The Pure 2500's own sound quality is great. The bass and treble equalisation is basic but effective, clarity is good and there's no errant noise to annoy in the background. However, it's tricky to tell the full extent of quite how high-quality the radio's sound circuitry is because the output is limited the DAB signal itself.
DAB radio is broadcast using MPEG2 encoding, which by today's standards is woefully inefficient. As much as DAB radio's marketing over the years has suggested that it's better and clearer than FM, this is often simply not true. Especially these days, now that the DAB "pipe" is being spread further across more stations. This has resulted in ever-decreasing bitrates in radio station broadcasts (although it seems to have remained more-or-less stable in the last couple of years).
The Pure 2500 does support DAB , which uses the much better eAAC codec, but this isn't currently isn't broadcast in the UK. There are no plans for it to roll out any time soon either. Higher quality can be found in Freeview stations and, of more significance here, internet radio.
In real-life use, the limited quality offered by DAB leaves music sounding rather like a fairly low bit-rate MP3, with the loss of dynamics associated with this. Of course, radio stations don't tend to output tracks in their plainest form anyway (using compression and the like) which mitigates for this somewhat. As does the array of fantastic stations you won't find on an FM dial, like BBC 6 Music and BBC 5 Live. Speech-based recordings are affected much less significantly. Radio 4 sounds great on the Pure Move 2500.
Why are we mentioning this problem when we probably wouldn’t in a home radio? We find the experience of listening with headphones makes the quality conundrum all the more apparent.
The key benefit of DAB, that allows marketers to claim increased clarity, is that with a reasonably strength of signal, you'll receive the signal as-intended. DAB is either free from interference or pretty much destroyed - there's no room for the slight fuzz you'll hear in FM radio.
With a good signal, this makes DAB radio a joy to listen to, and why we can forgive it for its pretty poor audio quality. Unfortunately, getting a good signal with the Pure Move 2500 is far from guaranteed. Like its forbears, it uses the headphone cable as the antenna, rather than the telescopic aerial you'll find on home radios or the Roberts Sports DAB II.
Out in the open air, this is enough to provide the Move with a strong signal. You can roam the streets with mostly distortion-free radio all day long. Step inside a building or, even worse, onto a train or bus, though, and the signal breaks down almost completely. After more than five years of development, the headphone aerial doesn’t offer anything like the quality of experience you’d get from a kitchentop Pure radio with a telecopic aerial at its disposal.
We still find DAB on-the-go impractical. Curiously, we also found FM radio reception to be unimpressive when compared directly with a budget smartphone’s FM signal under the same conditions. Maximum volume isn’t particularly high either. Seemingly a victim of overzealous AVLS (automatic volume limiting system), we found we had to max-out the volume with any headphones that were remotely hard to drive.
Whether the lack of progress on reception is Pure’s fault or a sad immovable feature of portable DAB, the lack of innovation elsewhere is hard to forgive. It looks better, and has a snazzier control interface than the PocketDAB 1500, but doesn’t solve its key issues. If you must have DAB, this is the best portable option out there. But that’s down to a lack of high-flying competition rather than a triumph on Pure’s part.
The Pure Move 2500 takes over from the PocketDAB 1500 as the DAB king’s key pocket offering. It improves on this predecessor with a neat scroll wheel and a more attractive design. The key issues remain though. Signal is still wholly unreliable on-the-move, and without any non-radio features to boast about, it looks decidedly behind-the-times and expensive. That said, for dedicated pocket-sized DAB you can’t do much better.