Realistic question - Breaking the threshold?

[varietyguy]

BTW, with current woofer technology we will never see scores over 186 dB in a vehicle. And I will tell you why.

High SPL is all about pressure. Positive pressure and negative pressure, compression and vacuum.

In a vehicle and especially according to SPL organization rules, we are limited as to how small a vehicle's interior can be.

The smaller we can make a pressure chamber, the easier it is to pressurize and create vacuum.

Even if we make a test chamber as small as we want, we run into what I call a frequency paradox.

See, we can have a woofer displace 1 cubic foot for example. So we put it into a 1 cubic foot chamber and it should be able to create a perfect vacuum upon rarefraction. Which is technically possible when dealing with pressure, but we are dealing with SOUND pressure. So this 1 cubic foot chamber has a resonance. And the way the SPL sensor works and the way that sound pressure in general works is that we would now have to play a super high frequency to couple the pressure wave to the sensor. Now we have a woofer that will need to displace 1 cubic ft of airspace at a frequency that is beyond its reproduction capabilities.

So you see where we are at?

Woofers today can only move so much against pressure, and the option of reducing cabin size to compensate will only put optimal frequencies out of the range of the woofer. So we are at a point where technology must change in order to advance SPL.

If you can make a tweeter that can displace 1 cubic foot with extreme pressure pushing against it, then you have a chance.

I am going to agree and disagree with you on that.

I do agree that we will hit a peak with what limits we have for rules and technology but i dont think it will be at 186db.

Now that they have came out with that new meter that is just as accurate as a TL all the way up to 180 db and even more accurate and true above 180db i think you will see some more scores like Hal Shokers 185. Coming out with that new meter solved alot of the problems that the TL was having reading over 180db accurateness and the peak of 183db.

I think it will liven up the extreme class a little more since they have a new number to chase. But sooner or later it will come to a point where there is no possible more. I mean it took Craig what 125,000 more rms just to gain a few tenths

whoa when did it become 185 last i heard it was at 17X

the 180 barrier was broken with Scott Owens a bunch of years ago.

The 185 he was referring to is a testing score on a new meter I believe. Not an official record.

Isn't this 185 an old score that popped up on an audiocontrol?

ok...still last i heard there was a guiness world record of 170 something good info tho

BTW, with current woofer technology we will never see scores over 186 dB in a vehicle. And I will tell you why.

High SPL is all about pressure. Positive pressure and negative pressure, compression and vacuum.

In a vehicle and especially according to SPL organization rules, we are limited as to how small a vehicle's interior can be.

The smaller we can make a pressure chamber, the easier it is to pressurize and create vacuum.

Even if we make a test chamber as small as we want, we run into what I call a frequency paradox.

See, we can have a woofer displace 1 cubic foot for example. So we put it into a 1 cubic foot chamber and it should be able to create a perfect vacuum upon rarefraction. Which is technically possible when dealing with pressure, but we are dealing with SOUND pressure. So this 1 cubic foot chamber has a resonance. And the way the SPL sensor works and the way that sound pressure in general works is that we would now have to play a super high frequency to couple the pressure wave to the sensor. Now we have a woofer that will need to displace 1 cubic ft of airspace at a frequency that is beyond its reproduction capabilities.

So you see where we are at?

Woofers today can only move so much against pressure, and the option of reducing cabin size to compensate will only put optimal frequencies out of the range of the woofer. So we are at a point where technology must change in order to advance SPL.

If you can make a tweeter that can displace 1 cubic foot with extreme pressure pushing against it, then you have a chance.

I am going to agree and disagree with you on that.

I do agree that we will hit a peak with what limits we have for rules and technology but i dont think it will be at 186db.

Now that they have came out with that new meter that is just as accurate as a TL all the way up to 180 db and even more accurate and true above 180db i think you will see some more scores like Hal Shokers 185. Coming out with that new meter solved alot of the problems that the TL was having reading over 180db accurateness and the peak of 183db.

I think it will liven up the extreme class a little more since they have a new number to chase. But sooner or later it will come to a point where there is no possible more. I mean it took Craig what 125,000 more rms just to gain a few tenths

See then you run into the law of diminishing returns.

This is where we see less and less return in relation to how much we put in.

At low SPL, say 120dB, we can double power and achieve a 3dB gain. And this is especially easy if we are doubling from 500w to 1000w. Because we only had to add 500w.

Now at 180dB we can double power from 30,000w to 60,000w and gain a few tenths of a dB.

Mainly this is because of power compression. The greater the amount of pressure that the woofer is creating means the greater the resistance to its movement.

So we can add more power to a woofer to make it push stronger, but the more it moves, the more pressure it pushes against.

This is similar when describing particle accelerators and why we cannot push matter past 99.9999999....% the speed of light.

So current woofer motor strength and cone materials will not allow a woofer to play past a certain pressure point, and that limit of 186 dB had been proposed by Alan Dante and Scott Owens and is supported by the results that the 180+ guys have been seeing.

If a stronger motor can be created, we can push past that number though.

True. The sad part is i dont think you will really see a huge push to create a stronger motor unless one of these companies like DD realize they are going to loose that one thing they are known for and thats having the loudest subwoofer on the planet.

Really for the most part nothing dd has not done all that much to make the Z any better than what it is. And i cant really blame them because there is just not a big enough market out there to put alot of time and money into creating a subwoofer that will take some to another level.

There are a few companies catching up to the Z with a ferrite motor. B2, DC, Shocker.

If there was a huge push to from one of them 4 companies to have the loudest sub i bet it would bring things to a new level but right now its just a matter of time till they hit that peak

This sounds a lot like the Rockford Fosgate TRF matter.

[quakecitystudio]

We would need to work backwards. What is the ideal goal of sound would we want to achieve and calculate how much acoustic pressure we need in the given chamber to reach that goal. Each woofer applies a certain lbs. of pressure to the sealed chamber. But like you said earlier that there's only so much pressure that can be applied when it involves woofers, because at a point I feel that when everything is sealed tight, the woofer would be the first to break apart. Ideally it would be like trying to drive a woofer that is bolted face down on concrete. It is going to push down, but the air between the cone and the concrete is going to be so compressed, it's going to force the cone to a stopping point. And when the cone tries to pull back the air between the cone and the concrete is going to be stretched because the concrete is solid and will not move, so the cone is going to stop at it's farthest pulling distance.

We would have to advice a method of using fluid compression and expansion by means of wavelengths, inorder to achieve sound pressure greater than what we'd be able to do by woofers. Basically at what interval can you pump water into and out of a chamber to represent a certain frequency.

[Dman1320]

found this on youtube a while back probably not offiicial but cool none the less.