Subwoofer Tests - Fall 2007

**cjwhitehouse** · **10-09-07, 01:34 PM**

Quote:

Ilkka wrote:

I don't see it like that. Performance at higher frequencies is usually even more important, and there the f113 is a good 6 dB better than the SVS cylinder. There is also a quite considerable size difference.

And these CEA-2010 numbers do not definitely tell the whole story. They offer a quick reference but more detailed measurements and results are still needed.

Heh, I know that. But many round here wouldn't consider a subwoofer worthy of the name unless it had strong output in the 20-31.5Hz range, preferably rather lower. If we were comparing two manufacturer's quoted specs for the CEA-2010 standard consisting of just the two output numbers for low-bass and ultra-low-bass then one might come to a questionable conclusion. As you say, the CEA-2010 numbers only tell you part of the story.

**Ilkka** · **10-09-07, 01:58 PM**

Quote:

cjwhitehouse wrote:

Heh, I know that. But many round here wouldn't consider a subwoofer worthy of the name unless it had strong output in the 20-31.5Hz range, preferably rather lower. If we were comparing two manufacturer's quoted specs for the CEA-2010 standard consisting of just the two output numbers for low-bass and ultra-low-bass then one might come to a questionable conclusion. As you say, the CEA-2010 numbers only tell you part of the story.

I know you knew that, I just wanted to make it clear to the others as well.

**Ilkka** · **10-09-07, 05:44 PM**

Quote:

SteveCallas wrote:

Can't wait for the full results, but uhhh....I'm actually a little disappointed in the LMS 18 with two 18" passive radiators. At no frequency can it provide a clean 6db advantage over the TC2k 15" sub using a 6" diameter port. Ignoring the cost of the driver, PRs ain't exactly cheap. I dunno, I guess I was expecting more

Well that can be debated, but at least wait until you see the rest of the data. The more traditional distortion sweeps are pretty much out of this world. It is by far the cleanest subwoofer/driver I have ever measured.

Do I see a dual LMS-5400 18" sealed 200L (with two CE4000s) in the future?

That would be pretty close to my ideal subwoofer. Talk about some crazy output in relatively small package. And the total should still stay below ~$3500.

**ISLAND1000** · **10-09-07, 06:18 PM**

Quote:

Ilkka wrote:

Well that can be debated, but at least wait until you see the rest of the data. The more traditional distortion sweeps are pretty much out of this world. It is by far the cleanest subwoofer/driver I have ever measured.

Do I see a dual LMS-5400 18" sealed 200L (with two CE4000s) in the future?

That would be pretty close to my ideal subwoofer. Talk about some crazy output in relatively small package. And the total should still stay below ~$3500.

And I'm guessing the reason you'd choose sealed over ported or PRed is because of the lower distortion numbers and flatter, lower, frequency response possibilities using EQ for the sealed subs. At least that's what TC Sounds has lead us to believe.

**Ilkka** · **10-10-07, 07:56 AM**

It has finally arrived. Unfortunately a few days too late. Hopefully we will get one more clear weekend...

**mojomike** · **10-10-07, 08:13 AM**

Quote:

Ilkka wrote:

It has finally arrived. Unfortunately a few days too late. Hopefully we will get one more clear weekend...

Yes, please!

**jakeman** · **10-10-07, 10:12 AM**

Quote:

Ilkka wrote:

Thanks, Roger.

I don't see it like that. Performance at higher frequencies is usually even more important, and there the f113 is a good 6 dB better than the SVS cylinder. There is also a quite considerable size difference.

And these CEA-2010 numbers do not definitely tell the whole story. They offer a quick reference but more detailed measurements and results are still needed.

One suggestion to the way you present the data. Like others, I find myself averaging all six max SPL measurements from the 6.5 cycle long sine burst. Another column of Avg. 20hz-63hz would be useful. I believe the distinction of the two categories evolved from the Committee trying to account for the different behaviours of sealed and ported alignments, a distinction which has become more blurred with several of the new subs coming to market in the past year.

**Ilkka** · **10-10-07, 10:41 AM**

Quote:

jakeman wrote:

One suggestion to the way you present the data. Like others, I find myself averaging all six max SPL measurements from the 6.5 cycle long sine burst. Another column of Avg. 20hz-63hz would be useful. I believe the distinction of the two categories evolved from the Committee trying to account for the different behaviours of sealed and ported alignments, a distinction which has become more blurred with several of the new subs coming to market in the past year.

