You think you have total turntable isolation?

Or build a dedicated house around an isolated pedestal for the TT. Sorry, couldn't resist

 

My turntable is coupled to a sandbox by means of 3 chunky aluminium/brass spiked feet. The sandbox has 4 rubber feet and sits on a solid, heavy sideboard, which in turn sits on a carpeted concrete floor. You can jump about the room as much as you like and it won't have the slightest effect on the turntable. In fact I could probably drive a herd of wildebeest through the room if they could get through the front door. Interestingly, before I replaced the turntable's stock feet with spikes I would get a dull thud coming through my speakers when I tapped the turntable's plinth with the stylus sitting on a stationary record. Since fitting the spikes I no longer hear a thud through the speakers just the sound of my finger making contact with the plinth.

 

I just put a 30mm MDF platter under my table and it has had the effect of totaly isolating it.

My son who is a Luthier and restores antique furniture for a living faced it with African Walnut and Veneered it with the same wood.

 

The short answer to your question is no, in a normal domestic setting almost impossible, presuming your system can reproduced substantial bass.

Although I don't have a deck, I lived with a LP12 for 20 years and had it in 10 different houses, both concrete and wooden floors. I also had the opportunity to try a number of different supports and with a LP12 the best option was low mass and rigid.

In fact the best table I used weighed less than one kilo and the best flooring was wooden, the worst support was a Townshend Seismic Sink.

The problem with adding another vertical suspension system is 'Wave interference', as has been mentioned particularly a problem if the frequency is the same or close.

So if I had my LP12 the first thing I'd do is through that table away, hope that doesn't offend but as some one's already said but ugly as well!

I know three people who sort of went with the build a new house, as in extensions with separate flooring but even that won't fully isolate a deck.

 

I specified a thick concrete floor & solid walls for the kids playroom 30 years ago - with a mind for it to become the music room when they grew up. The rest of the house has suspended wooden flooring & too many stud/plasterboard walls.

The greatest benefit has been 'wife isolation' when listening to music (not that she's buried beneath the concrete) but because I can play as loud as I want & without irritating ether her or the platter/tonearm/cartridge. Happy days !

 

For some of the best isolation tables in the world, check out Minus K Technology. Look at their BM-6 or BM-8.

 

Or even really reinforcement. If you have two systems piled up with resonant frequencies at 3 Hz and you start exciting vibrations at 3 Hz, you're gonna have a bouncy, oscillating mess (and of course the stand itself and the floor too have resonant frequencies). Just a guess based on typical cases but the OP's turntable has a sprung suspension which is probably isolating down to 5 - 10 Hz, and has a resonant frequency in the 3- 6 Hz range. Probably that ain't gonna be excited by playing music in the room, or even by average footfalls, just this stomp straight down. And it's going to be very pricey and challenging to find something that will isolate lower that 3 Hz or that doesn't resonate in the vicinity of footfall frequencies. Coupling the stand to the floor with something like cones can potentially help if it serves as kind of a mechanical high pass filter (as also maybe can moving the stand to an area of the floor where the resonances are in the frequencies where the stand doesn't resonate or where the floor footfall resonances are higher, if they're ever high enough to be up in the range where the sprung suspension works but doesn't oscillate), not really allowing 2 and 3 Hz frequencies up from the floor into the stand, but without being knowledgeable of how to calculate the resonances of the stand, the floor, the shelves, etc, it's just gonna be guesswork and trial and error anyway (and sometime a massier stand isn't as ideal a choice as a less massive stand). Again, I'd say a dull, short-lived thud, with no uncontrolled oscillation of the turntable suspension, by stomping on the floor but not necessarily even by average force footfalls, with the volume control up to 75% is not something to go crazy trying to solve at the risk of piling up additional systems with similar resonant frequencies. I thought this was a pretty interesting read: Bad Vibes! Page 5 »

 

If you're willing to spend around $3K you definitely can get isolation below 2 Hz in both the vertical and horizontal planes. The question is, is it necessary in the OP's application? When he's sitting and listening to music, is there any standborne vibration at 2 or 3 kHz? Does he walk around heavily a lot when listening to music? Do normal force footfalls excite the resonance?

 

Some years ago I was shown around the Gamma Knife installation in Sheffield, all the equipment was protected by something similar to the Minus K approach but the whole thing floated on tons of concrete, as there was a bus route a quarter of a mile away! I think the technology used was the same employed in earthquake zones. Now that would be a solution, how much though(?)!

 

There are very good ideas above. I would wonder if some absorbent floor covering and thick pad might damp the footfall vibrations enough. If you have moisture/wetness down there though it might not be good. In my own experience I have tried all kinds of vibration control. I found most of them isolated asymetrically which was worse than a more random isolation of frequencies. My TT sits on a heavy MDF cabinet with rounded edges but I have had the best luck with simple sorbothane and the Mapleshade wood platforms. YMMV.

 

The best isolation I've ever found for a turntable is also quite cheap: a three-inch thick slab of foam rubber. I doubt if there is anything better.

 

Well my butt ugly turntable stand is going nowhere, I built it for free and it is simply a matter of form follows function. It does look better with the table and records on it.
I added a second bag of lead shot on the other side after this pic was taken:



It holds 30" of albums on the bottom shelf, and as I said is 100% immune to anything that would cause the turntable to skip.

