Battle of the Monsters

[funky_waves]

Measurements to follow, initial impressions. The Acoupower definitly gives the LMS a run for the money, first few min of listening, upper to mid bass seems to sound better, low stuff seems to be as good. The Acoupower can realy move some air!! a lot more so than you think just by looking at it.

The RE XXX will be in testing ASAP, should be under a week.

next time i pass through sechelt im going to drool all over those.
well, iv already drooled on a few.
infact i bought a few, hehe

[vinculum]

funky_waves wrote:

Measurements to follow, initial impressions. The Acoupower definitly gives the LMS a run for the money, first few min of listening, upper to mid bass seems to sound better, low stuff seems to be as good. The Acoupower can realy move some air!! a lot more so than you think just by looking at it.

What alignment cabinet is your Acoupower in? Sealed? Better mid to upper bass than the LMS and equal lows. I'm happy to hear that!

I've had my drivers since January and I still don't have boxes built! I just did a free air test the other week. You can see videos of the test on youtube. But they aren't terribly exciting to watch. And I'm currently doing a fan mod on a couple CE4000's to drive them with. Boxes will be next!

I'll certainly be interested to hear and SEE anything Acoupower related that you want to post!

Dr V

[funky_waves]

I put it in my LMS enclousure, 340L tuned to 16hz so I cant compare them side by side but I am very impressed.

[Ricci]

Sweet! I didn't know you had an Acoupower Nathan. I'm looking forward to your impressions of the XXX and the Acoupower compared to the LMS.

Bring on the testing!!!

[funky_waves]

Blue line is Acoupower the other line is LMS5400. No EQ at LP in 900 square foot room with 8-11foot vaulted ceiling.

[Blaser]

WOW, pretty impressive that blue curve. Any idea on the pricing?

[vinculum]

funky_waves wrote:

I put it in my LMS enclousure, 340L tuned to 16hz so I cant compare them side by side but I am very impressed.

The ACP could probably use more volume than the LMS, but the results are impressive nonetheless. I'm not familiar with your LMS box. Whats the vent configuration?

Dr V

[funky_waves]

vinculum wrote:

The ACP could probably use more volume than the LMS, but the results are impressive nonetheless. I'm not familiar with your LMS box. Whats the vent configuration?

Dr V

It has dual 6" large flare ports.

[mdrake]

WOW very impressive!!! Pricing in located here.

[vinculum]

Ahhh.. I see now.. You put it in your custom sonotube.

[funky_waves]

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 @10Hz
114.4db @15Hz
125.5db @20Hz
118.7db @25Hz
117.7db @30Hz
123.7db @ 40 Hz (amp limited)

LMS5400 did:
105.4db @10Hz
119.4db @15Hz
126.3db @20Hz
116.9db @25Hz
115.4db @30Hz
123.7db @ 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

[vinculum]

Very comparable. The LMS ramped up sooner @ 15 Hz, probably due to its lower Fs being closer to tune.

I assume there were no problems with vent noise and the Acoupower?

Thanks for sharing.
Dr V

[funky_waves]

I have been pondering the results, and have a theory. At tuning there is some port noise, but with real world material I have never heard any port noise with either driver. But! At 15hz the amp is not clipping, the driver is not at max travel, and there is some port noise, so perhaps the limiting factor near tuning is port compression(the noise is low due to the large flares but compression still may be occurring) Why the Acoupower compresses the ports at a lower level is interesting, maybe it is a good thing(drives the ports harder as Carlos claims), maybe with larger ports it would benefit more. might just have to build another box to test theory.

Ps, I ran the ts parameters on the acoupower, I have not seen many, if any, drivers measure better than published specs, some very very close, but most often drivers measure with a higher Fs, Qes, and Le. It therfore models a tiny bit better for low end.

