how do I x-over a 4 way 6x9?
 

What i'm doing is buying a set of ID horns, but for the time being i'm going to run my existing 6x9's for midbass. I know how to send all frequencies high or low to a speaker with a xover, but how would I send say 110hz-1000hz to a speaker effectivly cutting out the tweeters on the 6x9? Any Ideas?

with an electronic cross over having "band" pass capability, or using passive components (capacitors and inductors) to first high pass everything above 110hz and then low pass everything below 1000 hz to your speakers. Requires knowledge, a good passive xo calculator, time, and accuracy. Additionally, passives tend to be less accurate, and can affect the SQ more that active electronic cross overs. Another way is to use a combination of your amp's built in active xo (if it has one that's usable) to high pass the signal and an inductor to low pass it to the speaker...this effectively gives you a band passed signal.