What user510 said. In addition, altering the distance between the platter bearing center and the tonearm pivot must necessarily create a speed anomaly, as the belt must stretch or contract to accommodate changes in the distance between the motor pulley and the platter, where the motor is not mounted on the suspension.
How to isolate turntable from footstep shake or vibration
Even while the Oracle turnable that I use has a built-in springs suspension by design there is a low or even sub-low frequency boom every time someone walks in a room. This becomes really bad with the subwoofer’s volume set high as the low frequency footsteps make straight to subwoofer where they are amplified shaking everything around. It seems the cartridge is picking up the footsteps very efficiently as even a lightest foot down becomes audioable. What can be done to attempt to isolate the turntable from the low frequency vibrations? Interesting, that the lower the volume of the subwoofer, the less the footstep shake is evident and with the subwoofer turned off it is a barely a problem at all.
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Quote/ esputnix OP16 posts06-15-2021 2:42pmThank you for all your suggestions! I’ve double checked the suspension. And it appeared that the right tonearm side needed a stiffer spring as the aluminum housing was so low that it touched the base. It was simply sitting on the turnable instead of "floating in air". I have replaced the spring with the stiffer one and viola! The effect was instant. The footsteps rattle is gone. Even with the maximum subwoofer volume it is dead silent. It doesn’t even respond to me jumping in a room or shutting the door. It feels like I’ve got a free upgrade as it appears it sounds better!" /unquote Above quote from page one. Aha...the solution was to correctly adjust the suspension of the TT by replacing the spring nearest the tonearm with a stronger one. Perhaps at one point the tonearm had been replaced with a heavier one...(speculation) Those Oracles apparently require a different technique to their adjustment than do the earlier designs based on the original AR. And now he doesn’t have any footfall issues. Probably his floor isn’t as -flexy- as some are known to be...or perhaps the Oracle, when correctly adjusted, is less prone toward footfall.. I don’t know..... Still we don’t know exactly which design the Oracle in question is. A Delphi or Alexandria. Both seem to use a very similar subchassis. agree with ghdprentice , the proper solution is to isolate the turntable from the "trampoline" via wall shelf....That is when you live on a trampoline floor, I know I have. Others on this list have very solid flooring entirely suitable for situating a turntable over...yet...among those that do.... many will insert an isolation device between said turntable and the floor mounted rack it sits on in order to improve overall sonic performance of the TT. I think the idea is to isolate the turntable from its environment as much as is possible.-Steve |
I’ve been following this thread with interest as I’ve just changed from a (fully suspended) Avid Acutus to a Techdas Airforce V which has no suspension. The Techdas is amazing and has near CD silence between tracks and the dynamics and scale of presentation is terrific. However, I’ve been wondering how some sort of isolation might work with the Techdas. I read a lot about the Townshed isolation platform after the comments from @millercarbon and purchased one out of curiosity. The Townshend platform has a spring/pod at each corner and is easy to set up and level. The results are quite startling with a big improvement in the ability to separate vocalists along with improved bass. In fact there just seems to be slightly more of everything. I’m rather surprised at the difference this has made and I’m now wondering what sort of impact this might make under my Atmasphere OTL amp! |
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