Acoupower subs: 15% off.

[Looneybomber]

http://www.acoupower.com/news.php

While this looks an 8" sub...

...it's actually a 15"

You've got to see their video's. They talk about how they're made and other information on them. These are some phenominal speakers. One of the video's shows how much air the motor moves to help cool it. A kid holds a plastic bag open 4 ft behind the woofer and it's blowing the bag wide open. Insane the amount of air it moves to cool the voice coil.

http://www.acoupower.com/picsandvideo.php

Their "Genesis Device", a bandpass enclosure consists of two 18's and those exterior ports are their 10" ports with 16" flares. "Up against a back wall, you will get +6dB. In a corner, you will get +12dB, for a staggering 150dB sustainable dB at 40Hz. [At 1 meter] Please also note the response shape - the response rolls off gradually to below 25Hz. Given the typical room transfer function, this box will be -3dB at approximately 25Hz. Exhaustive in room measurements and listening tests by critical listeners has confirmed the information. Also keep in mind this is a very low distortion box. Total Harmonic Distortion at full power (4kW) never exceeds 10%, compared to 100% to 200% for horn load boxes when hit with very low frequency information."http://www.acoupower.com/18b.php

As said in one of their video's, with 2,000w of power, over an extended period of time, the motor temp rose 50 degrees F above ambient. Quite a few speakers can handle that for a few seconds, but much longer and the voice coils will melt. Which is why it can produce those db levels continuously.
Modified by Looneybomber at 9:03 PM 4/24/2008

[Looneybomber]

The 15" could be used in a 2-3 ft sealed box. That would fill the trunk rather nicely and you could easily use a 3000w amp (along with upgrading your charging system) to power it nicely.

[JoeyChains]

That's a great setup...................if you have a truck. I don't think I would want to cram that in the back of my Z, and run the risk of completely MANGLING my handling and 1/4 mile time!

[Looneybomber]

What's an extra 100lbs in a car that already weighs more than my dad's pickup.

[PoorManQ45]

Unfortunately it appears to have the surface area of a 10~12.

A high roll design would have greatly improved output.

I'd take a TC LMS driver over those anyday

[Looneybomber]

15" acoupower = 680cm^2SDX-15 = 790cm^2So it has the SD of what a 13" would, given the same build as the SDX. But since the 18" driver is $25 more, you could always go that route.

Sure there is a bit of a difference, but the surround is specially designed by them for their specfic need and results in lower 2nd and 4th harmonic distortions. If someone was wanting to have continuous high outputs of bass, acoupower is the way to go. I'd put money on it that it'll handle power compression better than the LMS-5400/Ultra.

[PoorManQ45]

15" acoupower = 680cm^2SDX-15 = 790cm^2So it has the SD of what a 13" would, given the same build as the SDX. But since the 18" driver is $25 more, you could always go that route.

Sure there is a bit of a difference, but the surround is specially designed by them for their specfic need and results in lower 2nd and 4th harmonic distortions. If someone was wanting to have continuous high outputs of bass, acoupower is the way to go. I'd put money on it that it'll handle power compression better than the LMS-5400/Ultra.

Bah, I'd take a couple of SDXs and horn load them. Horn load the port on the back box.

I dont know what they're talking about with the THD % that they listed. Maybe they're talking about when you try to play below the horns cutoff frequency. But is anyone really that dumb?

For a house a pair of Folded Corner Horns(if you have the right dimensions) is your ticket to super efficient, ultra high ouput, clean bass reproduction

BTW, where did you get that SD measurement? It seems that someone is playing tricks with the numbers. If I could see that driver next to a regular 15" that'd be a good reference.

Remember, the Surround is NOT part of the SD. This is one of the main reasons behind the high roll surround. High excursion while still maximizing SD.

I'd like to see an independent measurement of that SD.

*edit* maybe what is throwing me off is that they extended the surround to the edge of the basket. This gives it a smaller overall apperance.

[Looneybomber]

For a house a pair of Folded Corner Horns(if you have the right dimensions) is your ticket to super efficient, ultra high ouput, clean bass reproduction

BTW, where did you get that SD measurement? It seems that someone is playing tricks with the numbers. If I could see that driver next to a regular 15" that'd be a good reference.