Published:
Fs: 28.2hz
Re: 6.2
Qms: 8.9
Qes: 0.62
Vas: 174L
Le: 1.2mH

Measured
Fs: 24.9hz
Re: 6.16ohm
Qms: 4.18
Qes: 0.59
Vas: 177L
Le: 0.72mH

I also ran the ReXXX, the more typical higher Fs and Qes, it is not fully broken in however, so the Fs may go down slightly and the Vas up slightly.
Published
Fs: 15.6hz
Re: 4.2ohm(coils series)
Qms: 2.82
Qes: 0.68
Vas: 482L
Le: N/A

Measured
Fs: 17.5hz
Re: 4.39ohm
Qms: 6.2
Qes: 0.83
Vas: 296.5L
Le: 3.88mH

[Ricci]

Great thread Nathan and thanks for the test data. I don't know of anyone else who has these 3 driver's and the ability to test them.

Looks like the Acoupower is no paper tiger (Good news eh Dr V!). I think you may be right about the port compression but it does seem weird that it would limit so much earlier than the LMS at 15hz. especially since it's a solid match at 10hz. I really hope Illka tests one of these.

Could you email me your WFT3 test data for my XXX? It would save me from testing it myself. I did test my other one and it was similar to what you got. FS was 17.6 on that one. QE and QMS were similar also.

Seems like a good xmax figure for the Acoupower's is around 30mm one way. 82.5mm p-p xmax on the XXX? Hey it may not be the 108mm claimed but it's still quite ridiculous.

Awesome stuff!

[noah katz]

Thanks, Nathan, finally some 3rd party measurements of the Acoupower.

"might just have to build another box to test theory."

Or plug the ports.

I'm a bit puzzled by something - if the 24.9 vs. 28.2 Hz Fs is due to less compliance and not more mass, the Vas would be 28% higher than spec.

"the Acoupower is 8ohm so only has 2500rms available, vs. 3600rms for the LMS5400"

Just to be clear, you're saying the ACP's similar output was achieved with 2500 vs 3600 W, right?

[funky_waves]

I may plug the ports and retest both drivers when I get some time.

Yes the Acoupower had simmilar output with over 1000watts less!!

Note about the cone travel, my measuerments are just manual to compare driver to driver, when under power all three drivers move about 5-10mm more each way before distortion.

[funky_waves]

RE XXX max ouput:

118.6db @10Hz WOW!!
120.4db @15Hz
124.0db @20Hz
114.5db @25Hz
114.2db @30Hz
117.7db @ 40 Hz (amp limited)


Little less above 15hz but below! felt like my ears were going to bleed when testing it at 10hz

Red, REXXX
Blue, LMS5400
Purple, Acoupower

[Ricci]

Just like I thought. The Acoupower and LMS have more output and sensitivity up high, but the XXX brings the pain on the really low stuff. Thanks for these tests Nate! It appears that all 3 drivers are true beasts. Looks like the lower readings at 25 and 30hz are partially due to your room, since it affects all 3 drivers.

How about some comments on the XXX powerport system? It appears as though it works as suggested eh? 11hz tune check...gargantuan low freq output...check. Did you hear any bad noises or chuffing? Think it compressed on that 10hz spl test? I must say I'm feeling.

118.6db at 10hz I think that legitimately calls for this one

[funky_waves]

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.

[Ricci]

That's about what I expected.
Acoupower for music
XXX for HT
LMS splits the difference.
None of them really being "bad" in either application.

Is the Acoupower yours? If it is, I am guessing that you will build it it's own dedicated enclosure. Any ideas on what you might go with for it yet?

[funky_waves]

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!

[funky_waves]

Ricci wrote:

Is the Acoupower yours? If it is, I am guessing that you will build it it's own dedicated enclosure. Any ideas on what you might go with for it yet?

I got it to try out, I have a couple ideas, one I realy want to do, but it would be heavy I will likely biuld a smallish sealed enclosure for it. 20"cube maybe.

[Ricci]

That's good to hear about the port noise. I don't think I'll be listening to many 116db 11hz sine waves. It probably won't be an issue for program material then. Man I've gotta ask... what does that kind of output at those frequencies sound like? Is it like a train going by, is everything rattling in your room or what?


This heavy Acoupower enclosure idea...that wouldn't be an aluminum one would it? I vote

[vinculum]

An aluminum enclosure would make that Acoupower driver the ultimate "cool" subwoofer! Talk about low thermal compression, you could really crank the juice!


Wonder what those enclosures would cost....


Dr V