds best sounding speakers and they do ok without a 4k cross over point. it's just a shame not every install/interior is the same..


that tells me this:



bikinpunk said:


> There is no real 'right' or 'wrong' in car audio. There are a whole lot of variables (driver used and install to name a few).


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## Ludemandan (Jul 13, 2005)

bikinpunk said:


> Good reads:
> Equal Loudness Curves
> &
> Interactive Ear Sensitivity Chart - Independent Recording Network
> ...


These graphs support the idea of having a nice large gap between 2khz and 5khz, and letting the slopes fill it in. I can't wait to start playing with this when I get my install all buttoned up.


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## vrdublu (Apr 13, 2009)

mdechgan said:


> The article does have a point, but there are so many variables.
> I have yet to see a high quality component crossover network not crossed over between 2-4khz
> Dynaudios in the 2khz range, focals 4khz, MB quarts 3khz
> And these are some the best sounding speakers on the market.


Really I have had two seperate MB Quart components sets both crossed at 6khz or so. I think it comes down to economics really, does it cost more to make a mid play higher effectively or a tweeter play lower? I mean there are tons of mids out there that play well to about 2-3khz without any major dips or humps and still have exceptionaly low distortion. How many can you count that are capable of playing up to 10khz, well? I use a tweeter that is more than capable of playing into the 2-3khz range but I find it sounds better at 5-6.3khz range, and makes my sound stage more coherent, meaning there are no voids between ranges, if that makes any sense.


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## mdechgan (Dec 16, 2010)

vrdublu said:


> Really I have had two seperate MB Quart components sets both crossed at 6khz or so. I think it comes down to economics really, does it cost more to make a mid play higher effectively or a tweeter play lower? I mean there are tons of mids out there that play well to about 2-3khz without any major dips or humps and still have exceptionaly low distortion. How many can you count that are capable of playing up to 10khz, well? I use a tweeter that is more than capable of playing into the 2-3khz range but I find it sounds better at 5-6.3khz range, and makes my sound stage more coherent, meaning there are no voids between ranges, if that makes any sense.


The old school mb quarts were crossed at 3k using the supplied networks.
The reference series cross the tweeters @ 5k 12db but the lowpass uses a single first order inductor @ around 2k 6db
The new premium series high pass @ 3k 12db

Most of us and many installers just use the crossovers that come in the box.
So it makes this thread only a theoretical discussion.

Most of the factory networks almost always have a gap betweeen 2-4k


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## Ludemandan (Jul 13, 2005)

mdechgan said:


> Most of us and many installers just use the crossovers that come in the box.
> So it makes this thread only a theoretical discussion.


But for those of us with an active lifestyle, it's not theoretical.


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## subwoofery (Nov 9, 2008)

I actually understand why Scott likes 4kHz for a tweet crossover. 

Our ears are really sensitive to the 1kHz to 4kHz range. Below 2kHz ITD is more important and over 2kHz IID takes over. 

Most people tend to install their midrange in the doors and tweets up high. Having a low crossover point often introduces phase shifts. Phase problems get more difficult the higher we go in freq - but between 1kHz and 4kHz it's really easy to hear a phase problem. You end up with a nice center stage for freqs below 2kHz but 3, 4 or 5 center stage above that. 
I believe Scott states that the tweeter must be located within a distance of 1/4 wavelength at the crossover point from the midrange in order to use low crossover points. 

Some manufacturer sometimes copy others but don't know what they're doing. Played with 1 set of speakers and it was just ear piercing. Xover point of 2.5kHz @ 12dB/oct slope for a that particular 1" tweeter was way too low. No gap between the mid and the tweeter there. 

Kelvin


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## SSSnake (Mar 8, 2007)

Wow! So a lot of you guys believe that gapping the mid to tweet crosssover is a good idea. You pretty much guarantee some interesting phase interactions with this approach. Remember that a xover affects magnitude AND phase.

IMO - start with no gap and steep slopes and modify from there as necessary to get the optimal sound. BTW - I very seldom end up with a gap in this range. Usually playing with levels of the mid and tweet and xover slope get the job done.


