# Who uses a Horn Subwoofer in their car? Chad, Patrick Bateman, and the PWK horn



## captainscarlett (Mar 15, 2011)

I just wanted to know who is using a horn or a tapped horn in their car. I guess I'm appealing to Patrick Bateman, who seems to be the most knowledgeable about this. Also Chad are you out there & Brian Steele?



chad said:


> If the mouth dimensions are smaller than they need to be to facilitate loading in its pass-band, these calculations are out there, you basically have a flared vent on a bandpass enclosure.
> 
> It can be HORN SHAPED, but this in no way means that it's going to act as a proper horn.





chad said:


> Welcome! Pro audio guy here too.
> 
> nope
> 
> ...


I hope I don't miss quote anyone, I get the impression the Patrick thinks it can work, Chad says that basically it doesn't, and I just want to get a better idea about this. 

Now I came across this PWK Horn design. Pete gave me some info to read about horns, but if I'm reading Patrick and Chad correctly, this isn't a horn .. or is it?

The new Digital Design SW 6.5 sub - YouTube



DD T/S specs suggests to me that the SW6.5 would be very suitable for a horn, however I do like going low, 30-32hz tune. How achievable is this given that (form what I understand)

1) with horns you nee to go big to be low
2) The SW6.5 FS is 59hz

Series SW6.5
Voice Coil Diameter 1.5"
Magnet Weight 80 oz
Power Handling RMS/Peak 250/600
Suspension Travel 30 mm
Nominal Impedance D4.0 Ohm
Model SW6.5
Rec Box (cubic ft) .4
Port Area (sq in) 7.5sq"
Port Length (inches) 17"
Cutout Diameter (inches) 5.63"
Mounting Depth (inches) 4.125"
FS 59.22Hz 
Qts 1.041
Qes 1.187
Qms 8.417
Vas 1.369L
Sensitivity 75.69dB
Shipping Weight 9lbs


----------



## thehatedguy (May 4, 2007)

It's not a horn.


----------



## nubz69 (Aug 27, 2005)

I ran a wicked one with 2 RF 8" DVC subwoofers. With a flea market amp I bought for $25 that was rated at 400watts peak I was hitting 135. With a true 800 wrms amp I was in the mid to low 140's. This was in the early 2000's so it was a little easier to hit those numbers. 

If you want to run a horn, go for it but you will lose all your storage space.


----------



## thehatedguy (May 4, 2007)

There is not enough air inside a car to properly load a horn.

Technically a tapped horn is not a real horn...neither is the Decware thing. 

And if you want a smaller horn, you need LARGE drivers. Smaller drivers/cone area makes for larger horns.


----------



## thehatedguy (May 4, 2007)

I mean that's a nice enclosure in the video, but with that amount of space a pair of 12s or 15s would fit in the same footprint...

And there isn't enough LSD on the planet to convince me that 1 6.5 in ANY enclosure would be louder, lower distortion, or have the bandwidth the pairs of larger speakers would have.


----------



## captainscarlett (Mar 15, 2011)

thehatedguy said:


> I mean that's a nice enclosure in the video, but with that amount of space a pair of 12s or 15s would fit in the same footprint...
> 
> And there isn't enough LSD on the planet to convince me that 1 6.5 in ANY enclosure would be louder, lower distortion, or have the bandwidth the pairs of larger speakers would have.


So ... is PWK the God of enclosure design then, or is he pulling the wool over people's eyes? If he's suggesting one thing and the 'Horn' Fraternity are all screaming "Its not a horn." "it doesn't work like that" etc, etc. 

in Pete's defense - it could be the matter of Pete's customer already having the 6.5, and this designs was what Pete felt was best for the customer given said customers requirements.


----------



## The Baron Groog (Mar 15, 2010)

I've briefly looked into PWKs designs, well contructed boxes-but I wouldn't describe many/any as "horns"-most seem to be a transmission line with a massive flared vent-however I'm in the process of building my 1st horn (well, still at the design stage) and have seen there is much variance in the discription of designs and will add that I am by no means an expert!

This is my 1st "design"-I literally worked out the space and then sketched it out, someone on another forum entered into hornresp for me (that programme confuddles the fook outa me) and modeled the response, came out surprisingly well considering I was just guessing. The diagram below shows the enclosure (not to scale and outer depth wrong). I was in Alpine UK's tech dept the other week and was discussing this design and various others-his opinion was that this was a flared transmission line and not a tapped horn:


----------



## SSSnake (Mar 8, 2007)

A couple of comments. 

A tapped horn is a Tom danley thing. And appears to be a blend of tline and horn. 

Cars are too small for standard horn designs and many of the benefits (namely more efficient coupling of the cone to the air) are already present due to the small air volume in our cars compared to rooms. 

Additionally I can't think of single gain that horns would provide over bandpass enclosures in an automotive env.


----------



## dragonxwas (Sep 21, 2011)

thehatedguy said:


> I mean that's a nice enclosure in the video, but with that amount of space a pair of 12s or 15s would fit in the same footprint...
> 
> And there isn't enough LSD on the planet to convince me that 1 6.5 in ANY enclosure would be louder, lower distortion, or have the bandwidth the pairs of larger speakers would have.


I guess in pwk designs he is just using cabin gain+ bandwith limiting to get more response out of that small box..


----------



## The Baron Groog (Mar 15, 2010)

SSSnake said:


> A couple of comments.
> 
> A tapped horn is a Tom danley thing. And appears to be a blend of tline and horn.


The classifcation of these types of designs is one of the many things I'm yet to get my head round-hornresp will probably take longer though!



SSSnake said:


> Cars are too small for standard horn designs and many of the benefits (namely more efficient coupling of the cone to the air) are already present due to the small air volume in our cars compared to rooms.


I'd presume you're not including "conventional horns" as those done by ID! PB has used horns in his car-if he chirps contra to that statement I'd be inclined to believe him. If a tapped horn is a cross between a T-line and a horn surely T-lines wouldn't really work in car? As far as I know a horn is just an "air" pump.



SSSnake said:


> Additionally I can't think of single gain that horns would provide over bandpass enclosures in an automotive env.


IIRC reduced xmax and therefore increased power handling-to the thermal limit anyway. To that matter I have also seen horns being refered to as a bandpass design. Also look at what the SPL guys are doing-a lot of installs look like Danley's Matterhorn but scaled down to fit in a vehicle.


----------



## thehatedguy (May 4, 2007)

I would really suggest you guys get on a home forum like DIY Audio and learn more about tapped horns.

