active vibration management

Penance - you are exactly right, perhaps you should drop hints to bub that pneumatic suspension can dissapate vibration as heat, that being the point - but pls can i ask you not to quote bubs post so extensively on this thread as I have blocked him and I dont want to read his erroneous views whole sale? Thanks!

 

bbv you are dull

 

The quote was relevant to my reply, hence quoted

 

Please say why I am wrong.

 

Penance - aw ... all of it?

John - fine, thats your perogative to have that opinion - do you have anything to say that is both relevent and interesting to add to the thread?

 

Haddock is better than Skate.

 

Pneumatic suspension disipates vibration by transfering it to heat. It is a well know principle.

FWIW, I agree, hadock is better.

 

All vibration eventually turns to heat.

Seismic Stink didn't work for me, YMMV.

 

To say it doesnt work is off the mark.

As always, it may have a good effect for some and not others.

 

Yes it was. Shame its gone now, replaced by yet another bland pub.

 

I prefer Skate - with black butter, capers and posh chips.

 

posh chips?

 

Well, real ones not thin strips of lukewarm cardboard.

 

ah, true.

 

Hi all,

Having avoided any isolation threads for ages the question of active vibration management comes up. I may have missed something here but active means that you have a control system to control the motion of the platform. Where does the seismic sink etc have this?

"I have to say, I don't get on with pneumatic supports. They are either poorly designed and require constant attention (Townsend) or ridiculously expensive."

In general easy to make but getting the best transfer function for the turntable you use may be very difficult. Different turntables, arms and cartridges require different transfer functions.

"I have to say, there is a lot to be said for a turntable that features it's own optimised suspension system that is designed to work on an inert surface. " Stereo Mic

Yes but inert surfaces are very difficult to find. One method (probably not that good for home use though!!) that I have heard of is used by companies that measure seismic disturbances. They use concrete columns that are earthed a significant depth below ground (i.e are unsupported until 30 or 40 feet down). Thereby avoiding ground borne acoustic energy which is generally transmitted close to the surface.

"The Sounds of Silence isolation feet might well work well with these products if sandwiched between a couple of slbs of slate on a heavy mass loaded platform."

If you just put different components together you are likely to end up with a bit of a mess. The mass of the slabs, the interface to the ground the stiffness and damping characteristics of the feet will all have an effect. The transfer function that results from that could be a real disaster.

If it sounds good then great but that doesn't mean that you couldn't have a far better solution as this is likely to be a long way from optimum.

Ian

 

Hi bbv,

"Turntable manufacturers dont make their own active isolation platforms for the same reasons Morgan dont supply Morgan tyres with their cars. They either supply a third partys tyres or you choose your own!"

Car manufacturers recommend tyres for use on the cars that they design. This is because they have worked with the tyre manufacturers to get a good handling / ride compromise. And often have a strong financial relationship with that tyre manufacturer. Fitting tyres (of the allowed size) from other companies will change the car's handling etc. Fitting tyres of different sizes would make for bigger ride and handling differences and could be very dangerous.

And that is just from fitting slightly different tyres. No use of very different technologies involved!!

I am sure that there are better analogies out there.

Ian

 

Ian,

the Sound Of Silence isolation is very similar to that used very effectively in conjunction with high mass by Blue Pearl. Having listened to their budget model, I would say it is very effective in that application.

The concrete pillar solution is also used by a number of professional installations for isolation of loudspeakers. Pretty impractical for most homes though.

Given the variability of results possible from trying different options, as you have highlighted, the advantages of having built in predicable isolation of some sort becomes even more apparent. I did not consider an unsuspended deck for this very reason - they are all far to dependent on their supports for my tastes.

The Vpi HRX has a lighter touch than most high end decks in my experience, with a more expansive soundstage than the Yorke or the BL going from hazy memory. It trades some dynamic impact to achieve this although that failing is redressed when replacing the air bladders with the new ball supports according to my sources in the US.

The Blue Pearl has it all. As it should. Turntables at these horrendous prices surely should not cast their own shadow over the music but sadly the vast majority seem to.

 

Ian,

I currently have a TSS which is an air suspension system but it does not have active control, air supply or levelling - this is why I am looking at alternatives and started this thread. I am curious as to whether something like a SEM active bench would be an improvement given the enhancement in isolation.

I have heard of people drilling down into the floor in exactly the way you have described but it is surely very rare in a domestic lounge.

You have taken my analogy some way further - but I agree with you totally and that is the reason why both Yorke and Brinkmann recommend isolation products for use with their decks. I doubt morgan work with the tyre manufacturers though.

SM - given all active sem benches do the same thing one should pretty much do as well as any other so there should be no support dependency so long as you have the right type. In fact with both decks the only support dependency is really the difference between using it with the correct table type or with an incorrect table type. Obviously all the incorrect tables will give varying results according to where they dont meet the spec. All turntables are dependent on their support but non-suspended decks require suspended isolation. This is therefore not a "problem" as such any more than fitting the right tonearm or cartridge that matches your deck, say. The support is an intregal part of the design statement.

Have you compared these directly in the same system and room, or some other common thread between each dem?

Nick.

 

Hi SM,

"The Blue Pearl has it all. As it should. Turntables at these horrendous prices surely should not cast their own shadow over the music but sadly the vast majority seem to."

Very interested to hear that somebody as seemingly sorted out a better way of isolating a turntable.

I have never heard any of these expensive turntables but if I get the chance I will do so now.

bbv,

I would be careful of just installing a system like that as you need to know what your turntable, arm and cartridge requires and what the SEM system can actually give you.

The same issues that I have explained for passive isolation will exist for active.

Ian

 

Yup I agree - hence seeking this seeking of others opinions. I beleive penance is getting some figures for me - many thanks to him for that.