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## dkh (Apr 2, 2008)

Do tweeters tend not to play frequencies they don't like ie xover at 2.5khz but tweeter starts to play around 4-5khz?

I ask this because if midbass are in the doors and tweeters in the a-pillars, between the critical mid ranges of 1-4khz the speakers would be in their respective roll-off / in stages.

I have heard a few cars that sound like this with two-way front ends...


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## asp87 (Dec 14, 2010)

dkh said:


> Do tweeters tend not to play frequencies they don't like ie xover at 2.5khz but tweeter starts to play around 4-5khz?
> 
> I ask this because if midbass are in the doors and tweeters in the a-pillars, between the critical mid ranges of 1-4khz the speakers would be in their respective roll-off / in stages.
> 
> I have heard a few cars that sound like this with two-way front ends...


If you're telling your driver to play something, it will play it at whatever level it can given the input.

Every driver is different... Some roll on higher and lower than others. The 4" mids I'll be putting in are reasonably flat to 3 kHz and the tweeters are flat between ~ 900 hz and 20 khz. If your mids roll off before your tweeters roll on you'll have to do some monkeying with the EQ no matter what you set the crossover at.

I don't know what my opinion is on the 4khz or bust topic. I'm installing my 3 way front with an active crossover and I plan to experiment with crossover points between 1.5 khz and 3 khz.


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## ryan s (Dec 19, 2006)

SSSnake said:


> Wow! So a lot of you guys believe that gapping the mid to tweet crosssover is a good idea. You pretty much guarantee some interesting phase interactions with this approach. Remember that a xover affects magnitude AND phase.
> 
> IMO - start with no gap and steep slopes and modify from there as necessary to get the optimal sound. BTW - I very seldom end up with a gap in this range. Usually playing with levels of the mid and tweet and xover slope get the job done.


Underlapping seemed like a foreign concept to me earlier this year, but now I have a 500Hz gap between the midbass and tweeter. Started with them "meeting" at the same frequency but lowered the midbass and it got rid of a peak that wouldn't go away with all the EQ action I could throw at it 

What I've tried:
-Mid LP 3.15kHz/Tw HP 3.15 (18dB)
-Mid LP 2kHz/Tw HP 4 (12dB, 24dB respectively)
-Mid LP 2kHz/Tw HP 2.5 (18dB)

I don't think it's a coincidence that I now have 1-4kHz almost flat on the EQ with my final choice. The first was reallllllly nasty at 2000Hz. Second one just didn't sound right...why, I can't place my finger on it.

(I know I'm playing my tweeters pretty low, but they're mounted up high and heavily attenuated. Haven't smoked em yet :surprised


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## The Baron Groog (Mar 15, 2010)

ryan s said:


> Underlapping seemed like a foreign concept to me earlier this year


It'd never occured to me either until I went on a Pioneer training course (2004/5?) when the 88RS (800RS in US?) came out, we were quickly shown how to set the crossovers and i was surprised to find what seemed like HUGE gaps in a very sweet sounding set up (it was all PRS).

Their PRS CD was a great disc for setting up-shame I've lost it and been unable to find a copy


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## sqnut (Dec 24, 2009)

I'm with the 4+khz crowd and ambivalent on the staggered/overlapping issue. Just feel that the staggered/overlapping bit is driver dependent as well as on the level of dsp at hand. For my setup and speakers, I seem to get better results with matched xover points.


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## subwoofery (Nov 9, 2008)

The Baron Groog said:


> It'd never occured to me either until I went on a Pioneer training course (2004/5?) when the 88RS (800RS in US?) came out, we were quickly shown how to set the crossovers and i was surprised to find what seemed like HUGE gaps in a very sweet sounding set up (it was all PRS).
> 
> Their PRS CD was a great disc for setting up-shame _*I've lost it*_ and been unable to find a copy


SHAME ON YOU... SHAME!!!!!  

Kelvin


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## The Baron Groog (Mar 15, 2010)

subwoofery said:


> SHAME ON YOU... SHAME!!!!!
> 
> Kelvin


:behead: me-that's what I deserve

Unfortunately Pioneer culled most of their UK staff when the credit crunch hit, so all my old budies are now up to something else and none of the new guys have a scooby do what I'm on about

I've heard one of the reps for Celsus (JL/MTX/Dynamat/Stinger distrobutors) may have a copy so am hunting him down!

