I never liked my AKG K701 headphone though I've owned it for several years. I thought it lacked dynamic punch and the bass, and too sterile. I was using M-stage headphone/DAC with it.

Wow, it really came a live with Taboo III. Very enjoyable. Detailed, great imaging and very musical. Taboo bring that tube realism to the guitar, cello, voice, sax, piano and etc.

Pure sound detail and frequency response wise, initially I didn't think it was much different from M-stage, but it is WAY more musical. I haven't tabbed my toes using headphone ever before. Taboo has much cleaner separation between instruments as well.

M-stage does have one thing that is better - bass control. I get much tighter bass with it - fast sharp attack and quick decay, while Taboo tend to have more bass but less tight. My PBS M4U2 sound amazing with M-stage. It has the most awesome thumping bass for pop/rock/dance music.

I think K701 is my favorite so far with Taboo out of about 6 different decent headphones I have. I wish K701 had a bit more thumping bass and it would be about perfect.

What would be that headphone? Audeze LCD3 or 2.2? Never heard them, but I was told 2.2 is dark and narrow in staging? LCD3 is probably out of my price range for a while.

If you have a chance check out the modified Fostex T50RP. I have the ones modified by Smeggs but I am not sure if he does that anymore. But there are a lot of other companies that do the same or close to same modifications like the Alpha dogs from MR. Speaker. The ones I have sound great on the MK III.