TW Raven Acustic AC Owners

I have a Clearaudio MontBlanc dedicated turntable stand and it never ceases to amaze me, I can play music loud until their is bass in your chest and the Transrotor Apollon / Clearaudio rack combination are something I never have to worry about. I do not get any acoustical or resonance feedback into the source. My basement is entirely concrete, with double concrete double insulation exterior walls and a concrete ceiling with about a thickness of about 15" inches. yes, the basement is my bomb shelter, haha. I think with the mass of the AC, I would add more mass via a heavy rack for a combined weight of whatever the rack and AC weigh. The Apollon and the Clearaudio rack together are almost 400lbs of mass. I am just too skeptical of adding such heavy weight to the wall, it is a viable option for some, but to me, I rather use a rack first then wall mount last. It seems way too scary for me to see your work of art sitting so high off the floor and then held in place by a rack with anchored points on the wall. See my rack option in my virtual gallery.
Ciao,
Audioquest4life

Elinor,

Please look up my system page to see what i did. I made my own stand via springs etc purchased from Machina Dynamica. In my system I had feedback which caused some lack of resolution due to the bass. All these problems were removed with the deployment of the stand. Not all rooms will have the same needs but in my system the bass is down to 20 Hz w. subwoofer & fullrange speakers. It was clearly audible. I also agree wall mounting (if you can do it) probably is the best solution short of a very expensive rack or a DIY job.

HI Elinor

Nice table you have chosen. Your rack is probably more than adequate, from the pics I have seen of them for sale. If it is the low type of Adona racks it would probably be better, lower center of gravity, less chance of it swaying, and vibrations being trapped in a bigger taller rack.
For a shelf Thomas of TW uses and recommends a type of slate found in Europe. Prior to getting the Minus-K I just used the rack I built made ot of birch ply almost three inces thick. I found isolation to be very good as the TW handles if farily well. You could try maple butcher block type boards of at least two inches thick. Make sure it is good white hard maple not the cheap soft stuff some guys pass off as butcher blocks. Birch ply is cheap and something you can do yourself. Glue stack and cut to size. Home Depot sells it in 48"x24" sheets.

I have seen custom built wall mounts that can support serious weights, and have heard stories of guys making some to support over three hundred pounds(Vibraplanes supporting an SME 30). But unless you have access to run long bolts through a wall with support plates on the other side, forget about that. I would not trust just some good lag screw to support such a crazy structure. If you do a wall mount keep in mind your location of that table is fixed to that spot in your room, and if later it becomes a bad spot that you have some more work to do.

If you can try either the HRS or SRA, which BTW has a working relationship with TW and High Water Sound, is probably more informed on the TW than any other isolation manufacture. Neither are cheap if you can try before you buy look into it. The HRS stuff is more generic, and SRA is purely custom. I will say SRA improved the sound of my SME 30 when I used it under that, and the guy that bought my old setup will say the same thing enthusiastically.

If you have a concrete floors you will not have to worry as much about vibrations as someone on a upper floor, like me. But I found mine to work very well without any vibration cancelling assistance.

Paul
Paul

I am a Raven AC user myself and have been wondering if my isolation is adequate. My Raven sits on a Japanese made TAOC rack. When I knock on the rack or the shelf, i hear a fair bit of acoustic feedback. Is that a sign of inadequate isolation? My Raven comes with the Stillpoint feet. When I do the test, the stylus is on a stationary LP and the volume is turned up to normal listening level. Comments appreciated.

Mount the TT on a shelf firmly cantilevered from the wall.
Sound is transmitted it 2 basic ways:
AIR-BOURNE
STRUCTURE-BOURNE
90% of audiophiles mount their TTs on racks sitting on the floor.
This is a disaster for both types of transmission.
Even a concrete floor (which is not generally bouncing around like a timber-framed one) is a great transmitter of sound, so that any rack sitting on the floor is receiving BOTH types of transmission.
This is why Continuum Audio Labs create a rack for their Caliburn that costs $25,000. That's how much technology is required to overcome this basic problem of physics.
When you cantilever off a wall, you are disconnected from the floor (USA stud frame tradition can often short-circuit this advantage).
The materials to fix to the wall, project from the wall and form the shelf for support, generally act to physically 'de-couple' the shelf from the wall.
Thus all or most STRUCTURE-BORNE and AIR-BORNE sound transmission within the floors and walls are eliminated.
The only transmission to now worry about, is the AIR-BORNE transmission directly into the supporting shelf (and here is where Jon's granite shelf is NOT a good idea.
Granite rings like a bell and transmits sound deliciously throughout many audible frequencies without much absorption or dampening. Timber is a better insulator and dampener.
However it may be academic because all one has to do is DE-COUPLE the turntable from the supporting shelf to eliminate the transmission of this air-bourne absorbed sound.
Stillpoint cones with ceramic balls is a good way and there are many others.
Then the only sound transmission to worry about is the AIRBOURNE sound which the TT base and platter are able to absorb THEMSELVES.
This is where the turntable designer earns his crust with the elimination, absorption and dissipation of this air-bourne feedback setting his TT apart from the rest.
Of course the ability of the tonearm and cartridge to absorb and dissipate this same air-bourne transmission (feedback) is equally important but the frequencies are much higher and smaller.
So the moral is......do everything possible to wall-mount your turntable.