Will post a track list/link to download if and when I track it down


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## Wesayso (Jul 20, 2010)

The Baron Groog said:


> :behead: me-that's what I deserve
> 
> Unfortunately Pioneer culled most of their UK staff when the credit crunch hit, so all my old budies are now up to something else and none of the new guys have a scooby do what I'm on about
> 
> ...


Please do!


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## The Baron Groog (Mar 15, 2010)

I will, worry not!

Has just occured to me I may have a copy on my old PC-but my f!cking sister killed the PC along with my fiancee's laptop and her own notebook in the space of a week and the hard drive isn't compatible with my newer PC! (any tips appreciated, though keep it simple, despite my many hours on here I'm the computer anti-christ)


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## Wesayso (Jul 20, 2010)

Let me guess, an older IDE harddisk that won't fit your current sata PC.
There should be an IDE socket on your motherboard though for that wide flat cable fitting your old harddisk. All you need is the flat cable from the old PC and a 4 pin power lead.


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## The Baron Groog (Mar 15, 2010)

^ Really? I'll give it a go-got 30g of music on it and it's been doing my nut not having it! Will have a butchers


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## Wesayso (Jul 20, 2010)

This thread did make me alter my crossover settings. Right now I have the mids till 2 khz/12db and the tweeters at 4Khz /12 db. It sounds better then I expected. The stage hight is a bit higer than before even though my tweeters are mounted low in the doors. It was just above the dash and now it has moved up to halfway window hight.


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## The Baron Groog (Mar 15, 2010)

Nice one If I get home thru the snow I'll be trying that tonight

and SORRY to the OP for the thread jack! Mods if you can delete these go for it


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## hottcakes (Jul 14, 2010)

The Baron Groog said:


> ...and SORRY to the OP for the thread jack! Mods if you can delete these go for it


i think most people know THAT isn't going to happen. anytime soon at the very least. there's a whole other thread in another forum category mentioning something similar to this.


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## 6262ms3 (Feb 27, 2008)

No single tuning concept is going to work for every system. There are so many different speakers and mounting locations, not to mention personal preferences. I like knowing what settings people are using on this forum because I'm always open to trying something different. If I don't like it then I can easily go back. I'm glad to learn about our sensitivity between 2-4k, I thought my tweets were getting harsh at loud volumes (4k/24db) but it ended up being my mids, dropping them from 2.5k/12db to 2k/12db smoothed things very nicely. I lost a little bite on barry saxes and electric guitars but the tradeoff was worth it. I was worried that much underlap meant I was missing something, but screw it, I'm happier with my system now!


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## vrdublu (Apr 13, 2009)

6262ms3 said:


> No single tuning concept is going to work for every system. There are so many different speakers and mounting locations, not to mention personal preferences. I like knowing what settings people are using on this forum because I'm always open to trying something different. If I don't like it then I can easily go back. I'm glad to learn about our sensitivity between 2-4k, I thought my tweets were getting harsh at loud volumes (4k/24db) but it ended up being my mids, dropping them from 2.5k/12db to 2k/12db smoothed things very nicely. I lost a little bite on barry saxes and electric guitars but the tradeoff was worth it. I was worried that much underlap meant I was missing something, but screw it, I'm happier with my system now!


You're right about the fact that every system is different, but the same in so many respects. The fact that if you use a higher cuttoff Freq. on the tweeter it will raise your sound stage, this will not change, no matter where you put them. How much will your mid suffer if it's not on axis, you could actually apply this to any speaker.

The reason why people will leave a gap between 2-4k is because their tweeters can't play that low effectively, giving them a nice high sound stage and handle the power. Better yet, their mids are not up to par and they have a nice big hump in that region which they can't seem to manage with an EQ. Perhaps their ears are sensitive to that frequency range, can't say for sure.

Now I'm not saying it's as simple as picking a mid that can play up to say 6khz and you're golden. There's always a trade off it seems, smooth response, or low distortion, or efficiency and power handling. You can never seem to have all three, this is why DIY IMHO is so much better than buying prefabbed kits with passive crossovers which most people on these forums don't use anyways.

