What is the loudest records holding subwoofer\subwoofers in size.

[Buffalohed 10+ year member]

That just seems insane to me. I'm sure with more experience I would understand this better, but here is my question now. With 6 woofers and 24 amps (they say 200,000 watts on his profile???) and he hits a 169. How is a 180 possible? To me it seems like Scottie Johnson is already at the very upper limit of equipment, wattage, and woofers that is capable of fitting in a normal vehicle.

Thanks for the great information guys. I'm learning a lot //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

 

[Flipx99 5,000+ posts]

very true.
Sending a single driver in excess of 15kw is a task. The eclosure has to be perfect. Even sending a driver more than 5,000 watts can be challenging for someone doing it the first time.

Is there a particular formula for "perfect"? It seems car audio is very much a gray science where most of the results come from testing rather than mathematical models.

 

[Chevyaudio 5,000+ posts]

Is there a particular formula for "perfect"? It seems car audio is very much a gray science where most of the results come from testing rather than mathematical models.

No mathmatical equation can tell you whats going to be loudest. I have about 20 boxes in my garage...And they probably differ from each other by less than a 1 cube and they all pretty much use the same port(s) even though some of the designs were better suited to using shorter ports. Yet only one of them works nicely in my truck...

Of course im a streetclass competitor so my truck isnt as "modified" as the USACi Mod class/Super mod classes, or the Drag Street-max, Super Street, and Extreme.

The only thing that will help is a termlab. Best investment an SPL competitor can make.

 

[Flipx99 5,000+ posts]

That just seems insane to me. I'm sure with more experience I would understand this better, but here is my question now. With 6 woofers and 24 amps (they say 200,000 watts on his profile???) and he hits a 169. How is a 180 possible? To me it seems like Scottie Johnson is already at the very upper limit of equipment, wattage, and woofers that is capable of fitting in a normal vehicle.
Thanks for the great information guys. I'm learning a lot //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

The materials used in the vehicle-concept from what I would suppose. Scottie's van is something you can actually drive around and Steve Cook (another competitor) has a really nice paint scheme to go with his van. It seems like their vehicles are bit more "streetable".

When I saw the vehciles in the extreme class, they looked more like vehicles battling IEDs in Iraq. Very thick plexiglass, no seats, and the interior was not functional. The interior's only purpose was to faciliate sound pressure capacity. Vehicles were transported by pushing rather than driving.

I would say it is the difference between a modified street car and an ethanol based funny car. It's hard to compare because the theme and class of the car are different.

A little //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif on my background. I have never competed and am only a spectator.

 

[Chevyaudio 5,000+ posts]

Kinda give you an example.

One box with nothing on the inside no resin, no angles, just external ports and the sub...will cause the cone to go crazy, it builds wild pressure behind the sub which isn't good ( I think at one point I threw the TL in the box behind the sub and it was doing high 165s with a single W3v2 JL audio sub and less than 1000 watts, Just to give you an Idea what kind of pressure it was building in there. It can cause plastic cones (SoloX) to crack/break, or paper cones to fold (MT/DD 95s)...but If I put 1 45 degree angle in the box...it gets about 1.2-1.4 dB louder and the cone stays controled in the gap.

Just takes testing.

 

[Jeremiah25 10+ year member]

The difference in score comes from the differences in the vehicles. Scotty's van is in the Super Street division, whereas Alan's car is in the Extreme division. Basically the interior of the vehicle in front of the B pillar must be stock in the Super Street division, with a few exceptions, like the seats may be removed, and you can apply a limited amount of sound deadening. The glass and sheet metal must be stock though.

In the extreme division, there is nothing stock about the interior of the vehicle. The floors are raised, and usually layed with concrete or grout. The doors are filled with concrete or grout. The roof is built down, and filled with concrete. All the glass has been removed and replaced with plexiglass that is several inches thick.

So imagine setting off a fire cracker in a thin metal tin box, then setting off a fire cracker in a thick concrete box. Which would develop more pressure on the inside? That should answer your question.

