Huge Acoustic Feedback on TT

[Saket]

Hello FMs,

Finally I set up my TT, amp & speakers in my living room in my new house. My Set up is Technics SLQ33 DD, pioneer int amp, 2 unpowered bookshelves & 2 Floor standers with built in amps.
Now the problem: The set up plays good music at low to moderate volume levels but when I try to increase the volume, I get huge acoustic feedback in form of extremely low freq humming sound which had all kitchen utensils shattering last night. Its like a microphone close to speakers.
Without the floor standers, it plays fine (but I need the FS for the obvious reasons!) I tried putting cushions under the floor standers but didnt do any good.
Please let me know if you have any ideas for addressing this problem. The TT is fairly far from the FS.

Thanks & regards,
Saket

 

[Saket]

I found this article...very nice & simplified

look at the second post here
Turntable isolation

Please also share your ideas. Need to solve it ASAP.

 

[anm]

shattered? that must be something!

 

[Saket]

shattered? that must be something!

Really it was something! Even the chimney in kitchen was making that noise...not to mention the window frames. Actually the floor standers are really powerful & that 'sonic boom' coming out of its 4 powerful woofers was responsible for it.
Lets see what I can do today evening to solve this problem.

 

[Saket]

Ok, some good news...I solved the problem last evening. What I did is put foams under each feet of the TT.
It lessened the problem but not eliminated the problem completely. Then there was this one...I had placed the TT on the top surface of a showcase which had 2 shelves under it. These shelves were enclosed with an openable glass shutter kind of (fixed by a hinge). I have place my phono amp in these shelves. Now this space inside the shelves were acting like acoustic vibrations collector and hence added more vibrations to the surface of the showcase top. This was resulting in the acoustic feedback at high volumes. To address this problem, I just filled the last empty shelf with my DVD player & some CDs. Lastly, what I need to do while playing music at higher volumes is to open the glass shutter so that the vibrations do not get 'collected' in the cabin like area of the showcase. This solves the problem completely.
Now as happy as a pig in slop!:yahoo:

So, thats the moral of the story, not to use cabin type shelves for TTs.