Subwoofer Tests - Fall 2007

[Ilkka]

SteveCallas wrote:

Did a search and found it was actually Bob, not Brian.

Yeah, I remember that. That's obviously a mechanical failure. Most probably he bottomed out (VC/former hit the back plate) the driver since the dust cap has been torn off. He was using a passive radiator design.

I have yet to seen a picture of a thermally damaged VC on these forums. Every single one has been a mechanical failure.

[ISLAND1000]

Ilkka wrote:

So are you trying to find at what level and after what period of time the subwoofer breaks? Please see my explanation above.

I'm certainly not suggesting a test be run till break point only to determine uhmmm . . . . . a drivers level of what might be called "severe service" , a point where stress becomes noticeable.

[WillyD]

I have yet to seen a picture of a thermally damaged VC on these forums. Every single one has been a mechanical failure.

I've been saying the same thing for a while now. The only person I've heard from who has supposedly fried a VC in a home setting is Chuck, and that was a DVC. Well now folks understand the real deal about the VCs on these modern drivers and that they are quite hard to fry.

There is an old test made by Richard Clark where he tested an AA Brahma and a JL Audio 13W7. They both could take 32 kW at 80 Hz when using burst signal.

The peak spec for the LMS-5400 is 8000 watts, but I'm guessing that's way way underrated. It should be able to take 40-50 kW (above ~65-70 Hz) or more in a small sealed enclosure when using burst signal (when distortion is not limited naturally).

[bobgpsr]

Ilkka wrote:

Yeah, I remember that. That's obviously a mechanical failure. Most probably he bottomed out (VC/former hit the back plate) the driver since the dust cap has been torn off. He was using a passive radiator design.

I have yet to seen a picture of a thermally damaged VC on these forums. Every single one has been a mechanical failure.

Yep no burnt VC smell. I had earlier (other times before it blew) thought that I had been hearing extra noises flapping/rattling from the Tumult at louder levels. Since others also have have mech failure problems with the Tumult MK II's (the Chilean built ones) that might indicate that they had a design weakness unlike the original MK I's. No problems so far with the CSS SDX15 that replaced it. Though I am more carefull with the driving amp. I am now using the soft limiters of the Mackie M1400 pro amp and only one channel of the amp for driving the sub. Nice to have some subwoofage capability present even though can't get reference level in the big basememt room it is in. Better WAF this way anyway.

[Exocer]

bobgpsr wrote:

Yep no burnt VC smell. I had earlier (other times before it blew) thought that I had been hearing extra noises flapping/rattling from the Tumult at louder levels. Since others also have have mech failure problems with the Tumult MK II's (the Chilean built ones) that might indicate that they had a design weakness unlike the original MK I's. No problems so far with the CSS SDX15 that replaced it. Though I am more carefull with the driving amp. I am now using the soft limiters of the Mackie M1400 pro amp and only one channel of the amp for driving the sub. Nice to have some subwoofage capability present even though can't get reference level in the big basememt room it is in. Better WAF this way anyway.

Sorry to take this thread off topic...but bob, have you noticed any subjective differences between the two drivers?

[bobgpsr]

Exocer wrote:

Sorry to take this thread off topic...but bob, have you noticed any subjective differences between the two drivers?

Other than no extra unwanted noises? No. The SDX15 just disappears normally, like a well integrated/calibrated sub should. Extra deep LFE from movies or low bass from organ music is "there" like it should be. So I feel that not noticing (rattling, buzzes, port chuffing) the subwoofer is good.

So for me a subjective good criteria, is not noticing the speakers or the subwoofer. If I crank up the sub level above calibration -- then I notice the sub.

[Exocer]

bobgpsr wrote:

Other than no extra unwanted noises? No. The SDX15 just disappears normally, like a well integrated/calibrated sub should. Extra deep LFE from movies or low bass from organ music is "there" like it should be. So I feel that not noticing (rattling, buzzes, port chuffing) the subwoofer is good.

So for me a subjective good criteria, is not noticing the speakers or the subwoofer. If I crank up the sub level above calibration -- then I notice the sub.

Well that sounds brilliant! I had given some thought to sending my Tumult to Robot Underground for a re-cone, but am having a hard time deciding if i should trade-in the Tumult and go with an SDX-15 or get my Tumult fixed for $110 to complete my subjective SQ thread.

Honestly I may go the re-cone route, since theres already so much objective information about the SDX-15 at this point. Thanks again Ilkka

[ISLAND1000]

Ilkka wrote:

The peak spec for the LMS-5400 is 8000 watts, but I'm guessing that's way way underrated.

I have yet to push my own LMS to it's limits. I'm hesitant (more careful) using my Crown XTi 4000 since I HAVE already fried a 400 watt VC accidentally switching the wires from the LMS to a Cadence 18" with the 400 watt rating without first shutting down the amp. Everyone makes mistakes in the heat of excitement
A fried VC is hard to see unless you remove the damaged parts. I'm leaving the the Cadence speaker as is while I decide whether or not to have it reconed.
The Cadence voice coil of course had bottomed out and then blew the dust cap off just before the VC separated from the cone and tore off almost all of the suspension spider. The VC remains attached to the wire leads and the surround was not torn from the basket or damaged.
I checked the VC for electrical continuity and of course there was none.

