>They look like Brainwavz HM5
That's because they're the same OEM model. Accessories can differ.
RE-400 isn't exactly bass light, unless you screw up the fit or just really want a lot of bass. It has a downward tilt and some general bass boost to it. HF5 is slightly midbassy and but far less than the other sets mentioned. Has a less general downward tilt than RE400, above 5kHz or so.
The Senn/1More/RHA/Shure sets are all bass heavy.
MA750 highs are more spiky, maybe even a bit of V-shape, Momentum's upper-midrange takes a hard plunge (the Sennheiser in-ear veil).
The 1More Triple and SE215 would best be called bassy, SE215 has more subbass, the Triple puts emphasis higher up, closer to 100 Hz or so.
As far as isolation is considered, the real outlier is the 1More, which is too heavily vented to isolate decently. The Etys should isolate best, followed by the Shures and the rest. Depending on the eartips used and the fit, the actual isolation will vary a bit.
SE215 has a serious advantage of removable cables with a popular connector, but not everyone likes the MMCX style.
RE400 build is very poor, thin wires lacking reinforcement at strain points.
MA750 build is made of steel, but the earpieces weight quite a bit much for it. Housings can still crack
>there is a TON of other things beside the frequency response though.
The frequency response (actually the magnitude response) generally dominates over everything else.
There are other things such as non-linear distortion, which is kept low on most decently well made sets, and isolation/crosstalk which is generally of minimum significance.
Anyway 1-4 KHz, headphones for that.
I already mentioned the Beyer T90, and possible issues it has.
HD600 can have a little peak around 4-5kHz. It that proves bothersome, there's the HD650. That usually tends to be more recessed in the treble range than the HD600 already was, and the 100-300 Hz boost they have can be an issue in itself.
Cont.