Sennheiser IE 200 In-Ear Headphones

Before I go any further, I must stress that this review is about the product: Bax themselves have been good as gold, as usual.
That said, I wouldn't recommend the IE200s.
Despite trying all the supplied earpads, the only way I've succeeded in getting anything like a decent LF response is to actually push them into my ears and hold them there, which isn't a workable solution. Just playing a series of test tones off spotify shows that there's not much at 60Hz, slightly more at 100Hz, and it's only by 250Hz that the response starts to sound plausible. And even when the low end starts to work, there then seems to be a dip in the upper LF that means they're tinny and unpleasant to listen to, and insufficiently linear to be trustworthy for serious monitoring. Rejection of external sound seems ok: I'm now listening to Daft Punk while Bake Off is playing through a decent pair of floorstanding speakers, and I can't hear much of it, mercifully.
I don't have extensive experience of IEMs, so I don't know whether spending more money gets you a better frequency response; but I think the lesson I've learned here is that it's wise to listen before buying.
Had I done that in this case, I wouldn't have bought these.
Lyndon Jones