Do Polk crossovers have a baffle step circuit?

Mazeroth

For those of you that know about BSC, do they contain one? Mainly the RTi and LSi series. Any of the speakers that are an x.5 probably don't, but was curious about the others.

Thanks!

gatemplin

They dont have the full compensation for 6 dB for sure. I would guess they probably compensate for 1-2 dB on average.

Usually the BSC is done by increasing the size of the first inductor in the LP filter, and then padding the tweeter down. Or with the .5 woofer.

If you emailed Ken he could probably tell you exactly how much BSC they use.

RuSsMaN

Ok, anyone care to 'splain baffle step in laymans terms?

Cheers,
Common Man

gatemplin

No problem.

At high frequencies, the wavelengths are shorter than the width of the baffle, and sound waves are radiating into half space (like in wall speakers).

At lower frequencies, around 1-1.5 kHz if I recall correctly, the wavelengths begin to exceed the lengths of the baffles and gradually begin to radiate into full space. This means the low end output is 6 dB lower measured anechoically.

To compensate for the decrease in output on axis, the midrange output is attenuated, and the tweeter is padded down to achieve a flat response again.

This reduces the efficiency of the speakers. That is why many manufacturers ignore it. For example, many two ways are in the neighbourhood of 87-90 dB efficient. My speakers which use close to full BSC are about 80 dB, and no one would buy them.

Linky:

http://sound.westhost.com/bafflestep.htm