Eclipse TD speakers all pose a difficult question for the audio enthusiast… have we all taken an almighty wrong turn somewhere? And in a way, the TD508MK3 is perhaps the purest expression of that question, being considered the company’s core model.
The latest version of the 508 has a single 80mm fibreglass drive unit. That’s it. No tweeter, no midrange, no woofers, no crossover. Nada. Just the one drive unit connected to a pair of speaker terminals. Nothing is ever that simple, of course, and the custom made unit is not only extremely light and housed in a very flexible surround, but it’s one of the few drive units where the high-flux magnet is the virtually the same size as the cone. This is still a lightweight unit, so it sports a mass anchor at the rear of the magnet.
This mass anchor fits (more accurately, floats) in what Eclipse TD calls a ‘diffusion stay’. Looking like an X-shaped internal brace, this holds the driver in place within the cabinet, but minimising interaction with the cabinet. This means the driver is near-as-possible decoupled from the ‘egg-shaped’ (again more accurately, engine cowl-shaped) rear-ported cabinet. The internal chamber is filled with wadding, and the base of the diffusion stay connects the speaker to the outside world, through a clever and adjustable three-point contact; the desktop plate can be attached to a disc-shaped CB1 bracket for wall and ceiling mounting, or removed and what’s left attaches to the spindly 508DMK3 floor-stand. If you have seen or tried any Eclipse TD speaker (smaller, larger or older), you’ll know all this; although there is no wall hanging options for the bigger speakers, the one unit, no crossover, egg-shape, decoupled from the cabinet concepts are common across the range.
However, this doesn’t mean they are all alike, and the differences between the TD508II and TD508MK3 represent a complete ‘ground up’ redesign, with new drive unit, cabinet, base… the works. In fact the only thing that didn’t change was the crossover network; there wasn’t one in the TD508II and the TD508MK3 shares the same complete lack of crossover and crossover components.