[Chris Brunhaver]

I would strongly recommend against using Robot underground for reconing your Tumult. I've met Patrick before and he seems like a nice guy and everything. However, he's using the wrong coil design. XBL^2 design are sensitivity to using the right coil length and he's not even close. This totally screws up the BL curve (creating a huge BL peak in the center 5 mm or so of travel).

I'd definitely talk to Scott at www.ficaraudio.com (or in his forum here). I believe that he still stocks that coil. If not, he could use the REXXX aluminum coil (but with a single soft spider).

[Exocer]

Chris Brunhaver wrote:

I would strongly recommend against using Robot underground for reconing your Tumult. I've met Patrick before and he seems like a nice guy and everything. However, he's using the wrong coil design. XBL^2 design are sensitivity to using the right coil length and he's not even close. This totally screws up the BL curve (creating a huge BL peak in the center 5 mm or so of travel).

I'd definitely talk to Scott at www.ficaraudio.com (or in his forum here). I believe that he still stocks that coil. If not, he could use the REXXX aluminum coil (but with a single soft spider).

Very glad my post caught your attention...Thanks a lot.

I'll wait to hear back from Fi.

[mojomike]

Hi Ilkka. How are the prospects for that 13Ultra test? Do you think you will get a chance any time soon?

[JimP]

mojomike wrote:

Hi Ilkka. How are the prospects for that 13Ultra test? Do you think you will get a chance any time soon?

Ditto.

Your test are highly respected and others including myself are very interested in how it objectively test out. Especially in the distortion area.

[Ilkka]

mojomike wrote:

Hi Ilkka. How are the prospects for that 13Ultra test? Do you think you will get a chance any time soon?

Does this answer to your question?

[mojomike]

Yes indeedy! That's what I'm talkin' about.

[Ilkka]

The lists below now contain these new entries:

SVS PB12-NSD new
SVS PB13-Ultra 10 Hz
SVS PB13-Ultra 15 Hz
SVS PB13-Ultra 20 Hz
SVS PB13-Ultra sealed

I believe Ultra's four tuning frequencies/settings go without saying. The "PB12-NSD new" is the latest revision of this model. Performance of the new PB13-Ultra in all settings, but especially in 20 Hz and 15 Hz, is very convincing. From all the subwoofers I have tested thus far (using the CEA-2010 test), in addition to the JL Audio Fathom f113, the new Ultra is the only commercial subwoofer that can even slightly tremble the "top 10" ruled by the all mighty DIY subwoofers.

Pictures from today (starting from #93)

Yes, I was able to blow the internal main fuse of the PB13-Ultra - twice. It didn't seem to like my 30 second long sine sweeps at extreme levels (I was expecting this based on AV Talk's measurements though). More dynamic signals like the CEA-2010 bursts didn't cause any troubles, even at extreme levels. It shouldn't be possible to blow the fuse using regular program material. This "problem" doesn't have anything to do with the other PB13-Ultra amp problem (shut-down due to bad batch of components combined with sagging 110 V voltage). There are no reports of shutting down 230 V versions of the new Ultra.

Alphabetical list:



"Low-bass Avg. 40 Hz - 63 Hz" list:



"Ultra low-bass Avg. 20 Hz - 31.5 Hz" list:



"Avg. 20 Hz - 80 Hz" list (operating range of a normal/good subwoofer):

[funky_waves]

I would like to see how the css sdx15 stacks up in a 200L vented. tuned to about 18hz. Maybe I'll have to send you one(Fw 15.1) the singe tc2000 ported seems to outdo the dual tc2000 sealed. SDX 15 would do the same?

[Sonnie]

The PB13-Ultra is definitely no slouch... nice!

[Ilkka]

funky_waves wrote:

I would like to see how the css sdx15 stacks up in a 200L vented. tuned to about 18hz. Maybe I'll have to send you one(Fw 15.1)

I think that can be arranged. But isn't 200 liters slightly small? Around 300L sounds better.

the singe tc2000 ported seems to outdo the dual tc2000 sealed. SDX 15 would do the same?

The dual TC-2000 140L sealed had a broken surround (other driver), so its results below 50 Hz do not represent its real performance. In reality it would score a little bit higher than the dual SDX15 140L sealed.

Also the single TC-2000 90L had an off-spec driver, so its performance either doesn't represent a "proper" TC-2000 in a 90L sealed enclosure. Hopefully I will be able to test these again some day.

[mojomike]

Those Ultra results are really amazing, especially in the 16hz tuning, although actually SVS calls it 15hz.

[Ilkka]

mojomike wrote:

Those Ultra results are really amazing, especially in the 16hz tuning, although actually SVS calls it 15hz.

LOL, good catch, Mike! I'm so accustomed to writing "16 Hz" based on older SVS subs, that I wrote it again even though I thought of writing 15 Hz. Doh!

It's corrected now.

Although I haven't yet checked the real measured tuning frequencies. I will promise to do that soon.

[funky_waves]

Ilkka wrote:

I think that can be arranged. But isn't 200 liters slightly small? Around 300L sounds better.

Yah I tried to keep it on the smaller side without loosing too much 200L seemed to be reasonable. I may offer a larger one with a little lower tuneing later on.

[Ilkka]

funky_waves wrote:

Yah I tried to keep it on the smaller side without loosing too much 200L seemed to be reasonable. I may offer a larger one with a little lower tuneing later on.

Yeah, I was just joking. Not everyone can or want to accommodate a 300 liter enclosure.