To give an example of prefabbed kits and the uncertainty you get when you purchase one of these kits: I recently got a Diamond Audio S500A comp set and was debating using it in my car. Now this is not world class component set by the standards set forth on this forum, but they did retail for $400 at one point, so I put them up there. I called up DA to see if I can get some background on the individual drivers aforementioned. After spending more than 15 minutes on the phone I found out they had no frequency response graphs whatsoever for any of the drivers other than the one posted on their website for marketing purposes. In short, if you use their passive crossovers you can be pretty certain what you get, outside of that it's a crap shoot as to the individual performance of each driver. 

OK I'm done now :laugh:


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## mdechgan (Dec 16, 2010)

vrdublu said:


> To give an example of prefabbed kits and the uncertainty you get when you purchase one of these kits: I recently got a Diamond Audio S500A comp set and was debating using it in my car. Now this is not world class component set by the standards set forth on this forum, but they did retail for $400 at one point, so I put them up there. I called up DA to see if I can get some background on the individual drivers aforementioned. After spending more than 15 minutes on the phone I found out they had no frequency response graphs whatsoever for any of the drivers other than the one posted on their website for marketing purposes. In short, if you use their passive crossovers you can be pretty certain what you get, outside of that it's a crap shoot as to the individual performance of each driver.
> 
> OK I'm done now :laugh:


Other than subs it is almost impossible to get any graphs or thiel small parameters for a specific tweeter or woofer.

That is why most people as I mentioned just use the stuff packed in the box.
Other than that, choosing crossover frequencies without any graphs or parameters is just like picking a lottery number. Even with that no one would know how it will sound in the car.

Only a few of us go active for the tweet and mids and even fewer have that golden ear "oh you are about 1db over between 2.5 and 3khz"


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## The Baron Groog (Mar 15, 2010)

Re the last two posts about TS parameters-woofer tester 3 is about £80 on PartsExpress, once set up it's a doddle tto use.


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## mdechgan (Dec 16, 2010)

The Baron Groog said:


> Re the last two posts about TS parameters-woofer tester 3 is about £80 on PartsExpress, once set up it's a doddle tto use.


I'm very interested in getting one.
Anyone use one?
Can it measure tweeters and the inductance also?


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## The Baron Groog (Mar 15, 2010)

Yes, it can measure tweeters and will measure inductance-just make sure you alter the test frequency range to one suited to your tweeters. Will also measure a complete set of T/S parameters including your speaker wire with the measurements if you wished. For a full set of T/S parameters you'll need to add a known mass to the cone or fit the driver in a known box volume.


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## stalintc (Dec 6, 2007)

vrdublu said:


> You're right about the fact that every system is different, but the same in so many respects. *The fact that if you use a higher cuttoff Freq. on the tweeter it will raise your sound stage, this will not change, no matter where you put them.* How much will your mid suffer if it's not on axis, you could actually apply this to any speaker.
> 
> The reason why people will leave a gap between 2-4k is because their tweeters can't play that low effectively, giving them a nice high sound stage and handle the power. Better yet, their mids are not up to par and they have a nice big hump in that region which they can't seem to manage with an EQ. Perhaps their ears are sensitive to that frequency range, can't say for sure.


This "absolute" you speak of is not true. It may be applicable to some, or even many cases, but it is certainly not an absolute. There are so many factors that change how a driver performs, and crossover selection is certainly one of them. Placement completely matters. In fact, there is an interesting AES paper on just this issue, _Optimal Location and Orientation for Midrange and High Frequency Loudspeakers in the Instrument Panel of an
Automotive Interior_ by Roger Shively, Jérôme Halley , François Malbos, and Gabriel Ruiz. I would also like to note that even a small horn on a tweeter (say 2-3x it's diameter) can boost efficiency and response into the 1800k realm. 

