What Class D amps will drive a 2 ohm load


Just asking.

I see specs into 4 ohms but nothing into difficult speaker loads (like Thiel CS5's).

Thanks for listening, 

Dsper


dsper
Atmasphere,
I follow what you are saying about how a voltage source SS amp invariant to impedance theoretically would sound bright driving an electrostatic speaker.  But in practice I don't find this to be the case.  Years ago, for fun, I put my tonearm leads into the line stage, bypassing the RIAA curve of the phone stage.  Of course, that produced very bright sound due to the 30 dB boost at HF compared to low freq.  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.  But I have found similar tonal differences A/B'ing 2 amps on different speakers.  For example, SS amps generally sound brighter than tube amps, which I have found to be true regardless of whether I used dynamic or stat speakers.  I am puzzled by my different listening findings compared to your theory.

I wasn't saying that amps don't make much difference, because obviously I pursue finding amps that offer more clarity, etc.  But it is clear that whatever sonic differences there are among amps, the sonic differences among transducers like speakers are vastly greater.  This is also true of transducers like cartridges which are really inverse speakers.  
@ georgehifi

All the amplifiers in the world double when drop in ohm to half, but when you reach their current limit then you will not see the doubling when you drop in ohm
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!

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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...