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Azuur
10-31-2001, 07:13 PM
Kim -

"I would suggest looking for a amplifier that has a power rating of
85 to 125 Watts per channel and has a built in high pass
crossover. A good crossover frequency for the MM465's and the DX7's is 80 to 90 Hertz. Depending on the rate of the slope of the crossover, you may have to invert the front or rear speakers or even both pair, to get the best bass integration with you subwoofer. "

Why a high pass crossover? Is this saying I should set my highpass x-over on the amp to something other then the highest setting?

And whats the inverting speakers stuff mean in english lol

Thanks as always

Kim
11-01-2001, 10:50 AM
A high pass crossover blocks out lower bass frequencies. The idea is that when you are using a subwoofer and you have set the low pass filter which sends a specific bandwidth of information to the woofer. You don't want the front and rear speaker reproducing the same bass information. If the front and rear speakers are not crossed over and are operating full range along with the woofer, then they can actually cancel bass frequencies because of the of the speakers location,
and the rate of the slope of the crossover. Plus this will limit the dynamic range of the system because of driver distortion from reproducing low bass frequencies that are intended for the subwoofer. Most 12 dB and 24 dB per octave crossover do invert or reverse phase. 18 dB per octave crossovers are phase correct and don't require the inversion of the polarity.
So to obtain correct phase and get the best bass response,
simply just reverse the positive and negative leads on the speaker. Don't set the crossover to its highest setting beacuse this will not correct this. You need to do correct it mechanically. The 80 to 90 Hertz crossover frequency is usually a very good crossover point in most cars. Hope this is able to clear up some confusion.

Thanks,
Kim