Request / suggestion - add distortion measurements graph from REW to reviews
Pretty please :) With the plot normalized to the fundamental so it's easy to read the % If you post REW measurement files too that would be amazing.
I suspect your objection would be that it's hard to explain what % levels at what frequencies are audible and make a difference. But, I think that would be a bit of a cop-out.
Very few reviewers do this, yet I've found it very helpful. For example, Soundstage network's P162 measurements.
There are a couple distortion spikes in the ~1.5KHz - 2.5KHz region which, to me, seem audible. I always thought I heard some harshness from these in the mid/high range. So I measured my P153 using REW and got similar spikes in the same area as Soundstage (woofer entering cone breakup? explains why they need to use a 4th order x-over). After adding some filters there using EQ APO, it's much cleaner and less bothersome.
I think this can be a big differentiating factor between speakers which otherwise perform similarly in most other ways (e.g 2 way cone speakers with similar on and off-axis response).
Posted Feb 17, 2016, 3:57 PM UTC
How far below the noise floor was this distortion? I think I would really need a room designed to get these kind of measurements accurate.
My measurements are pretty shit I'm sure of it as I'm just learning, but anyway I'm getting similar results to soundstage, with my big peak being around 2.7KHz (fundamental 71dB, thd relative -27.5dB so >4%; I know I should measure louder eh?). My noise floor is around 40dB?
I'm not sure if what I'm doing should considered invalid but looking at my REW does seem to match. I could pm you some REW measurements.
I'm going to need to read up on best practices for these measurements. The only small time guy I know doing distortion measurements is Zaph audio, and he has a home made anechoic chamber.