bitflipper
But I see no reason why a many-band hardware equalizer can't do as good a job as ARC, which ultimately is just a parametric equalizer, albeit with some fancy software to set it up for you. Take the compensation curve that ARC creates and smooth it to remove the dips and peaks that are too narrow to be significant, and you're left with a handful of broad corrections that can be easily recreated with any equalizer.

You might want to consider phase response and reconsider that statement.

You're thinking that group delays are significant, Drew? I'll concede that minimum-phase equalizers can never be truly transparent, but whatever coloration phase shifts cause is orders of magnitude less-significant than the effects of room resonance.

bitflipper
You're thinking that group delays are significant, Drew? I'll concede that minimum-phase equalizers can never be truly transparent, but whatever coloration phase shifts cause is orders of magnitude less-significant than the effects of room resonance.

If you just use an EQ, you are applying whatever phase response that particular EQ gives you. They are at least attempting to correct for both phase and frequency response in the room. That's why they can say it addresses the time as well as frequency issues.
 
Having said that, I can't really say how much audible difference it makes one way or the other.

So ARC claims to "correct phase response"? What do you suppose that even means? Rooms don't shift phase, so what is it that needs correcting?.
 

I know you know this, but if you add 2 sine waves of identical frequency but different amplitude and phase you output a sine wave of the same frequency but different amplitude and phase from the inputs.

Not following, Drew. You are correct, I do know how sine waves add, but I'm not understanding what it has to do with ARC and room correction.
 
Are you thinking that perhaps shifting the phase of a resonant frequency might prevent a wavefront from meeting its own reflection exactly in phase or exactly 180 degrees out of phase? 

The direct and room reflections add together at different levels and phases, simple as that. 
 
The impulse response of a filter in the time domain equates to the frequency and phase response of the filter in the frequency domain, so the room's IR can be thought of as an FIR filter that modifies frequency and phase response at the listening position. All an FIR filter does is convolve the signal with the filter's IR, just like (in theory) a convolution reverb does with it's IR.
 
So if you think of the room as a filter, you just need another filter to undo its effects at the listening position without screwing things up too much in the process.