But what SSSnake said about not being enough air in the car is true for a real horn. A real horn is an impedance transformer. And there simply isn't enough air in a car to load the throat of a real horn.

But tapped horns are not real horns...do some reading and researching and you will discover why.


----------



## The Baron Groog (Mar 15, 2010)

thehatedguy said:


> I would really suggest you guys get on a home forum like DIY Audio and learn more about tapped horns.
> 
> But what SSSnake said about not being enough air in the car is true for a real horn. A real horn is an impedance transformer. And there simply isn't enough air in a car to load the throat of a real horn.
> 
> But tapped horns are not real horns...do some reading and researching and you will discover why.


I'm on it already, reading all I can-however its very hard finding any definitive guide to what seperates one type of design from another!

Please explain how there's not enough air in a car to load the throat of a real horn-surely it's easier in car as there's no where for the air to go?


----------



## chad (Jun 30, 2005)

thehatedguy said:


> I would really suggest you guys get on a home forum like DIY Audio and learn more about tapped horns.
> 
> But what SSSnake said about not being enough air in the car is true for a real horn. A real horn is an impedance transformer. And there simply isn't enough air in a car to load the throat of a real horn.
> 
> But tapped horns are not real horns...do some reading and researching and you will discover why.


That pretty much sums it up.


----------



## thehatedguy (May 4, 2007)

The volume of air inside a car or a van isn't enough to load the throat of a horn.

There used to be a guy back in the day in the UK on some of the forums who went by the name Firestarter. He had a red VW van. At first he was messing around with scoop style horns for a pair of Stroker 15s. These enclosures were placed at the very back of the van to give them as much air volume as possible...still wasn't enough air volume in the car to load the throats. He went to a ported design and his scores jumped up pretty good over the on paper much more efficient horns.

Richard Clark has said the same thing about bass horns in a car on the Carsound forums back in the day too.


----------



## chad (Jun 30, 2005)

As said before, horns work by generating a high pressure in the throat and coupling it to a low pressure at the mouth, the cuttoff point on the horn is directly correlated to the mouth or the coupling of the existing mouth to a structure (like a Klipshorn.)

As the environment goes from modal to pressure the increase in environmental pressure at the mouth causes the high to low pressure ratio of the device to lower, as this ratio goes down it acts less and less like a horn, at a 1:1 ratio it's basically a woofer in a tiny-ass enclosure.

As quoted by me, and said by THG, it's an acoustic "lever" or an acoustic transformer, nothing more. Well, with the exception to be able to control directivity above the mouth cutoff, which is not happening in a car.


----------



## captainscarlett (Mar 15, 2011)

So is PWK and Bill Fitzmaurice telling us porkies?

This is what Pete told me. I don't want to get in trouble by cross linking to another forum, so here's a picture:blush:










Pete's design to me ... as a no knowing newbie, looks to be a tapped horn with one extra bend, to the normal horns I've seen. The enclosure itself is still big, but it must have some advantage somewhere. Or do we throw our hands in the air and scream: forget horns, or T-lines, lets just stick to sealed and ported for ever more.... maybe an occasional IB or iso now and again (sorry everyone its been a long day). 

However isn't efficiency with low power an advantage of such enclosures. Isn't that what Patrick was getting at, or have i read wrong?



The Baron Groog said:


> I'm on it already, reading all I can-however its very hard finding any definitive guide to what seperates one type of design from another!


Agreed! I saw one site when there explanation of the difference between a ported and T-line enclosure was wadding ... wadding. Not the 1/4 theory or anything but simply ... wadding! That's not what I've read!


----------



## chad (Jun 30, 2005)

captainscarlett said:


> So is PWK and Bill Fitzmaurice telling us porkies?


Just because you are famous on the internet does not mean that you understand how horns work.


FWIW I don't have many trophies, more in Pinewood Derby than car audio. But then again I don't make my living in Pinewood Derby, or car audio


----------



## captainscarlett (Mar 15, 2011)

chad said:


> Just because you are famous on the internet does not mean that you understand how horns work.


In comparison to most of you guys I know very little. OK .. I built my first T-line speakers for my Technics tape deck and Yamaha amp 20 years ago. 

As most of you might know I run fakeheadphones.com I got into car audio working for Dominos Pizza whilst i was at uni studying Drawing and Image making (Art). £65 Sony stereo and a pair of 10watt 4" Toyota Starlet speakers. Then got bitten by the bug. 

However it seems the more I learn the more I realise I don't understand. So here goes for the next question. For a simpleton like me, please explain what you mean by 'Loading'? I'm the kind of person that asks if I don't know. I'd rather be laughed at, than live in ignorance. 

When you say there's not enough air to 'load' the throat, what does that mean ... there's not enough air pressure or resistance???


----------



## chad (Jun 30, 2005)

I wish I was not in the middle of a big project that I have to concentrate on.

horns work by having a high pressure in the throat an a low pressure outside, everything takes the path of least resistance.... and this is a VERY simple explanation.


In free-space or on a big flare the atmospheric resistance is very low compared to the pressure in the throat. In a car, because it's closed, the cabin pressure increases, it's no longer modal, it's pressure related, you are simply adding pressure to the cabin below a certain frequency... This is either the most kickass thing ever or the biggest pain in the ass, depending how you look at it.

Problem with horns, and even vented enclosures at high SPL, which PWK designs around in his vented designs is that as the pressure increases, things change. That's the challenge, the FR of the venting will change, and with a horn, as the atmospheric pressure changes, the higher it goes, the less it acts as a horn because the pressure does not allow it to work as a horn anymore. the mouth pressure begins to equal the throat pressure. Not only that, the mouth dictates cutoff frequency and a horn that plays flat to even 40 cycles is HUGE, bigger than a standard vehicle can take. Even in free space.


----------



## thehatedguy (May 4, 2007)

I am going to attach some pictures of a conical front horn that I built for an old home stereo of mine.

Things to consider- a conical does not effectively load to the lower Fc of the horn. An exponential does a much better job at doing that, but is much more complex to build. Yes, I could have made a 2 or 3 step approximation to fit the exponential flare...but very little would have been gained other than making it much more complex to build.

This particular horn was a 3/16th sized horn meant for boundary reinforcement from 2 corners. This was as about as small as you would want to go with a real horn. You can do an 1/8th sized throat if you have them pushed into 2 corners like a Klipsch corner horn.

This horn was a midbass horn. It's Fc was 78-80 hertz.

It used a 15 in each horn.

Remember for a front horn, the larger the speaker the shorter the horn can become. And the closer you get to boundaries, the small you CAN make the horn, but bigger is better.


