Herzan/Table Stable "Active" Isolation table.

[Halcro]

Jarek,
You mentioned earlier about actually seeing the low-frequency structure-borne feedback in a system by connecting a soundcard to the preamp......
Assuming you've done many of these tests (as you've designed products to combat the problem).....have you ever tested a turntable installation in a room which didn't record any 'noise' even though there was no isolation at all for the turntable?
And if so.....can you describe the construction of the room?

 

[PeterA]

Deleted to keep the thread on topic. I just started another tread to discuss the differences between active and passive approaches here:

http://www.whatsbestforum.com/showthread.php?22658-Active-versus-Passive-Isolation-Platforms-for-turntables

 

[Stacore]

Jarek,
You mentioned earlier about actually seeing the low-frequency structure-borne feedback in a system by connecting a soundcard to the preamp......
Assuming you've done many of these tests (as you've designed products to combat the problem).....have you ever tested a turntable installation in a room which didn't record any 'noise' even though there was no isolation at all for the turntable?
And if so.....can you describe the construction of the room?

Henry, to hear the feedback you would have to play some other source keeping the needle down on non rotating TT.
Which is actually a very nice idea My initial one was simpler-no music payed, just to see the
natural structure vibrations (not the feedback). We haven't done many such tests actually as they lack sense a bit-each time we deal with a different system so there is no common reference point - each time I measure different structural spectra, but the systems are also different so their influence is different. But no, I've never seen a zero output. Remember that usually there is always some rack in the picture (although we have successfully worked more than one time directly on a floor), so what you measure is the room + the rack.

 

[Halcro]

Test Results

Here are some interesting Screen Shots of the Herzan Display with the Isolation Active versus Isolation Inactive....


This is Isolation ACTIVE-At Rest


This is Isolation INACTIVE-At Rest


This is Isolation ACTIVE-Turntable Spinning


This is Isolation INACTIVE-Turntable Spinning


This is Isolation ACTIVE-Music Playing

See next Post for Isolation INACTIVE

 

[Halcro]

Continuation.....


This is Isolation INACTIVE-Music Playing

The top line is Vertical Displacement.
The H1 is Horizontal Displacement in one direction
The H2 is Horizontal Displacement at right angles

 

[Stacore]

Henry, very good illustration! Thank you!
Does the platform output the accelerometer data
so that you can view them on a computer instead of the simple display?
FIY, I checked recently one room with the TT installed on
an off-the wall shelf (mounted on short, 8x8cm steel profiles filled with concrete).
The room was on the ground floor, pre-war building, springy floor (prob suspended),
very busy street nearby. It was pretty clean modulo my simple test arrangement,
but had a well pronounced 18Hz fundamental mode, which sensed pretty well
the upstairs neighbors' live pretty well. The problem with the needle-in-the-groove test
is that it is also sensitive to direct air coupling.


Cheers,

 

[Halcro]

Jarek, as far as I know.....I can't see that the output display can be up-loaded directly to a computer display but perhaps Whitney can confirm...?
I was actually surprised to see that the spinning turntable caused visible vibrations in the platform
Of course I knew that there was an equal and opposite reaction to the spinning turntable.....but I imagined that this small reaction was able to be absorbed in the mass of the granite cradle/plinth. Welcome to reality....
I wonder if the Kronos turntable with its two counter-rotating platters would actually 'null' this vibration......although a belt-drive motor is turning at a far greater speed than my direct-drive
It's also fascinating to see the reactions with music playing.....although I suspect that, in my case.....it may more likely be the result of my two Vandersteen 2Wq subwoofers (situated directly below the shelf supporting the turntable) transferring their energy into the main supporting shelf.



I will disconnect the subs and run the test again to see....

 

[Stacore]

Henry, you could check that: please take kids bike inner tube of the largest diameter that would fit under your subs.
Suspend them and check the results. Of course there is a percentage of the direct air coupling plus a tire is what it is,
but you could get an interesting result

Cheers,

 

[Halcro]

Jarek, it's only of academic interest as the Herzan removes all the vibrations.
I don't need to make its job too easy...

 

[Stacore]

Henry, but you can make the job of your sub different

Cheers,

 

[Reid.Whitney]

Jarek, as far as I know.....I can't see that the output display can be up-loaded directly to a computer display but perhaps Whitney can confirm...?
I was actually surprised to see that the spinning turntable caused visible vibrations in the platform
Of course I knew that there was an equal and opposite reaction to the spinning turntable.....but I imagined that this small reaction was able to be absorbed in the mass of the granite cradle/plinth. Welcome to reality....
I wonder if the Kronos turntable with its two counter-rotating platters would actually 'null' this vibration......although a belt-drive motor is turning at a far greater speed than my direct-drive
It's also fascinating to see the reactions with music playing.....although I suspect that, in my case.....it may more likely be the result of my two Vandersteen 2Wq subwoofers (situated directly below the shelf supporting the turntable) transferring their energy into the main supporting shelf.

