for iems that are marketed as bass giants (Twinwoofers?!), the entire lower end of the spectrum is extremely poor and the bass lack any punch and pace whatsoever. The overall sound is quite boring which is particularly disappointing considering that they are far from being neutral and flat across the spectrum. I compared them with my old Soundmagic E30s (a fair comparison as they cost roughly the same)- while the E30 is quite blatantly coloured in its sound signature, the crunchy mids and surprisingly controlled bass make them an easy choice over these rather uncomfortable, heavy and oddly shaped earphones which offer absolutely nothing special.

 
Okay so even though i'm not an audiophile in the sense that I don't necessarily look for the most neutral, flat IEMs, I do want to enjoy the music I listen to (mainly rock/ classic rock) the best I can and have spent many hundreds of dollars over the last 3 years trying out different IEMs ranging from shures to etys UEs etc. 
I never cared much for earphones that cost over a 100-150 because i never really manage to stick with a pair so I probably havent yet tried the better sounding IEMs on the market just yet but of all the ones i've ever listened to, E30s have been the most pleasing to my ears by far.
 
I have a couple of pairs of PL 30s and PL50s so I'm not very new to soundmagic's design philosophy and do not intend to discuss any of those aspects here. Very quickly but, I dint instantly like the way they look. Plastic feels cheap and the chrome bits on the phones with the shiny aluminium embellishments at different places on the cable are a step down from the low-profile, professional feel of their other monitors. 
 
They are still almost as comfortable as the PL50s (which are the most comfy phones ive tried) and the shallow fit which they offer makes it easy to keep them on for hours together without fatigue and makes them my first choice for casual listening or when working out etc. Isolation, quite simply is VERY ordinary and even though using Complys makes them a bit more comfortable, the fundamental design of these prevents all measures to improve isolation from truly delivering. 
 
Now here's the best part which really makes me loves these suckers- the audio quality. 
Before I turned to these, I was using amped Altec Im716 for almost a month because they had a very balanced sound, clear tone a extra bass on demand. Plus they worked well with my guitar so i wasnt switching between phones so often. First thing I noticed about the e30s was the bass. The best bass, most controlled bass ever produced by things so small. very clear, very punchy, no signal bleeding, and added colour on just the right frequencies helps them pick up on the most subtle basslines. Rock music really comes alive with thumping bass drums and sturdy upper bass frequencies. 
I'm not sure if this affords them the "neutral" tag, but they are too much fun for anyone to bother picking on these technical aspects to beyond a certain extent. 
The bassy sound makes them sound warm whn compared with BA driven phones like the im716s or PL50s. The mid range through treble is fairly neutral but by no means recessed. Again, the clarity is good and the densest of guitar gatherings are well accommodated with no distortion or aliasing.  Frequencies towards the top end of the spectrum may occasionally sound somewhat subdued when listening on lower volume but a good sound source where you can keep the post-processing volume fixed at max and control noise level through a pre-amp will prevent any low-volume roll-offs and the phones would sound great without any EQ settings. Else, a linear gain starting at 2dB for 3000Hz going upto 5 db for 16000Hz sorts out the minor tendency of the upper range to hold back and makes the E30s shine. 
Great phones for the price and the warm sound, awesome bass and gravely mids make them a great choice for listening to genres such as rock, metal and grunge. Nice, raw earphones love them.