I had a big woofer pumping issue
In my case we finally isolated it
The bearing in the tonearm wasn't moving properly so there was cyclic woofer movement as the cantilever took the brunt of the motion
We did a feather test suggested by Thom Mackris and that was it
A tonearm tune up and no more issues
One of my threads on it
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1400370649&read&keyw&zzwoofer=pumping
What is your flooring type, turntable rack / isolation?
Is it more apparent on the outside grooves of the record?
Is it cyclic or keyed to loud passages or bass heavy parts of the music?
Search engine is your friend
I found 8 threads putting in the words woofer pumping
In my case we finally isolated it
The bearing in the tonearm wasn't moving properly so there was cyclic woofer movement as the cantilever took the brunt of the motion
We did a feather test suggested by Thom Mackris and that was it
A tonearm tune up and no more issues
One of my threads on it
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1400370649&read&keyw&zzwoofer=pumping
What is your flooring type, turntable rack / isolation?
Is it more apparent on the outside grooves of the record?
Is it cyclic or keyed to loud passages or bass heavy parts of the music?
Search engine is your friend
I found 8 threads putting in the words woofer pumping