What Class D amps will drive a 2 ohm load

Atmasphere,
While you and Ric Schultz are technically correct that higher impedance speakers get better performance from amps than low impedance speakers, this ignores the overwhelming superiority of low impedance electrostatics for most musical criteria, except in large SPL dynamics where the conventional dynamic speaker excels.  If someone designed a higher impedance stat, that would be great, but the disadvantage of somewhat higher distortion (and it is still fairly low) into their very low impedance is vastly outweighed by their superior transient response, clarity, coherence, less coloration, etc.  The old dictum is still true--the speaker is the most important element in the chain, with the possible exception of source quality.  Get the best speaker you can afford, then get the best amp that will drive that speaker.  

Sez you, some of the very best are insanely hard to drive, and why class-d, OTL and you have a problem with that.

Sez the specs of all amps. Obviously this statement is misleading; George is cherry picking. On the one hand he likes to trot out Stereophile ratings to support his claims but when that same source doesn't support his claims then its ignored.

Some of the very best speakers are also very **easy** to drive.  The issue is simple: Do you want the sound of a good hifi or the sound of real music?? If the latter, then you will want a speaker that is both state of the art and easy to drive since distortion is what separates the men from the boys.

While you and Ric Schultz are technically correct that higher impedance speakers get better performance from amps than low impedance speakers, this ignores the overwhelming superiority of low impedance electrostatics for most musical criteria, except in large SPL dynamics where the conventional dynamic speaker excels.  If someone designed a higher impedance stat, that would be great, but the disadvantage of somewhat higher distortion (and it is still fairly low) into their very low impedance is vastly outweighed by their superior transient response, clarity, coherence, less coloration, etc.  The old dictum is still true--the speaker is the most important element in the chain, with the possible exception of source quality.  Get the best speaker you can afford, then get the best amp that will drive that speaker. 

Electrostats are a bit of an exception. Their low impedance derives from a capacitance and is at the upper frequency extreme where very little energy exists! So you don't need a powerhouse to drive them. Sound Labs are a great example and some of the very best ESLs ever made. We have lots of Sound Lab customers- about 80-85% of all our MA-2s go to Sound Lab owners. IMO, the Sound Lab is one of the top 5 speakers made price no object. Even Martin Logans don't need that much power- we've driven them with our M-60s (and a set of ZEROs) no worries.

But I don't agree about the 'best speaker you can afford' thing! The reason is simple- you may find that you have a preference for an amplifier technology- tubes for example- and if that is the case buying an incompatible speaker will simply be money down the loo. So- if you know what kind of amp you prefer, then get the best **compatible** speaker you can for it.

As per bel canto - their Black Integrated ACI 600's output is stable into a 2 ohm minimum load.

As per Devialet - their Expert Pro Dual 1000's and 440's output are both stable into a 1 ohm minimum load.

I recently shopped / compared all 3 and found them to be excellent sounding and aesthetically pleasing Class D & Class A/D Integrateds.

I just saw the impedance curve. Wow, that's pretty brutal. I would love to see the schematics for this beastie and see if it can be made more amplifier friendly.


On another note, one thing I've found about amps and low impedance in the bass:



- Amps can be more susceptible to sounding weak due to low impedance than you'd think.
- This is easily audible. Basically pick the amp that produces the deepest tightest bass. :)
- Sometimes speakers have horrible impedance issues for lack of better simulation tools (i.e. old speakers designed empirically) and sometimes they get there to make them seem more demanding. Audiophiles often equate a demanding speaker with a better speaker.



To the OP: Buy what you like, I think the impedance issue, so long as it meets the amps minimum impedance requirements, will be something you can 100% hear for yourself, either way.

Best,

E

I just saw the impedance curve. Wow, that’s pretty brutal.

They do do this for laughs do they?.
Put it this way, what advantage is there for a speaker manufacturer like Wilson, Thiel, ML esl’s, MBL, Sonus Faber JM labs ect ect ect ect to make their speakers so hard to drive, because complexity of design, complex xovers used, that you have to spend big bucks on an amp with enough current to be able drive them.

THE ANSWER IS NONE!! They do it to make them as close to perfect as possible, and reward is reaped when driven right with as little compromises as possible.
If you want a gutless amp then look for a speaker to suit, they in most cases won’t be designed like the ones above.