Rock Jaw Kommand Hybrid IEM

Anyone who knows anything about headphones can tell you the difference between balanced armature and dynamic drivers. Typically, headphones use one or the other but not both. Each has its pros and cons, with balanced armature delivering excellent detail and clarity for high frequencies and dynamic drivers offering better bass and warmth for mid-tones.

That’s why Rock Jaw has gone for an 8mm dynamic driver as well balanced armature in its flagship Kommand IEM. IEM is another headphone acronym, which stands for in-ear monitor. They’re just ear buds to everyone else.

Of course, at £119, these aren’t just ear buds. As well as their hybrid nature, they also have interchangeable filters just like the company’s more affordable Alfa Genus earphones – priced £50. You get three sets of screwin components which change the characteristics of the sound.

By default, the silver ‘bass’ filters are installed. These enhance low frequencies but, unlike with the Alfa Genus, not at the expense of treble clarity. If you prefer a neutral sound that doesn’t favour low or highs, the champagne coloured filters might be the ones you use most of the time.

The black filters are called ‘reference class’ rather than ‘treble’ as with the Alfa Genus.

Design and build

The Kommand has a hand-built quality, being crafted from ebony and aluminium. They use the same twisted cable as the Alfa Genus and have a built-in microphone and button on the left-hand ear-bud wire.

The button works with iOS, Android and Windows Phones to pause and skip tracks, as well as answering calls or calling up Siri with a long press on an iPhone.

You get a soft carry case in the box, but you’ll be better off keeping the two sets of filters you’re not using in the main box, as they’re easy to lose if kept at the bottom of the carry bag.

The filters are larger than the Alfa Genus’, but we struggled to tighten them. Some Loctite would help stop them constantly coming loose. Otherwise you risk dropping a filter with attached ear tip, something that happened to us, although fortunately in the office rather than while commuting.

Unusually, the ear buds have a metal hook that is covered in silicone for grip and comfort. They rotate because each person’s ears are a different size, and rotating changes the distance between the bud and the top of the ear. They are not removable.

We found them hard to live with and not especially comfortable, and this was echoed by other testers around the office. You also get only three sizes of silicone tips and, unlike with the Alfa Genus, none were the perfect fit.

Sound quality

For good bass you need a tight fit, and this is why we recommend custom sleeves (acscustom.com/uk).

After running in the Kommands for the recommended 20 hours, we were initially impressed with them. The level of clarity on offer means there’s a great soundstage where instruments are welldefined and separated.

Depending on the quality of your music, you may hear sounds, effects and instruments you didn’t even know were in a particular track. The down side is that you’ll quickly want to replace poor-quality MP3s with better-quality versions.

With the bass filters installed, bass is good if you can get that perfect seal. It’s punchy and tight and sounded great on everything from Michael Jackson’s Billy Jean to Diana Krall’s Peel Me A Grape.

The main criticism is that treble is a little harsh, and this is all the more noticeable when you turn up the volume.

Vocals, as we had expected, had a nice warmth to them and were clear with all three sets of tuning filters. Treble wasn’t as brash with the black filters installed, but bass was understandably more subdued as well.

Verdict

Earphones are a highly personal product, and no one type or sound suits all. There’s no doubt that the Kommand IEM is a step up from the Alpha Genus and they’re good value given what you can spend on earphones with multiple drivers.

For us, we found the Alpha Genus more comfortable to wear and easier on the ears in terms of sound. You may love the ear hooks and prefer the extra detail from the balanced armature drivers, so it’s well worth trying some out – if you can – before buying.