iRiver SlimX iMP-550 CD/MP3 Player with Ultraslim Design

Rating:
Summary: great performance, amazing sound, bad support
Review: I actually owned the original Rio Volt that iRiver designed and manufactured, so I knew what I was getting into when I bought this CD/MP3 player.

The good: sound, overall user interface (once you get used to the clunky button layout), battery life, and of course, the sweet design

The bad: firmware support (Ogg support is very questionable, newest firmware has clicks at the beginning of MP3 tracks, I'm using beta Korean firmware instead), some slight mechanical noise, audio CD's take a little while to spin up

I recommend this player, but caveat emptor -- don't believe what iRiver says about what formats the player will support in the future (they've been claiming AAC support since the Rio Volt days, and it's never going to happen.)

Rating:
Summary: imp-550 and 450 sonic showdown
Review: I went and purchased an imp-550 and an imp-450 and got the chance to get to the bottom of the imp 450 and 550 sonic differences in relation to my trusty imp-350.

First off, no disrespect to the imp-350; it's no slouch; it's sound quality is great, basically bombproof and the user EQ has plenty of bass boost. At times, however, with older tracks that need that little extra boost the 350 didn't quite cut it--it's only shortfall, and a slight one at that.

So, out of curiosity, I stepped into an imp-550 Initially, it was great because of the small size, but it FEELS delicate and reports of quirky behaviors and bugs (of which some I did experience) stopped me short. Plus there are sonic oddities which I will now address.

Sonically, with a flat EQ, the 350/400, 450, and 550 are all about equal in terms of warmth detail and clarity. The only bonus out the the bunch is the imp-550's optical line out. I did not test it, but have read twice that it was decent---but nothing special. Where there are huge differences, and to me make or break two of the players, is with the EQ settings. (For the record the imp-350 and imp-400 are identical sonically in every way, with the 400 being a cosmetic change and that's it.)

Before I proceed, yes, the imp line and possibly the iRiver line in general is not sonically as pure as some other media players (HDD's and vintage CDP's included), it is however, probably the most "fun" sounding line up of media players which can add amazing bass boosts and other sonic tweaks to stimulate the user...in small well designed packages.

Back to the imp-550. It features an Extreme 3D (a stereo imaging DSP processor that creates a virtual surround effect) and Extreme EQ. The 550 has the familiar iRiver EQ presets like Rock, Jazz, Metal, Blue-grass, uBass, etc, but instead of user1/2/3 EQ it utilizes the Extreme EQ feature. ExtremeEQ is a 5 band EQ adjustable both db+ and db-. The presets on the 550 are amazing. They color the sound greatly and very cleanly. The problem with the imp-550 sonically, is that when adjusting the sound with the Extreme EQ you can not achieve the levels of sonic adjustment that the presets offer. The presets are indeed good, but in my case I just want to boost the bass, like the rock preset, but without the added treble. I tried this with the Extreme EQ, but with the bass boosted to max it makes hardly a difference. iRiver has yet to address or rectify this problem with multiple firmware updates. I grew frustrated that with the imp-550 the bass was great but too treblely or the bass was not enough. Coupled with the nagging other bugs and quirks with firmware, and the 550 does not offer a worthwhile change from the imp-350/400.

From this point I contacted iRiver to find out the differences between the imp-550 and new imp-450, and was told that they share very similar components (including processor chips) and the the imp-550 is discontinued in the USA. Further, the imp-450 is its replacement, and as demand for a high-end mp3cd player is declining in the US, the upcoming imp-900 is not for the American market either.

So, my thoughts started to wonder about the imp-450. Upon further research which included downloading and thoroughly going through each players respective .pdf manual I discovered the the 450 and 550 are very similar players indeed with one notable sonic difference. there is no Extreme 3d/EQ in the imp-450. I began to theorize that perhaps the 450 could possibly remedy the 550's EQ bugs decided to try to dig in the forums to find out. To my surprise there wasn't much info out there. I did read in the imp-450 manual though that it had an EQ much like that of the imp-350/400, presets and 3 user EQ's. The major difference is that unlike the 12db bass boost on the 350 the 450 had a 18db boost. My suspicions were beginning to take shape.

Today my imp-450 arrived. It is a beauty. Considering I had a brand new imp-550 last week, I can say the 450, is esthetically more pleasing and much better built than the imp-550. For example, the lid does not feel loose or shift side to side slightly when closed. It is definitely smaller than the imp-350 and of course identical to the redesigned 350, the imp-400. Its weight feels about the same as the 350 and only slightly heavier than the imp-550. Overall the size differences between the 450 and 550 are slight at best. Hands down the imp-450 is the better more secure feeling and esthetically pleasing player. (note: the iRiver pics do not do this player justice at all....it REALLY looks nice and is QUITE small)

At this point, I would like to add that the presets on the imp-350/400, even without comparing them to the 450/550, offer very subtle change in sonic characteristic and one really must use the custom user EQ's to get sound to really maximize its potential.

Yes, and after much discussion, I can report that the preset EQs on the 450 and 550 are identical! They both offer amazing sound boost. Furthermore, the user EQ's DO offer 18db of adjustment, however the control on the remote offers the adjustment in steps of 2db (0,2,4,6,8,10,12,14,16,18). The treble is only a 6db adjustment as in 2db steps. I can also confirm that the user EQ's sonic adjustment equal that of the presets and it not deficient like the user EQ (Extreme EQ) on the imp-550.

Next I performed the following test.

imp-350 user EQ bass set to 12db, treble set to 0
imp-450 user EQ bass set to 12db, treble set to 0

The two units were identical in sound. Next, I boosted the imp-450 to a full 18db and, yes there was a substantial increase. Clear, clean, detailed, tight bass sprang from this little player. Its has all the bass boost of the recent firmwared imp-550, but with the user EQ control of the imp-350!!

I personally not only feel validated, but that I have reached my sonic nirvana. I was very pleasantly surprised, as I was expecting the imp-450 to fall short and have the similar problems of the imp-550.

So, in conclusion, the imp-450 is the definite winner here, and at a bargain price. I cannot see any reason one would choose an imp-550 over a 450. Physically and sonically superior, the imp-450 easily beats it. Im only slightly curious about the imp-900 now, as I cannot possibly see how it could be better, except for battery life. But since it shares the same micro 13.7mm size as the imp-550 I wonder how the build quality is.

My personal opinion, after owning all the major imp players, is that the imp-550 was a great concept that just didn't pan out. Not only that but I think that challenges of utilizing the Extreme3Q/EQ efficiently has been questionable as well. I think they countered the shortcomings and struggles of the imp-550 with a slam dunk of a release with the new improved and dare I say, perfect, imp-450.


*EDIT/UPDATE: Well, I must correct myself as I proceeded to do some further imp-350 and 450 tests. I ran a selected mp3 track in both players side by side with the EQ set flat on both, volume set to 30.
The headphones I tested were both a well broken in Sennheiser px200 as well as Sennheiser HD 25-1, also well burned-in.

The two players do indeed sound different, noticeably so. The 450 is defintely more punchy sounding and a bit more dynamic, open and involving, while the imp-350 sounds a bit thin, and slightly small sounding in comparison.

I am not a golden eared individual by any means, but I was easily able to tell a difference between the two.

Sorry to give the earlier impression that the various imp's are sonically similar. i can honestly say now that the later models do step it up a bit in the sound department. But hands down the imp-450 with its unflawed performance and quality wins, even without the added features of a optical line out, slightly larger size, and inability to charge whilst playing. Cool features of the imp-550, but not needed.