Pros: Great fit, wonderful isolation, superb mids, good clarity
Cons: Could use a little more treble extension, hard to remove the olive tips
Shure SE425 - Highly Impressed - Great Build, Great Sound
I received these as a replacement for my SE420 - which unfortunately had to be replaced due to the cable splitting at the relief (luckily inside warranty). Kudos to the fantastic team at Now Sound in NZ for their prompt work replacing them.
The biggest change from the older model has been the addition of a detachable cable - and the design for this is wonderful. It now includes a memory wire (some love it, some hate it - I find it handy). The housing is now hard plastic (the old one had a rubber cover which would keep splitting). The hard cover makes it a lot easier to insert and remove. The housing also seems smaller than the 420 - and once inserted fits flush to your ear.
Fit / Comfort
The new housing makes it very easy to fit - and get a great seal every time (for me). I did have to change from medium to large olives. The insertion is a lot shallower than the 420s - but the change in olive size ensures I get a perfect fit. The housing fits flush to my ear, and I have no issues with discomfort. These are comfortable enough to sleep in. I've also been running with them - and have had no issues with them falling out. The new memory wire makes looping over the ears very easy. The memory wire on the 425 is not as stiff as on my 315s - and is very comfortable.
To remove the iem's, all I do is swivel the cable out of the way, then grip the body and gently twist. It is very easy.
The microphonics on the 425 are very much reduced compared to the old 420's. I'm finding virtually no microphonics from the new cable. The fit I have is amazing for isolation as well. These isolate for me a lot more than the 420's did (and as I said above, the insertion is shallower).
Well I guess this is the main sub topic. Couple of disclaimers - I really like the Shure sound - I started on SE102's, went to SE420's - then got a set of 315's while my 420's were being replaced. I haven't heard much in the way of high end iem's - so can't really give a comparison / benchmark. So the following is solely based on my thoughts of the SE425 in isolation.
Bass - while the 425 is not an overly bassy iem, the bass is present, it extends well (better than the 315 or 420), and is tight and controlled. The best thing about the bass is that it doesn't bleed into the mids.
Mids - the Shure strength. Silky sooth and absolutely fantastic for vocals. Also great with acoustic guitar. Nils Lofgren's Acoustic Live album is simply blissfully enjoyable. The mids are very present - probably even accentuated, but they don't seem overly forward IMO. They are just really well balanced.
Highs - probably the only thing that I wish there was slightly more emphasis on (it can be achieved with a touch of EQ though ). The highs do roll off quicker than I'd like - and IMO this is the 425's only real weakness. They just need a little sparkle to make them great.
Clarity - another strength. Instruments are well separated, and the music is very well detailed and clean. I love listening to acoustics and picking up every nuance - fingers moving on a fret board etc
The 425's are a really good iem - well designed and built (these will last for years), superbly comfortable and really smooth and detailed. The mids are the strongest point - but the entire sound to me is balanced and relaxed. The one weakness (for me) is a slight lack of upper treble - but easily fixable with EQ.