To take this to another extreme, if I cross over my tweeters even higher then the 4k, then the range I have alloted these drivers to play will contain little (in regards to frequency) spatial information. I would like to bring up this example about the human ear, and it's inability to truly detect placement of frequencies say 7.5K and above as shown by papers such as this one: http://mue.music.miami.edu/thesis/robert_hartman/robert_hartman_thesis.pdf

On the positive, I agree with most of the statement about under/over lapping. It is just another tool for tuning a system, like a parametric band of EQ. For instance, purposely setting your crossover to have poor summation to account for a peak due to cabin gain, speaker characteristics, mounting location, etc is a perfectly good tool to help if you do not have any other options. 

Now the downside is this little thing called phase. If one (I am _not_ trying to point at anyone in specific) say, puts a tweeter completely out of phase from the rest of the system to account for this, then be prepared that a lot of spatial cues are going to be affected in more ways then just spectral. Similar things can happen with location, say if the reflection of a driver is 3dB louder then the driver itself as measured from the listener position. In my personal experience this is rare but I have measured this before in a vehicle. 

To sum up my points:
-Location matters
-Cross over matters and a generic "this is the only way" approach does not apply here
-over/under lapping is a tool to use for EQing when others are not available


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## vrdublu (Apr 13, 2009)

stalintc said:


> This "absolute" you speak of is not true. It may be applicable to some, or even many cases, but it is certainly not an absolute. There are so many factors that change how a driver performs, and crossover selection is certainly one of them. Placement completely matters. In fact, there is an interesting AES paper on just this issue, _Optimal Location and Orientation for Midrange and High Frequency Loudspeakers in the Instrument Panel of an
> Automotive Interior_ by Roger Shively, Jérôme Halley , François Malbos, and Gabriel Ruiz. I would also like to note that even a small horn on a tweeter (say 2-3x it's diameter) can boost efficiency and response into the 1800k realm.
> 
> To take this to another extreme, if I cross over my tweeters even higher then the 4k, then the range I have alloted these drivers to play will contain little (in regards to frequency) spatial information. I would like to bring up this example about the human ear, and it's inability to truly detect placement of frequencies say 7.5K and above as shown by papers such as this one: http://mue.music.miami.edu/thesis/robert_hartman/robert_hartman_thesis.pdf
> ...


Very good read, but there's so much going on in that article, lol. Location does matter, but the point I was trying to get across is that the higher the tweeter cross over frequency the higher your sound stage will appear to be. From my own experimenting, tweeter placement is not that big of an issue as frequency selection at this point, as long as it's in font of you, and your main objective is testing sound stage height. There are many other factors I agree that all play a role, I will not disspute this. I'm merely trying to give people a starting point and get them away from thinking that everything has to be cutoff at 2khz to sound great.

I do not agree in under/overlapping though, this can create more problems than it solves. I do agree with EQ, particularly in an automotive setting, and to be honest I don't know how you could go without it.


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## dkh (Apr 2, 2008)

stalintc said:


> This "absolute" you speak of is not true. It may be applicable to some, or even many cases, but it is certainly not an absolute. There are so many factors that change how a driver performs, and crossover selection is certainly one of them. Placement completely matters. In fact, there is an interesting AES paper on just this issue, _Optimal Location and Orientation for Midrange and High Frequency Loudspeakers in the Instrument Panel of an
> Automotive Interior_ by Roger Shively, Jérôme Halley , François Malbos, and Gabriel Ruiz. I would also like to note that even a small horn on a tweeter (say 2-3x it's diameter) can boost efficiency and response into the 1800k realm.
> 
> To take this to another extreme, if I cross over my tweeters even higher then the 4k, then the range I have alloted these drivers to play will contain little (in regards to frequency) spatial information. I would like to bring up this example about the human ear, and it's inability to truly detect placement of frequencies say 7.5K and above as shown by papers such as this one: http://mue.music.miami.edu/thesis/robert_hartman/robert_hartman_thesis.pdf
> ...


All this info is very good but, what happens if the mid/midbass and the tweeter are more than quarter wavelength apart in the critical mid-range frequencies? Is splitting this range more important/advantageous than the centre image coming from multiple places? 

Most installs use a midbass in the lower door and tweeters in the sail/a-pillars - crossing this type of setup at 2.5-3.5khz is going to bring up some very interesting results.


