Floor standing speaker isolation advice needed.


I have an older pair of KEF Reference Model Twos that currently sit on their brass(?) feet on the floor. The floor is tile but not solid cement underneath. I bought two .5" thick granite tiles for underneath the speakers and am wondering if I need to do anything else like put the spikes on the brass feet, add sorbothane under the granite tiles and/or under the brass feet or something else I should be considering? Things sound good on the top end but seem a bit subdued/muddy in the bass region. The KEFs are being driven by a Parasound Halo A23 and I’ve got a HSU VTF-3 MK 2 helping out the bass, mostly for movie duty.


Thanks for any advice.
asahitoro
Check out Herbies products, I use the Cone/Spike Decoupling Glider under my speakers & equipment rack, they work great.

http://herbiesaudiolab.net/spkrfeet.htm
+1 for herbies gliders .My best tweek in 50 yrs of audio .
Thanks for the replies,

Well I’ve got some various sizes of sorbothane. If I use that or the Herbies, do I put it under the granite tile between it and the floor or directly under the KEFs feet? Should I use spikes on the KEFs feet on top of the granite too if I put the other underneath the granite?
Dont use sorbothane directly underneath the speakers, it will absorb the bass and make it sound muddy and less detailed.
You can use the sorbothane under the granite, then try the speakers using their feet or spike them...see which gives you the clearest bass response. This way the speakers and granite bass will be decoupled from the floor.

And I agree, Herbie makes excellent isolation products. Try what you have on hand first.

Thanks lowrider,

That was my original plan, .25"-.5" sorbothane discs under the granite tile and the KEFs directly on top, maybe add the spikes to the KEFs feet. Where I lived before I had a solid, cement underneath carpet, floor and used the spikes to couple directly to the floor and it sounded good.

I've read good things about the Herbies stuff before and will look into it further.
Based on what I’ve read, if the floor is cement or tile, covered with carpet or not, it’s best to couple the speakers with the hard floor using spikes, direct or through the carpet. If the floor is suspended and is covered with hardwood, e.g., basement underneath, second floor, etc., it’s best to decouple using a semi hard material, e.g., sorbathane, etc. I can only attest to the second scenario and am using Herbies brass gliders with a layer of their Fat Dots together under the speaker spike. Happy with the results. YMMV.
I appreciate the input kalali,

Also, I can put sand in the plinths of my speakers. Overkill or not with the granite tile/sorbothane underneath and possible spikes under KEFs feet?
You can try Isoacoustics GAIAs.
Thanks ricred,

I'm really not looking to drop that much coin this setup. Trying to do this with $100ish and under stuff I already have or can easily get. If I step out over the sorbothane/granite, it will probably be for something from Herbies.
Stiff Springs under a wide footprint board supporting the speakers should do the trick. It’s two, two mints in one! Isolates the speakers and isolates everything else from the speakers. 👯‍♀️ Mass-on-spring. Accept no substitutes.
Within the budget you mention, I think you should consider @geoffkait's suggestion.  He does understand the mechanics of springs. I am personally familiar with the Townshend speaker podiums which perhaps are above your budget.  The Townshends are superb at the kind of isolation Geoff is talking about.  But I expect Geoff's solution will get you much of the way to the Townshends' level. Springs in my experience are better than other devices for isolation.  I have a bunch of springs (Geoff's actually) under my other components though not my speakers. 
I would nix the granite too.
If you want great  improvement get Symposium Super Plus bases with copper spikes.Im using them under my Magico Q3s the improvement in bass definition and detail was staggering.
Whatever form of isolation you chose (sorbothane or springs) will need to be compliant/soft enough to get as low as possible (<10Hz).

That will make the speakers very wobbly so will you need to use some form of wedges underneath the speakers or the platform with a minimum clearance of say 1-2mm to prevent accidents.

The benefits of isolating speakers have been well documented. Spikes induce resonance in the baffle hundreds of times greater than that of even soft rubber when the speaker is in use.

