End result is that the Purity has one of the least noticeable interchanges between treble and bass of any MartinLogan hybrid design. It’s not completely inaudiable – there’s a small part of Leslie Feist’s vocal range that just wavers on the cross-over point on the title track of Let it Die that robs her voice of some of its modern-day Rickie Lee Jones clarity. For the most part, though, the Purity does an excellent job of integrating the dynamic bass with the panel top, both temporally and across the frequency spectrum. What is particularly clever is the excellent lack of box coloration; you expect the mids and top to be free from boxiness and honk, but the bass does well to minimise the sound of the box, too. A lot of that is down to the non-parallel cabinet.
The Purity is all about easy compatibility. It has speaker terminals and a phono plug, so you aren’t limited by the components elsewhere in the chain. It is also extremely forgiving of source (up to a point) and makes the best of even less than fabulous MP3 recordings. Of course, the better the recording, the better the Purity sound… which is where the ‘up to a point’ kicks in. This is, for the most part, an electrostatic design, with all the uncanny disappearing qualities that bestows on the sound. Yes, the Purity is electrically unfussy enough to make it compatible with a £250 one-box micro-fi system in theory, but it isn’t going to sound that good in that context. However, as much for fun as for the sake of thoroughness, I hooked my Apple laptop to the Purity speakers, using a naff mini-jack to two phono cable. It was a lash-up of the worst degree, but in fairness, the Purity speakers more than rose to the challenge. Although it’s close to an abomination given the family history, Quad’s 99 series combined CD and pre-amp would be the perfect partner for this speaker system, making it a very reasonably entry into distinctly audiophile territory. Just add a 909 power amp later when funds allow.
It’s that beguiling openness to the midrange, the almost ‘there’ sound of instruments with a strong mid and high frequency component that keeps you coming back for more. They really sound as if they are in the room with you… and nowhere near those panels, too. Meanwhile, the subwoofer section gives the MartinLogan design something most panels never attain… dynamic range. Of course, the bass, while full, isn’t ultimately that cavernous, but the bass limits performance less than before and complements the performance of the panel.
There’s an almost unconscious received wisdom that if you want good electrostatic performance, you have to pay big bucks and end up living with a speaker the size of a cricket sight screen. The Purity is neither of those things; it’s small and reasonably priced and yet it works extremely well, especially in British-sized listening rooms. With such easy performance and an easy upgrade path to boot, the Purity will likely be many people’s first panel speaker, making many a convert to the panel speaker cause. High-end speakers start here.