----------



## thehatedguy (May 4, 2007)

And if you look at Pete's rear horn designs, the mouth is really really small compared to what you would find in the home. He can get away with a smaller mouth due to boundary enforcement, but combined with the length of the throat and size of the mouth...one wonders how effect the "horn" is and rather if it is acting merely as a flared port.

And if you read between the lines with the size and length of the flare controlling the amount of loading, you could say that he is using the trunk or wherever the enclosure is placed as an extension of the horn. And this could be true to a degree given the lengths of the waves we are talking about, your flare wouldn't have to be super critical in shape. But also remember how long the waves are and if they would physically fit INSIDE the cabin of the car.


----------



## chad (Jun 30, 2005)

thehatedguy said:


> I am going to attach some pictures of a conical front horn that I built for an old home stereo of mine.
> 
> 
> This horn was a midbass horn. It's Fc was 78-80 hertz.
> ...


And that is a tiny ass horn for not being folded.


Just sayin.

but I bet it romps from about 160-800


----------



## thehatedguy (May 4, 2007)

2005 CES Coverage - Event Reports - Dagogo

Go about half way down the page for the physical dimensions of the Edgarhorn horn sub with an 18 in it...and it even needs some EQ help to get past 25 hertz.

Listen all of the horn math that we use was primarily derived from the late great Dr. Marshall Leach...that was published in JAES. And you hear some unknown (really in the grand scheme of things) car box builder talking about all of this "old" math not working and he has some sort of "new" math...well, is just a bit more than absurd. Obviously if there was some sort of "new" math going on out there, it wouldn't be coming from some 30 year old internet sensation...and it would be a great topic to be presented at ALMA and JAES. But it hasn't been yet. Reason for that? 

http://users.ece.gatech.edu/~mleach/papers/HornPaper/HornPaper.pdf

W. Marshall Leach, Jr.


----------



## captainscarlett (Mar 15, 2011)

chad said:


> I wish I was not in the middle of a big project that I have to concentrate on.
> 
> horns work by having a high pressure in the throat an a low pressure outside, everything takes the path of least resistance.... and this is a VERY simple explanation.
> 
> ...



Thanks for the explanation. sometimes i get the gist of what people are talking about, however you guys always speak in (what I consider) more technical terms and so i just need to know that we're singing from the same song sheet.

And what about Bill Fitzmaurice's Autotuba, is that not effective either? 

And what about the 'efficiency' argument? people are still claiming big figure for low wattage.


----------



## thehatedguy (May 4, 2007)

Back in the 90s I was all about some exotic enclosures to get the most bass out of small speakers- iso 6th order bandpasses and dual reflex ported enclosures. But today I would rather keep it simple and uncomplicated because bass in a car doesn't have to be complicated...it is really easy to do. I am not down on squeezing the most out of some small speakers, go for it especially if you already have the speakers, have the space, and have the ability to design and fabricate these enclosures.


----------



## Patrick Bateman (Sep 11, 2006)

captainscarlett said:


> I just wanted to know who is using a horn or a tapped horn in their car. I guess I'm appealing to Patrick Bateman, who seems to be the most knowledgeable about this. Also Chad are you out there & Brian Steele?


I'd love to type up a huge post on this, because there's a lot of misinformation out there about horns. Unfortunately to do it justice would take three or four hours and a lot of sims in hornresp. If you have a weekend to spare, take a few hours to get a feel for hornresp and it will really make it easier to understand the various enclosure types.

First off, go watch this video:
Making standing waves - YouTube

The video illustrates how standing waves work. *It's a lot easier to understand horns once you watch the video.*

OK, now that you've watched the video, *lets talk horns.* In audio, there are only two enclosure types. Sealed and vented. While people talk about transmission lines and tapped horns and passive radiator boxes, *they all boil down to two types in the end.*









Let's start with sealed. You basically take a woofer and seal off the basket, so that the rear wave is isolated from the front wave. (If you didn't do this, they'd null each other out below a certain frequency.)









If you put a coupling chamber in front of the woofer, the port acts as a helmholtz resonator at a specific frequency. Due to the fact that the port is tuned at a specific frequency, you'll see the output roll off on either side of the frequency. That's why it's called a bandpass box. There's one critical feature though - *there are also standing waves in both the front chamber AND the port.* This is really important for our next enclosure type...









A front loaded horn and a single reflex bandpass are the same thing. This is really important to 'grok' to understand PWK's designs. 









Both a front loaded horn and a bandpass box have a quarter wave resonance in the chamber and in the port, *the only difference is the frequency.* For instance, if you have a bandpass box with a 12" port, you'll get a QWR (quarter wave resonance) at 281hz. (speed of sound / 12 " / 4)









At this point, you're probably wondering "if a horn and a bandpass box are the same thing, why is a horn shaped like that?" That's because a horn is designed to resonate over a specific bandwidth. We're not just amplifying a single frequency, we're amplifying a series of frequencies. In the pic above, we're exciting just TWO frequencies. One is due to the length of the pipe, and the other is due to the width of the pipe. Horns resonate over a series of frequencies, not just two.

If all of that makes sense, we can get to your question:

*Why use a horn sub in the car?*
The upside of using a horn is a massive efficiency gain. Standing waves are powerful - check out my site for a video of standing waves tearing concrete and steel.* The downside - the size gets ridiculous. Forty hertz is twenty eight feet long, so you need a seven foot long horn to do forty hertz.









Which brings us to the main reason NOT to use a horn in the car. The damn car makes a fine quarter wave resonator.

Does that make sense? The dimensions of the cabin itself is horn loading our drivers. (Not just subs - every driver.)

For instance, take a look at JBL's measurements of various cars. See how the Mini Cooper has seven dB more cabin gain than a Honda Accord at 100hertz? That's a huge bump, and it's due to standing waves. *The shorter length of the Mini Cooper cabin is moving the standing wave up in frequency.*

My Honda Accord has a cabin that's 110" long, 43" tall, and 55" wide. That works out to standing waves at 30.7hz, 78.5hz and 61.4hz.

Do you see the correlation in Andy's graphs? See how the cabin gain peaks at those frequencies for the Accord?

*When it's all said and done, if efficiency is your goal, you're probably better off using the whole damned car as a quarter wave resonator than building a horn.*

Just ask Sundown:

One Sundown SA-8 : 149.9 dB - YouTube

This creates a little problem though. It means that you'll probably have to go out and buy a Mini Cooper or a Honda CRX if you want to hit big numbers. Or build a wall in your car. (I'm not sure if it was by accident or design, but walling off your vehicle will change the standing wave frequencies, to great effect.)