 

[Flipx99 5,000+ posts]

Kinda give you an example.
One box with nothing on the inside no resin, no angles, just external ports and the sub...will cause the cone to go crazy, it builds wild pressure behind the sub which isn't good ( I think at one point I threw the TL in the box behind the sub and it was doing high 165s with a single W3v2 JL audio sub and less than 1000 watts, Just to give you an Idea what kind of pressure it was building in there. It can cause plastic cones (SoloX) to crack/break, or paper cones to fold (MT/DD 95s)...but If I put 1 45 degree angle in the box...it gets about 1.2-1.4 dB louder and the cone stays controled in the gap.

Just takes testing.

Why don't they make cones with the ability to flex? A weave of sorts....

Yes, I know this has already been thought of. I am now curious why it fails.

 

[Chevyaudio 5,000+ posts]

Breaking/Folding cones isn't the only issue. Keeping the coil under control is a huge part of it to. and when the cone is being forced in wierd driections it causes the coil to rock in the gap.

I wish I could find my cameral...i have a folded MT cone here at the house I coudl show...but no camera //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[Buffalohed 10+ year member]

We need more threads with info this good //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

But yeah that makes a lot of sense. I think the "extreme" vehicles are ridiculous, and yeah they look like armored troop carriers more than actual cars/trucks. I mean, the smaller and sturdier the space you are trying to pressurize with sound the less displacement it takes. To me, it crosses over from "car audio" to something else when you basically just have a thick metal box and the goal is to have as little air space as possible inside it. When you get to that point, why not just have a "metal box audio" competition, and just have people wheel up pressurized metal globes and throw a sensor in there to see how loud it gets.

 

[Buffalohed 10+ year member]

I hear people talk about how Astros and WRXs are the loudest vehicles or whatever. Why not just get one of those deep sea exploration submarines and throw some subs in there. I bet it would be louder than an astrovan //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Flipx99 5,000+ posts]

Breaking/Folding cones isn't the only issue. Keeping the coil under control is a huge part of it to. and when the cone is being forced in wierd driections it causes the coil to rock in the gap.
I wish I could find my cameral...i have a folded MT cone here at the house I coudl show...but no camera //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

I often thought about that...even in non-spl applications where the cone is horizontal, it would seem like that would be more apt to happen. I would think the magnet field around the motor would keep it somewhat aligned during normal applications. At higher pressures, I could see how minor deflections in the cone would cause the coil to wobble or rock in the gap.

I assume someone is working on proposed solutions...My knowlegde of electromagnetic dynamics is quite limited where I could not think of a way (electronically) to keep the coil perfectly centered in the gap in extreme situations. I would assume driver orientation plays a part but to what extent, I do not know. Furthermore, it would seem that driver orientation plays a key role in achieveing a higher SPL. Perhaps any gains that driver orientation could provide is eroded by loss of SPL.

Sorry if this seems like rambling. Just want to be sure if what I am thinking is atleast somewhat correct.

 

[Chevyaudio 5,000+ posts]

there is much more than just building a concrete shell and throwing speakers in it.

The designs are very intricate. I mean look at Dante and the enclosure he is using...an adaptation of an 8th order bandpass. You could line a van with concrete and steel replace the glass with plexi, and throw a few ported boxes in there, and be no where near where they are at. Acoustical design is a HUGE portion of the extreme class.

 

[Flipx99 5,000+ posts]

We need more threads with info this good //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif
But yeah that makes a lot of sense. I think the "extreme" vehicles are ridiculous, and yeah they look like armored troop carriers more than actual cars/trucks. I mean, the smaller and sturdier the space you are trying to pressurize with sound the less displacement it takes. To me, it crosses over from "car audio" to something else when you basically just have a thick metal box and the goal is to have as little air space as possible inside it. When you get to that point, why not just have a "metal box audio" competition, and just have people wheel up pressurized metal globes and throw a sensor in there to see how loud it gets.

They make rules to prevent this. Remeber, it is car audio and people are pushing the limits of what is and isn't car audio.

