Thiel Owners

On this and other fora, it has been repeatedly stated that Thiel speakers need big amps, specifically big currents, in order to "sing" and sound their best. I plan to find a way to test this common reported experience as I got these new 3.7 and have now in addition to the bryston 3b St, a set of 7b St. These amps are very similar except for output  and provide a way to compare a regular 125 watt amp with limited current, to a high output 800 watt with limited current (serial bridged), to a 500 watt with abundent current (parallel bridged). I'll do a comparison of sweep with rem software. Please suggest any other measurements that may capture a difference. What is a good piece of music that would reveal any differences? I'll record the music through the different amps at a 90dB loudness with a high resolution recording and do a blind test where you can vote to identify the recording. Any volunteers to help out with this? Thanks

Beetle - by 'sweet spot' I also include the price. The 3 generally out-sold the 2. But in those cases of smallish room / lowish levels and deepest bass not needed, the 2 shines for a lot lower price.

Rules - go for it. Remember that amp 'distress' is nearly invisible in tests. And, of course, listening is more difficult to objectify. I suggest you will learn more at a higher listening level. Look for things like 'glare', 'anemic', 'hard' and similar adjectives. Mono testing works well, switching between A & B in near real time.

Keep us posted.

@thielrules

Music Reference Amp designer, Roger Modjeski, has been pointing out on a thread in the amps forum something I think we often forget: that most audiophiles often overestimate how much amp power they actually need. Most are barely using the power available in their amps, given typical listening levels. It often takes some significant volume to get them out of a couple watts. I tend to listen when sitting in front of the speaker to an average level of 70 to 75 db at most (though I crank it up when listening from another room). Apparently, my amp would just be cruising, barely breaking a sweat at those levels, even though I’m using a 140W tube amp.


I also have never noticed any sense of strain when I turn it up louder.Now if I truly cranked it REALLY loud levels, it could be a different story.  But, as I understand it, if one’s listening levels aren’t terribly loud to begin with, then there’s no reason lower powered amps should be a problem on Thiels or many other speakers.


(I sometimes use my Eico HF81 on my MBL speakers which are a brutal 82 dB sensitivity, and it sounds plenty good to me, no strain that I notice).

There are of course other variables to consider: current, damping factor, bass quality, possible impedance interactions, the type of music one listens to in terms of dynamics/peaks and how loud. But in terms of sheer power, from what I understand, there’s not mystery why tube amps, which are so often much lower power than one can find in SS amps, often sound good with Thiels.

@thielrules, I measured my 3.7s with a single Cambridge 840w because I felt the bass was lacking.  I did it using test tones and my Behringer ultracurve and measurement mic.  The weak bass didn't show up in the measurements as it measured fine.  I bought a second identical amp to run bridged mono and the bass improved significantly.  The power went from 350 watts/channel into 4 ohms to 800.  The difference wasn't in the volume of the bass but in transients and texture.  As far as recordings go I'd find some with sustained, textured bass and also some with deep and punchy bass.  

This is Edgar Meyer playing his bass with a bow.  Lots of texture.
https://www.youtube.com/watch?v=QcXQcsAOx0I&list=RDQcXQcsAOx0I&start_radio=1

Lots of sustained synth in this silly and possibly creepy eighties music video from Queen
https://www.youtube.com/watch?v=NeL25_Ee5A0