Field hardening for speaker impedance

[raintalk]

Originally posted by phase_accurate
One reason might be to adapt the output filter to the load - my preferred method for achieving flat FR is still post-filter feedback though.

Good thought - extra bonus for hi-fi usage.

Originally posted by sx881663
Having an amplifier optimized for one load means a more cost effective and possibly a better sounding one too boot.
...
All this is a moot point for a UcD type design as it can handle the various loads with no problem.

Could be, but I'm not sure.

AFAIK - Hypex modules actually don't hande various loads - you can't get max power at 8 Ohms (unless you use a autoformer)

Not all amps are going to be stable at lower loads - like 2 ohms. They would be if the power supply voltage was dropped. (And they were designed to work at a lower voltage)

Originally posted by sreten
Hi,

not many people know this.........

The cheapo NAD amps had a 4/8 ohm switch.

And I've seen things like the Zero autoformer to allow you to squeeze out wattage at higher speaker impedance, but it seems cleaner if you can do the same with a SMPS and keep a transformer out of the speaker path.

Class-H isn't really the same as it switches voltage based on input signal. I'm saying switch based upon load, but only once per setup.

In any case, it looks like the filter needs to be transparent at audio frequencies so there would need to be another way to sense the load for an impedance sweep.