Alright, a few impressions around ATH-A700 and Equation RP-21.
First, aesthetics.
The RP-21s, in my opinion, are much more stylish than the A700s, with a cool bronze color, as compared to the awkward wing-top and big round cups of the A700s. I'd much rather be seen in public wearing the RP-21s.
Comfort.
The A700s definitely take the cake here. Reminiscent of almost all Audio-Technicas, these are ridiculously comfortable, with pleather pads that don't squeeze whatsoever. Definitely not as comfy as velour, but damn close.
The RP-21s, on the other hand, have quite some clamping force that can cause discomfort, especially with long usage.
Isolation.
The RP-21s isolate noticeably more than the A700s, which isn't a surprise, as the A700s don't really create a seal around your ears, they simply rest on them. The A700s will indeed prevent sound from leaking and definitely HAS isolation, but in loud situations, I'd reach for the RP-21s first to block everything out.
Sound quality.
The RP-21s, at first, were actually a disappointment. They seemed far too recessed at the high end, and created an extremely in your face presentation overall. The bass seemed to dominate the rest of the scene. However, though some burn in helped a tad, the main difference was the quick mod suggested in the Equation Audio megathread, in which you take the earpad off, and remove the thick piece of foam from the driver. After performing this mod, the sound really opened up, mainly the higher notes. The sound was able to sound less as if it originated in my brain, and sound more like a pair of open headphones. With the mids and highs opened up, the bass feels more neutral now, and the headphones as a whole feel very even.
As for the A700s, well, they're great. Straight out of the box, I recognized the familiar Audio-Technica sound. The wonderful separation of parts in a huge soundstage, the warm mids and clear highs. Simply wonderful. I have a pair of ATH-AD900s, and I have to say the A700s do a GREAT job of sounding like open headphones while still being closed. No comparison to the ADs, but extremely impressive for what they are. However, beyond the larger soundstage, more sparkling highs, and more warm, emotion-filled sound of the ADs, the A700s indeed has the punchy bass that was missed by some with the open series.
Differences
Some direct differences between the RP-21s and A700s. The RP-21s bass is definitely more prominent, yet the A700 seems more detailed. The A700 definitely has better separation and soundstage, but removing the foam of the RP-21s gave it extra separation on the high end, making it a much more formidable contender. The RP-21s are missing some of the intimacy and emotion offered by the ATHs. Overall, I liked the A700s more. Better soundstage, more warmth, and just an overall feeling of comfort, both physically and sound-wise, compared to the squeeze of the RP-21 as well as the slightly more tiring sound signature.
Gaming (Threw this one in for anyone who might be interested)
As for gaming, A700s, on this board as well as others, have quite some regard for being EXCELLENT for gaming. Great soundstage, for hearing placement of enemy's footsteps, quite sufficient isolation to eliminate distractions, enough bass for you to 'feel' the explosions, just good all-around. The RP-21s will suffice as well, but without quite the pin-point sound-placement of the A700s. I feel as if I'm cheating when I can follow where someone is through the wall, and dispose of them as soon as they appear. A700s are the definite winner here.
MY Decision
However, as of now, I believe I'll be sending back the A700s. These were meant to be headphones for the bus, and the RP-21s are far more portable than the A700s. The more stylish design is also a plus. The sound quality from the RP-21s wasn't enough of a drop to warrant squeezing the A700s into my backpack somewhere. HOWEVER, this decision was LARGELY made on the fact that I already have ATH-AD900s for home music and gaming use, so I won't miss the sound of the A700s by any real means. If I didn't have the AD900s, it'd be A700s ALL the way, despite portability, style, and any idiosyncrasies of the sort.
My Suggestion
For you, I'd easily suggest the A700 over RP-21s, as it seems you don't need the extra isolation (just leak prevention) or portability, as you'll use it at home (I believe). The A700 is definitely the more impressive of the two, and will give you a good impression of the ATH sound, which only improves with the open models. So actually, if you wouldn't mind losing a bit of bass 'punch' but gaining some bass detail, I'd say, forget both of these, and go for the AD700 or even the AD900s. There would be some sound leakage, of course, but as long as you're not in the same room as people attempting to sleep, it should be fine.
Thanks,
Michael