Back to the topic.

Being anal about things, once I discovered the transmission of a foot stomp, I now want to try and isolate that if possible & cheaply, even if it does not affect the music when being played.

If some budget tricks don't work or make matters worse, well I'll let that issue go and then move on.

My cheap isolation footers and pads should be here this week. I'll play around with those. I did buy another form of footer pads for the turntable to sit on, instead of cork rubber these have dense foam/rubber. Again, under $12. So now I'll have 2 different pads to test the table to sit on as well as the isolation footers for the stand.





These arrived today as possible replacement stand footers, they are extremely firm rubber, I was concerned that they would be a bit "mushy" but they are extremely firm, 125 pound capacity each:




I also found these stuff rubber door bumpers as possible feet for the turntable (ball there for size comparison):





In the end it's all in good fun toying with this, a few folks are getting a bit too serious and insulting here, please drop all of that.

Thanks again to the posters who contributed some great thoughts, ideas and explanations.

 

I do now have about 70% of the floor covered with some very heavy rugs which did help somewhat.

Thinking about this I think the key may be with the turntable. Original design had NO feet, nothing, it just sat on the wood base edge. I added some small feet years ago to make it easier to run the wires out from under the base rather than the hole provided in the back of the base. I'm going to try the isolation pads pictured above when they come, but now I'm thinking some cone/point footers for the turntable might work the best. Guess those will be my next purchase if the pads don't help or make matters worse.

Again, the system right now sounds very good, but I'm just wondering how much better it could sound if I reduce or eliminate this problem.

 

This is not Brian Gupton's thread about isolating a Garrard in a megaplinth...

 

Tried the tap test with the stylus in the leadout groove of a stopped record. Turntable (w/ feet resting on hockey pucks): loud and clear through the speakers. Tapped the shelf (a KALLAX full of records): nothing. Light heel stomp on wood floor in front if shelves: negligible (couldn't tell if anything was coming from speakers or not).

Once the record is on, I usually stay on the couch, so this works for me.

 

On one occasion I had to move my LP12 from an upstairs wooden floor to a concrete ground floor. I found it beneficial to use a MDF kitchen top as a base, supported by spikes (I submit this in defense of my but ugly joke!).

MDF, due to its random structure is an effective energy barrier and it's resonant frequencies seemed sympathetic. I certainly consider this as a project, an even better material is Bamboo, although given the size required this could possibly only be a sub shelf for your deck.

I'm surprised that a deck wouldn't have feet, have you tried it as intended recently?

Despite what I said about wave interference, as we know nothing about the engineered oscillating frequency of the suspension or how well it's being achieved, I'd experiment with the inner tube method. It's extremely cheap and it'd be beneficial for your electronics, if it doesn’t work for your deck.

 

OP said it was a homemade turntable. So apparently no feet was intended?

 

HRS isolation bases. Can't beat 'em!

M3X »

A discussion of their products generally:

6moons audio reviews: HRS M1R »

And a review from several years ago:

SoundStage! Equipment Review - Harmonic Resolution System M3 Isolation Base (6/2004) »

 

My understanding is that is was the turntable stand, which is DIY.

If you're correct then absolutely try the inner tube Bamboo approach. Anyway it is a matter of synergy so experimentation will be fun.

One other observation, I've tried Sorbothane under all types of equipment and never found it to produce desirable results, I'm speculating that it traps airborne energy in the equipment

 

I believe one of the key thing is to have an isolation somewhere, with a res frequency that is very low (3-4Hz) and also with a low damping.
Everything else should be very rigid. So in this case I woulld test very compliant feet at the TT, and keep all else rigid.

 

Agree, this was my experience with a LP12. Of course there's the issue, a whole thread here, concerning energy getting into the floor from the speakers.

 

It´s mostly about how far we want to take the isolation. The floor will always vibrate, more or less. The heavier floor, the lower vibrating frequency, and the higher freq reduced. All in all I think the OP has the circumstances as about as good as it gets, the parts missing seem to be a good isolation somewhere.

 

Again I agree but you're never going to stop low frequencies totally, I think that's why concrete floors have their problems, it's much easier to deal with the resonant frequencies of wood. If you can minamise those low frequencies getting into the floor all the better

 

As Rolls Royce use to say when anyone inquired about the power of the engine: "adequate." I don't think it makes sense to pursue isolation beyond the point of adequate isolation.

It would be unfortunate if any measures taken somehow compromise other aspects of performance, such as minimizing self generated noise/vibration. Turntable suspensions and suspension-less rigid coupling approaches affect both external vibration reaching the stylus and how self generated noise is dissipated.

Note too, that turntable design has to take into account how other sources of noise are dissipated, specifically, the vibrational energy imparted in the tonearm and energy imparted in the record itself from the action of the stylus tracking the groove. For example, a scheme designed to dissipate energy imparted in the record by transferring that energy to the platter (e.g., clamping the record to a hard platter) might, to some degree, compromise isolation from external vibration vis-a-vis use of a soft platter mat.

There are trade-offs involved in any design approach, and it may not make sense to pursue the highest degree of isolation from external vibration if it means compromising other aspects of performance.