greg@olivej.UUCP (Greg Paley) (02/01/85)
The importance of isolation for CD players has been raised here several times and seems to nearly rival the situation with turntables. I don't own a CD player (yet), but have several friends who've lent me theirs for extended periods of time and I've found some of them very susceptible to shock and external vibration. One idea I would be inclined to try if I owned one is what a friend did, with dramatic results, with his Thorens turntable. He mounted a shelf for the turntable onto brackets that were, in turn, directly secured into the wall studs. Being suspended from the vertical studs, there was a notable improvement vs. mounting the unit on anything that was ultimately resting on the floor. The table now appears virtually impervious to either footfalls or acoustic feedback, whereas previously, with it sitting on a cabinet, even walking past gently could send it mistracking. This clearly causes some decorating problems, since it puts the unit in a fixed location in the room, allowing for no flexibility of rearranging. However, if this is as effective for a CD player, it could turn out to be far more economical than spending a large amount of money just to have internal isolation in the unit itself. This might make feasible the purchase of such units as the recent Sanyo model which sounded good but was exceptionally vulnerable to mechanical shock. In fact, footfalls in the area which left an AR turntable completely unperturbed, were able to audibly upset the Sanyo. - Greg Paley
rcd@opus.UUCP (Dick Dunn) (02/04/85)
> The importance of isolation for CD players has been raised > here several times and seems to nearly rival the situation > with turntables... But be aware of the real nature of the problem. A CD player can recover up to an extent with its servo, then the error-correction, finally it fails and (should) mute. It's not going to distort the sound unless you actually start doing serious error correcting, and it's not going to damage the disk the way a turntable can when bounced. >...I don't own a CD player (yet), but have > several friends who've lent me theirs for extended periods > of time and I've found some of them very susceptible to > shock and external vibration. Treat this as a criterion when shopping. Some players are much more sensitive than others, so look for one that isn't too sensitive. Keep in mind that current technology produces CD players which will work in cars or as walkaround units, so a stationary unit CAN be stable. Most units seem to have rubbery (yes, I know it's really some magic polymer) feet which do a certain amount of isolation. It probably would be a bad idea to defeat this--for example, don't try to rack-mount a CD player unless it's meant to be, since that will couple vibrations directly into the cabinet from the rack. -- Dick Dunn {hao,ucbvax,allegra}!nbires!rcd (303)444-5710 x3086 ...Never offend with style when you can offend with substance.
idallen@watmath.UUCP (02/04/85)
In one old house with sagging floors, I put the turntable in an outside
window. The outside window glazing was tight enough to keep the snow
out -- the turntable sat straddling the ledge where the inner sash came
down. The house had nice, thick brick walls and the resulting solidity
meant you could do gymnastics in the room without bothering the tracking.
I've often thought of hanging turntables from the ceiling...
--
-IAN! (Ian! D. Allen) University of Waterloojlg@lanl.ARPA (02/07/85)
Since this has turned into a discussion about turntable isolation, I would
like to solicit information about any product that will minimize the low
frequency noise I get when I walk near my turntable. I understand that
there are products which you put your turntable on that have a resonant
frequency of about 1Hz. Where do I get such a thing? Are there homebrew
devices that would work as well?
Thanks in advance
or
adva-thanks-nce
J. Giles