Speaker isolation or absorbtion - what is best?

Some speakers vibrate (resonate) at certain frequencies. Some do not do so, noticeably, at any frequency. (I just use the hand test.) If you want to effectively drain this resonance, assuming you could do so at all, you need to know the frequency at which the resonance occurs and then find materiel that will absorb that frequency.

IMHO, concrete floors inhibit any 'drain' potential, with or without coupling with spikes etc. If you think draining away vibrations from your speakers will benefit the sound you need something between the speakers and the floor that will absorb the resonance frequency that the speaker is creating. To some degree your carpet and pad are already giving you some 'drain' potential. Absent specific information regarding the speakers resonance you can use a broad base absorbing materiel like sorbothane.

Now, my opinion about 'draining' vibrations - for the most part I think the theory was created by an artful salesman. Consider that the real damage is done when the resonance frequency causes some sonic damage. This has already happened before you could effectively 'drain' any vibrations. Unless the speaker actually has the capacity to store this energy, thus magnifying succeeding identical resonances, it is too late. I am unaware of any high quality speakers that actually have the capacity to store energy.

The only reason I would put spikes/cones between my speakers and a concrete floor would be to help stabilize them and I would be sure to penetrate the carpet/pad.

That stuff comes from my experience years ago with concrete floors. I now have wood floors and I use soft absorbant materiel to neutralize vibrations flowing in either direction.

BTW, play around with the alternatives and then trust your ears. If you can't hear it (the differences) then they must not, for you at least, exist.

FWIW, just my humble opinion.

BTW, nice speakers! Very nice.................

The only way to really know what will work best is to experiment. This is a matter of "tuning" so a change will alter the sound, but, there is no way to know if you will like or dislike the alteration.

As a broad generalization, the Symposium shelf under the speaker approach (I do that myself) works best when the speaker is over a suspended wooden floor. That is because transferring energy to floor causes the floor to act as a sounding board that muddies the sound. I have the flat bottom of my speakers sitting on a large Svelte Shelf with nothing between the shelf and the speaker (maximum transfer of energy from the cabinet into the shelf).

A shelf under your speaker could also change the tuning of your speaker by absorbing energy from the cabinet, but, I would bet the overall change in sound would not be that dramatic because you probably do not need to suppress the floor acting as a sounding board. Still, the only way to know is to experiment.

You also may send an email to VERITY AUDIO to see what they might recommended you for an improvement....
Good luck

Lateley I have had the opportunity to experiment with some products from UK manufacturer Vertex AQ, who approach the problem of vibration transmission within a hi fi system from a novel perspective.

I own Avalon Indra speakers supported by their heavy Apex couplers (spikes) to my carpeted concrete floor. The Indras are pretty well damped as enclosures go but I had been thinking of the vibration transmitted back from the speaker terminals to the amplifier and so on into the system and the negative effects of that vibration.

I am a complete disciple of Stillpoints technology and use the ESS405 equipment rack for my source components with Stillpoints + Risers under each unit on each acrylic shelf.

AC power distribution and CJ Premier 350SA amp are both supported on Stillpoints Component Stands with intermediate Stillpoints + Risers.

I use MIT Oracle MA-X interconnects and MIT Magnum MA speaker cables which have network boxes containig circuitry.

I have enjoyed a substantial improvement to resolution and soundstage/imagery by utilising a pair of Vertex AQ Moncayo speaker links between the MAgnum MA's and the Indra speaker terminals.

As a picture is worth a thousand words, here is a link to my Photobucket album pages http://s3.photobucket.com/albums/y76/crystalref/
The first picture on page 1 shows the Vertex speaker links.

The boxes on the speaker links contain an acoustic labrynth with single point contact on the silver cables, which pass through the box unbroken. The acoustic labrynth is designed to 'drain' vibrational energy from the cables, preventing it from travelling back to the amplifier and source.

In my case, an extra benefit is to isolate the network circuitry in the MIT boxes as well.

Vertex AQ manufacture complete system solutions for support, mains EMI/RFI reduction and viibration control. Check out their website here http://www.vertexaq.com/

Vertex Pico boxes can also be placed on top of speakers where this allows and are designed to drain energy from the enclosure via the acoustic labrynths within the boxes.

I have absolutely no commercial connection with Vertex other than as a satisfied customer.

I think my non-UK enthusiasts would be interested in reading about their products as I rarely find any references to them on Audiogon.

With reference to the original question. I have tried Stillpoints + Inverse Risers under the Indras but prefer the stability offered by Avalon's Apex couplers.

Now Stillpoints Component stands under each speaker would be another proposition!