Subwoofer Tests - Fall 2007

**Ilkka** · **10-07-07, 04:51 PM**

I have kept you all under the radar thus far, but I have just completed my fall 2007 subwoofer test session. These are the subwoofers (and one speaker) I tested today. Results and pictures will follow.

Anthony Gallo TR-1
Audio Pro Level 110
BK XLS300/PR
BK Extreme
Gradient Evidence MKII
DIY CSS SDX15 sealed 100L
DIY CSS 2xSDX15 sealed 140L
DIY TC Sounds LMS-5400 18" sealed 100L
DIY TC Sounds LMS-5400 18" + 2x18" PR 200L
DIY Servo v2 (see. round 3)
JL Audio Fathom f113
SVS PB12-NSD
SVS PB13-Ultra (all four settings)
Velodyne SPL-1200 MKII
Yamaha YST-SW1500

Pictures!

Here are the results for the CEA-2010 standard I also used last time (round 4). I would recommend everyone to read this document regarding the standard. The CEA-2010 standard defines a new way for measuring and determining the clean maximum output level for a subwoofer. The signal used is a 6.5 cycle long sine burst which allows a safe measurement of the maximum output level. The max SPL is limited by the stepped distortion threshold (allows less distortion for higher harmonics) or the limitations/limiters of the subwoofer itself, which ever is reached first. The standard defines the max SPL normalized to 1 meter distance (half-space) and peak value of the sine burst, but I use the more familiar 2 meter distance and the RMS value of the sine burst. That way these figures are more comparable to the results measured by using the more common sine wave sweep/tone method.

The amplifier for all the DIY subwoofers (except the "DIY Servo v2") measured during round 5 was a Crown CE4000. The rated output at 4 ohms bridged is 3600 watts. With "DIY CSS 2xSDX15 sealed 140L" I used two of these amplifiers.

The "Gradient Evidence MK2" is a Finnish main speaker that I own (naturally a pair of them). I wanted to measure its bass performance because I haven't seen this kind of measurements done on speakers, even though their role in achieving well balanced sound system is absolutely critical. It is a 3-way speaker using a 6.5" coaxial driver and an 8" woofer in a ~35-40 liter ported enclosure. I used only one speaker during the measurements, but later on added 6 dB for the second speaker (assuming full coupling).

Below are the results for the newest (fall 2007/round 5) and the one prior to that (spring 2007/round 4) measurement session organized in "Low-bass Avg." (average of the 40-63 Hz values) column order.

Below are the results for the newest (fall 2007/round 5) and the one prior to that (spring 2007/round 4) measurement session organized in "Ultra low-bass Avg." (average of the 20-31.5 Hz values) column order.

Below are the results for the newest (fall 2007/round 5) and the one prior to that (spring 2007/round 4) measurement session organized in average of the 20-80 Hz order. 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.

*** Notice that the TC Sounds 2xTC-2000 15" sealed 140L had a bad second driver (surround came off due to a manuf. defect) during the CEA-2010 test so it's results at 40 Hz and down are NOT what they should be. The real numbers at the low end should be slightly higher than the numbers for the CSS 2xSDX15 sealed 140L.

**SteveCallas** · **10-07-07, 07:18 PM**

Sly dog

**darrellh44** · **10-07-07, 08:57 PM**

subscribing

**Sonnie** · **10-07-07, 09:15 PM**

This should be very interesting...

**Ilkka** · **10-08-07, 08:44 AM**

Pictures are up!

http://jumi.lut.fi/~maeronen/sub/syksy/

**anidabi** · **10-08-07, 09:08 AM**

Man those LMS drivers look cool. Gives some serious authority.

BTW, those LMS enclosures are the best looking I have ever seen.

**Ilkka** · **10-08-07, 09:20 AM**

Quote:

anidabi wrote:

BTW, those LMS enclosures are the best looking I have ever seen.

Thanks a lot fellow Finn. These are the particular comments I like to read after a long measuring session. Thanks again.

I had only one week to desing and build those two large enclosures. Outlook isn't top priority then, performance is. I have plenty of time to finish them now when the measurements are done.

**anidabi** · **10-08-07, 11:53 AM**

Quote:

Ilkka wrote:

Thanks a lot fellow Finn. These are the particular comments I like to read after a long measuring session. Thanks again.

I had only one week to desing and build those two large enclosures. Outlook isn't top priority then, performance is. I have plenty of time to finish them now when the measurements are done.

Haha, don't take it so seriously. I was just teasing because I knew that you made those in very short time. The looks are not important, only performance is.

**Mark Seaton** · **10-08-07, 01:06 PM**

Another impressive endeavor Ilkka.

Very interested in seeing the results of more than a few the subs you tested.

**JCD** · **10-08-07, 03:24 PM**

Ooogly Moogly! That 18" with the passive radiator is quite impressive! Very impressive for something that you had to "slap together". Woof, that thing is huge..

As with everyone else, looking forward to the results..