That is a good idea.

Tough the spreadsheet is already pretty wide, so I made a separate one. And I averaged the values from 20 Hz to 80 Hz. I had to estimate the 20 Hz and 25 Hz values for the HSU MBM-12 and the Gradient Evidence MK2. I subtracted 9 dB from the 31.5 Hz and 18 dB from the 25 Hz values.

**Ricci** · **10-10-07, 11:29 AM**

Quote:

SteveCallas wrote:

Not only have you outdone everyone else in terms of testing subs, now you went and outdid yourself. Two tests within 6 months - very impressive

Can't wait for the full results, but uhhh....I'm actually a little disappointed in the LMS 18 with two 18" passive radiators. At no frequency can it provide a clean 6db advantage over the TC2k 15" sub using a 6" diameter port. Ignoring the cost of the driver, PRs ain't exactly cheap. I dunno, I guess I was expecting more

It doesn't outdo it by 6db at any one frequency but an average of 4.45db greater across the board in a smaller enclosure isn't too shabby in my book. A pair of the TC2K's would only provide roughly 1.5-2db greater average output and would need 540L.

Ilkka,
What was the limitating factor for the LMS PR system?

**Ilkka** · **10-10-07, 12:21 PM**

Quote:

Ricci wrote:

Ilkka,
What was the limitating factor for the LMS PR system?

It depends of the frequency. Around the tuning frequency it was the PR excursion, above that the active driver excursion/power handling. The CE4000 still had some (not much) juice in the tank but the driver distortion was already hitting the CEA-2010 limits. The distortion threshold is pretty tight for higher harmonics, for example only 1% for 8th and higher. That's where the suspension (mainly the tall profile surround) starts to make bad noises (it wrinkles) at high excursion. Traditional half-roll surround (like the one in f113 or SDX15) is quieter because it doesn't wrinkle. IMO that's the soft spot of the LMS drivers (and any other drivers using the tall profile surround).

**ssabripo** · **10-10-07, 01:37 PM**

Ilkka, stop being such a wimp !

Get that Ultra out there and measure it.

btw, I've been trying to get an Epik Conquest or Tower shipped to you, but still nothing concrete. But if you are done for the fall/winter testing, then we have time work on Chad to get you something out there later on

**funky_waves** · **10-10-07, 01:49 PM**

Quote:

Ilkka wrote:

It depends of the frequency. Around the tuning frequency it was the PR excursion, above that the active driver excursion/power handling. The CE4000 still had some (not much) juice in the tank but the driver distortion was already hitting the CEA-2010 limits. The distortion threshold is pretty tight for higher harmonics, for example only 1% for 8th and higher. That's where the suspension (mainly the tall profile surround) starts to make bad noises (it wrinkles) at high excursion. Traditional half-roll surround (like the one in f113 or SDX15) is quieter because it doesn't wrinkle. IMO that's the soft spot of the LMS drivers (and any other drivers using the tall profile surround).

When I was talking to Mike at Tc he said the were working on a new rubber for the tall surouds specificaly for the Audiopulse LMS ultra that dosn't cavitate(wrinkle) nearly as much. Would be nice to see measurements of the LMS Ultra to compare. Too bad they are $2999 and anyone who sells them can only sell them in there local area, I know because I am going to be selling them, localy only of course.

**jakeman** · **10-10-07, 02:34 PM**

Quote:

ssabripo wrote:

Ilkka, stop being such a wimp !

Get that Ultra out there and measure it.

btw, I've been trying to get an Epik Conquest or Tower shipped to you, but still nothing concrete. But if you are done for the fall/winter testing, then we have time work on Chad to get you something out there later on

That begs the question on the minds of all subwoofer affaciondos everywhere these days: What's the weather like in Lappeenranta?

From the CEA-2010 guidelines: "Testing shall be conducted at an ambient temperature of 22C -/+5C and relative humidity of 30% to 80%."

**Ilkka** · **10-10-07, 03:02 PM**

Quote:

ssabripo wrote:

Ilkka, stop being such a wimp !

Get that Ultra out there and measure it.

btw, I've been trying to get an Epik Conquest or Tower shipped to you, but still nothing concrete. But if you are done for the fall/winter testing, then we have time work on Chad to get you something out there later on

I have recently found out that their amps do not support 230V, so no worth sending them before they do.

