What Class D amps will drive a 2 ohm load

With the stat speaker, impedances can be as high as 30-100 ohms in the upper/lower bass, and 1 ohm or less in HF.  This is more than the 10:1 ratio you cite, but still nowhere near as much as the inverse RIAA curve.  Still, according to your theory, the stat speaker should sound like a less drastic inverted RIAA curve, which I didn't find in the listening.  Also, all dynamic speakers have marked variations in their impedances, and your theory would predict that a SS amp would produce markedly different sound from different speakers in relation to each speaker's impedance curve.

@viber6  this isn't correct. (BTW what I'm talking about here isn't theory, its more like audio history. The Power Paradigm is what was around before MacIntosh and ElectroVoice developed the Voltage rules in the late 1950s.) With most dynamic speakers (there are exceptions in high end audio) the speaker is meant to be 'voltage driven' so variable power output is what you're looking for in the amplifier in order to get flat frequency response. The idea is plug and play, no need to adjust any midrange or treble controls (like you see on older speakers, stuff from the 50s and 60s). Of course like anything else, this approach solves one problem while introducing others.


The brightness of an unequalized RIAA curve would **not** have been compensated by the way the ESL and solid state amps work together.  I think you will find though that the 10:1 ratio I described is generally pretty close- that describes Quads, Martin Logans, Accoustats and Sound Labs which are the ESLs with which I have the most experience. If you can find one that is outside of that (for example: 100:1) I'd be very interested in knowing about it!

Wow!
The Wilson Alexia's get into areas of the Kappa 9's for difficult to drive?
Did not know that, thought all Wilson's were very efficient speakers.

We're gonna need a bigger boat...

I’ve had Thiels for 12 years but have since moved onto to Magnepan 20.7’s. The best amp I ever found for my Thiel 2.7s was the Pass X series and a Pass x150.8 would probably work but an x250.8 would be better. As far as "digital" amps goe, if you poke around the Thiel users groups you’ll find that ALOT and I do mean ALOT of Thiel owners were using Bel Canto digital amps most often the Ref 1000 to drive them. I tried those amps with my own speakers and they worked really really well for my classical and jazz listening but not quite so well as the Pass products.

Bel Canto digital amps most often the Ref 1000, I tried those amps with my own speakers and they worked really really well for my classical and jazz listening but not quite so well as the Pass products.

I said pages back the "better" Class-D’s like the BC Ref-1000 will work, and probably to the owner sound fine with the op’s Thiel CS-5’s.
But "he" hasn’t heard the CS5’s at their best yet until he’s heard an amp that can do <2ohms without breaking a sweat far better, like the Pass X150.8, then he’ll know that Class-D was doing it hard.

Cheers George