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## mdechgan (Dec 16, 2010)

Some say if you do mount the tweets and mids far from each other there will be localization problems. So some say you have to have a bit of overlap to overcome this or use time alignment and EQ. But then there are others where if the frequencies are high enough one's ears can't tell where they are coming from.

I tried putting my tweets in the a pillars. They did bring the sound up and in your face but the reflections from the dash and windshield really made it a havoc. And the distance between the a pillars were not as wide compared to my kick panels in my car.
If I closed my eyes I could tell exactly where the tweeters were and they were not near the mids. I used the kick panels and no one sitting in my car could tell where the tweets were without looking. I do not think there is a problem with stage height with the tweets mounted low. I think I have better stage height with the tweets in the kick panels. The only problem is there is this big round thing in my car that I use to drive with that gets in the way.


I think there is this rule for competition where the tweeter can only be so far from the mid driver. Is it 8" or 18" No problem for 3 way but most of us use 2 way with the mids in the doors which only leaves the kick panels as a viable placement.


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## stalintc (Dec 6, 2007)

Gents and ladies (not to be sexist),

The above posts are bringing up great questions, which I will add to, however later as I am too tired and almost too inebriated to reply in a concise manner. I only say this so that you don't think I made the above single comment to only create a "**** storm."

Sorry for this empty post!


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## stalintc (Dec 6, 2007)

vrdublu said:


> Very good read, but there's so much going on in that article, lol. Location does matter, but the point I was trying to get across is that the higher the tweeter cross over frequency the higher your sound stage will appear to be. From my own experimenting, tweeter placement is not that big of an issue as frequency selection at this point, as long as it's in font of you, and your main objective is testing sound stage height. There are many other factors I agree that all play a role, I will not disspute this. I'm merely trying to give people a starting point and get them away from thinking that everything has to be cutoff at 2khz to sound great.
> 
> I do not agree in under/overlapping though, this can create more problems than it solves. I do agree with EQ, particularly in an automotive setting, and to be honest I don't know how you could go without it.


Thanks for the Compliment! As far as cross-over vs. position etc I have some interesting points to bring up, which have been brought up before in such forum posts as one about Hartman's paper. 

Frequencies >2.5KHz are tough for the human hearing system to localize (1) and at >10KHz localization is nearly impossible. (2). 2-4KHz it is very difficult to detect a change in vertical position. The dominant localization cues in midrange to upper midrange are in order; ITD (time difference between when each ear hears an event), ILD (level difference between ears for an event), and Monaural cues. Monaural cues (describes the interaction of the outside of the ear and how our brain perceives the information) are very important in the 5-12K region. 

So, with this seemingly "stating-it-so-I-look-smarts" pile of information we can start to see what might be at play in what you are experiencing. As raise your HP filter's frequency are you adding gain to the channel? I ask this because if gain remains constant SPL will diminish as the HP is raised. The ILD changes with level, especially in a small room such as a car. More then just that, as the filter frequency is changing, so is the phase relationship with the rest of the system. IPD (phase difference between the ears for an event) can steer localization and increase in effect from 1.5KHz and down (2) Depending on the slope and type of HP/LP filter if it is set low at say 2KHz, it would be safe to assume that an octave below will still be effected by these phase differences. as you raise the HP filter's frequency you may be changing this relationship for better alignment with the mid, causing the height to appear higher. 

Another interesting thought is that Monaural cues are causing the change in height. As an event is generated from different positions, the in ear response changes due to the shape of the pinna. This is another "tool" the human auditory system uses to locate sound. So if these differences are measured it may be possible to quantify how to change perceived height by changing only response. A spike at 7Khz for instance, can raise stage height. Other spatial effects from simply EQ changes are described as preference bands by Blauert(3). Again, depending on the Q or bandwidth of the HP filter, you may be causing an increase at 7KHz when pushing the filter frequency up.

As far as the under/over lap argument, I tend to agree with you again, it is something I do not like to rely on for tuning. However, it is effective when your crossover is set to the 2KHz region where most vehicles exhibit a peak in response due to size, reflections, typical position of drivers, dash layout, etc. If you make an alignment that is not perfect, but still sums in the crossover region say by only 4dB, there is no destruction but a nice "free" parametric filter at the crossover point of -2dB. If MacGuyver was a sound guy, it would be his duct tape.