Subwoofer location will dramatically alter standing waves. For instance, if I located a subwoofer near the B-Pillar in my car, I would have an astonishing amount of bass, because I would excite the 61.4hz frequency THREE times. First the sound from the subwoofer would be excited by the width of the car (55"), and then also due to the distance from the midpoint of the car to the front of the car (55") and to the back of the car (55") Then again, I have no idea how to mount a subwoofer in my B Pillar. But you get the idea right? *This is the reason that Sundown gets big numbers when they put their subs in the center of the car, instead of the back.* Location matters.

Obviously I have a lot of respect for the SPL guys, some of them really know what they're doing.

So why do I run horn subs?

Because vented boxes sound horrible. The rear wave is 180 degrees out of sync. For instance, with a 40hz tuning, the rear wave is 12.5 milliseconds out-of-sync with the front wave. That's a long time!

Now there's a way to fix this - which is the reason I don't have time to do four hours of sims to better illustrate this post. Keep an eye on my forum and I'll be publishing a way to move your port so that the rear wave and the front wave are in-sync. (Basically making a vented box sound like a sealed box, but with more bandwidth and higher power handling.)

Keep in mind that everyone has different priorities. For instance, I'm really sensitive to timing problems. I can perceive timing problem on the order of a few milliseconds. (For instance, have you ever talked on a VOIP phone and noticed that the sound is out-of-sync? That type of stuff makes me nuts.) Getting the timing right is very important to me, and the timing of most vented subs is just awful on the low end. Like when i hear the subs at IMAX theaters, it just makes me want to run out of the theater screaming.

Go get a copy of Hornresp and play around with this stuff. Take a look at the group delay curve. You'll notice that the back-loaded horns that PWK is selling have half the group delay of a vented box. So even though they're "SPL boxes", I'd bet they sound more natural than a typical vented box, due to the reduction in group delay. Tapped horns work the same way. The advantage of a tapped horn is a smaller footprint and they're pretty idiot-proof to build. The reduction in group delay is because the rear wave is only 90 degrees out-of-phase, instead of 180.

Keep in mind for sheer output, it's all about displacement. If you're goal is SPL, you're going to get better numbers using a lot of power and a lot of displacement. (IE, lots of woofers, lots of power.) Some of my older posts don't reflect this view, and I changed my mind once I realized that the car cabin could be used to horn load a plain ol' sealed or vented box. (As long as you locate the box to excite the natural standing waves of the cabin.)

* Audio Psychosis • View topic - How to Build a Bass Weapon


----------



## johnvroom (May 5, 2009)

Well I dont think I have heard a convincing argument for a horn loaded bass in the car yet. a fun experiment perhaps, but how can it make my life better (in two or three sentences not the multi page rant please)


----------



## Patrick Bateman (Sep 11, 2006)

johnvroom said:


> Well I dont think I have heard a convincing argument for a horn loaded bass in the car yet. a fun experiment perhaps, but how can it make my life better (in two or three sentences not the multi page rant please)


Quarter wave resonators have half the group delay of a vented box. If you're senstive to timing problems like I am, you'll probably prefer the sound of a QWR. Go grab a copy of hornresp and take a look at the group delay curves.

You're never going to fit a 'real' horn in a car, so I use the term QWR to talk about any box that gets it's efficiency from a quarter wave resonance. This includes front loaded horns, tapped horns, transmission lines, back loaded horns, etc...


----------



## captainscarlett (Mar 15, 2011)

Patrick, Thanks for laying this out in a way a simpleton like me can understand and hopefully I do understand a little more. 



Patrick Bateman said:


> First off, go watch this video:
> Making standing waves - YouTube




As a Former life guard at Lusty Glaze Beach Newquay, Cornwall, that's the freakiest thing I've ever seen. 



Patrick Bateman said:


> For instance, if you have a bandpass box with a 12" port, you'll get a QWR (quarter wave resonance) at 281hz. (speed of sound / 12 " / 4)




I see for that equation (if that's the right word for it) you use the speaker cone size to work out the 1/4 R.F. I understand the the 1/4 theory for box building: speed of sound / FS / 4 .... i hope!



Patrick Bateman said:


> Does that make sense? The dimensions of the cabin itself is horn loading our drivers. (Not just subs - every driver.)




So the Car is part of the enclosure/horn so to speak, and so the enclosure is redundant?


For quick route to SQ it's Horns and T-Lines then.


So do you think PWK's horn could hit low? 
http://www.youtube.com/watch?v=38Ya9bH2UZI


----------



## Patrick Bateman (Sep 11, 2006)

captainscarlett said:


> Patrick, Thanks for laying this out in a way a simpleton like me can understand and hopefully I do understand a little more.


thanks!



captainscarlett said:


> As a Former life guard at Lusty Glaze Beach Newquay, Cornwall, that's the freakiest thing I've ever seen.


yep, same idea. If you can get two waves to line up in sync, you get twice the output. The key is that the two waves *must be in sync.* So timing is critical.



captainscarlett said:


> I see for that equation (if that's the right word for it) you use the speaker cone size to work out the 1/4 R.F. I understand the the 1/4 theory for box building: speed of sound / FS / 4 .... i hope!


The cone size doesn't apply to this equation. All that matters is the dimensions of the duct. And, yes, it's _speed of sound / dimensions of duct / 4_. So for a port that's 12" long with a diameter of 3", you'll get a standing wave at 281hz due to the length and 1125hz due to the width. Note that the duct has three resonances. One due to the helmholtz resonance, and two due to standing waves.



captainscarlett said:


> So the Car is part of the enclosure/horn so to speak, and so the enclosure is redundant?


IMHO, yes, the dimensions of the cabin have a significant effect. Most of the articles about cabin gain focus on how cabin gain raises efficiency at low frequency. But IMHO, a big parts of cabin gain is due to four standing waves. There's one due to the width of the cabin, one due to the height, one due to the length, and there's a standing wave null around 60hz.

You can use these to good effect by playing around with various sub locations, particulary if you put the sub near the middle of the car, like Sundown does.



captainscarlett said:


> For quick route to SQ it's Horns and T-Lines then.


I think group delay is a pretty big deal. It's pretty easy to have low group delay with a sealed box. *If you know what you're doing* you can get low group delay with front loaded horns and dual-reflex bandpass boxes. Tapped horns have pretty low group delay too and I think that's part of the reason that people think they sound great. Vented boxes have terrible group delay, but you can fix this if you put the port waaaaaaay in front of the woofer... We're talking a LOT, a few feet at least. In a vented box you don't want the port anywhere close to the woofer, unless the port is extremely long.

