The back of each earpiece has a small hole which you'd almost never suspect as being part of the design - a bass port to be specific - without it being called out as such by Jays. It certainly seems to have the intended effect - the a-Jays Three earphones have a resounding, deep bass response. It's not the purest of sounds, but there's plenty of warmth and some music sees a positive impact.
Importantly this full low-end doesn't overwhelm the rest of the mix. There are occasions when it sounds a little unbalanced, a touch overemphasised, but they're few and far between. Indeed, some genres of music will outright benefit from the slight bias towards bassier tones.
The mid-range is also reproduced as well as could be expected. Vocals stand out distinctly, though not to the extent that they feel disconnected. The high end is the weakest area; there's nothing exactly wrong, but it lacks that certain sparkle that turns a good set of earphones into a great set. Not, we hasten to say, that for £36 we expect anything else. The a-Jays Three earphones are just as good as many other earphones of similar price.
What they lack in precision and poise the a-Jays Three earphones make up for in their punchy drive, which may even be more desirable to some listeners. There's no noticeable distortion even at high volumes, and because the a-Jays Three earphones are of low impedance they're easily driven - even by the weedy output of an iPod.
The Jays a-Jays Three earphones offer a good mix of clarity and power for a compelling price. Some may find the low-end emphasis of the tone not to their tastes, but in general it's not so extreme as to be distasteful.