Originally Posted by mikeaj
"Correcting the non-linearities"?
That kind of language makes me nervous. Equalization is correcting linear features like frequency and phase response, via a linear operation (multiplication in frequency domain, or convolution in time domain; or what is the actual implementation in practical audio equalizers? in hardware you can do an RLC network with a certain transfer function, which we're hoping has few nonlinearities)
The nonlinearities are exhibited in features like harmonic distortion and resonances, which are not being directly compensated for.
Or am I missing something here?
Sorry about that. As you can see English is obviously not my primary language. Should I say peaks and valleys? I was obviously referring to frequency response.
Originally Posted by xnor
I agree with most of what you wrote, but linear-phase means pre-ringing. For the equalization of dynamic drivers you want minimum phase, i.e. there's no energy before an impulse and most of the energy is concentrated near the start of an impulse. That way you can not only correct the magnitude but also the phase of the frequency response.
As for "hi quality". Imo an EQ either works properly or it doesn't. Even free ones usually operate with 64-bit floating point and use textbook formulas that work perfectly. Things get hairy when the developers think they have to add hidden filters or oversampling or other special "features".
It really depends on the algorithm implemented in that linear phase eq. Thats why some sound super transparent (and are equally expensive, like the Algoritmix Red) while others don't.
Hi quality can mean oversampling to avoid aliasing, but also "analog" phase algorithms (like in EQuality) or analog like curves (like those in the Eiosis Eq). To me the "extreme" setting in the iOS app named "Equalizer Pro" sounds superior to the sound of another excellent app named "Equalizer" which also has a full parametric eq. But I prefer to fiddle with the interface of Eq Pro for that.
Actualy for listening to the Tesla T1 I admit I use a minimum phase eq which is included with the Metric Halo ULN-2 I use at home, but the mixer on that has 80bit resolution, and the eq sounds great. You gave me a reason to test minimum/linear phase eq vs dynamic/ba based phones
Edited by tumburu - 12/6/12 at 12:02pm