It's
xnor's ⅓ octave Graphic Equalizer for
foobar2000. After using
foobar for a while and looking for a good equalizer – preferrably parametric – it was the only one I could find. And it turned out to be so good and useful that I stuck to it. I think it suits my needs even better than a parametric equalizer, since it allows for tiny 0.1 dB steps within a limited frequency band, ideal for experimenting – and I use to apply tiny steps. A parametric equalizer is good if you have your mind set on a curve based on an existing frequency-response graph, but not so practical for experimenting further on the basis of the original curve. I don't trust available frequency-response graphs at all (all compensation functions I've seen so far are heavily flawed in my experience), but do use them as rough guidelines – building a curve out of the air bears too much risk of endless erring in the wrong directions.
I have used a parametric equalizer in the past, a Technics SA-9010 – thus an analogue hardware equalizer. From its functionality it was perfect, but it degraded the sound quality too much to be of any use for listening to music: As soon as it was in the signal path, the sound became rough and spatially flat. So it got relegated to be a tool for developing crossover networks during my extensive speaker-builder occupation.
I don't expect the same from digital equalizers. Although I'm no programming expert, I imagine it to be hard building a software equalizer that degrades sound quality. Can you point me to one?
xnor is a Head-Fi member, although it's been a long while since I saw him posting. I can guarantee you that his equalizer doesn't degrade the sound. I even suspect that criticisms on existing software equalizers are rather based on users with limited experience than the software itself. Or maybe impractical frequency bands – like with some HiFiMan DAPs (maybe they're improved meanwhile). In this context the worst thing I can imagine are octave equalizers with frequency-band Q factors of less than 1 – which still don't degrade sound quality per se, just limit usability.
The reason for my SA-9010's bad sound are without a doubt the countless electronics components in the signal path. Now imagine the impact of a complete headphone amp attached to the Hugo's headphone output – a technically redundant gain stage with a bunch of electronics components. It may not sound as bad as my Technics equalizer, but it will degrade the sound to a considerable degree as well. Maybe that's even wanted: Quoting Rob Watts: «Some people like harmonic distortion.» It's true, harmonic distortion in the homeopathic doses like the ones in amps have the ability to make the sound richer, fuller and more forgiving. Unfortunately they represent an invitation to use them as quasi-equalizers for people with no interest to occupy themselves with the real thing. And that's a pity! The consumer attitude even leads them to spend $600 or $1600 for technically questionable solutions, although they could have the best solution for free.
