Bottlehead Forum: Speaker for SEX by Paul Joppa

Yesterday while I was at Doc's, we listened to a second candidate for a SEX speaker. This one was better than the first one, and worth considering.

It's very simple, but it requires the use of a subwoofer, and benefits from a baffle step correction (BSC) circuit as well.

The basic idea is a Fostex FE166E in a small sealed box. We used the 0.25 cubic foot boxes from Parts Express - very pretty, inexpensive, well-made, and pre-assembled. Cut a hole in the front panel, mount the speaker, stuff the box, and screw down the front panel - you're done! :^)

Best operation is with two subs, one speaker on top of each sub. Set the crossover to around 130Hz, select the phase to avoid a hole at crossover, and set the level to sound right. We listened with a single sub - it works acceptably, though the integration is only adequate. The sealed box reduces the cone excursion enough to clean up the intermodulation we heard with the FE167E in a larger reflex box. There is still some whizzer weirdness, but that will improve significantly with break in. (I was at Terry Cain's last weekend, listening to his Abbys again - they are well broken in, and much smoother than the new drivers we have!)

I also insisted on listening with no sub and no BSC. It sounds like a 13-inch TV. Maybe a pretty darn good 13 inch TV, but still ... you will want a sub for sure. My vore is to drive the sub from the speaker signal, especially with the SEX which is pretty quiet and hum-free.

I'll follow up with a BSC after the Fourth - family obligations means no time until then.