The problem with isolation is that it’s cheap to implement and the sonic gains are huge (bass starts to play notes) but apart from a few companies like Townshend or Herbie’s there is little profit in it. Whereas with spikes the opposite is true.
ebm
If you want great improvement get Symposium Super Plus bases with copper spikes.Im using them under my Magico Q3s the improvement in bass definition and detail was staggering.

>>>>Staggering? Are you sure you weren’t drunk? 🤡
It would probably be easier and you'd get better results if you used a Herbies product rather than an unbalanced granite platform.
http://herbiesaudiolab.net/spkrfeet.htm

I use Decoupling Gliders on my hardwood floor. Heavy brass tip-toes on my speakers sit in the decoupler and there is no resonance introduced into the floor or back into the speaker (as far as I can tell).
Or you could try the threaded stud glider. Seems like many are getting good results with Herbies.
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So I'm looking at the Big Fat Dots or X-Large Fat Dots on Herbie's site and am thinking skip the granite and spikes and just put 8 of these under the KEFs feet?

Thoughts?

Thanks again everyone!
Wouldn’t hurt to call Paul at Soundocity.com before you do anything. 
I know you said Gaia and Townshend are out of budget, but if they ever come into budget please do trial them. I found both upgraded my speaker in the bass department to an unexpected and astounding level. In Munich Isoacoustics were demoing their Gaia in the noisy main hall on an open stand. Two sets of speakers were running next to each other, one on Gaia one not. Even in this noisy place the differences were so apparent, as they switched between them A/B fashion.

I have tried thick foam in the past, under each corner, folded over so that the speakers gently rock on the four wedges. That did something and is nearly cost-free. Worth a try.

In the meantime, definitely try the spikes if you have a set as they will probably help a little.
You should email Herbie if you're considering trying a product. You'll get advice on the best way to isolate your speakers. 

If you already have the spikes in place, you can consider using the Herbies with the brass fitting for the spike and the decoupler attached. I like the spring idea but finding ones with the right compliance to create a stable platform might be a little challenging.

geoffkait  If you think its a joke i really don't care.What do you have under your speakers???
I think he was kidding. :)
ebm, I was joking with you. Ha Ha. Uh, especially in light of the fact you’ve promoted those stands over 1,000 times according to my trusty calculator. Actually that’s about all you post. What’s up with that? 🙄
@kalali, yes finding springs with the optimum compliance can be a problem especially if large heavy drivers render your speakers front heavy.

Like with most things in audio, it can be a fools mission to pursue perfection, but springs are probably the way to go if you insist. Otherwise rest easy in the knowledge that even bits of soft rubber can offer huge improvement in isolating the baffle from unnecessary resonance.

Since Sorbothane is measured in shore durometers it shouldn't be too difficult to mix and match to get decent isolation. For anyone with kids, don't forget to spoil their fun by preventing any unnecessary wobbling by placing some wedges underneath!
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I find Sorbothane to suck the life out of the sound. There are materials that look just like Sorbothane I have used in the past that really do work, especially in viscoelastic damping situations. I have also used some other similar materials that didn’t work. So I guess you never really can tell just by looking at the stuff.
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Thanks for the input geoffkait,

I was wondering about Sorbothane, Vibrapods and the various Herbie’s offerings and what materials are being used? I have some 2.5" diameter x .25" high 70 duro sorbothane discs and I also have a bunch of various Vibrapods that I could use under my KEFs feet (which are about 1.75" diameter). Now I’m thinking use the sorbothane discs under the granite tile slabs (which are .4"ish thick) and then the KEFs with spikes installed in the brass feet on top of the granite. Again, it’s a tile holllowish floor underneath. My KEFs sounded really good at my last place with just the spikes through carpet on a solid cement floor.

