Okay so trying for the 2nd time. (IE crashed and lost my entire post and review just now...)
There are 4 things that I suspected that have definitely been borne-out in my opinion:
- The kingdom of BASS has not gotten a new king. The JVC SZ2000s continue to reign supreme if you are willing to EQ and AMP.
- The JC ESNSYs are quite the headphones for the money, (~$56.00 USD) and they are a bargain at even twice the price.
- You can get your "slam on" straight from even an iPhone EQ's with "BASS BOOSTER", DEEP, or HIP HOP, but the ESNSYs need amplification to really shine just like the SZ2000s.
- The SZ2000s far-outstrip the ESNSYs in terms of build quality and comfort. The first is clear to anyone I'd say, and the comfort is obviously a purely subject evaluation.
So here we go:
Point ESNSYs -
Soundstage is wider. SZ2000s are almost "claustrophobic feeling" in comparison
Price. The ESNSYs are a real steal at their current sub-$60 USD price point.
UNAMPED, I enjoy the ESNSYs much more. They are just "fun" to listen to straight out of your phone or MP3 player. On many songs there was noticeably more bass than I heard from the SZ2000s.
Mids aren't quite as recessed as they are on the SZ2000s
Weight. These are MUCH lighter to have on your head
Point SZ2000s -
Build quality. These things are TANKS. If you dropped these on a ceramic tile floor, I'd say goodbye to your tiles before I'd expect to see these show any damage.
Comfort. I can see wearing the SZ2000s for hours on end (And I have) without any concerns about comfort. The ESNSYs just clamp too much for me to ever "forget they are there" like I can sometimes do with the SZ2000s.
Beyond maybe 70% bass overdrive capacity, the SZ2000s just keep eating the power and offering-up more slam. The ESNSYs start to break up and get progressively worse while the SZ2000s just keep going.
BASS QUALITY COMPARISON:
Different enough that I didn't want to reduce this to simple advantage "X headphone" over "Y headphone".
There are two modes I compare them in. "Bass-centric", and "Beast-mode"
Bass-centric - The ESNSYs arguably win in this segment. If you are a casual listener who dabbles in bass when the mood strikes you, then these are arguably the better choice, all other considerations aside. The bass is deep and pervasive while the mids are not as recessed as the SZ2000s. In fact, the mids are surprisingly up-front. Almost to the point of being "in your face", but not quite. The Highs are just "there", not shouty, and not recessed. Everything from Madness (One Step Beyond) to Journey's (Faithfully) just sounds great for casual listening. Not overly analytical or too buttery. Just enjoyable.
The SZ2000s are just fair, quite honestly. These isn't really anything remarkable about the bass which is almost balanced with the highs rather than pronounced. There is definite recession of the mids, and the soundstage being so small just draws more attention to the mids lacking. The music detail overall is lower than I would like for even casual listening. In short, I wouldn't buy these headphones if you just want to listen to typical "vanilla" music everyday, and they wouldn't be my first choice for rap, hip hop, dance, etc.. either.
BEAST-MODE - Simply put, the SZ2000s destroy the ESNSYs in this segment. It's not that the ESNSYs don't perform well, because they do. It's just that the SZ2000s can go SO much further than anything else that it's almost impractical to compare them. If you go beast-mode, you typically want to push the envelope. The ESNSYs can get you maybe 70% there before they start to break up and rattle. More a limitation of materials used and the driver limitations than a bad/poor design in my opinion. Up to that 70% mark, you have two AMAZING headphones that thump enjoyably. Completely different "feel" to the bass, while the quantities are quite comparable. The SZ2000s have a deep, "rattle your bones" that you feel inside. The ESNSYs have a sharper, crisper "Hit" that you feel more on the surface. It's really a matter of preference at this point I think.
Video: Proof in the pudding of BASS at same levels between the SZ2000 and ESNSY. I made separate videos so that you can see the evidence side-by-side if you wish, but honestly the difference is pretty clear.
SETTINGS FOR BOTH:
iBASSO DX90
VOLUME: 255 - Full digital so no signal loss going into amp.
EQ: Custom - 33=10, 63=10, 100=5, 330=-4, 630=-5, 1k=1, 3.3k=-9, 6.3k=-6, 10k=-9, 16k=-5
iFi iDSD
VOLUME: 1 'oclock
XBASS=On
3D=On
ieMatch=Off
Filter=Standard (Not Bit-Perfect)
Polarity= Negative
Power Mode=TURBO
CONNECTION
"Coaxial out" DX90 to "SPDIF In" on iDSD
Ken's short answer: BUY BOTH! They are COMPLETELY different headphones for completely different purposes offering completely different sound experiences!
Your wallets now hate me.... Mission accomplished!
Enjoy, and all power to the BASS BROTHERHOOD!