What Class D amps will drive a 2 ohm load

I'd say to the OP, contact Nord directly and run your thoughts by them. I'm pretty sure the last thing Colin will want to do is sell an amp that turns out to be useless!

Now your twisting things by saying "useless".
Of course it will "work" and he will say so, but will it get the very best out of the speakers?, DEFINITELY NOT! especially in the bass where they are a pig of a load.

I have a Classe Class D Sigma Amp 2 driving Wilson's which I am told dip down to 2 ohms.  They sound GREAT.

Here is what Classe states:

All amplifiers except the CA/CT-5300 have a virtually linear doubling of output between 8 ohms and 4 ohms but since it can be a misleading figure, we do not supply details of their performance at 2 ohms.

This by no means implies that our amplifiers cannot operate at 2 ohms, which they obviously can. Impedance varies with frequency and most high quality speakers have the capacity dip to 2 ohms. Since our amplifiers are specifically designed to drive the world’s best speakers, they will have no problem driving a 2 ohm load.

Nevertheless, driving 2 ohms in the real world requires an enormous amount of power, which is sometimes technically unavailable from the AC mains power outlet. This means that these types of specifications are vulnerable to external conditions, and can therefore be misleading. Clearly, we do not want our customers to make decisions based on potentially misleading information.

I have seen some commercial speakers from Focal introduce a 2 Ohm low deliberately in the crossover. Took quite a number of caps and resistors too.


My guess is that amps with low impedance around 100-150 Hz sound more discerning, more snobbish of amplifiers. "Look at me, I can only be driven by high current amps, so I must be better."


I have also seen designs from Infinity which were an utter part crap fest. My guess for them is that at the time they were designed good simulation and measurement tools were far too expensive, and they reached their sound empirically with no concern for the amps. You may think "well, nothing wrong with voicing by ear" but the designs I’m talking about could easily have achieved equivalent results with easier to drive impedances.


Kudos to Joseph Audio for going the other way, and actually adding crossover components which make them easier to drive by a wider range of amps.

Best,
E

I have a Classe Class D Sigma Amp 2 driving Wilson's which I am told dip down to 2 ohms. They sound GREAT.

Not saying they don't, but if you have Wilsons that go to 2ohms (your not saying what ones) then your not hearing them at the their best. And you maybe happy with that, because you don't know better.

Cheers George

Kudos to Joseph Audio for going the other way, and actually adding crossover components

That’s just adding series resistance to the perceived load to make it look higher to the amps output stage so it doesn’t complain, and what that does is lower the damping factor and raise the output impedance as seen by the amp 

You get a similar effect by using a ZERO output transformer with amps that aren’t right, and we all know know that is just a band aid fix, better off having the right amp to start with.