Depends on the crossover. Typically they split one speaker output into two, a low and a high frequency. Other times they split into three frequency bands. I used the triple 303 crossovers on front and rear sets of speakers because you don't want to sent the ultra high signal of a two way crossover to a mid bass rear speaker.

Of course if you know your ohms and want to mess around with series and parallel wiring then you theoretically could rum a crap tom of speakers.

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Portland, OR - 2004 e53 - 4.4L - 90,000m