I Have Airborne Feedback And Never Realized It...Till Now


  While my ZYX Airy is out for a rebuild, I hooked up my CAL cd player/transport and started playing CD`s that I had recorded from vinyl using a Tascam 900.
When I do the recording, nothing is on but the TT setup and the recorder. Room is dead silent. No speakers

I`ve  been listening to a disc or two over the last few nights.

Last night, I was listening to a CD I made of Lindsey Stirling`s 'Shatter Me' LP
I was hearing so many odd/different sounds that I never picked up on before using the TT.

For example, I heard growling sounds (seriously) back ground noises and other THINGS that all were hidden when I was playing the TT.
This LP is Bass Heavy! Lots of energy in the air. With 3 15" subs I know that.

My TT is pretty much isolated IMO
I use a Rega wall mount bracket that is bolted to my equipment rack not the wall.
I have the TT sitting on a SRM isolation platform that sits on the Rega bracket
Concrete slab floor.

No doubt the cartridge is picking up on all energy that and resubmitting it.

This won`t be an easy fix I`m afraid..  :(



scm

Showing 5 responses by millercarbon

Have to say the Townshend guy’s videos make an awful lot of sense. MC is making a lot of sense on this too. Slap your table on one of those platforms and I bet most problems go away


Right. Here's some more common sense. 

Ever notice how you can hear the music even without the turntable being hooked up or anything turned on? The stylus tracking the groove causes the whole cartridge body and arm to vibrate so much you can hear it.  

It's not that airborne vibrations aren't making it back into the signal. They are. It's that they are orders of magnitude lower in amplitude than the mechanical vibrations already going on. The sound you hear tracking a record are mechanical in nature. You hear the sound, but the source of the sound is mechanically tracking the groove.   

Still more common sense. Airborne vibrations are super easy to deal with. You can hold a 5 gal plastic bucket over the table, this all by itself will eliminate the majority of the sound reaching the table. Add a little acoustic damping material, drop what's left 90%. People talking about a whole different room simply are not thinking things through. All you need is a good dust cover. But one that is not mechanically connected to the turntable.  

I would take a large plastic tote, big enough to cover the whole turntable, line it with OC703. Cut some strips of OC703, place them on the rack. Set the cover on the strips. This will seal the table off from airborne vibration, while the strips will decouple the tote from the rack and the turntable. This will be the equivalent of an isolation room for the turntable. 

Make it big enough so when you get Pods or a Podium for the turntable you can still use the acoustic cover, and you will have a really sweet isolated rig.
Here is Max Townshend stamping his foot on the floor, proving once and for all vibrations travel just fine through solid concrete. https://youtu.be/BOPXJDdwtk4?t=86 

I am constantly astounded at the ability of people to ignore solid evidence and persist in wrong thinking, even to the point of talking about moving a turntable to a whole different room, rather than just try what has actually been shown to work. The guy repeating the concrete good to go BS knows it is BS, but keeps repeating it. The guy talking about moving his turntable to another room can solve his problem with some $30 Nobsound springs or even a $5 box of sand. But no, the Good Ship Nonsense has a full head of steam, full speed ahead! Absolutely amazing.
I remember back when I used to record my lp`s to cassette, I could very  loudly talk right at the cartridge while recording and I could hear my voice on the tape afterwards.
That's what is happening here I`m pretty sure.
It's not mechanical IMO

So you're sure the one rules out the other. Interesting.

You are on the right track but I seriously doubt it is acoustic, it is almost certainly mechanical. Speakers on spikes transmit energy right through the floor, up the wall and into your turntable. Same happens with CD just nowhere near as obvious. When it is gone you will hear it though even with CD. 

Concrete floor, one of the great misconceptions is you cannot have these problems because, concrete floor. But concrete transmits vibrations just fine, only the frequency and speed of transmission varies. There is nothing inherently vibration damping or absorbing about concrete. Quite the opposite. Rings like a bell. 

So your solution is very simple, what you need is to isolate the speakers from the floor, and the turntable from the rack. The SRM you are using is kinda sort okay, better than nothing, but obviously not enough.  

There's a couple ways you can go. Least expensive will be something like Nobsound springs under your turntable or under the SRM. Not sure which one you have. The one I found on-line is not very impressive but it could work as a shelf with springs under it. You can use these springs under the speakers as well. Very effective. Surprisingly effective for the money.  

If you can afford it however the best solution will be Townshend Pods and Podiums. Which is best will depend on the size and weight of your Rega. Podiums for sure will be best under your speakers. The vast majority of your problem is coming from direct transmission of vibrations from the speakers through the floor and walls into the turntable. I had this even with my massive 750lb turntable rack. Dramatically improved clarity and detail. 

Not cheap but will totally solve your problem, while taking your whole system up a step in the process. Or if you want to try Nobsound springs do a search, there was a very informative thread on them last year. I used them before going to Townshend, they really do work, quite well in fact, just nowhere near as good as Pods and Podiums.