[R300]

I'm trialling a several pairs of iems at the moment, one of which being the Shure se420. I'm an iem newbie btw.
 
Whilst there is plenty to commend these phones, there are a couple of big problems. I don't know if this is because they need burning in, or maybe I'm not fitting them correctly.
 
1) Sibilant and "splashy" treble. They sound like cannot handle treble energy correctly, but this is surprising for a product of this price.
 
2) Drums and some vocals have a "boxy" sound. Can't put my finger on it but they don't sound natural to me.
 
Any advice about burning in or fitting them correctly? Or is the above just a characteristic of se420s? I'm running them amped from my Rega cd player.

 

[kchui999]

I've had my pair of 420's for a couple years now, and they're great buds. 
 
1.  I definitely noticed the sibilance in the treble right out of the box, but that goes away after 20-30 hours. 
 
2.  The se420 is a really neutral IEM, which is why I use it primarily for monitoring.  I definitely get a relatively neutral response from drums, and vocals don't seem to sound as brilliant or natural through these, but I feel that these are just characteristics of the equipment. 
 
Not sure how you're wearing them, but I think as long as you've got a good seal, and the bud isn't going too far into your ear canal, it should be fine. 
 
What other IEMs are you trialing?

 

[R300]

The se420 has many good things about it - balanced response, timing, bass attack (for an iem). I like a few accoustic fireworks, so maybe se420 presentation just isn't for me.
 
I've been trying a few different iems and fullsize phones (in addition to my hd-580Js):
 
Grado 225 and rs-2, ety hf2, se420, senn hd-650
 
Waiting to try:
 
ue10, akg k701, beyer dt-800

 

[ProtegeManiac]

If you like those cans cahnces are the SE420's sound isn't for you. It's mostly flat and transparent, which for cheaper cans primarily designed for monitoring means they'll need a lot of current and yet are brutally transparent (my AKG K66 is a b*tch to drive with cheap amplification save for the E7 and Icon Mobile, and otherwise sounds reeeaaaallly boring; and any system with a tube anywhere on the signal chain sounds nasal on it.) The SE420 though is an IEM and is easier to drive, although there is really some harshness in the treble. I'm jsut not sure whether it's because it's transparent or could be an issue with the crossover design, but just to give you an idea of how balanced it is, my preferred EQ setting on it is just a +1 boost in Band 2, 3, 4 set to Wide with a -2 on Band 2 set to Normal width at 6.9khz. Even with a flat EQ though it still sounds great.