JCD

**Ilkka** · **10-08-07, 05:11 PM**

The first post in this thread now contains the CEA-2010 standard results. Notice that these are NOT the full results yet. Full results (frequency response, power compression sweeps, distortion, group delay, spectral contimination etc.) will follow after I have processed them.

**itte** · **10-08-07, 05:44 PM**

Thanks for the tests in this forum also.

**Ilkka** · **10-08-07, 05:50 PM**

Some of you may wonder the absence of the SVS PB13-Ultra. I was supposed to test it too, but unfortunately SVS/L-Sound wasn't able to provide it in time. It's still on its way and it's uncertain whether I will be able to test it this fall due to bad weather.

**Blaser** · **10-08-07, 07:10 PM**

Great Job Ilkka....Very much appreciate all your effots!

That LMS 18 is definitely the strongest driver I have seen according to any measurements you have done.

I wish I could afford 2

**SteveCallas** · **10-08-07, 09:28 PM**

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

**Ricci** · **10-08-07, 10:25 PM**

The LMS is looking mighty strong, especially the 100L sealed. The fathom put up some impressive #'s too.

**mojomike** · **10-08-07, 11:52 PM**

Ilkka, how comparable are your tests to the AV Talk tests?

**mike c** · **10-09-07, 01:01 AM**

nice! when do you think we'll see the standard FR, PC, GD, THD charts

sorry, I'm totally unfamiliar with these new CEA standards.

thanks for doing all the work!

finally, someones done some tests on the yamaha yst-sw1500. can't wait to see the PC chart on this one. looks like the tuning is really high - hehe - where did the yamaha quoted frequency extension come from?

-20db?

**mike c** · **10-09-07, 01:10 AM**

i'll echo mojomike's question:

everything else seems comparable to the AVTALK tests, but a layman like me is having a hard time comparing the power compression charts ...

**mike c** · **10-09-07, 01:15 AM**

the yst-sw1500 looks to be a great replacement for the mbm-12 (to those who have no access to HSU)

**Ilkka** · **10-09-07, 03:47 AM**

Quote:

mojomike wrote:

Ilkka, how comparable are your tests to the AV Talk tests?

Based on earlier tests performed on same subwoofers (not the exact same units though), our tests are very comparable when it comes to absolute SPL. Though one must notice that the exact measuring methodologies are slightly different. Both of us have also altered our methods along the way, for example I have always used a reversed sine sweep method (starts at higher frequencies), while AV Talk used a forward sweep until recently switched to reversed, too. So I'd say some of the older results are less comparable due to this difference. For example AV Talk managed to bottom out some of the SVS cylinder models and they had to terminate the forward sweeps, and therefore the difference seems to be larger than it really is. AV Talk was also using a much shorter sweep in the past, which results in lower THD (distortion) levels with most subwoofers due to less VC heating. Now they are using much longer, though still shorter than mine, reversed sweep.

The largest difference is that the AV Talk doesn't use the new CEA-2010 standard. It is currently the only safe and accurate method for determining the clean maximum SPL at every frequency (nine 1/3 octave wide bands in 12.5 - 80 Hz range). Traditional sine sweep method doesn't necessarily show the maximum SPL at all frequencies because the highest sweep doesn't show high/full compression at all frequencies. Usually compression is higher at lower frequencies, but higher frequencies are still relatively compression free at this sweep level.

Let's take the new SVS PB13-Ultra for example. You can see that there is already ~5 dB of compression near the tuning frequency (15-16 Hz), but only 1 dB or less at higher. That means that the highest sweep (110 dB) doesn't show the maximum output in the mid and upper bass range. I'm suspecting it would still have around 2-4 dB juice in the tank above ~30 Hz. So therefore one can not compare those figures with the CEA-2010 maximum output figures.

Recap: Our tests are pretty similar but there are some differences in measuring methods that can cause pretty significant differences if you don't know how to interpret them, and also depending of the subwoofers that you are comparing. If you want to compare some specific subwoofers, please let me know and I will help you to make the comparison more accurate.

AV Talk's test are really good and I applaud to Roger for performing them. If it would be easy or cheap to perform the test we take, more people would be doing them.

**Ilkka** · **10-09-07, 03:49 AM**

Quote:

mike c wrote:

nice! when do you think we'll see the standard FR, PC, GD, THD charts

Any guess at this point would be purely academical.

Quote:

sorry, I'm totally unfamiliar with these new CEA standards.

Have you read this document?

http://personal.inet.fi/private/zipm...in_CEA2010.pdf

It should explain the CEA-2010 pretty easily and thoroughly. It is actually much more easier to understand than most of the other tests I take.

**JimP** · **10-09-07, 05:39 AM**

Quote:

Ilkka wrote:

Some of you may wonder the absence of the SVS PB13-Ultra. I was supposed to test it too, but unfortunately SVS/L-Sound wasn't able to provide it in time. It's still on its way and it's uncertain whether I will be able to test it this fall due to bad weather.

The one sub that I'm interested in and it doesn't make it to the test.

**Vaughan100** · **10-09-07, 05:52 AM**

Ilkka, could you please add the SVS PB10 NSD to the list ? I curre

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