**Ilkka** · **10-10-07, 03:02 PM**

Quote:

funky_waves wrote:

When I was talking to Mike at Tc he said the were working on a new rubber for the tall surouds specificaly for the Audiopulse LMS ultra that dosn't cavitate(wrinkle) nearly as much. Would be nice to see measurements of the LMS Ultra to compare. Too bad they are $2999 and anyone who sells them can only sell them in there local area, I know because I am going to be selling them, localy only of course.

OK, good news.

**Ilkka** · **10-10-07, 03:05 PM**

Quote:

jakeman wrote:

That begs the question on the minds of all subwoofer affaciondos everywhere these days: What's the weather like in Lappeenranta?

From the CEA-2010 guidelines: "Testing shall be conducted at an ambient temperature of 22C -/+5C and relative humidity of 30% to 80%."

Last weekend was pretty good but now it's really chilly, only around 5 C.

Around 20 C would of course be optimal but I accept ~10 C or higher. The difference will still be pretty minimal. Colder weather means slightly better results.

**brucek** · **10-10-07, 03:16 PM**

Quote:

Testing shall be conducted at an ambient temperature of 22C -/+5C and relative humidity of 30% to 80%

Little bit of rain, lightning and cold weather shouldn't stop testing..........

bad_weather.jpg

brucek

**jakeman** · **10-10-07, 03:20 PM**

Quote:

Ilkka wrote:

Last weekend was pretty good but now it's really chilly, only around 5 C.

Around 20 C would of course be optimal but I accept ~10 C or higher. The difference will still be pretty minimal. Colder weather means slightly better results.

The lower the temperature, the more deviation there will be in output and linearity. Normally I would agree the results would be minimal in an absolute sense, but with this many subs being ranked I can see how the lower temp could end up changing the order of ranking some of these subs. These are your tests of course but conducting them at less than 15C (-7C to give some room) starts to affect the validity of the results for comparative purposes. That would be a shame in light of the excellent work and great effort.

**Ilkka** · **10-10-07, 03:37 PM**

Quote:

jakeman wrote:

The lower the temperature, the more deviation there will be in output and linearity. Normally I would agree the results would be minimal in an absolute sense, but with this many subs being ranked I can see how the lower temp could end up changing the order of ranking some of these subs. These are your tests of course but conducting them at less than 15C (-7C to give some room) starts to affect the validity of the results for comparative purposes. That would be a shame in light of the excellent work and great effort.

How can you say that? Have you done any testing at different temperatures?

When I said that lower temperature means slightly better results, I meant regular long sine sweep tests. They put a lot of heat into VC and ambient temperature plays some role on how the VC dissipates this heat. But the short burst of the CEA-2010 is vastly different. Because it's only 6.5 cycles long, it doesn't create much heat at all. Therefore ambient temperature doesn't matter that much. 10 C or 20 C will give very close to identical results. That is one more reason why I started to use it: accuracy and especially consistency.

And in any case, the ambient temperature for rounds 4 and 5 was within 2-3 C.

**itte** · **10-10-07, 04:11 PM**

Quote:

funky_waves wrote:

When I was talking to Mike at Tc he said the were working on a new rubber for the tall surouds specificaly for the Audiopulse LMS ultra that dosn't cavitate(wrinkle) nearly as much. Would be nice to see measurements of the LMS Ultra to compare. Too bad they are $2999 and anyone who sells them can only sell them in there local area, I know because I am going to be selling them, localy only of course.

Sorry OT, but that price is ridiculous,it is about triple what it was, so it won´t be a bestseller,pity because it seems to be such a nice driver.

**kyle_k** · **10-10-07, 04:30 PM**

We're well aware of that higher order harmonic in the surround, its a trade off of excursion. We're working in a few different FEA programs and designing a new tall surround which will probably be made out of a new material too to shave mass and not not cavitate.,We should be able to attenuate that distortion substantially, in fact we already have a working miniature prototype in a 5.25" model. We wont have our new surrounds done for a long while, but its already in the works.

I want to give a big thanks to Ilkka for making all these measurements. Simply posting data without any relative comparisons is not nearly as meaning full. Its interesting to see how different products stack up again ts one another.

I'm curious to see this new SVS, I know they did a great job on the driver and that big under hung motor should be very linear.

**funky_waves** · **10-10-07, 04:40 PM**

Quote:

kyle_k wrote:

We're well aware of that higher order harmonic in the

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