Finally, I will end my diatribe here, but please note I am not writing this to be pointed at anyone in particular. I am including my sources for 2 reasons; so others can follow the research I have done and make their own conclusions, and so that I can actually feel as if I contributed something of substance to DIYMA instead of the ever-rampant "I know cuz im right lolz". 


(1) M. Smyth "An Overview of the Coherent Acoustics System"
(2) R. Hartman "Spatially Relocated Frequencies and Their Effect on the Localization of a Stereo Image"
(3) J. Blauert "Sound localization in the median plane"


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## The Baron Groog (Mar 15, 2010)

Just to add some fuel to the fire, Pioneer "claim" this about their new PRS set:

"New PRS speakers conceived for low frequency crossover points : TS-C172 tweeter easily usable down to 1kHz !!"

on their facebook page. Asked one poster, who claims 2nd at Emma Euro finals using them, what x-over point he was using. Will let you know.


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## dkh (Apr 2, 2008)

The Baron Groog said:


> Just to add some fuel to the fire, Pioneer "claim" this about their new PRS set:
> 
> "New PRS speakers conceived for low frequency crossover points : TS-C172 tweeter easily usable down to 1kHz !!"
> 
> on their facebook page. Asked one poster, who claims 2nd at Emma Euro finals using them, what x-over point he was using. Will let you know.


:laugh:
I thought I got it clarified that any speaker can play any range - it's just how it plays when the volume goes up or how you think mid/midbass should sound compared to a tweeter that the discussion of validity arises - e.g. max excursion of said pioneer tweeters?


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## The Baron Groog (Mar 15, 2010)

dkh said:


> :laugh:
> I thought I got it clarified that any speaker can play any range - it's just how it plays when the volume goes up or how you think mid/midbass should sound compared to a tweeter that the discussion of validity arises - e.g. max excursion of said pioneer tweeters?


The difference between what you and they are saying is that "easily usable down to 1kHz" means that Pioneer are saying they can actually be used in the 1Khz and up range-quite different to it "playing" a 500Hz tone. Their statement more than implies it would be capable of keeping up with the paired mid at 1Khz and up....


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## dkh (Apr 2, 2008)

The Baron Groog said:


> The difference between what you and they are saying is that "easily usable down to 1kHz" means that Pioneer are saying they can actually be used in the 1Khz and up range-quite different to it "playing" a 500Hz tone. Their statement more than implies it would be capable of keeping up with the paired mid at 1Khz and up....


Team Pioneer (Turners) use the ODR MKII tweeters xover'd @ 2.5khz - ask them to let you play with the volume control a 'little' and see what response you get


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## The Baron Groog (Mar 15, 2010)

dkh said:


> Team Pioneer (Turners) use the ODR MKII tweeters xover'd @ 2.5khz - ask them to let you play with the volume control a 'little' and see what response you get


Bit far away from me, in the mids! So are you saying they lose SQ at higher levels? It's actually Andrew Liddle I'm waiting for the info back from..


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## subwoofery (Nov 9, 2008)

dkh said:


> Team Pioneer (Turners) use the ODR MKII tweeters xover'd @ 2.5khz - ask them to let you play with the volume control a 'little' and see what response you get


Might be wrong but I bet the tweets is mounted next to the midrange. 

Kelvin


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## dkh (Apr 2, 2008)

The Baron Groog said:


> Bit far away from me, in the mids! So are you saying they lose SQ at higher levels? It's actually Andrew Liddle I'm waiting for the info back from..


definitely yes. Tweeters play high frequencies and don't really move or have much of a voice-coil compared to a Midrange speaker which in turn doesn't have much of a voice-coil compared to a midbass and so on.

This is fine if used conservatively, but as you soon as you get friendly with the volume control - you'll initially start to get a strange smell, then smoke (if you're lucky) followed by new tweeter time.


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## dkh (Apr 2, 2008)

subwoofery said:


> Might be wrong but I bet the tweets is mounted next to the midrange.
> 
> Kelvin


Strangely enough they're not, the mid is at the bottom of the a-pillar and the tweeter is in the sail panel.


