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Discussion Starter · #1 ·
Klipsch RW-12d

SVS Sb12- Plus

HSU VTF3-MK3 with Turbo

Outlaw Audio LFM-1EX (Prototype)

Velodyne DLS-5000R

http://www.soundandvisionmag.com/spe...ubwoofers.html


Ken Pohlman, Tom Nousaine and S&V went all out on this one.


I haven't had time to read, as I'm on a deadline at work today, but I wanted to post for everyone else.
 

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wow, alot of reading here. i skimmed most of it. way to go hsu!
 

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Discussion Starter · #3 ·
Here's how those subs stacked up against the other in the lab tests:

 

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Discussion Starter · #5 ·
Curtis, I can only fit so much info onto one page! :)


Let me see how I can change that.
 

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TN's measurement results have always been a bit strange when compared to others.


For example, look at the Klipsch RT12 D that in TN's test measures [email protected]@10%THD, but when tested by EM it does [email protected]@10%THD.


TN measures the subs indoors, so that could explain the difference, but the problem is that there is no trend.


The PB12-NSD puts out [email protected]@10%THD. From Ilkkas latest test we know that the 12-NSD is pretty close to the Plus with both of them measuring exactly the same at 20hz. In EMs test of the PB12-Plus it manages to do [email protected]@10%THD.


So what we have is


Klipsch RT12


TN: 91db

EM:87db


SVS PB12-NSD/PB12-Plus


TN:96db

EM:101.3db


There are several other strange results both with regard to FR and output.


Does anyone have an idea why?
 

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Also. take a look at TNs comment about output at 20hz without the turbo.

Quote:
Removing the Turbo extension reduced maximum output about 2.3 dB from 25 to 62 Hz and 10 dB at 20 Hz,

So what he is saying is that without the turbo the Hsu delivered 83db, compare that to the 96db for the PB12-NSD. And then take a look at Illkas test results for both subs and it all starts looking very, very strange indeed.
 

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Personally, I think this technique for measuring frequency response is absurd. Nousaine is measuring the frequency response at maximum output and with the distortion under 10%. Is this an accurate evaluation of the true frequency response of a sub? How many of us are playing our subs at their maximum clean output level all the time? We shouldn't be. If we are, then we need more woofage. How do you think the frequency response would look at, say, 3db less than max? Or at 6db less than max? Which do you think would be a more accurate evaluation of frequency response?


What is really being measured here is the power response, not the frequency response. These are different animals and should be called such.
 

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Discussion Starter · #13 ·
No one has ever referred to these tests as frequency response tests. They obviously lay out the performance at each subs bass limits.


Nousaine provides frequency response ranges, but those are not relevant, because everyone will have different results in their own room.


This is just a gauge to compare subs that were measured in a similar room, under similar conditions, so we can see what they are capable of.


Other than AVtalk, Ilkka's tests, and Ed Mullen's Secrets reviews, there is no other large collection of subs measured under similar conditions for true comparison. It ain't perfect, but it's better than nothing.
 

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Since the results are so different from every other test I'm not really sure if its better than nothing.


Even though the FR part of the riddle is explained, it still leaves the maximum output part. How can one sub benefit from being measured indoors while another performs worse? Does Tom Nousaines room suit some subs better than others, is not 20hz produced by one sub the same as 20hz produced by another?
 

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My point is, it gives an idea of sub performance at limits that we shouldn't even be using the sub at. The test data gives no real indication of what the subs sound like under normal listening conditions.


For example, the test of the SB12+ would lead one to believe that the sub has very strong output down to 32hz... and then nothing! I have personally evaluated and tested this sub and can say without doubt that it has a very flat and usable frequency response down to the low 20's, but not when it's played near it's maximum levels. Obviously, at these levels you are hitting compression and limiters are kicking in. Again, these levels are not where the sub should be routinely operated.
 

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Quote:
Originally Posted by mojomike /forum/post/0


My point is, it gives an idea of sub performance at limits that we should even be using the sub at. The test data gives no real indication of what the subs sound like under normal listening conditions.

I kind of agree, but he does give listening impressions also. He did find the Velo to be very satisfying musically despite less output below 25Hz (he hinted that it almost as if by design). Maybe Velodyne made this compromise for better performance above 25Hz. We know from experience here on this forum and tests like craigsub's, and the overall feeling of high end subs like F113 that sound quality is not directly related to performance at maximum output.


I prefer the charts such as the ones at avtalk which give compression curves at various levels. I look at the 85-90-95dB curves and the rest of curves are inconsequential to me.
 

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Wow. this is a really impressive review and I hope others compare the numbers to other S&V similarly reviewed subs.

I wish SVS had gotten a cylinder reviewed, but I'll take any 3rd party review of them by a company like S&V. The SB12 does not stack up to the subs in this competition except for by price. It needs to be compared to similarly sized subs. Despite what some say Price is not the end-all-be-all.


The Outlaw sub is basically a HSU sub right? Can we make inferences there?


Considering how cheap the Velodyne is online, how can people ignore this company's products?


I really like this type of review. Thanks Rockem.
 

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Thank you for pointing this out rockem!


There appears to be a typo in the full lab results. The text of the VTF-3 Mk3 should say: Removing the Turbo extension increased maximum output about 2.3 dB from 25 to 62 Hz and 10 dB at 20 Hz.


The VTF-3 Mk3 in maximum output mode (both ports open, no turbo) would have the following THD-limited output:


32-62Hz (avg): 107.9db (approx.)

25-62Hz (avg): 107.3db

20-62Hz (avg): 106.6db

25Hz: 105db (approx.)

20Hz: 103db

Frequency response: 24 to 85 Hz ±1.6 dB


Regarding the VTF-3 Mk3 with Turbo, there is something strange about the deep bass results (16-25Hz). The THD-limited output at these frequencies should be much higher. For instance, the 20Hz output should be very close between maximum output mode and turbo mode, and 16Hz should be close to the 20Hz output. I noticed that there was a comment made in the review about needing to prop the unit up against the wall to get it to stay in place. This shouldn't be necessary. After all, how else could we test the unit outdoors with good results then? What might have happened is that there was an air leak from the turbocharger due to lack of a good seal between turbo ports and base enclosure. Or perhaps even the carpet grip was not placed underneath the turbo to keep it from moving around. Also, microphone position may have had some affect depending on where it was placed. It is important to keep the microphone equidistant from all radiating sources (ie. driver and port centroid) to ensure an accurate representation of the actual acoustic output of the subwoofer. Dr. Hsu will be contacting TN to discuss.


I would like to thank Sound and Vision magazine for the very kind review!


Sincerely,
 

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One more thing I forgot to point out is that the Outlaw LFM-1 EX is a variable tuning subwoofer that was measured in extended bass mode (with one port plugged). With both ports open in maximum output mode, I would expect at least 2-3db more avg. output over the 25-62Hz range.
 

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Discussion Starter · #20 ·
Those results without the turbo did seem confusing Peter.


Please keep up updated on the what Tom Nousaine says he experienced.


Thanks for chiming in.
 
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