Without a doubt, the best way to figure out the proper enclosure is to spend some time with hornresp




captainscarlett said:


> So do you think PWK's horn could hit low?
> The new Digital Design SW 6.5 sub - YouTube


[/quote]

No, horns excel at raising efficiency. If low bass is your goal, nothing beats a sealed box. The only good reason to explore all the exotic boxes (vented, tapped horn, FLH, bandpass, etc) is because you want more efficiency or lower distortion. All of those alignments are going to require more space than a plain ol' sealed box.


----------



## Patrick Bateman (Sep 11, 2006)

The Baron Groog said:


> I've briefly looked into PWKs designs, well contructed boxes-but I wouldn't describe many/any as "horns"-most seem to be a transmission line with a massive flared vent-however I'm in the process of building my 1st horn (well, still at the design stage) and have seen there is much variance in the discription of designs and will add that I am by no means an expert!
> 
> This is my 1st "design"-I literally worked out the space and then sketched it out, someone on another forum entered into hornresp for me (that programme confuddles the fook outa me) and modeled the response, came out surprisingly well considering I was just guessing. The diagram below shows the enclosure (not to scale and outer depth wrong). I was in Alpine UK's tech dept the other week and was discussing this design and various others-his opinion was that this was a flared transmission line and not a tapped horn:


Hey I recognize that box 










Audio Psychosis • View topic - Bandpass Horns

Bring a big amp - it's designed to soak up a few thousand watts!


----------



## Brian Steele (Jun 1, 2007)

The problem for me with the higher-order alignments like t-lines, THs and the like is that, while they may result in the most efficient use of a particular driver, they are not the most efficient use of the volume that the boxes tend to occupy, and the latter IMO is usually more important for car audio stuff. That said, I've had a number of requests for TH and Tline designs for car audio, so I'm busy looking at a number of different options.


----------



## The Baron Groog (Mar 15, 2010)

Patrick Bateman said:


> Hey I recognize that box
> 
> 
> 
> ...


Ah, uncanny resemblence to yours-did you ever build that? I'll have to have another look at my design-drop the throat volume down and increase the mouth


----------



## Thoraudio (Aug 9, 2005)

thehatedguy said:


> The volume of air inside a car or a van isn't enough to load the throat of a horn.
> 
> There used to be a guy back in the day in the UK on some of the forums who went by the name Firestarter. He had a red VW van. At first he was messing around with scoop style horns for a pair of Stroker 15s. These enclosures were placed at the very back of the van to give them as much air volume as possible...still wasn't enough air volume in the car to load the throats. He went to a ported design and his scores jumped up pretty good over the on paper much more efficient horns.
> 
> Richard Clark has said the same thing about bass horns in a car on the Carsound forums back in the day too.


Was this the day hell froze over?


----------



## Patrick Bateman (Sep 11, 2006)

thehatedguy said:


> The volume of air inside a car or a van isn't enough to load the throat of a horn.
> 
> There used to be a guy back in the day in the UK on some of the forums who went by the name Firestarter. He had a red VW van. At first he was messing around with scoop style horns for a pair of Stroker 15s. These enclosures were placed at the very back of the van to give them as much air volume as possible...still wasn't enough air volume in the car to load the throats. He went to a ported design and his scores jumped up pretty good over the on paper much more efficient horns.
> 
> Richard Clark has said the same thing about bass horns in a car on the Carsound forums back in the day too.


If there wasn't enough air in the car to load the throats, we wouldn't see an efficiency gain. But we DO see an efficiency gain.

*So I think there is something else going on here.*

(Note that I don't disagree with you on the larger point)

The interior of a car has predictable resonances. The reason that his SPL scores went up with a ported box *was not because horn loading doesn't work.* His SPL scores went up because the ported box plays lower than the horn, *and by playing lower he could excite the resonances of the van.*

I hope that makes sense. His horn loaded scoops were probably good to sixty hertz, maybe fifty. Those Cerwin Vega scoops just don't go low - they're designed for SPL, not low bass. But in the car you MUST go low, because that's the only way you'll excite the quarter wave resonances of the car. (Unless you wall off the car, or drive a CRX or a pickup truck.) For instance, if the scoop started to roll off at 60hz, it would be 12dB down at 40hz, right where cabin gain is giving us a "free" 12dB or so. But swapping in a ported box, that's flat to 40hz, would raise his scores immediately. Another problem with scoops is that they are nothing more than sealed boxes below the horn cutoff. So all of his horn gain is likely in the range where he DOESN'T need it - from sixty hertz on up.

That's the key here - if you want to get big SPL numbers, you need to look at the cabin as part of the enclosure. PWK says this too.


























You may have seen some of these horns I've built, using laughably small drivers. We're talking $10 woofers that belong in computer speakers, not in an SPL competition.

The thing is, you *can get real horn loading in the car.* But horn loading is semi pointless below 100hz, *because the car itself is basically horn-loading below that frequency.*

But above 100hz, it's not difficult to get three to six dB of gain in a horn, and that kind of gain is enough to make a 2" computer as loud as a 6.5" midbass. A side bonus is horizontal radiation control.

The big downside is computer speakers can't take much power. I'm currently working on a way to use compression drivers in vented, tapped horn and rear loaded horn enclosures. That should make a beefy substitute to computer speakers, while retaining the small diaphragm that's important for directivity control. (Also, if anyone feels like doing this at home, DO NOT use large speakers. Group delay goes to hell. You MUST use small drivers if you want to keep the mouth small. That's why guys like Clark and Eldridge used such enormous horns. Big drivers need big mouths. You can only reduce mouth size if you reduce driver size, unless you want it to sound like crap.)

More pics here:

Audio Psychosis • View topic - Simulating a B&C DE25


----------



## Patrick Bateman (Sep 11, 2006)

The Baron Groog said:


> Ah, uncanny resemblence to yours-did you ever build that? I'll have to have another look at my design-drop the throat volume down and increase the mouth


It's half built in my garage.

I've run a few tapped horns, but none of them went particularly low. For instance, the one I like the best is only good to 40hz. (The TH-Mini clone that's documented on here.)

Once I started making tapped horns that were good to ten and twenty hertz, *flex became a huge problem.*

It's a real p.i.t.a. - these are monstrously braced boxes, and they STILL flex. It's just the frequencies we're dealing with. It takes a crap ton of power to produce ten hertz with any kind of authority, and that makes the box flex.

