The coolest, smallest CD/MP3 Player is chock full of features and ease of use at a great price. The SlimX line keeps getting better and better, and continues to capture the Editor's Choice Award.

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The quality and features of the iRiver SlimX 550 really stand out. It’s “the” CD/MP3 player to get. The form factor is perfect with the ease of control, great battery life, great sound, and numerous features that put it ahead of anything else out on the market. iRiver continues to achieve excellence in the SlimX line. With a relatively low price point of $179.99, we believe you will not find a better similarly equipped CD player than iRiver’s SlimX iMP-550 today.

iRiver is at it again. In the past they have continually put out great products, earning great praise from Designtechnica for their SlimX 350 and SlimX 400 line. It’s easy to say that the SlimX 550 not only includes the excellent features of the previous models, but it builds on them in an impressive way. Touting what they claim to be the thinnest CD/MP3 Player with the longest battery life, the SlimX 550 is packed with great features, great build quality and ease of use.

To keep up with the popular hard drive based MP3 players such as Apple’s iPod and Nomad’s Zen, the CD based MP3 players must be more robust in features while keeping a low price point. The iRiver SlimX 550 does both extremely well. Gone are the days of bulky CD players. The SlimX 550 is a mere 13.7mm thin. To put that into perspective, that’s thinner than a DVD case. The circumference of the SlimX 550 is barely larger than the CD itself. It can fit into the front pocket of a backpack or even cargo pants/shorts pockets easily. With the weight coming in around 145 grams, carrying it around is barely noticeable.

The SlimX 550 utilizes a wired control, which has a comforting light blue back light. The four line LCD screen supports graphics such as 3 visualizations, up to 39 languages (including French, German, Spanish, Italian, Japanese, Korean and Chinese.) and ID3 v1 through v3 track information.

The firmware can be upgraded to support new features and possibly new codecs. A quick check of the iRiver site shows that a new firmware version is available along with Caption Editor. Caption Editor is a tool that allows the addition of lyrics to songs along with time syncs for when each line of the lyrics are displayed. This allows viewing of lyrics while playing the files back on the SlimX 550.

Folder and M3U support are available including shuffle play within a single folder, all folders or skip folders completely, and shuffle based off the order the files have been written to the disk (saves at least an hour of battery life.)

WMA and ASF files are also supported for playback including traditional RedBook Audio CDs. Let’s keep crossing our fingers that Ogg Vorbis will eventually be added as a supported codec through a firmware update. The anti-shock is especially good of up to 32 minutes.

Overall, the FM Tuner works well. The control device appears to act as the antenna, giving decent reception. It could pick up most local stations with a strong signal and while maintaining excellent sound. The SlimX 550 supports up to 20 presets for the radio and there is also an auto-scan feature. However, the auto-scan did not seem to work that great in the tests, picking up some dead stations and not picking up stronger signals near the upper end of the spectrum.

A pleasant surprise is that the iRiver SlimX 550 package comes with everything needed for use in the car. This includes a cassette adapter and power adapter. Sound performance will differ depending on the car’s audio system. But using the stock Bose system that came with the Mercedes Benz it was tested in, the audio sounded great.

Also included in the iRiver SlimX 550 package are two rechargeable NiMH batteries, an external battery pack (which allows up to 55 hours of playback time when used with the internal batteries!), a carrying case, an AC power adapter, a headphone adapter, and an extremely well written manual.

The SlimX 550 will not work until the included NiMH batteries are charged (unless the external battery adapter with two AA batteries is used.). The SlimX 550 allows for the batteries to be fully discharged and recharged (iRiver recommends doing a full discharge once a month.) Charging a completely drained battery will typically take about 4 hours, doing a discharge then charge will take about 5 hours. The SlimX 550 can be charged and used at the same time, which is great for using in the car.

The control has a ton of features and can be a little overwhelming at first. However, a quick read of the manual will get the owner up to speed quickly on functionality that may seem non-intuitive. Using two hands when first exploring the features is recommended, since testers experienced hand cramps using one hand. Operating the controller becomes second nature after a short time of use and becomes much easier to use with one hand. The controller houses a headphone jack. If the use of different headphones or ear buds other then the ones provided is required, the SlimX 550 comes included with a headphone adapter cord. This was one of the few limited design drawbacks. If one happens to have good headphones with a gold plated jack, then the expected listening experience may not be up to par. Needless to say, losing the adapter cable would limit the choices to what one could use to listen through. The manual clearly states that attempting to plug in headphones that need the adapter can and will damage the jack.

Some distortion was experienced on the upper range of the volume level, especially when listening to 128 Kbps MP3 or WMA files using Sony MDR-V300 headphones. Experiences may vary depending on the quality of digital files and listening devices used.

There may be a slight pause (about two seconds) when first initiating playback of a CD containing digital media as the player reads the metadata and prepares the anti-shock. After the initial pause, switching songs is quick and responsive.

The preset EQ settings of Normal, Rock, Classic, Ubase and Metal work great and do dramatically change the sound of digital playback. There is a customizable EQ option called Extreme EQ which allows for editing for five different settings. Unfortunately, the EQ and visualizations are not available for the FM Tuner.

The included ear buds sound good, but caused some ear discomfort after about half an hour. Upgrading to some decent headphones or ear buds is highly recommended.

The folder support is phenomenal and the controls to browse through folders are extremely easy to use. It is easy to skip through folders via one of the three jog dials on the control or browse track by track.

The OnePlus Buds Clip are a new pair of open-ear earbuds built around a simple convenience. They join Sony’s LinkBuds Clip in the growing ear-cuff category, but either OnePlus bud can go on either ear.

Sensors recognize how the earbuds are being worn and route the audio channels accordingly. There’s no label to check before putting them on, and the feature also works when only one bud is used.

We buy fitness bands and activity trackers to keep tabs on our exercise, but it is easy to forget to start tracking or switch modes when moving between different activities. For Fitbit and Pixel Watch users, that could soon become a lot less annoying, as Google is rolling out a major upgrade to automatic activity tracking that can recognize more than 100 types of exercise, up from just 10 before.

Google first showed off the improved tracking earlier this month alongside the Fitbit Edge. It is now coming to Fitbit Air and the Pixel Watch 3, 4, and 5, and Google claims the added context behind the system makes workout detection nearly twice as accurate while cutting missed activities by more than half. Fitbit Edge will support it too.

iRiver SlimX iMP-550 Review