S.E.Xy Speaker Suggestion Question

[fromnowon]

Hello,

I really like the Fostex driver / subwoofer speaker idea for a 2-watt amp like the S.E.X.

https://bottlehead.com/s-e-xy-speakers/

It makes sense to run the subs from the monitors, but I wonder why the wiring to the subs are reversed like this:

"with the woofer connections reversed (red post on monitor to black post on woofer, black post on monitor to red post on woofer)." 

Just curious!

Thanks

 

[Paul Joppa]

This is a characteristic of second-order (12dB/octave) crossovers - at crossover, the sealed box highpass function has a phase shift of +90 degrees, and the lowpass has a -90 degrees phase shift. That 180 degree phase difference makes them cancel each other, leaving a deep hole in the room response at the crossover frequency. By reversing one of them, they are in phase and the hole is filled in.

Of course, this assumes the sub has a second-order lowpass crossover, and it follows the same red/black phase standard as the fullrange driver. Since the described subwoofer has not been in production for many years, one would probably need to experiment with phasing if a current production sub is used.

 

[fromnowon]

Thanks!