So that leaves us three options:

#1 - more braces? I tried that and I am reaching my limit. I'm really sick of adding braces. And the box is getting heavier and heavier and heavier.
#2 - Thicker lumber? I really like using 1/2" plywood. 3/4" plywood gets insanely heavy, and I wouldn't even consider MDF
#3 - Composites? This is where I am leaning. A composite of aluminum and fiberglass is stronger than steel, with weight like aluminum. But bamboo is even more promising I think, because you can orient the bamboo fibers so that you get maximum strength and minimum weight. And then add some layers of fiberglass to form the composite.

Side benefit of composites is that they look way cool.

Bamboo plywood is something like $200 a sheet, but you can screw around with this stuff by buying bamboo cutting boards, or even complete bamboo boxes.

Be careful cutting it though - I already ruined my table saw. Bamboo is tough as nails. Don't hurt yourself.


----------



## thehatedguy (May 4, 2007)

That might be the case with the SPL guy, but they were at the time playing the van around 70 hertz...or higher.

There are and have been very few SPL guys playing anything below 50 to get metered on. The car interior is less likely to leak down as you increase the frequency- like an air compressor.


----------



## captainscarlett (Mar 15, 2011)

(without opening many tags and PDF files) remind me, can a horn play down to 40hz ...even 30hz and still fit in my boot? I guess I need to ask Pete about the DD6.5 on youtube.


----------



## thehatedguy (May 4, 2007)

Not a chance in hell that it would do 30 with any balls...and 40 would be pushing it.


----------



## SSSnake (Mar 8, 2007)

> you can get low group delay with front loaded horns and dual-reflex bandpass boxes.


Which is why I wonder why more people aren't using them...


----------



## thehatedguy (May 4, 2007)

Space. Complexity to build. Better performance with something simpler to build.


----------



## chad (Jun 30, 2005)

SSSnake said:


> Which is why I wonder why more people aren't using them...





thehatedguy said:


> Space. Complexity to build. Better performance with something simpler to build.


As for dual reflex BP, complexity and they got a bad rap because everyone has heard a really ****ty one.

Like that one time in Tijuana, I still can't look a Donkey in the eye.


----------



## captainscarlett (Mar 15, 2011)

thehatedguy said:


> Space. Complexity to build. Better performance with something simpler to build.


You're right, however I think the world would be a more boring place without such hair-brain schemes. But like i said before and as Patrick says about phase, there must be some advantage somewhere!


----------



## chad (Jun 30, 2005)

some are not as sensitive to phase response as long as the passband is not meeting up with another driver. Like the phase response of a sub getting wacky down low... It's pretty much inherent the second you put a sub in a car anyway.


----------



## thehatedguy (May 4, 2007)

Don't let me dissuade you if you want to build one.

10 or 15 years a go I would be all about something like this for the car. Just now the novelty of it doesn't out weigh other options...for my own personal use. When I was working retail and someone wanted something like this I would be all about it.


----------



## Patrick Bateman (Sep 11, 2006)

SSSnake said:


> Which is why I wonder why more people aren't using them...


Geddes is a big fan of single reflex bandpass. In the 90s, I tried building some of the Bose-style dual reflex bandpass boxes, and my results were just terrible. Boomy and weird sounding.

On my forum, a member asked about one of these, and I modeled it. Much to my shock, *they can perform really well!*










I'm still trying to figure out the SM60-F speaker, but *I think that's the secret sauce.*

In a badly designed dual reflex, you get this massive disconnect between the front and the back wave. The Boss Wave Cannons were infamous for this.

But if you juggles the variables, *you can delay the front wave* so that it flattens out the group delay and the phase.

The phase plot on the SM60f is just crazy - it's flatter than a single woofer in a sealed box(!)

This despite having two woofers, one midrange, one tweeter, and twelve ports(!!!)

The design is waaaaaaay beyond my capabilities, but I think the 'secret sauce' could be used with anything. A sub, a midrange, possibly even a tweeter.

More ramblings on this here:

Audio Psychosis • View topic - Under Dash Horn Alternative

I'm basically trying to apply the synergy horn concepts to a plain ol' underdash horn, with just one woofer.


----------



## thehatedguy (May 4, 2007)

Danley is a mad man for sure.

I want Unity/Synergy horns as my next home system.


----------



## chad (Jun 30, 2005)

Patrick Bateman said:


> Geddes is a big fan of single reflex bandpass. In the 90s, I tried building some of the Bose-style dual reflex bandpass boxes, and my results were just terrible. Boomy and weird sounding.




Before I decided to go IB for my shop subs I had grand plans of a single reflex BP using peerless XXLS12's and a pair of large passive radiators. I have to say,it looked fantastic on paper and went really low, albeit huge.


----------



## captainscarlett (Mar 15, 2011)

thehatedguy said:


> Don't let me dissuade you if you want to build one.
> 
> 10 or 15 years a go I would be all about something like this for the car. Just now the novelty of it doesn't out weigh other options...for my own personal use. When I was working retail and someone wanted something like this I would be all about it.


Few people build them but i'm sure people would be interested in hearing one. I am! I'm sure there are better options though!


----------



## Patrick Bateman (Sep 11, 2006)

chad said:


> Before I decided to go IB for my shop subs I had grand plans of a single reflex BP using peerless XXLS12's and a pair of large passive radiators. I have to say,it looked fantastic on paper and went really low, albeit huge.


Too bad hornresp can't do passive radiators. One of the 'tricks' with the synergy horns seems to be delaying the front wave so that it's in phase with the rear wave. And the use of a passive radiator for the front of the box, and a port for the back, might accomplish this. (Since the port introduces a delay, due to the the distance traveled through the port, but the passive radiator does not.)

We could also do some bizarre things with these designs, such as putting the woofer in the trunk and the port up front, and then getting them to sum in phase at the driver's seat. (Since the port introduces a delay, you want it closer to you.)

Then again, I'm probably making things WAY more complicated than necessary 

Fast forward to 3:00, and you'll get the general idea of how most of my projects go:

The Young Ones - Summer Holiday - Part 1 - YouTube


----------



## BlackFx4InTn (Apr 11, 2009)

Patrick Bateman said:


> For instance, take a look at JBL's measurements of various cars.


Does JBL have a site I can go to, to see various measurements, in particular my car, an 08 G35 Sedan?


----------



## Patrick Bateman (Sep 11, 2006)

BlackFx4InTn said:


> Does JBL have a site I can go to, to see various measurements, in particular my car, an 08 G35 Sedan?


Not that I'm aware of. I took it from JBL's global product line manager, Andy Wehmeyer.

The data in there will be fairly accurate as long as your car is similar in dimension. (IE, just use whatever car is close.)

