Help! Tweaking My Lovan Rack for new Big A**ed Transrotor Turntable!

@prof, 

What makes this hobby fun is the shared interests and experiences of others to help each other out. In terms of isolation, the more rigid and robust in terms of mass your base platform is, the better it will isolate the rest of the equipment from vibrations. My experience with that method is to spike the base platform to isolation footers to your floor, tile,  carpet, bamboo, concrete, wood, or whatever. This type of isolation works extremely well especially if the base platform sits on a rigid base...non floating floors, etc. Minimal vibration transfer will occur using this method. Then, the platform on which your components sit, you can experiment with a variety of absorbers, cones, or rubber feet,in the pursuit of vibration free happiness. I for one have relied on the spiked feet platform approach, and the turntable rests on a one inch thick plexiglass with semi-rigid rubber cushions. Works fine for me. The knock on the platform test does not reveal any vibration through the turntable. Of course, my platform mass consists of nearly 300 pounds of concrete poured stainless steel columns, ala, Clearaudio, with the aforementioned spikes. The mass of your Fat Bob will aid in helping to damp any vibrations as well. At the dentist nd of the day, spiked feet to the floor is one step in the pursuit of isolating vibrations. 

On another note, if you play music extremely loud, I have not found any way to isolate high pressure air disturbances on the tonearm due to extremely loud volume, which is probably not safe for hearing anyway, LOL. Unless, you move the turntable into another room. Once you pressurize a room to cause harmonic and resonant distortions, you are in another league, haha. I have not reached that point in my new room yet! 

@mulveling,

I fully agree with this statement “But your beautiful table really deserves a rigid-framed, 4-point rack”. 

Cheers,

Audioquest4life

mulveling,

Thanks for the input.  Believe me, I'd love to get a new rack.  Unfortunately the Adona racks are too big.  I'm working with a really restricted level of space, which is one reason the small size of the Lovan has worked well for many years.  If I get rid of the Lovan it will be for a custom design rack, but as I've said, financially that's a ways off.

audioquest4life,

Fortunately my turntable is in a different room, down the hall, from the speakers so air-transmitted vibrations won't be a problem.

When you suggest spiking the rack into footers, would you be thinking of something like these?

http://herbiesaudiolab.net/spkrfeet.htm

@prof, 

Yes, exactly. Something like that should aid tremendously in your vibration mitigation strategies. Glad that you don’t have to worry about airborne transmitted vibrations either👍😀

BTW, interesting test results:

In putting away some audio boxes I re-discovered my old Auralex Subwoofer platform that I never really used. It’s a thicker-foamed version of the turntable platform. I tried a little experimenting with the Auralex and my Townsend pods, using my iphone seismic measuring app placed on various surfaces.

First, I have tried the app on top of my Lovan, where the Transrotor table is now sitting. Right now I have a 3/4" sheet of MDF sitting on top of the lovan rack, then the thinner Lovan MDF shelf, then the Turntable.

What’s interesting, maybe a bit alarming, is that when I place my iphone with the siesmic vibration measuring app on the top of the MDF shelf, and rap the other side of the shelf (that is rapping the top of the shelf to the far left of the iphone), there is impressively little transmittion occuring. The raps show a small spike, but almost no ringing.

But when I place the iphone on the turntable platter and rap the same part of the shelf, there is actually a little bit larger bump registering, with a tiny bit MORE ringing. And I would have thought all the heroic efforts at dampening with this turntable would have yielded the opposite - less vibration transmission.

Then I tried the app on various surfaces. Putting it on my kitchen granite countertops and rapping about a foot from the iphone yields very little result on the app - so little vibration transmission. Pretty solid I guess.

Then I went downstairs to our pool table, placed the iphone on the table and measured the effect of rapping the table with my knuckle about a foot away. Definitely registered some bumps. Then I put the Auralex platform on the pool table, the iphone on top, and rapped the pool table top again. Still quite a bit of vibration registering. Hmm. (I found the same when I tried the Auralex on my wooden dining table).

Ok, pulled out the Micro Seiki turntable, put it on the pool table, iphone on the turntable platter. Rapped the pool table at the same spot....whoa! BIG seismic vibrations registering! It’s like the turntable platter amplifies vibration and ringing. Graphically on the app, it looked quite bad. Then put the turntable on the Auralex, rapped the pool table. STILL big vibration registered through the turntable platter, almost the same as without the Auralex. This was surprising to me as my intuition presumed such a big thick platform full of foam would have done better than that.

Next, tried putting the turntable held up by the Townsend Isolation Pods.
Rapped the pool table and...this time MUCH better! The height of the spike was much smaller and most of the awful ringing was gone.

I tried some other combinations - pulled out a squat, thick wood speaker stand I’d built a while back. Placed that on the pool table, then an MDF shelf from the lovan, and I measured raps on the pool table in that configuration, and putting in the Auralex, and switching the Auralex for the Pods. Placing the iphone on top of the speaker stand, under the turntable showed fairly significant vibrations on all axises traveling up through the stand from rapping the pool table.

As before, it got even worse placing the iphone on the Micro Seiki turntable, and was barely mitigated by the Auralex. And as before, putting the Townsend pods under between the speaker stand top and the MDF shelf holding the turntable - far less vibration transmission and ringing! In fact, though there was still some vertical vibration transmitted a bit, all the other axis L/R axis vibrating virtually disappears completely.

When I put my hand on top of the MDF shelf that the turntable was sitting on, and rapped the pool table, I could really feel the vibrations in my hand resting on the stand.  But moving my hand on to the turntable base, which was held up by the Townsend pods, and then I could barely feel any vibration transmission at all.  It was quite a difference and pretty impressive.

One thing though: actually rapping the turntable itself lightly yielded slightly different results. On only the turntable sitting on the stand, rapping the table near the tone arm yielded minor vibration spikes - interesting far less vibration registered than rapping the surface the turntable sits on. Putting it on the Auralex yielded similar results, but if anything maybe a slight reduction in vibration. But when on the Pods, rapping the turntable actually yielded, if anything, slightly more vibration or ringing than the turntable by itself. Though of the several times I tried this, it didn’t seem like a big difference. To the extent that was accurate, I wonder if that means the Townsend Pods are better at isolating from exterior vibration, vs interior coming from the table.

Anyway, those are my results thus far.

Seeing the results, I’m less inclined to buy the Auralex turntable platform than I was before. (Though, in fairness, if isolation should be matched closely with equipment weight, the Micro Seiki turntable may have been too light for the Auralex to do it’s thing. Then again, it’s also significantly lighter than the Townsend pods are rated for - I got the pods rated to hold up about 80 lbs - the Transrotor and it’s coming thick wood-block base. The micro seiki is far lighter than the pods are rated for, so I don’t think they were at their best either).

Thanks for posting that; extremely detailed and informative, and interesting! I'm going to parse through it again. I think this can help others, if nothing else to get us thinking about things. The isolation/coupling interfaces for high-end turntables are so crucial!