It's not concrete box on wheels audio.

IMO, I think TommyK hitting 15x.x off 1 10 is more impressive than others doing 16x.x with many more woofers and amps. But that is why they make different classes.

 

[Flipx99 5,000+ posts]

there is much more than just building a concrete shell and throwing speakers in it.
The designs are very intricate. I mean look at Dante and the enclosure he is using...an adaptation of an 8th order bandpass. You could line a van with concrete and steel replace the glass with plexi, and throw a few ported boxes in there, and be no where near where they are at. Acoustical design is a HUGE portion of the extreme class.

But I never see any of the competitors holding advanced degrees in physics, mechanical engineering, etc. It seems like there is a better way to model besides build and test, build and test.

 

[Chevyaudio 5,000+ posts]

I often thought about that...even in non-spl applications where the cone is horizontal, it would seem like that would be more apt to happen. I would think the magnet field around the motor would keep it somewhat aligned during normal applications. At higher pressures, I could see how minor deflections in the cone would cause the coil to wobble or rock in the gap.
I assume someone is working on proposed solutions...My knowlegde of electromagnetic dynamics is quite limited where I could not think of a way (electronically) to keep the coil perfectly centered in the gap in extreme situations. I would assume driver orientation plays a part but to what extent, I do not know. Furthermore, it would seem that driver orientation plays a key role in achieveing a higher SPL. Perhaps any gains that driver orientation could provide is eroded by loss of SPL.

Sorry if this seems like rambling. Just want to be sure if what I am thinking is atleast somewhat correct.

yes, you are on the right track.

driver orientation in certain aplications can help this problem...mainly through loading. Take my unique situation for example.

I compete in a single cab truck...with the driver forward firing (towards the seat) the sub does all kinds of funky things when I start put some power to it...mainly because of the proximity to that seat that is in front of it...even though the seat is a foot or more away it still affects the way the driver "loads".

When I upfire the sub in the same box I gain a few 10ths and sub is fine.

 

[Chevyaudio 5,000+ posts]

They make rules to prevent this. Remeber, it is car audio and people are pushing the limits of what is and isn't car audio.
It's not concrete box on wheels audio.

IMO, I think TommyK hitting 15x.x off 1 10 is more impressive than others doing 16x.x with many more woofers and amps. But that is why they make different classes.

But Tommy is gay fairy? //content.invisioncic.com/y282845/emoticons/wow.gif.23d729408e9177caa2a0ed6a2ba6588e.gif

 

[Buffalohed 10+ year member]

On the subject of coil alignment, I bet some kind of very dense non-reactive fluid suspension would help. Of course, that would be expensive as ****, hard to design, and a hell of a lot more complicated than your average SPL woofer. It would be cool as **** though.

I'm not sure exactly how subwoofers work but another idea would be a magnetic field perpendicular to that of the coil, with a functional radius small enough to keep the coil away from the gap. Kind of like how particles in a super collider are kept in the center of the accelerator.

 

[Chevyaudio 5,000+ posts]

But I never see any of the competitors holding advanced degrees in physics, mechanical engineering, etc. It seems like there is a better way to model besides build and test, build and test.

But then you run into "what works on paper wont work in the real world" situations.

99% of this sport is experience.

 

[Jeremiah25 10+ year member]

But I never see any of the competitors holding advanced degrees in physics, mechanical engineering, etc. It seems like there is a better way to model besides build and test, build and test.

That's because you don't know much about the competitors. I already have a minor in mathematics, and physics and am working on a double major in Mechanical Engineering and Industrial Management. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Chevyaudio 5,000+ posts]

That's because you don't know much about the competitors. I already have a minor in mathematics, and physics and am working on a double major in Mechanical Engineering and Industrial Management. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif...

Contrary to popular belief this sport is not entirly comprised of rednecks in the back yard with a table saw and a few Lawn Mower batteries (even though those guys do exist), lol

Also kinda off topic...Jeremiah are you going to Streetbeat again this year is USACi.