Whenever a manufacturer uses the "DJ" tag alongside its headphones, an alarm sounds at Trusted towers. It means there's only one thing we can go in expecting - a low-end as bloated as Mr Cresote's belly pre wafer thin mint. And unfortunately it's what you get here.
This low-end isn't well well-controlled, deep or taut. In technical terms, it's a poor show. However, to ears less pedantic than ours, it could well sound good. The success of the massively popular Sennheiser CX300 series is partly down to that earphone's tendency to inflate its bass above what's strictly accurate.
Detail is unspectacular, lending vocals a veiled sensibility. If you're after accuracy and insight, the Radiopaq Duo shelf is the wrong one to alight at. However, their sound is also inoffensive - unless you have truly irrational expectations from £20 headphones. Treble isn't beautifully smooth, but it's not harsh either, and that DJ bass gives an impression of warmth - if not a particularly high-grade one.
The ear (well, the brain technically) will acclimatise quickly to the non-sibilant tone of the Duo headphones quickly, so you could do worse if the looks of these orange beauties have your heart all a'flutter. After EQ'ing down the bass, we were able to find a sound we'd happily listen to.
There are several very convincing arguments to be made against the Radiopaq Duo though - the cast of on-ear headphones available in the £20-30 price range. The classic Koss PortaPro, the Sennheiser PX100 and HD218, and the MEElectronics HT-21 all offer better sound for the same price - or a little bit more. Of course what they don't have are the Radiopaq Duo's neat colours. And that could mean a lot if you're looking for a present for an adolescent, or sub-adolescent, kid. In contrast we can't imagine many tweens happy to wear the Koss PortaPro - which look like they've been lost in the post since 1982.
The Radiopaq Duo are cheap, and with five metallic shades to choose from, they're more cheerful than an episode of Glee. However, like many "DJ" branded headphones, they're far too bassy for their own good - filling-in the low end with bloat rather than taut, refined bass.
You might ask, what do you expect for £20? Well, rivals like the Koss PortaPro prove that you don't need to spend a penny more to get better sound. The Radiopaq Duo may look better to most retinas, but how much does style matter to you?