Thiel Owners

I would like to explain the basic principle behind Outriggers or spikes under the speakers, so that each of us can answer the question of "need" for ourselves. Basically, when a woofer’s motor structure (this means the magnet and voice coil) applies force to the cone, causing it to move in and out, the woofer itself has enough mass that an equal-and-opposite force is applied to the entire speaker cabinet. If the bottom of the speaker cabinet is not firmly coupled to the floor and rigidly stable, the speaker will rock in the opposite direction as the woofer, causing inaccurate sound from the woofer (primarily Doppler distortion). So we apply cone feet under the speaker, to stabilize it, and even better, puncture through the carpet to the floor itself. We are simply trying to make sure there is not even very slight cabinet motion possible, under the force of woofer motion.

Since Thiel speakers have a relatively small footprint compared to their height, it can be helpful for the cones to be situated farther apart than the depth and width of the cabinet. The Outriggers help in this regard, compared to simply adding cones under the speaker, due to their greater separation distance, as well as their firm attachment to the bottom of the speaker.

But, however you stabilize each speaker, if you cannot rock either one, and so they are firmly unable to move even the tiniest bit, then you have accomplished this "rigidly stable" condition, that I am claiming is so important to producing accurate bass. A well known TAS reviewer from the 70’s and 80’s, Enid Lumley, claimed she stabilized the speakers by hanging them from the ceiling with fishing line. She claimed that the weight of the speaker, and the long length of the line, did the trick, PLUS decoupled the speaker from the floor completely, so there was absolutely no interaction of vibrations in the floor with the speakers. I have noticed recently there is a growing number of audiophiles applying heavily damped, but not rigid, feet under speakers to accomplish this. This is a current "fad" that is growing in popularity. But that is another story, beyond this spike/Outriggers explanation.

By the way, Enid’s speakers were Magnepans, so their moving panels had lower mass, and therefore applied lower "equal and opposite" force on the cabinet, than cone woofers.

--Warren (aka "Sandy")

I've experimented a bit with stuff under my Thiels - spikes, isoacoustics footers etc.
I preferred the sound of the Thiels just sitting on my rug, no footers (beneath that, wood floor).  Just by lifting a speaker up you can expect some changes to the sound, which means it's not necessarily coming from the material or footer you've used to raise it.  And "different" sound of course may not be better.

I've tried my 2.7s  without and then with the outriggers.They're located three feet from the wall on a carpet with a floor mat.  I played a variety of music, including several CDs with substantial bass with near-instantaneous bass impact, as well as with sustained bass.  I couldn't tell any difference between using the outriggers and just leaving the speakers on the carpet. 

Just my experience, YMMV.

I'd like to share my thoughts regarding spikes; I performed the investigations way-back which led to our incorporation of spikes in the CS3 in 1983. As Sandy said, the chief problem is recoil. The effects, however, depend greatly on the floor system and are generally more evident in odd ways.
On carpeted floors the speakers sway and those motion effects become quite significant at high frequencies. A firm carpet may exhibit little to no symptoms, but a foam pad or bouncy carpet may allow considerable movement. On the other hand, coupling to a bouncy / resonant floor may introduce greater problems than allowing the speaker to float on the carpet. Some floor systems can be stimulated into resonant modes by spike-coupled speakers. Those vibrations can often be felt via bare feet in the listening position, offering clues to what's going on.

The sonic effects seem to congregate around image stability. The subtle spatial cues that convey image specificity can be scrambled by a moving speaker. Vague imaging, especially front-to-back depth, can be caused by unstable speakers.
Early Thiel spikes , (up to at least 3.6) were 3-point, non adjustable - explicitly defining a plane of contact. Those spikes had 3 lengths for various tilt strategies to arrive at 3' launch point aimed at your seated ears. Later models adopted 4-corner adjustable spikes. Caution: if those 4 spikes are not very carefully adjusted, problems could result from the insecure foundation.

This afternoon I tested my 2.2s under development. My floor is glued 5/8 + 5/8 plywood on 2x12 joists on 16" centers. That's stiffer than many domestic floors. My covering is commercial (old ski-lodge) tight, hard rubber backed carpet squares. My spiked speakers transmitted a little more vibration to my bare feet. I sum to mono in my preamp and pan left or right speaker for comparison using self-recorded material - in this case Dana Cunningham's Dancing at the Gate - with lots of detail. The spiked speaker produced more subtlety, nuance, detail, complexity. Highest single notes sounded more dimensional and more ambience was apparent across the range, with bass decay remaining more musical for longer times.

The improvements could be reliably noted in my setup. These are the kinds of performance particulars which I hope to increase with upgrades. However, I must note that this incisive precision is not always appreciated. Many manufacturers purposely make cap bundles to spread out such transient information; and I suspect that many listeners would find the added detail to be a negative, especially with recordings that lack the spatial and ambient clues that add enjoyment when present.

To batmanfan's original question: outriggers will do more than plain spikes. And I don't know the configuration of the bottoms of his speakers. If they are flat like the 1.6s, then some kind of feet are almost certainly an advantage. (I have seen marbles set into the corner sockets.) Threaded feet allow more precise bearing. And if your floor is resonant, then some kind of isolator pad might help decouple from those resonances.

Have fun.Tom