What's Rattling ?

[George Bellefontaine]

I set my sub up according to Hoyle with an SPL meter, but every now and then (very noteworthy on U-571) something rattles on one of my back walls.There's a storage room on the other side of that wall and some crap lying around. I cleaned it all up and still something is rattling. Do I have the sub set too high ? The rattles only happen when when the lows are extra extra low, like U-571. At first I thought it may be the second sub at the back of the room that was causing the problem. But no. I shut down that sub and played the U-571 depth charge scene and rattle is still there. Any ideas ? It's not intolerable, just annoying.




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[Andrew Pratt]

Do I have the sub set too high ?

I can get my walls ratteling pretty easy on movies like U571 and Toy Story 2...I think there's pipes or wires in there that rattle but it might well just be the joists themselves Of all the problems to have in a HT this one isn't so bad LOL

[John Holmes]

I doubt that it is too high. I have athe same problem but with a double-pane window. Not much I can do about it (without major work and funds) so I live with it.

It also seems to favor a specific freq for, it only does it now and then.




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[Markj]

My HT is next to the kitchen so I just consider the extra rattling a feature! No way to get all of the cups and dishes to be quiet!

[KennyG]

You are hitting the "resonant" frequency of something in or on that wall.
Something in the wall is getting excited (or resonating) by that certain freq. It could be something left in the wall during construction, a pipe, perhaps shelves on the other side of the wall? Perhaps part of the wall to not nailed tightly to the framing so the wall rattles against the frame, loose trim molding.
A good way to hunt is down would be with a test disc that has low freq's on it...play the freq sweep and find out which frequency gets this mystery item excited...set your player up to repeat that freq, then go on a hunt to find the item/spot it's coming from.

[Susan]

I finally figured out where some of my rattling in my 50-yr old home was coming from...I took three months and mounted about 60 framed pictures in the stairwell leading down to my den (which is my HT)...we call it my "Rogue's Gallery", with hub's family on one side and mine on the other...

U-571 was probably the first one that really made the glass and frames against the wall go really crazy. Up until that time they were "free-hangling" but since them I bought a tube of clear silicome caulk and put a blob at the lower corners on the back sides of the frames...in essence I padded and insulated the wall from the frames...and it has cut down on the racket considerably (plus they don't skew off of level now..really used to look like an earthquake had come thru after a low-frequency movie and before I added the silicone...). If the frequencies go really low we still get rattling windows, twangs and "cymbal" sounds...but those aren't that bothersome..kinda goes along with the "...good, good, good (butt) vibrations..."
SS

[Lex]

If the rattles keep going when the HT is off, you have something to worry about. Either call the Seismic authority or Ghostbusters, lol.

I gave up long ago on a fix for this. Bass can even rattle concrete I think! It's not totally unlike earthquaqe activity IMO.

Lex

[George Bellefontaine]

Thanks, folks. Nice to know I am not the only one with the rattles. Like Andrew says, it's not such a bad problem to have. Anyway, I'm going to take Kenny's suggestion and see if I can find the culprit.




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[ThomasW]

George

When JonMarsh was here in Denver 2 weeks ago, we were EQing the IB subs using swept sine wave signals generated by the CLIO board. The entire 2500 sq ft brick house resonates at 16Hz. Sounds like it's coming apart at the seams, but fortunately it stays together




theAudioWorx
Klone-Audio

[Buzz Goddard]

Some test discs (the THX WOW! laser disc comes to mind) have a slow swept sine wave that is labelled Rattle Test. You'd be amazed how many things rattle at quite a number of frequencies.
Light fixtures, ventilation ducts, window and picture frames, even gear on and in racks!




Buzz Goddard
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[George Bellefontaine]

Well my HT is in the basement and as long as the concrete walls don't crumble, I'll be okay with the rattles.




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