hightone Posted August 11, 2003 Share Posted August 11, 2003 I just recently picked up a turntable. I was listening to a record and noticed the speaker was vibrating a bit more than usual. I inquired at the local audio shop bout what this could be. I was informed that it was low distortion feedback. The louder I play it the more the woofers go nuts. It is fine with cd however. How do you guys fix this problem? I live on the third floor and its a suspended floor and could use a better rack. Any short term ideas short of a heavy duty rack or concerate floor? Quote Link to comment Share on other sites More sharing options...
reel 2 reel Posted August 11, 2003 Share Posted August 11, 2003 subsonic filter ......filters the frequencies below 15-20 hz...these frequencies steal a lot of power and give nuthing in return but distortion....gc Quote Link to comment Share on other sites More sharing options...
lynnm Posted August 11, 2003 Share Posted August 11, 2003 Generally speaking providing some means to isolate the turntable from vibration will go a long way toward correcting this problem. The thing to bear in mind is that this type of behaviour will muddy the sound of your recordings even though you are not necessarily aware of the effect until such time as you have eliminated it. The sub-sonic filter mentioned by reel 2 reel would be helpful to a degree but would deal only with the most extreme low frequencies. I was experiencing acoustic feedback due to vibration and ressurected an old Discwasher turntable isolation platform and the improvement in the overall sound of my vinyl is astounding. There are many devices available that can provide a high degree of isolation and a high degree of isolation can be achieved relatively inexpensively. One device worth considering is produced by Aural Thrills and involves a platform suspended on an inflatable bladder. One caveat however, one of our members has recently had a very negative experience with that company. There was a thread recently that detailed a rather nasty chain of events regarding their return policy. Quote Link to comment Share on other sites More sharing options...
hightone Posted August 11, 2003 Author Share Posted August 11, 2003 Thanks for the feedback. I will have to investigate both of your ideas. It is frustrating but I am glad I found the problem. Quote Link to comment Share on other sites More sharing options...
jnorv Posted August 11, 2003 Share Posted August 11, 2003 A mounted shelf will sometimes cure the problem. JIm N Quote Link to comment Share on other sites More sharing options...
hightone Posted August 11, 2003 Author Share Posted August 11, 2003 Where could I get a sub sonic filter? Quote Link to comment Share on other sites More sharing options...
WMcD Posted August 11, 2003 Share Posted August 11, 2003 Let me suggest a no cost experiment. Fold up some bath towels and put them under the turntable. It shouldn't be be too difficult to build up a 1 inch layer without creating a leveling problem. That may solve the problem. Gil Quote Link to comment Share on other sites More sharing options...
hightone Posted August 12, 2003 Author Share Posted August 12, 2003 Thanks That I can try today. Quote Link to comment Share on other sites More sharing options...
LarryC Posted August 12, 2003 Share Posted August 12, 2003 I had big floor-based vibration problems with my turntable until it was moved onto a Target wall-mounted stand, which fixed it. Vibration damping under the turntable was an added benefit. I don't know if Targets are still made. Quote Link to comment Share on other sites More sharing options...
hightone Posted August 12, 2003 Author Share Posted August 12, 2003 Yes Target wall mount stands are still made I am gona give this a shot. What are you using to dampen it further with? I was also told that some woofer movement is normal with records in comparison to say cd because of subsonic frequencies. Is this true? Quote Link to comment Share on other sites More sharing options...
lynnm Posted August 12, 2003 Share Posted August 12, 2003 " I was also told that some woofer movement is normal with records in comparison to say cd because of subsonic frequencies. Is this true? " Not really. Subsonics generally only occur when warped records are played. Subsonic content has doubtlessly been recorded in some cases but is almost never problematic with a decently set up turntable. What turntable are you using BTW ? Quote Link to comment Share on other sites More sharing options...
hightone Posted August 13, 2003 Author Share Posted August 13, 2003 Roksan radius 5 Quote Link to comment Share on other sites More sharing options...
LarryC Posted August 13, 2003 Share Posted August 13, 2003 ***Yes Target wall mount stands are still made I am gona give this a shot. What are you using to dampen it further with? I was also told that some woofer movement is normal with records in comparison to say cd because of subsonic frequencies. Is this true?*** A Towshend sink (inflatable tubes inside very heavily damped upper and lower plates). I have the older "2-D" model under the turntable. The good news: it smoothed out and purified the reproduction to some noticeable degree. The less-good news: they do leak slowly and must be pumped up periodically (a pump comes with the sink). I'm not sure it's widely distributed in the U.S. any more, there are probably other products that do as well. I can't see my woofer (K-horns) so I don't really know, wouldn't be surprised. Quote Link to comment Share on other sites More sharing options...
hightone Posted August 16, 2003 Author Share Posted August 16, 2003 Thanks to all. I put the turntable on a wall mounted rack and WOW it cleaned it up. Much cleaner sound and no more tiptoeing around. I can now fully appreciate what this very fine table can do. I did notice the record that gave me some trouble was not perfectly flat I am sure that made it worse. By the time it got tward the third track the woofer flutter was not even close to what it was on the first track. Thanks again. Quote Link to comment Share on other sites More sharing options...
minn_male42 Posted August 16, 2003 Share Posted August 16, 2003 about 25 years ago i had the same problem in an apartment that i was living in..... i suspended the turntable from the ceiling with heavy duty fishing line... it worked like a charm.... absolutely no vibration to the turntable..... Quote Link to comment Share on other sites More sharing options...
djk Posted August 16, 2003 Share Posted August 16, 2003 "By the time it got tward the third track the woofer flutter was not even close to what it was on the first track" Warped record pinch warp=8hz saddle warp=1/2hz Tone arm and Cartridge resonance 8hz~14hz RIAA EQ curve boosts the LF at a 6dB/oct rate which amplifies all of the above. Particularly dangerous to vented speakers. Remove with high pass filter in tape loop or between preamp and power amplifier. 20hz 18dB/oct 30hz 12dB/oct Virtually all Audio Control products have an 18dB/oct 20hz filter built in, some also have a rumble reducer to get rid of turntable vertical bearing noise without rolling off the bass. Quote Link to comment Share on other sites More sharing options...
hightone Posted August 17, 2003 Author Share Posted August 17, 2003 Ok I have been looking for around for a high pass filter and with not to much luck. What do you think about an EQ with a high pass filter between the phono stage and amp? Or where could I get a high pass filter? Quote Link to comment Share on other sites More sharing options...
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