Horns are great (for bass) and my favorite alignment. Not a fan of them for anything but bass though. The downfall is they require a huge box in order to play fairly low. 40hz, no problem, 25hz and now we're talking a big box. For movies...Fail. In a house, due to their limited frequency response down low, I am not the biggest fan of them. May as well just use some Lambda 15's (or SDX's or Maelstrom-X's) in sealed enclosures. However, if continuous loud output is the goal, these Acoupowers breathe like non other. And cooling is the name of the game.

Driver parameters here.http://www.acoupower.com/parameters.phpCheck out their video's.

[PoorManQ45]

Hang on, I just checked out their website:

"4) Super linearity. 100% linear BL product for +18mm of travel in EACH direction. Proprietary spider and precise details in the surround provide exceptional mechanical linearity and smooth overdrive characteristics. "

Is it just me, or is that extremely low excursion? Wasn't the LMS at around 38mm One Way excursion while maintaining linearity?

"6) We are experts in Acoustic Power Density. These drivers have the highest low frequency output ever obtained in standard 15" and 18" sizes thanks to 78mm of travel, high power handling and low power compression. In many applications, one driver can be used where two are being used now. "

It can do 39mm one way peak, but it's only Linear for the first 18mm! Is it just me, or is that horrible?

[Looneybomber]

Hang on, I just checked out their website:

"4) Super linearity. 100% linear BL product for +18mm of travel in EACH direction. Proprietary spider and precise details in the surround provide exceptional mechanical linearity and smooth overdrive characteristics. "

Is it just me, or is that extremely low excursion? Wasn't the LMS at around 38mm One Way excursion while maintaining linearity?

"6) We are experts in Acoustic Power Density. These drivers have the highest low frequency output ever obtained in standard 15" and 18" sizes thanks to 78mm of travel, high power handling and low power compression. In many applications, one driver can be used where two are being used now. "

It can do 39mm one way peak, but it's only Linear for the first 18mm! Is it just me, or is that horrible?

xmax doesn't have a set guide line, but typically companies will use a 70% linearity in BL. At the point of excursion where BL drops by 30% they say that's it's xmax. A 100% BL usually is only maintaned for just a few mm's. 18mm (each way) with 100% BL is awesome! It's xmax value is somewhere around 30mm. I'd have to look that one up.

The LMS did have more overall excursion and a lower fs which made it more condusive for home audio, however car audio (and pro-audio), which typically abuses subs with loud continuous high frequency bass, could benefit greatly from the Acoupower's cooling ability, which helps reduce power compression. And is also their target audiance.

[PoorManQ45]

Any Idea what these things cost?

I suspect this is one of those "wonder" drivers that is so expensive that you could purchase multiple other "lower quality" drivers for the price of one of these. And beat the snot out of it

You know me, i'm all about multiple medium quality drivers in an array just loafing around to make one badass setup

I'd rather have 4 drivers moving 10mm then one driver moving 40mm. Assume same SD

[Looneybomber]

It's been shown by Ilkka's tests that, when limiting by distortion (CEA 2010 dictates 10% max) and not SPL, 1, 18" LMS-5400 bests 2 SDX-15's in the same sealed alignment. It would take 4 SDX's to best 1, LMS 18" while spending more on drivers and taking up 4x the enclosure space.

One good driver vs multiple so-so drivers is yet another on going debate that will likely never have an answer due to anecdotal evidence and stereotypes. In the end, it's all a matter of compromises and only you know what's most important to you.

Oh the 18" acoupowers are 900.00, but they were 15% off. A guy on AVS, TheEAR bought two of them and another guy bought two. We're all just kind of waiting to see how well these perform. So far we know they're very quiet, which is great. Nothing's more annoying than a speaker that has a lot of mechanical noises.

[PoorManQ45]

A guy on AVS, TheEAR bought two of them

Hangon, isn't that the guy that claims to have like 60 subs, but has never showed any pictures? LOL

Put anyways, Given to similar quality drivers, one having more excursion, I'd rather having multiples of the lower excursion model.

Example: How do two of the 15" LMS drivers compare to 1 of the 18" LMS?

[Looneybomber]

I can get you pictures of his subs, and stacks of boxed subs.http://profile.imageshack.us/user/myry8rfw/

As for the 2 LMS 15's vs 1 18, I haven't seen SPL and distortion tests on the 15", only the 18. I would hypothisize that the two 15's would best the 18", but would also cost nearly twice as much given their past MSRP.

[PoorManQ45]

You get what im saying though, right?

It seems that none of the tests comparing multiple drivers to a single driver use similar quality drivers

[Looneybomber]

You get what im saying though, right?

