crossover frequencies??

[snappyjb67]

So i was on the POLK website looking at the polk custom installs and i saw the page featuring the ford escape. it said the two component sets in the door are bandpassed from 50hz-250hz. What does that mean, it says it makes it so the amp doesnt have to work so hard? i ask this because i am trying to boost preformance from my DX 3055's. I currently have 2 polk DX 12's, dx 3065's in the back and dx 3055's in the front. the speakers get 40 watts RMS of power and the subs get 120watts each. The 3055 component set has some problems competing with the 3065's, i really wanted to put 6.75 midranges in the front but they wont fit!! and polk doesnt make any DX components in 6.5 :(
so is there anything i can do to get a little better preformance?? i guess i just have a lot of questions and need a lot of help....thanks! (i have a 92 ford escort)

[Kim]

A bandpass filter only allows a specified bandwidth of frequencies
to be reproduced. This consists of using a high pass and a low pass filter together. By allowing these frequencies to be driven
by a dedicated driver, the low bass frequency demand that normally would be placed on the mid/bass driver is greatly reduced and this will allow the driver to be played at louder listening levels without distorting. This will also make more efficient use of the power amplier's available power by not having to reproduce full range information. By using a dedicated low bass, midbass, and midrange to high frequency amplifier, this will increase the systems Dynamic Range and allow it to play much louder than using a single full range amplifier. Of course the expense is considerably more but so is the sonic impact of the system.

To improve your systems performance, I would suggest setting the high pass filter for the components to 80 Hertz, and set the low pass filter for your woofers at the same frequency. This will provide a smooth transistion from the bass to midrange frequencies. If the crossover is a 12 dB or 24 dB, you may need to invert the phase on the woofers to achieve the best bass response. Hope this helps.