At any rate I have a bunch of stuff to try and I’m also not against tossing some coin Herbie’s way. One thing about his cone/spike decoupling gliders, and lets face it, aesthetics matter, is that they aren’t too visually appealing for where I’ll be putting them. Also, they may look a little strange as the diameter is much less then the KEFs feet.

Thanks again for the input everyone. :)
A buddy of mine has his 80 lbs. speakers on a ceramic tile over half a dozen racquetballs on a floor similar to yours and it works for him. Trust your ears....
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Speaking of Cliffs shouldn’t you be standing on one somewhere?

Cheers!
Anyone (geoffkait?) think the IsoAcoustics Modular Aluminum Series stands will translate the same Performance as their smaller stands and footer devices???
Im thinking of trying them under Harbeth 40.2 (that I want lower than traditional stands for this speaker). The 40’s like the bottom to ‘resonate’ just like the rest of the cabinet and are getting good reports gently resting on top of the extended tenons on the TonTrager stands, so I’m wondering if the ‘rubber cups’ on the IsoAcoustics will kill some of the resonance that is making these speakers sing a bit more.  I know, Tough specific question here without trying... and no trial with the Modular Aluminum Series. Drat. 
I’m high on mass-on-spring isolation devices which have become ubiquitous. In the beginning there was Bright Star, Vibraplane, Townsend and yours truly. It’s like walking a tightrope or a razor blade trying to balance all the variables - internal damping, spring rate, number of directions of isolation and load capacity and of course cost. I eschew getting rubber but I suppose a little bit can’t hurt much, and too much slows things down too much. For myself I forego all rubber and almost all internal damping, preferring very hard cones, high carbon springs, high mass and extremely stiff boards.
@jriggy Whilst you may see improvement by trying out different stands with the Hatbeths don't forget that they are probably the most advanced speakers ever built when it comes to controlling resonances.

Everything from driver material, driver mounting, and panel resonances has been meticulously considered by the designer. In fact the designer, Alan Shaw once said that you could place them on a stack of telephone directories if you so wished and they would still sound good.

I'm sure he's right. I just wish all speakers were designed and built with such care.
@cd318, thanks for the reminder. While  choosing my stand solution and height, I have the speakers up on wood frame w/ granite platform amp stands. There were sorbothane ‘half-ball’ pads Gibbon under the granite—bad!
So I replaced with hardwood blocks—much better!
Then one step farther, was raising the speakers off the amp stand surface with 1 & 1/2 inch wood blocks at corners only—even better! Letting the bottom of the M40’s breath freely, like the TonTrager stands achieve, does seem to benefit... so with this finding, your reminders, and geoffkait’s comments on rubber (which is where my concern was), I think I’ll forego the IsoAcoustics Modular stands for these particular speakers. 
@jriggy Yes, you shouldn’t need fancy stands but it definitely a good idea to let all the speaker panels breathe freely. All Harbeths are constructed that way to allow the resonances to fall below the threshold of hearing in terms of frequency range.

The M40s have always been fantastic speakers and are the sum of one man’s attempt at getting as close to neutrality in the midband as possible with the fewest compromises. Does any speaker do voices better?

My best advice to the OP, keeping it cost effective and simple, is not to overwhelm yourself by trying to many things, in to many combinations. Using what you have, first try the individual items you have - by themselves. Listen and compare and if none of the products, by themselves - spikes, sorbothane, granite slabs, etc - brings the sound back to what it was when coupled to the cement with spikes, then try what you have in simple combinations. Usually the simplest solution ends up being the best solution....Jim
Has anyone compared IsoAcoustics Aperta 200 to Gaia (the former being able to accommodate my loudspeakers’ weight/footprint and within my budget)?
I haven’t compared to those but I have some IsoAcoustics Apertas under my KEF LS50 Wireless in my man cave setup. Excellent stands that helped clean things up a bit.

jhills, excellent advice that I’m taking. I have so much stuff already to play around with and if I do spend more, I’ll at least have an idea of what might work best based on materials, application, etc. from experimenting.