Thiel 3.6 and 'grounding' / insulating

I have a lovely old house with hardwood floors. I just bought a pair of Thiel 3.6. I plan to use the stabilizing pins / spikes provided with the speakers (probably put the spikes on quarters or something). My question: would it be worth my while buying a pair of thick (2 inches or so) granite slabs to put under the speakers with the spikes? Has anyone tried this and if so, what were the results? Thanks.
Congrat's on your house. Sometimes, with speakers that possess prodigious bass output like the 3.6's, it can be disadvantageous to postively couple the speakers to a more resonant suspended wood floor, especially if no carpet is laid, but it all depends on the particular situation. I would first experiment with setting them up the way you have been to see if there might be a problem at all. If there is, it is entirely possible that a combination of mass-loading the speaker base and distributing the load over more of the floor area as you propose could help out. The last resort for a severe problem would be damping/decoupling using some sort of compliant material underneath - such as carpet. (Or, if the floor in question is a ground level, you can look into ways to reinforce the floor from below - especially directly underneath the speaker positions - providing a more solid connection to the foundation.)
Thank you for your response. I will do some in-depth (no pun intended) testing of the bass performance with spikes on quarters. I just needed confirmation of my idea that, by adding a couple of massive slabs of granite, the bass-coupling to the floor would be diminished. I could always move the carper over to the speakers and put the slabs on the carpet, then the speakers with spikes on the slabs. Looks like I'll be shoving heavy boxes around again for a few days, hehe.
Thanks again.
Thiel 3.6's tend to have plumy bass on most any music except classical. I have found by using the brass Audiopoints from Star Sound the bass becomes more articulate with much better speed. Added benefit of cleaning up the bass is you now have a better defined midrange and more focused and quieter soundstage. If you have hardwood floors you will also need the brass coupling discs. A friend of mine was astounded by the substitution of the Audiopoints for the steel ones supplied by Thiel.
Thanks, audiotweek for your input on audiopoints. Has anyone tried sound anchors stands for the Thiel 3.6? I agree that the bass and midbass on the 3.6 could benefit from some 'tightening'. This may be a little extreme, but I also painted the insides of my thiels with a borosilicate dampening compound from Audio Concepts with excellent results. Even though the stock cabinet is very heavy, the treatment improved soundstaging and resolution and reduced the midbass 'hump' in my room. Premium high current amplification is also a prerequisite to getting the thiel's bass to behave.
Jph1 I agree with you, accoustic sealers painted on wooden panels do in fact improve soundstage and detail. I used a product available from Cascade Audio Engineering on my still somewhat Dunlavy SCIV's. What a royal pain to do, but oh what an improvement. Even better than Audiopoints are the Sistrum platforms from Star Sound they take all speakers to beyond the next level.
Thank you all for your input.
I'll be receiving the Thiel 3.6's this sleep for me this weekend .
The 3.6's will also benefit by the extra couple of inches elevation the granite slabs will provide. The optimum listening position seems to be (for me) near the midrange driver. Most chairs (mine included) are a little too high although a little extra distance between you and the 3.6's will help. I would plan on at least 10 feet between you and the 3.6's. Also,placement away from the back walls helps avoid any midbass emphasis - although I don't have too much problem with one of mine placed near a back wall.

Good luck and experiment lots with positioning - not easy with these big lugs....

So far, I have put the Thiels on the spikes provided by the manufacturer, and put the spikes on quarters. The speakers are well clear of back and side walls (3 or 4 feet from the back wall and 3 or 4 feet from the sidewalls). They are about 6 feet apart, slightly toed-in and 10 feet from the listening position.
The bass has tightened a bit, but I could do with a bit more. I'm looking for a supplier in my area, who will cut me a couple of stone/granite/marble slabs to my specs, so I can play with that.
Any speaker cable recommendations anyone? I'm currently using thick, multi-strand solid core Audioquest cable, with spade lugs added by the dealer.
Pvanosta I know your money will drasticaly be better spent on Audionpoints or better yet Sistrum Platforms. These devices will allow the cabinet resonance to leave the cabinet and shunt to ground. Placing the speakers on stone or marble is not going to dissipate the cabinet noise, it will only move it to a different frequency range. When cabinet noise is drained away you will hear a much more focused soundstage and one that is larger and quieter. Bass will become more extended with more weight,all the while being more tunefull. I have friends with Thiels, B+W's and Paradigm all were blown away by the improvement they heard by adding these devices. I have been using Sistrum Platforms under my Dunlavy's for 3+years now and would not bother to listen with out them.
Thank you. I will look into Audiopoints and Sistrum Platforms. I appreciate your input.
Mine seem to sound better 8 feet apart as opposed to 5 feet apart. Toe in mainly if your are having problems with early reflections from sidewalls. Did you try the Sistrums? I'm curious about those devives after reading the thread. I just got my 3.6s on 12-4. Quite a step up from the CS 2s I had been using since 1985. I think I need better electronics now...sigh.
Just curious Pvanosta, what is your amplification? I will say in my experience with my 2.2's, speaker cable of a heavier guage does work best for the bass, but only in terms of tonality, quantity, dynamics, and extension - lighter guage cable will just shortchange the speakers and give a thinner, less developed sound. The bass being somewhat 'loose' is probably a function of the amplifier chosen, and the 3.6's with their larger bass driver and radiator, and lower impedance dip, are tougher in this regard than mine. Since you don't mention it, I assume you don't consider this to be a potential culprit though, but then again there are many 3.6's out there in the world which are not partnered with truly adequate amps (or cables).
Pvanosta, I've had 3.6's for about 3 years now and find Goertz MI2's to be a nice match, Thiel does also. These cables give a more fleshed out, full bodied presentation in my setup. Also these speakers respond to every inch you move them which can be maddning. I currently have mine 9 feet apart and about 4 feet from the front wall and 3 to 4 from the side wall - which allows me to point them straight out with no toe in. This gives me a very wide seemless soundstage - the speakers also sound more open, less boxey when placed further apart - but YMMV
My Amp is a Classe DR 15, 175W/ch in 8 ohms, and doubling all the way down to two ohms (700W/ch in 2 ohms).
The preamp is the Adcom GFP750 in passive mode.
The pre - to - power cable is Transparent Audio, balanced. The cable to the speaker is heavy-gauge multi-strand solid-core Audioquest.

Thanks for the placement feedback. I'll play around with the distance between the speakers...
Thank you. That makes two votes for the 'farther apart' side. I will definitely play around with that (as far as possible in my listening room).

OK, I can see why you didn't suspect the amp...
I did own an older Classe once (a Seventy, not the same generation or as high-power as yours) that never sounded properly balanced until I put a Synergistic AC cord on it, but that really transformed it, made it much more smooth and open. If you can, do you use an upgraded AC cord?