Note that woofer location will make a dramatic difference. Heck, when it comes to standing waves, EVERYTHING makes a dramatic difference. Woofer location, microphone location, your height, etc.

For my car I built a strange looking contraption which allows me to measure SPL at eight different locations.

Geddes published some papers on this at the AES, back when he was doing car audio for Ford.


----------



## The Baron Groog (Mar 15, 2010)

Patrick Bateman said:


> It's half built in my garage.




Like all great inventions, they lie unfinished for decades-Babbage springs to mind



Patrick Bateman said:


> I've run a few tapped horns, but none of them went particularly low. For instance, the one I like the best is only good to 40hz. (The TH-Mini clone that's documented on here.)




Oddly mine seemed to gravitate to 40Hz-though with my limited skill on hornresp I haven't played with it much and the space I have can't be increased so probably as low as I'll get-will be fine for the app anyway



Patrick Bateman said:


> Once I started making tapped horns that were good to ten and twenty hertz, *flex became a huge problem.*
> 
> It's a real p.i.t.a. - these are monstrously braced boxes, and they STILL flex. It's just the frequencies we're dealing with. It takes a crap ton of power to produce ten hertz with any kind of authority, and that makes the box flex.
> 
> ...


Why no consideration for MDF? More flex? On diyaudio there's a guy who's made a box out of corian-would post a link but the site is down for maintainence-looks like pretty good material to work with if a little heavy!

What about external bracing a-la Lloyds Building?

At $200 a sheet bamboo ply is out for me-though it is an interesting looking material. While on AudioPsychosis I did have a look at your bike threads-I always wanted to make a bike from bamboo


----------



## Patrick Bateman (Sep 11, 2006)

The Baron Groog said:


> Like all great inventions, they lie unfinished for decades-Babbage springs to mind


Yeah too many ideas, not enough time to implement them



The Baron Groog said:


> Oddly mine seemed to gravitate to 40Hz-though with my limited skill on hornresp I haven't played with it much and the space I have can't be increased so probably as low as I'll get-will be fine for the app anyway


One great thing about horns is that they're less "picky" about what goes in them than a vented box is. The other day I was doing some sims for my new underdash horns, and found that two drivers yielded a response curve that was within 2dB in the pass band, even though one driver had double the cone area, and was more efficient! (IE, I was able to get real efficiency out of a tiny little 2" woofer - the Peerless 830970.)

So if you want good results - you might consider stealing an existing design. I've been screwing around with loudspeaker simulators for twenty years, and my best sub to date is still one that I cloned. There are a lot of designs that 'look good on paper' but don't work in the real world. What you want to find is one that works good in the real world, use it, or maybe tweak it a little bit. Kind of like the thing I did with the Insubnia.*



The Baron Groog said:


> Why no consideration for MDF? More flex? On diyaudio there's a guy who's made a box out of corian-would post a link but the site is down for maintainence-looks like pretty good material to work with if a little heavy!


Ever tried to break a board along the grain? Even a 1" thick piece of pine will split along the grain easily, but against the grain you need much MUCH more force. That's how I can get away with using 1/2" plywood for most of my subs. (Admittedly, for the ten hertz sub I should've used something beefier.)

All of these aerospace composites work along the same lines, but with carbon fiber or fiberglass "grains." The chopsticks thing works the same way, but with a wood that's ubiquitous, cheap, and easy to work with. (I use a bolt cutter, not a saw. It's easy to hurt yourself using power tools and bamboo, the stuff is too tough.)



The Baron Groog said:


> What about external bracing a-la Lloyds Building?
> 
> At $200 a sheet bamboo ply is out for me-though it is an interesting looking material. While on AudioPsychosis I did have a look at your bike threads-I always wanted to make a bike from bamboo


Yeah the bamboo plywoods are a little ridiculous right now. Seems to be a big markup on them. I crunched the numbers on what chopsticks cost, per square foot, and it was comparable to plain ol' plywood. But if my neighbors see me assembling a 4x8' sheet of chopsticks, they're probably going to have me institutionalized :O

* Audio Psychosis • View topic - Cheap and Different Sub


----------



## The Baron Groog (Mar 15, 2010)

Patrick Bateman said:


> Yeah too many ideas, not enough time to implement them




Know that feeling, rainy Birtish weather, 1 day off a week and a lack of any form of workshop leaves me in the same situation



Patrick Bateman said:


> One great thing about horns is that they're less "picky" about what goes in them than a vented box is. The other day I was doing some sims for my new underdash horns, and found that two drivers yielded a response curve that was within 2dB in the pass band, even though one driver had double the cone area, and was more efficient! (IE, I was able to get real efficiency out of a tiny little 2" woofer - the Peerless 830970.)
> 
> So if you want good results - you might consider stealing an existing design. I've been screwing around with loudspeaker simulators for twenty years, and my best sub to date is still one that I cloned. There are a lot of designs that 'look good on paper' but don't work in the real world. What you want to find is one that works good in the real world, use it, or maybe tweak it a little bit. Kind of like the thing I did with the Insubnia.*


I have tried to find some other pre-done designs-but living in a terraced house space is a real premium-the space I have to play with is under some piece of furniture the missus loves but I'd happily sacrifice for a better sub!



Patrick Bateman said:


> Ever tried to break a board along the grain? Even a 1" thick piece of pine will split along the grain easily, but against the grain you need much MUCH more force. That's how I can get away with using 1/2" plywood for most of my subs. (Admittedly, for the ten hertz sub I should've used something beefier.)
> 
> All of these aerospace composites work along the same lines, but with carbon fiber or fiberglass "grains." The chopsticks thing works the same way, but with a wood that's ubiquitous, cheap, and easy to work with. (I use a bolt cutter, not a saw. It's easy to hurt yourself using power tools and bamboo, the stuff is too tough.)


I've never really had the two (MDF and PLY) side by side to compare-I much prefer working with MDF (ply always splits or splinters me) and with my club fists tend to get better results!



Patrick Bateman said:


> Yeah the bamboo plywoods are a little ridiculous right now. Seems to be a big markup on them. I crunched the numbers on what chopsticks cost, per square foot, and it was comparable to plain ol' plywood. But if my neighbors see me assembling a 4x8' sheet of chopsticks, they're probably going to have me institutionalized :O
> 
> * Audio Psychosis • View topic - Cheap and Different Sub


Now, that I would like to see, a 3-ply chopstick sheet, sticks running at 3 different angles The sub I've already looked at-infact could you post some more on AP-I've read it all now

Edit: re-looking at that sub I may be able to re-model it for two B139s-I've got more length and depth to play with-you don't happen to have the enclosure saved in hornresp do you?


