Suspended vs. non suspended turntable

02-18-08: Dan_ed said:
"Mass, yes. Isolation, not so much."

Different correct answers to the same physics question.

My question is, what happens if you deaden structure-born resonance, but what about airborne vibrations? The arm and cartridge, unless islotate, are subject to performance degradation if not protected (isolated).

Dave

Dan_ed I am not thinking of DIY'ing my own turntable, I was thinking of DIY'ing my own turntable TABLE ... i.e, something to put the turntable on! As you can tell from my initial question, I know bugger all about designing turntables. I would rather pay someone who knows what they are doing :)

The learning curve I have in front of me is pretty steep, and i'm at the bottom of the curve :( Have been googling up as much information as I can find.

Piedpiper that was what we suspected when we did the comparison, because my table/arm combo was much cheaper than his. Unfortunately we did not repeat the shootout with a cartridge swap.

That's been in the back of my mind as well. For the moment, forget about vibrations that may be transfered through the stand or table. Short of playing records in a vacuum, I don't see how we get away from airborne vibrations no matter what we chose to put under our tables. But it seems to me that these are much less deleterious than the vibrations and resonances within the cartridge body and tonearm due to the physical vibrations imparted by the gyrations of the stylus. These are the real culprits to me. I've never been able to get a stylus to mistrack because of sound pressure, not that I've really tried beyond just cranking the volume to rock out. Maybe I've missed it, but I don't recall hearing of anyone ever reporting that happening either. Now I think anyone who has spent time in the analog world has experienced LF feedback. But that's not what I'm talking about here and I doubt that is an issue with several hundred pounds of mass involved.

Oh, you can hear it easily. I isolate my TT in a 100+lb armoire, loaded with probably 50 pounds of CD and spare cables and wires in the bottom and my control amp, universal player and TT in the top. All-in we may be talking about 200 lbs.

I've got a Korg MR1000 hard drive recorder that records in 1-bit DSD at 5.6MHz, twice SACD resolution. For the best recording quality I go straight from the phono preamp into the Korg with no speakers. When I record the same thing with doors open and the speakers on I get a less clear recording. With the doors closed and the speakers on the recording is almost as good as with no speakers.

The distortion presents itself as slight smearing or obscuring of detail. There's no outright mistracking. I haven't tried it at really high levels, merely the levels that I'd listen to music at (75 to 100dB at my listening position, with averages in the mid 80dB range).

My armoire and TT is 6 inches from the left speaker and about 18" from the right speaker, so there's a lot of energy right around the TT. After my little experiement I keep the armoire doors closed for all listening session and all recording is monitored with headphones. (I'm archiving my D2D recordings to DSD.

I've got 10" concrete floor and ceiling, so room-borne vibrations are not a big issue for me. Also, the mass of that armoire and all the stuff in it gives my turntable a nice headstart.

The demonstration is easy to replicate if you've got a high quality recorder and a way to isolate your TT from airborne sound waves. (Maybe move it outside the room door). The beauty of the recording is that you can set the level and then move things around quite a bit between test recordings, but when you play back you go very quickly from A to B to C, making it easy to hear the differeces.

Dave

nice test Dcstep! Have you figured out a way to burn SACDs from your Korg?