For the record, after much agonizing, I decided to forget about the UM2 for now. My experience with IEMs so far has not been entirely positive, and I didn't want to spend over $300 having something shipped to the UK that might well turn out to be a disappointment. In the end I went down to Digital Village and auditioned the Sennheiser HD 25, and liked it enough to fork out the required £120.
The phones are obviously not portable to the same degree as IEMs, but are very light (160 g with supplied cable) and robust enough to throw into a bag without worrying about them getting damaged.
I have replaced the pleather earpads with velour pads (#069417), which I find to be much preferable. The comfort level is fine, though less comfortable than circumaural phones. The split headband is novel and improves stability. Not being a DJ, the rotatable capsule feature is useless to me, and is actually an annoyance as it tends to cause the capsule to go off centre. It also means that the cable is to the right instead of to the left, as I would prefer.
The supplied cable is rather short (1.5 m), made from steel (supposedly for strength), and is rather stiff and microphonic. I measured the resistance as nearly 5 ohms, which is pretty shocking. I replaced the cable with the 3 metre copper-core cable (#74532), cutting off the monstrous 6.35 mm jack and replacing it with a Neutrik NTP3RC-B 3.5 mm plug. I measured the resistance of the copper cable as well under 1 ohm. I'm not generally a believer in the worth of cable upgrades, but in this case I would say there is definitely a noticeable improvement.
My phones now look just like
BavariaBarbarian's. I got the parts from
Thomann in Germany cheaper than I could find them in the UK, and the delivery was fast and reasonably priced. Thanks to all the folks on Head-Fi who provided the information I needed to get my phones the way I want them. It's really too bad that Sennheiser doesn't sell a version with this configuration in the first place.
Now for a slight whinge. Most websites advertise the frequency response as 16-22000 Hz. In fact, the frequency response to -3 dB is 30-16000 Hz. The 16-22000 Hz range actually refers to the -10 dB rolloff points. The only place I have seen this mentioned is on the side of the box. The Sennheiser website seems to deliberately confuse the issue by listing both 16-22000 and 30-16000 ranges without saying what rolloff the figures refer to. Naughty Sennheiser. Also, the sensitivity is generally stated as 120 dB. Again, this is untrue - it is actually 105 dB. (The 120 dB figure is the maximum SPL.)
Anyway, the sound quality is quite good, especially considering that this is marketed as a DJ headphone. It is somewhat brash in the upper mids and lacking in deep bass. Drums sound particularly good, and this is now my headphone of choice for using with my Roland electric kit. However, for general listening, the HD 25 does not really compare with the DT 770, which is only 2/3 the price and sounds quite a bit better.
Isolation is pretty good, actually slightly better than the DT 770, in part due to the HD 25 not having bass reflex ports for sound to leak through.
The HD 25 is expensive for what it is, so I cannot say that it represents great value for money. However, if you want a portable closed can for decent sound on the go, then the HD 25 is probably about the best on offer.
