Adam Smith(Date Added: Wednesday 17 August, 2011) This review is as much a story of my in-ear monitor (IEM) odyssey as a review! I started off with an ipod and a pair of Ultimate Ears Superfi 5 Pros, a great pair of IEMs that served as the perfect introduction to the joys of in-head - rather than on-head - listening. But after a couple of years, I fancied an upgrade - more bass, please! Better midrange, sir! And we could do with a wider soundstage to top the package off, as well! - and a bit of research turned up the Sennheiser IE8s. Armed with the foreknowledge of a hundred Internet reviews, I took the plunge, expecting a little difficulty with getting the right fit and decent isolation. Those webby pundits weren't wrong, either. I tried every single of the bundled tips - all rubbish, and some of them came straight from a torturer's fever dream. Next up, my trusty Comply T400s, which had transformed the Superfi's from good but frustrating, to great - also rubbish. Bah. Back to the internets for more research, and the next effort was modified Shure foam tips - success! Suddenly the IE8s sounded beautiful, more bass than I thought possible in an IEM and yet not at the expense of the rest of the audio spectrum, a nice warm midrange and sweet treble. Not to mention a wide, deep soundstage, with instruments twinkling at me from all over the place. The only trouble is, I couldn't get a consistently good fit with the Shures: I seemed to spend half my day taking them out of my ears and reinserting them, and they got dirty quickly, whereupon they wouldn't fit properly and I'd have to clean them every day or two. Boring.
I'd heard about ACS custom moulds on www.head-fi.org, and when I noticed that Advanced MP3 Players did an all-in deal - audiologist appointment to make ear impressions and the mould manufacture itself for £90 - I thought, "That looks great! But do I want to spend another £90 on IEMs that already cost me nearly £200? So I put it off for a few months. But eventually, the sheer frustration of messing around with the Shure tips all day got the better of me and I bought the AMP3 voucher.
It only took just over 2 weeks from clicking 'Buy' on the AMP3 website to receiving my custom moulds from ACS in a nice box, which comes with insertion instructions and a little tube of lubricant when inserting the moulds (I find that simply moistening them works just as well). I've been using them for 24 hours now, and I have to say it was worth every penny of the £90! The custom moulds fit the IE8s perfectly, extending around the body of the IEMs to give a very secure fit. Attaching them in the right orientation and getting them in my ears was a challenge, but after I worked it out, they're actually very easy to insert. I can't imagine them being shaken loose by jogging or whatever exercise floats your boat. They're very comfortable, as you'd expect for something that fits the contours of your ear canals perfectly. So my main problem is instantly solved: every time these go into my ears, I get a perfect fit and the IE8s can sing. Not only that, but the custom moulds actually improve the sound quality over the already amazing results with the Shure tips! Now, the soundstage is even wider, going way out beyond the sides of my head with well recorded material, and the bass, while not as prominent as before, is sweeter and more tuneful. The treble is less muddy as well.
So, all in all, a brilliant package at a brilliant price. Both ACS and AMP3 Players were a pleasure to deal with, and I'd recommend them both to anyone in a heartbeat. | 
