Active versus Passive Isolation Platforms for turntables
- Thread starter PeterA
- Start date
Adyc, not sure what you mean by platforms being in the same frequency range as subs.
If the platform resonance is within the sub effective range this is asking for trouble
due to the resonance.
I havent checked that yet, but what I suspect is that the most of the subs movement is lateral
so roller bearings should be ideal here.
BTW, check your PM
If the platform resonance is within the sub effective range this is asking for trouble
due to the resonance.
I havent checked that yet, but what I suspect is that the most of the subs movement is lateral
so roller bearings should be ideal here.
BTW, check your PM
Bruce, if you find a way how to make vibrations go in one direction but not in the opposite, I think you will be a strong
candidate for a Nobel prize
Gee thanks Jarek!ones enough
--but as I am over 75--the dudes in my Gym have already labelled me with the "Noball" prize Luv ya work!
BruceD
Adyc, not sure what you mean by platforms being in the same frequency range as subs.
If the platform resonance is within the sub effective range this is asking for trouble
due to the resonance.
I havent checked that yet, but what I suspect is that the most of the subs movement is lateral
so roller bearings should be ideal here.
BTW, check your PM
What I'm saying is that these platforms claim to provide isolation up to 200 Hz or more. These platforms may help to reduce subwoofers self vibrations, right? I thought you are suggesting to use your platforms under speakers to reduce self vibrations. It maybe easier to move subwoofers rather than speakers.
Jarek, though this is off topic for this thread, you can check out Magico's new MPods. The folks at Magico have done some serious investigations into the speaker/floor interface and I have heard the results with/without these devices under the outstanding MPro speaker. They do provide quite an improvement in sonics. I do think there are two issues going on here. One is the vibrations generated inside the cabinet and transferred to the floor through conventional spikes. The other is air borne vibrations created by the drivers exciting the floor and feeding back into the speaker through its interface with the floor. These new MPods are an attempt to address these issues.
Isolation, as long as it prevents movement of the speaker cabinet at the micro level, could be a very good thing. I just don't know enough about it. I think Townshend has also investigated this issue.
That's how I interpreted Jarek's comments also: to prevent speaker vibrations from exciting the floor and feeding back into the speaker system.
@adyc: I'm suggesting to try any subsonic-capable isolation under speakers. Mine or any other. Any isolation device will work both ways, not just active.
We did try our Basics under speakers (I linked somewhere above) with very nice results in that setup.
@PeterA Great point with the airborne feedback! This can inject nasty filtered, time delayed caricature of the output back in the speaker coils and also in the xover caps. Initially I thought rather about the floor transmission to the rack and the amps/source, but you are right there is this second mechanism as well.
I will check the solutions you are quoting.
We did try our Basics under speakers (I linked somewhere above) with very nice results in that setup.
@PeterA Great point with the airborne feedback! This can inject nasty filtered, time delayed caricature of the output back in the speaker coils and also in the xover caps. Initially I thought rather about the floor transmission to the rack and the amps/source, but you are right there is this second mechanism as well.
I will check the solutions you are quoting.
interesting video demos
https://m.youtube.com/watch?v=ybx5t53Ixtk
https://m.youtube.com/watch?v=RD-NK4mYG9A
https://m.youtube.com/watch?v=reYtUNLXvt8
Hmmm. . . . These demos are so impressive it makes me think that maybe the concern about a suspended turntable on an isolation table is misplaced.
https://m.youtube.com/watch?v=ybx5t53Ixtk
https://m.youtube.com/watch?v=RD-NK4mYG9A
https://m.youtube.com/watch?v=reYtUNLXvt8
Hmmm. . . . These demos are so impressive it makes me think that maybe the concern about a suspended turntable on an isolation table is misplaced.
Ron, the performance of those devices is nothing short of spectacular....with microscopes, wine shaking and invitro fertilization
If it is equally high with audio must be checked by ear.
If it is equally high with audio must be checked by ear.
Cool vids Ron - thanks for sharing. The IVF vid made me thinking about a cartridge and how the tip would behave pre and post isolation - amazing.
my TS-150 and TS-140 sound like those videos look like they should sound.
and your intuition and previous reference is not prepared for the delta of change.
Mike, I'm sure you have vastly covered your impressions of Herzan here, but if you were to name
one most important factor of this delta what it would be?