View attachment 31483

I will disconnect the subs and run the test again to see....

Hi Henry,

The TS Series allows for an output of the accelerometer data onto an oscilloscope, which is detailed in the manual provided with the table (Page 10). The data is a multiplexed output showing signals from all 8 accelerometers. While it is not capable of exporting this data to a computer, it can serve as a diagnostic tool providing information on the response of the accelerometers.

Best,

Reid, Herzan

 

[spiritofmusic]

Reid, I'm planning a TS-150 v Minus K BM-8 a/b demo on my tt v soon
The only spare rack I have to audition things on is my standard 5-tier AV rack
It's spiked and inert, but each shelf has a small elastomer pad at each of the shelves as it slots into each levels' sub chassis that converts vibn to heat
Ostensibly the shelves and rack as a whole are solid and not moving
But will these pads interfere w optimal operation of the TS-150?

 

[Reid.Whitney]

Reid, I'm planning a TS-150 v Minus K BM-8 a/b demo on my tt v soon
The only spare rack I have to audition things on is my standard 5-tier AV rack
It's spiked and inert, but each shelf has a small elastomer pad at each of the shelves as it slots into each levels' sub chassis that converts vibn to heat
Ostensibly the shelves and rack as a whole are solid and not moving
But will these pads interfere w optimal operation of the TS-150?

Hi Spirit,

If possible, I would test both systems on the floor to remove the variable of the support stand. This benefit assumes the floor is flat and rigid as well.

If testing the tables on the floor is not possible and the surface in which the TS table is supported has underlying elastomer pads, the performance of both tables may be impacted. If you can share pictures of your AV rack, I can speak more definitively on the matter.

Best,

Reid, Herzan

 

[spiritofmusic]

My floor is 18x60 total, new hardwood suspended on 1861 Victorian joists (roof space of our converted chapel)
System central to 18 width, 9 from rear wall
No major flex, but w 1000 sq ft of new suspended flr, bound to be some deviation
So, a/b them both on the floor?
I have to say, the Accurion/Halcyonics rep didn't advise this for the active i4 when I auditioned this in my London apartment 3 yrs ago

 

[spiritofmusic]

Reid, in my AV rack, each shelf has 3 tiny pads that sit in slight indents that the shelves slot into
These pads convert vibn energy to heat
A bare basic version of uber racks like HRS?
There is no spring in shelves, it's all a snug fit
But certainly not as rigid as hard coupling, or solid continuous structure

 

[Reid.Whitney]

My floor is 18x60 total, new hardwood suspended on 1861 Victorian joists (roof space of our converted chapel)
System central to 18 width, 9 from rear wall
No major flex, but w 1000 sq ft of new suspended flr, bound to be some deviation
So, a/b them both on the floor?
I have to say, the Accurion/Halcyonics rep didn't advise this for the active i4 when I auditioned this in my London apartment 3 yrs ago

Spirit,

I would suggest testing both on the floor as that configuration is recommended by the manufacturer of the TS (Table Stable) to receive optimal performance from the table. If you would like additional details on how to determine an effective support surface, the manual provided with the table briefly discusses the matter (Page 6). There is also a white paper written by the founder of Table Stable that discusses the technology at length as well. I'd be happy to share the manual and/or whitepaper in a PM if you would like.

I cannot speak specifically to Accurion/Halcyonics current technology(ies) or if they have changed from what they offered originally, but I am quite familiar with their voice coil design as that was iterated from Table Stable's original technology.

Fun fact: Halcyonics used to be a distributor of Table Stable back in the day until they branched off and started manufacturing/selling their own designs.

 

[spiritofmusic]

Reid, by all means PM me that info
I'll investigate more static solid options for supports on this a/b, but if no joy, will go for floor mounting
I have in mind the rack I'll buy if I go down one of these options, but demo is not poss of this atm
I was sure you were going to warn me off using a Herzan on a potentially flexing suspended flr over such a large span, but obv not

 

[theophile]

I'm guessing that any flexure of a suspended floor is amplified at the top of a rack. In the same manner that a point close to the pivot of a pendulum moves less than a point further away from the pivot, closer to the extended end of the pendulum.

 

[spiritofmusic]

Reid, got that PM thanks
The floor it is
Can my knees take it?

 

[MtnHam]

As a temporary measure to do the a/b test, I would go to Home depot and purchase a dozen concrete building blocks and stack them to create a stand, placing the solid side up on the top row. This would provide a high mass stable platform for the testing.


$1.69 each