The JBL On Air has stumbled into a problem. It's a £329 alarm clock. Yes, it's a lot more besides, but the relatively bedside-friendly form factor is always going to impact on the sound.
There are three drivers in total - two full range speakers, and one tweeter unit to supply the finest of high-end detail. With the volume kept fairly low, the sound is very good. With a bright sound signature, clarity is excellent and there's a strong sense of high-end detail being well-relayed. It's not overly sharp either - just crisp.
At low and mid-level volumes, the bass keeps up well too. It belies the design - the speakers essentially only have the outer ring of the On Air to work with. Unfortunately, when pushed it doesn't match what we expect to hear from a £300 dock.
The On Air fails to reproduce the very bottom end of the bass register entirely. This is only hugely noticeable in electronic music, where these ultra-low frequencies are sometimes singled-out - rather than being the bottom bit of a bass guitar rumble - but it's disappointing when similarly priced rivals don't fall down in this respect. This is presumably a limitation of the small full range drivers.
We also noticed distortion in the low end when the volume's pumped up beyond 60 or 70 percent. This isn't an incredibly loud dock either, so you could get away with reaching this level without risking eviction. Even at 100 percent volume, the JBL On Air can't blast out the deafening din a full-size dock can at a lesser setting.
The speaker positioning is also questionable. They are placed on the sizes of the dock, facing outwards. This is an increasingly common technique, lending smaller speaker units more of a room-filling sound, but it also means that the sound is never directed at you - only around you. Again, with a cheaper dock this wouldn't have been such a problem, but we're entering the territory of "audiophile" docks at this price, and the extreme positioning here makes the On Air dock only suitable for a fairly passive listening.
Sit down to actually listen to something intently and the experience is significantly less satisfying than a properly positioned 2-speaker set, or even a more conservatively-arranged dock like the Philips DS9000. Part of the On Air's price tag naturally goes towards its Airplay functionality, but we can't face swallowing the sound quality compromise that's involved - when this device is compared to less technologically-advanced price rivals.
The JBL On Air is a strange mix of conflicting ideas. It wants to be a stylish, lifestyle unit but trips up its own design intentions with some overly-brash controls and a great big snooze button on top. It's priced like a high-end iPod dock, but dilutes this message with a quasi-alarm clock form that ends up compromising sound quality. When was the last time you thought about spending £329 on an alarm clock?
If the JBL On Air dock was £80-100 less, it'd make a lot of sense. It sounds good at low volumes and packs-in plenty of features, including Airplay, an FM radio and full alarm clock functionality. However, at £329 it directly challenges some of the best iPod docks out there and both its design and sound don't stand up too well in comparison.