Thanks,
Jarek,
I apologize for missing this question earlier.
i'll cite two things, one of which is degree of need, the other a musical attribute. (I apologize to those who have read me reference these issues in prior posts)
I have a 7 foot tall, 750 pound, active bass tower, that is (on paper) -3db @ 7hz and -6db @ 3hz standing 6 feet from my gear rack with a Turntable on top of it (the rack , not the speaker
). 5 inches from the bass tower is 7 foot tall, 750 pound, main tower which has -4- 11" woofers going up to 250hz. so that is a whole lot of low frequency air (with 2500 watts (per side) on tap behind it) and structure movement occurring very close to my source gear. when I got these speakers a little over 4 years ago mysteriously at the same time, female vocals started distorting on my turntable and other similar occurrences that had never happened before. (this groove distortion was only the most manifest of a number of effects of the more dynamically capable speakers). it was infrequent enough that I did not connect the dots as to what was the cause. in 3 or 4 cases I assumed I had purchased a bad pressing and repurchased another one.....which, of course, had the same issues. my turntable had it's own passive isolation table that I liked.but 10 years prior I (in 2002) had had a Halcyonics active isolation table in my system, for 1 night, and had been blown away by it. so it was always in the back of my mind to acquire one for myself. I knew about Herzan, knew that they spec'd a bit better than the Halcyonics, and so I did order a TS-140 from Reid at Herzan. it arrived, I installed it......and no more distortion on those tracks (among many other benefits).
I needed maximum isolation; I needed the Herzan due to my room/set-up. to me these type products are contextual.....they earn their keep to different degrees in different systems. they always bring their benefits, but some systems get a higher ROI on those benefits.
'a' musical attribute that the Herzan brings that is very significant (I cannot say which attribute is most important....this is but one of them) is the utter ease and effortlessness it brings to full tilt boggie musical peaks on Lps, and my system can really lay the wood when called on without any dynamic limitations. the 'cringe' factor (my shoulders and jaw do not tighten) does not exist in my system as I'm always confident that any musical thread will sail through and fully develop. it (sometimes dramatically) changes your reference as to how a track is suppose to sound.
it's a thing to behold, which I enjoy.....beholding.
there are other things I like.......
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While I do not use a turntable, I would chime in - imaging tends to be at ease and not smeared with active isolation on. This tends to be more evident when I play it loud. I can imagine the needle from a turntable to be jolted out of its groove without active isolation.
Well, the one thing I was expecting in the change from 750 sq ft solid concrete flr to 1000 sq ft suspended timber flr was a muddying and bloating of bass, but actually my bass is the best thing in the new room
Go figure
No, I suspect any impvt w the MK or Herzan will be more subtle
Maybe greater ease, or a subtle lifting of haze, greater intelligibility
It'll prob be the last thing I expect will make the most impression
Or my combn of Rollerblocks and magnetic feet isoln as currently exists won't be significantly exceeded, and thus extra isoln will not sell itself
Go figure
No, I suspect any impvt w the MK or Herzan will be more subtle
Maybe greater ease, or a subtle lifting of haze, greater intelligibility
It'll prob be the last thing I expect will make the most impression
Or my combn of Rollerblocks and magnetic feet isoln as currently exists won't be significantly exceeded, and thus extra isoln will not sell itself
I thought this was more of a room attribute? Because it is in your room and Marty's that I have seen the crescendos and peaks develop without the cringe and the peaks just continue to go up limitlessly I always thought this was a complete room factor.
Ked, I suspect what Mike means is that even w his room so stellar as you've reported, a tt literally only a few feet from 4x15" <15Hz woofers, must have previously been deleteriously affected
The proof of the pudding being this extra ease since the Herzan went under
His tt is adjacent to 4x15" front firing subs
Mine is adjacent to 2x12" down firing subs
On paper at least, my tt will like Mike's be contending w a LOT if bass energy
And my subs to 16Hz are down firing into the flr which obv to a greater or lesser extent be coming up under the tt
The proof of the pudding being this extra ease since the Herzan went under
His tt is adjacent to 4x15" front firing subs
Mine is adjacent to 2x12" down firing subs
On paper at least, my tt will like Mike's be contending w a LOT if bass energy
And my subs to 16Hz are down firing into the flr which obv to a greater or lesser extent be coming up under the tt
Yes I understand that - it is just the ease of increase in peaks I was referring to. I understand everything would have improved with the Herzan, and he did mention to me when I was there how upgrading from MM3 to MM7 affected his TT till he put the Herzan in.
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