SVS and port noise... (1 Viewer)

[Chris Demaree]

While watching 'The Haunting' in DTS, I noticed quite a lot of weird noise comming from my 20-39pc during some scenes (an almost whistling, snorting kinda sound). This only occurs in 'The Haunting' and it only occurs when there is a lot of bass going and not much else. U-571, TPM etc. do not seem to generate the same type of sound. I know my sub is not bottoming out, it has been calibrated and EQ'd so that the THX intro on TPM will not bottom out the sub at a higher volume than I normally listen to. I do not believe that there is a leak, U-571 does not generate any odd noise (that I can hear anyway) and my BFD shows a LOT of bass going to the sub I'm mainly curious about what could be causing the noise, and potential fixes/adjustments any thoughts?
Equipment:
Outlaw 1050
Paradigm Titans, CC-170, Energy Take2 (surrounds)
Toshiba SD-2200
Sony KV36-FV26
BFD DSP1124
Room:
13'x12'x8', open on one side to the kitchen.

 

[Jack Gilvey]

Is there any way you can remove the grill which protects the port and try those scenes again?

 

[SVS-Ron]

Chris,

If Jack's idea of removing the grill changes things please let us know (we have never had a report of grill noise from the thousands of subs we've sold though). If it does NOT help, and you are certain the noise is coming from the sub and the sub is not being pushed to the point of distortion (the Haunting contains some insanely low and loud bass that could be over loading the driver if you are cranked) then let us know that too.

The fact it only happens with certain scenes is curious but not inexplicable, and not somehthing we'd accept unless it's truly at extreme levels. If it comes to it we'll exchange the sub and try to repeat the problem.

Ron

 

[Jack Gilvey]

If Jack's idea of removing the grill changes things please let us know (we have never had a report of grill noise from the thousands of subs we've sold though

I've never seen anyone post to that effect either. It just occured to me to suggest it because Howard Ferstler apparently heard grill noise on test tones (not rattling, but air moving through the grille) before actual "port noise" or distortion was present (details somewhere in here) .
The situation that Chris describes, lots of bass with little else to mask it, is unusual and seems as close as you'll get to test ones in a movie. Worth trying, I suppose, "whistling" sounds like air noise to me.

 

[SVS-Ron]

You had to dredge THAT thread up eh Jack?

Electrons are embarrased by some of the stuff in there.

What would you think "snorting" might be then? Please, no links for that one. ;^)

 

[Jack Gilvey]

Electrons are embarrased by some of the stuff in there.

Hehe, true, although a careful read reveals all kinds of interesting stuff.

 

[Chris Demaree]

I'll give that a try tonight, I will also take some SPL measurements during the scenes in question.
Hmmm, I think both of my cats are too big to fit in the SVS port..... I'd hate to have to start a 'how do I get my cat out of my SVS' thread

 

[Jack Gilvey]

Careful, you might get a call from PETS (People for the Ethical Treatment of Subwoofers). They're already demanding a recall of the Phantom Menace DVD.

 

[Tom Vodhanel]

Yeah, all kinds of stuff caked with questions of my/svs integrity and court room style question methods that I couldn't possibly answer in any accurate fashion. And some guys wonder why manufacturers like denon,marantz,vel,paraidgm,ect,ect don't bother with forums...?

TV

 

[Jack Gilvey]

People who would question your integrity aren't worth your time. I think that's why Dr. Hsu rarely bothers with the anonymous masses anymore.

 

[Chris Demaree]

ok, here are some measurements:
HT room 12x13x8, one 12' section opens into the kitchen (18x10x8). Taking SPL measurements from my listening position (9' from the sub) I came up with a peak of 105+dB (uncorrected). Since this is a LOT louder than I thought it was, am I just asking a bit too much out of one sub? I have the sub handling everything below 100hz (my mains generate a bad null at 90hz) :frowning:
P.S.
...105db of bass in the livingroom, thanks SVS!!

 

[Tom Vodhanel]

>>>ok, here are some measurements:

HT room 12x13x8, one 12' section opens into the kitchen (18x10x8). Taking SPL measurements from my listening position (9' from the sub) I came up with a peak of 105+dB (uncorrected). Since this is a LOT louder than I thought it was, am I just asking a bit too much out of one sub? I have the sub handling everything below 100hz (my mains generate a bad null at 90hz)

P.S.

...105db of bass in the livingroom, thanks SVS!!

 

[Chris Demaree]

Yes, the source was DTS Haunting and the sub sounds excellent for everything I've asked it to play. I calibrated it with AVIA (only test tone disk I own) and EQ'd it with a BFD. I'll take some sweep measurements tonight, at my normal listening level and post those (I don't remember what the average hovered around). I have absolutely no complaints about the sub, the low-frequency output is actually increasing when the test tones stop at 20hz

 

[Tom Vodhanel]

Hi Chris,
I think this is simply the 39PC running out of gas then.
It looks to be around 112dB(corrected) 3m away...with perhaps the most demanding DVD track out there(haunting-dts). So that's within a few dBs of full reference level capability(if all speakers were set to large) at a 3m distance in sort of a *bad* room for bass . I think that's about all we're going to squeeze from a single 20-39PC.
TV

 

[Chris Demaree]

Thanks, perfect excuse to save up for twins. One SVS is amazing, two would be