It seems that none of the tests comparing multiple drivers to a single driver use similar quality drivers

You mean like the SDX vs. TC2000 15"? There are tests by Ilkka for both of those drivers, but comparing multiples of one vs a single of the other is fairly pointless. Neither Vd, nor price is the same. I could see testing 4, 250.00 drivers vs one 1000.00 driver, or mulitple 8's vs a single 18, but comparing two oranges against one orange just seems pointless, because we'll all know the outcome. Roughly 6 more db of output or less THD at like outputs.

...or maybe I am missunderstanding you.

[PoorManQ45]

You hit it on the head with the 4 250$ drivers vs 1 $1000 driver

[Looneybomber]

Hmm, according to a newly found woofer test, the LMS may have some rivals.

I did a couple tests today on the Acoupower and LMS5400, for maximum output before audible distortion, I also measured the mechanical cone travel, on all three, up to the point where the suspension really starts to stiffen up/become non linear. The LMS5400 is 65mm p-p the Acoupower is 64mm p-p, and the REXXX is 82.5mm p-p.

Acoupower did:105.6db @10Hz114.4db @15Hz125.5db @20Hz118.7db @25Hz117.7db @30Hz123.7db @ 40 Hz (amp limited)

LMS5400 did:105.4db @10Hz119.4db @15Hz126.3db @20Hz116.9db @25Hz115.4db @30Hz123.7db @ 40 Hz (amp limited)

Measurements where taken at 5 feet from the sub in the corner with a pure sine wave, turned up until distortion is heard then down till it’s gone and a reading taken.

The icing on the cake as it were, the Acoupower is 8ohm so only has 2500rms available, vs. 3600rms for the LMS5400

Not super precise tests since we don't have a THD% but still cool. I had yet to see the Acoupower or RE-XXX get tested.http://www.hometheatershack.co....html

[PoorManQ45]

Man I wish the LMS had the old Aluminum look to them. That was so sexy!

Anyways, can you link me to a couple threads about the Acoupower subs. I haven't been keeping up with the different forums and cant seems to find any good threads about them

[Looneybomber]

There's only two guys on AVS that own Acoupower drivers. That's TheEAR and Dr.V. Both have a pair of 18's I believe. Otherwise there's not a lot of info on them yet. Funkywaves on HTS has one that they're testing, but otherwise, that's the only 3rd party testing I've seen.

[PoorManQ45]

Cool.

I just went over to AVS.

It's funny seeing the same threads in the build forum that have been there since about a year ago when I last visited. LOL

[Looneybomber]

Whatever happend with your HT sub you built with a Dayton Titanic. 15" MkIV?

[PoorManQ45]

I finished, or rather, got it up and running a long time ago. Like 2 years now.

I unfortunately never found anyone that would sell a small slab of granite to me.

And I never got around to making the legs. So it's sitting in use upside down right now. LOL.

I'm thinking about buy another Titanic and making a single box with dual woofers. I'll need to purchase a PA amp for that one though.

[Looneybomber]

Just lay it on it's side so it's not upfiring And now your subwoofer is complete.

More news.

"The port system seems to work as predicted I don’t recall hearing anything from the port. Although to be honest I did not pay close attention to it. I will do some more listening.

For real world material there is defiantly no noise at all, even my LMS enclosure with either the LMS or the Acoupower has no problems with real material, only with pure sine waves.

So far I think I prefer the Acoupower for music, the XXX for movies and the LMS for both. This seems to correlate with the max output numbers.

To use some "bad" subwoofer terms; the Acoupower is the "tightest", the XXX the "softest", but very weighty in the low end and the LMS is somewhere in-between for both aspects. None of them seem "slow", "boomy" ect.

All three are defiantly in the same league with each having there strong points. I think the Acoupower and the LMS are very close as do the people who have heard both. One person prefers the LMS but is not sure why, I am yet undecided. The XXX is the best at making it feel like a track hoe is trying to shake the building down, the other two maybe a smaller track hoe. The only "bad" thing about the XXX is that to really get the best out of it you need around 20cubic feet, whereas the LMS and Acoupower work in substantially smaller enclosures."

And a further comment from him on port noise, compression, etc from the powerport.

"I did some tests at 11 and 12hz and the amp clipped at about 116db, that is likely due to the fact that that is where minimum impedance occurs. There is some air noise from the port but not much at all. Defiantly a ton of air moving!"