Thiel Owners

Tomthiel, Interesting that you used Krell's  (though I can understand why)  for developing the CS5's, it's been long rumored it was the 250 Class A Watt mono Threshold 12e's.

A good amp for current hungry Thiels doubles power from 8 to 4 ohms and again doubles or nearly so into 2 ohms.

Neither Ayre or Pass give a 2 Ohm rating for the amps F1 is considering. I’m not convinced, however, that matters for a CS2.4. Unless you like to listen at *really* high SPLs and/or have a large room, either amp sound be more than enough to deliver musical bliss. Interesting observation, though, that something in the, um, Ayre might have caused the blown coax. I wonder what that might be.

The CS5, though, looks to be a supremely current hungry speaker. Stereophile’s measurement shows the impedance dropping <2 Ohm in the bass! Might not want to drive those with a SET :)

The observation of congestion of orchestral climaxes at high SPLs suggests, to me, the onset of clipping. Probably need a more powerful amp if that’s how you like to listen.

Rob,

I’m glad you enjoyed my ramblings on the Thiels. At one point I rambled in an online hi fi mag reviewing speakers (many years ago) so I’ve had a lot in my listening room. I drifted away somewhat from the hobby for a while (turning to designing my home theater room among other things). Still, both back then and now I have enough contact within the community to hear amazing gear.

I keep experimenting, modifying the positions of the 2.7s and find I can get them sounding almost however I want - smooth and lush, brighter more dynamic or a mix in between.

Right now I’ve dialed them to where they sound just super clear with incredible transient response, yet with a warm inviting timbre. Playing something like P. Glass’s Powaqquatsi with it’s ever changing layers of percussion sounds so exciting and life-like, the exact character of every different drum, block or triangle so vivid.

Like I said, I’ll miss the 3.7s scale, but the 2.7s portray more rhythmic drive and conjure sonic images with more solidity than anything else I’ve yet heard. So they are to my ears very much a “performance-first” speaker where the lively sense of musicians performing is the overall effect vs other speakers where soundstaging/spaciousness may leave the overriding impression.

ronkent,

Thanks for the REL recommendation. I used to be more familiar with that line years ago and they were my first thought.
However I’m in a situation where some room features rule out anything but very small subwoofers and the size/performance ratio of the JL Subwoofers I chose are tough to beat.

As I think I may have detailed earlier in the thread, the JL subs, though generally made to use the rca line ins also offer a high level speaker input - ala REL - and as that was easiest I started taking the feed off my 2.7
speaker posts.

Though I got some of the subwoofer benefits - larger, deeper sound - I also lost dynamics and the tone of the system went too dark/soft/rolled off.

i don’t know why (and I’m mostly a newbie with subwoofers as I’ve usually hated subs).

I tried using the rca inputs as well (sent from my preamp) and while it was a bit more dynamic the tone of the system changed too dark. In both cases this was running the 2.7s full range with a low crossover point.

JL Audio’s position, and that of most of the subwoofer aficionados I’ve read, is to go with the crossover and split the sub/mains, usually around 80hz. So that’s my next move. (I bought JL Audios high end analogue crossover).

We used a variety of amps in the lab and listening room. Threshold, Mark Levinson, Krell and Classé were always there. Unsound may be right about the TH12e, I don't remember. The Classe´amps were a pair of DR9s strapped to mono, which I still have, have hot-rodded and use every day. Their stereo rating is 8/4/2=100/200/400 and mono is 400/800/1100. An amazing thing to me is driving a pair of PowerPoint 1.2s, sealed box home theatre monitors rated at 89 db/w-m with 75 Hz cutoff into an easy room at "normal" playback levels . . . have you guessed? Their performance jumped a big notch going from stereo to mono with these amps. MUSIC IS TRANSIENT and impact requires power. These PPs are my mix and room monitors with stereo SmartSubs. (I'm still looking for a beat-up SS-2 or SW1). When people suggest your Thiels are sounding conjested on complex / demanding music, look to your amplifier.

An endemic design problem is second-guessing. If an amp designer assumes that low-impedance loads will be narrow-band / reactive, lasting instantaneous / short durations, then he can sign off on the particulars of his power supply. However, Thiel (and some other) speakers assume that a properly designed amp can deliver its rated output into resistive (easy) loads for longer term cycles (hard). The amp with enough power supply will love that load. The wimpy supply will starve the rails, clip the peaks, generally sound hashy and burn out drivers. I personally examined hundreds of burned-out Thiel drivers over my years (1975-1995) and every single one failed due to heat which means they were fed dirty signal. Conversely, over all the years of our listening and testing at well over 100dB (large) room levels, we NEVER burned out or otherwise failed a single driver. The specialty retailer and review magazines are supposed to do the educating, but that education is quite thin, in my opinion.

Jon, fiberglas is the cost effective standard. I tested and love genuine wool. Its naturally spiraled fiber works magic in converting pressure-motion to heat. We used 2 grades of SAE military pure wool felt on the back cabinet wall of the midrange enclosures to absorb the back-wave. Wool's performance can't be equalled by modern materials, which I call wishful engineering products. Wool fiber has a couple of problems in the cabinet. It acts very differently than fiberglas, so don't just replace the FG with Wool. And wool is inconsistent, so every cabinet would have to be trial-and-error optimized, which doesn't work well in a production environment. It is also hydroscopic (absorbs water in humid environments) and it's expensive. I will consider it if/ when we get to ultra-upgrade prospects, but wool must be re-engineered, not merely substituted.

Well, I don't think I listen THAT loud -- we were listening to the 2nd Beethoven piano concerto this weekend, it's got very quiet passages with just a few instruments, and then full orchestra passages. Our room's 20 x 21, speakers are 5 feet away from the wall. My Alpha DAC digital volume was 38, fed directly into the amp. So, not earsplitting! But the small ensemble music is very nice, great imaging, timbres, etc., and as I wrote, the climaxes seem a little "scrunched."  I've had the 3.7s for three months. before that the 2.2s. Nice speakers, also.