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## subwoofery (Nov 9, 2008)

dkh said:


> Strangely enough they're not, the mid is at the bottom of the a-pillar and the tweeter is in the sail panel.


When I said "right next", what I meant was that they aren't "mid at the bottom of the door and tweet in the sails or A-pillar" but more like separated within a distance of 1/4 wavelength at the crossover point. From your description of the system, it follows that rule. 

Kelvin


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## ErinH (Feb 14, 2007)

FWIW, I see talk of t/a not being valuable below 2khz due to ITD/ILD. That's not exactly true. T/A still affects the phase and while we may not be able to pick out phase issues in the tweeter range to the degree we can the mid-range, you can still hear the difference in out of phase and in phase (even if you don't realize it). So, to help make this a bit easier on yourself, you can drop down the crossover point of the tweeters to 500-800hz, KEEP THE VOLUME *LOW* and use t/a to center up vocalist (or whatever you choose to use to center your image) and then put the crossover back to the nominal point.
You still might have to play with things a bit to get the phase between mid and tweeter correct, but you'll almost guarantee your tweeters to be in phase, relative to each other. This helps to take a lot of the guesswork out if you haven't quite been able to tell when your tweeters are in/out of phase with each other.


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## sqnut (Dec 24, 2009)

bikinpunk said:


> drop down the crossover point of the tweeters to 500-800hz, KEEP THE VOLUME *LOW* and use t/a to center up vocalist (or whatever you choose to use to center your image) and then put the crossover back to the nominal point.
> You still might have to play with things a bit to get the phase between mid and tweeter correct, but you'll almost guarantee your tweeters to be in phase, relative to each other.


I've tried that and yes it works. But I just keep the delay between the tweets the same as that between the mids and that works great too. I don't know why it works, but it does . Probably something to do with the placement of the drivers and the PLD's.


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## Patrick Bateman (Sep 11, 2006)

A few comments:

It's true that u can manipulate soundstage height by using a tweeter with a high Xover point and locating it quite a distance from the mid. One thing that may surprise you is that you can get a wider soundstage by NARROWING the tweeters. It's completely counter intuitive. It's easy to try though. Check out my 'has anyone tried using one tweeter' thread.

A couple of other tricks are to pull the tweeter FORWARD to get a deeper stage, and also use an enclosure which reduces diffraction.

All three of these tricks exploit the fact that reflections create phantom imaging cues. So anything that you can do to reduce or delay those cues will make dramatic changes to your perception of the stage.

It's also a lot funner to do than screwing around with your EQ endlessly!

Ubiquitous plug: My new project uses the complete opposite approach, and is designed to approximate a point source for seven octaves. You can read about it on my forum.


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## The Baron Groog (Mar 15, 2010)

Pioneer just got back to me on their PRS tweeter, 900Hz Fs-lowest I've seen on a 28mm tweeter.


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## sqnut (Dec 24, 2009)

Not sure why anyone would want to xover slap bang in the vocal range. Unless they're running mids that are stronger in mid bass than the mid range. I'd just hate to split the vocals over 4 drivers, when I can do a much better job playing them off two.

Plus a high xover point on a shallow slope, will give you better height, depth and hence 'air'.


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## Spyke (Apr 20, 2012)

I know that this is an old thread but I think i'm finally done with my xo settings because of it. Here is what I came up with. IMO, I think that the only way that you could use a low xo (2k) is with a near perfect installation. That is, equal path lengths, close woofer/tweet spacing, and on axis with all drivers. In a typical installation where the woofer is off axis and usually on a different plane than the tweeter which is sometimes quite a distance from the woofer, I don't think a low xo is possible. I ended up with a mid lp of [email protected] and a tweet hp of [email protected] And yes I realize that my woofer can't "really" play that high, but this is where it's staying. I actually could have left the woofer crossed a little lower but I left it with a matching xo for 2 reasons. 1. To keep the xo point in phase(reversed) 2. It added a little more dynamics to the midrange. This is all just IMO with nothing to back it up but my ears.


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