----------



## Patrick Bateman (Sep 11, 2006)

I agree with Jason these days - in a car K.I.S.S. will generally get you the best results when it comes to bass.

Having said that, there *are* some neat tricks you can do with these weird enclosures.

For instance, if I had VERY limited space, such as a small apartment, I might have a sub 'hiding in plain sight.' For instance, picture a sub that's 3" deep, that you press up against a wall.










For instance, a subwoofer built into an Ikea Lack shelf.

In a horn or a tapped horn, it's not difficult to raise the efficiency of a driver by six dB. So that means you can do some really bizarre things, like use 3" woofers for subs, and other zany things.

An Ikea Lack shelf has a volume of 25 liters - that's a very "do-able" size for a small tapped horn.

If I were going to do it, I'd probably bump up the thickness to 3", make it out of a composite, and hang it right there on the wall.

The really cool part is that you could put three or four of them up without anyone knowing where the sub is.

It would also be very easy to hide the wires, since the damn sub is attached to the wall


----------



## The Baron Groog (Mar 15, 2010)

TS-WX77A Space-Saving Amplified Subwoofer (200W) - Pioneer Speakers & Subwoofers could just bolt 3 of these to your wall


----------



## The Baron Groog (Mar 15, 2010)

Just clocked you had the hornresp box up in the cheap and different sub thread on AP. Altered my design to that-hge bumpin output and depth-however very peaky! Also couldn't change F23-any ideas on that?


----------



## Patrick Bateman (Sep 11, 2006)

The Baron Groog said:


> Just clocked you had the hornresp box up in the cheap and different sub thread on AP. Altered my design to that-hge bumpin output and depth-however very peaky! Also couldn't change F23-any ideas on that?


When you type in something it doesn't take it?

I've noticed that you have to fill in something for all three fields on each line for it to take it. For instance, if you have a segment and you leave one of those three blank, it will blank out the whole line.

Also, notice that you can change the segment type by double clicking on the third entry. So you can change it from conical to exponential to hyperbolic, etc

I use conical for darn near everything. It's a lot easier to calculate the box that way.

Also, hornresp can do some really exotic curves automatically. Such as Le'Cleach. To do that, you only use the first line. Double click on the segment type and it will offer up a number of 'exotic' horn types, such as oblate spheroidal, tractrix, etc...

That doesn't work if there's anything on line 2, 3, 4 etc


----------



## The Baron Groog (Mar 15, 2010)

Everything else is filled in, so can't see why it won't take it-even prompts me for it then zeros it-will have more of a play today.

Being a Kraut I'm celebrating Chirstmas today Got a cool little stocking filler off the missus-sadly the 1st thing I thought of was you! Traditional Chinese Finger Traps | Unusual Gifts | Free Delivery | ShinyShack.com made from bamboo matting woven together-very strong and flexible and would make an interesting laminate? Sheets should be pretty cheap:


----------



## Patrick Bateman (Sep 11, 2006)

I'd heard Geddes throw out the statement that "only monopoles pressurize a room", and never bothered to study what he meant by that. After investing the time to do that, it really made me fundamentally change my mind on this topic.

Updates here: http://www.diymobileaudio.com/forum...anyone-understand-cabin-gain.html#post1510408

I'm not saying that the things I typed in this thread are 100% off base, but if what Geddes stated is true (and I think it is), *then the use of vented, tapped horn and back loaded horns is questionable in a car.*

Definitely a game-changer for my subs, because my last three subs fell into that category.










It gives me new appreciation for the autotuba though! I cloned one of these about half a decade back, and that sub took a punishing amount of abuse. I was literally giving it something like four or five times the rated power.

Now that I finally 'grok' what Geddes wrote, I understand what was going on there. On paper, the autotuba should explode with about 100 watts. But in the car, the pressurization effect is taking over *right where the horn is cutting off.* Basically from 60hz and up you have the horn increasing efficiency, and from 60hz to 0hz, the pressurization effect is increasing efficiency. Combine the two, and you got stupid crazy power handling.

Note that this isn't a blanket endorsement of the autotuba - I stopped using it because it didn't have the 'weight' that you get from a big sub. But it's an amazing performer at the price point (about $60 for wood *and* woofer)


----------



## captainscarlett (Mar 15, 2011)

I asked Pete (PWK) about his horn, he basically said that they work. However on another thread, he was addressing the issue (or not) of standing waves 'inside and enclosure'. Basically Pete says (paraphrasing); unless you build a sub enclosure the size of a small room, standing waves don't exists! 



Patrick Bateman said:


> Now that I finally 'grok' what Geddes wrote, I understand what was going on there. On paper, the autotuba should explode with about 100 watts. But in the car, the pressurization effect is taking over *right where the horn is cutting off.* Basically from 60hz and up you have the horn increasing efficiency, and from 60hz to 0hz, the pressurization effect is increasing efficiency. Combine the two, and you got stupid crazy power handling.




But not SPL competition loud, just loud with small to reasonable power?


----------



## captainscarlett (Mar 15, 2011)

forget the PWK question:

Standing Wave Info | HexiBase.com

trying to read three things at once. The Cabin gain thread is good, albeit another aspect of car audio I have to learn. 

Like I said before, the more i learn the more i realize i don't know!


----------



## Patrick Bateman (Sep 11, 2006)

captainscarlett said:


> I asked Pete (PWK) about his horn, he basically said that they work. However on another thread, he was addressing the issue (or not) of standing waves 'inside and enclosure'. Basically Pete says (paraphrasing); unless you build a sub enclosure the size of a small room, standing waves don't exists!
> 
> 
> 
> But not SPL competition loud, just loud with small to reasonable power?


I agree with PWK, standing waves aren't an issue INSIDE of a sealed sub enclosure*; but they're a very real problem in the car cabin. Unless your car has no roof lol

That's why it's hard to make bass in a convertible, and why your subs sound different when you roll down the windows.

The standing wave frequencies are simple to calculate - just get a tape measure and pull the formulas from this thread.

* note they *can* cause problems inside of a box, in certain circumstances, but that's a topic for another thread, and nowhere near as serious a problem as the standing waves IN the car


----------



## captainscarlett (Mar 15, 2011)

Sorry to resurect an old thread however I saw this Horn package build thing. Siad it goes down to 25hz (sub specific). I wonder if it'll work with other subs. 

Anarchy Tapped Horn - Subwoofer - Flat Packs DIY Sound Group


----------



## The Baron Groog (Mar 15, 2010)

Yes, it will. Go to audio psychosis-Patrick has already tried with other drivers.


----------

