Originally Posted by gaw
I have used the FAST system to hook up my EL8A and it works fine. My question, though, is I have a JVC HU that has crossover settings. Since I'm tapping into the speaker wires, how would I use the crossover on the HU to keep the bottom frequencies out of the 4 door speakers and just to the sub? HPF or LPF or SW? Or since I'm tapping into the wires, will the crossover on the HU make any difference?
Using the crossover on the headunit to filter out the low bass information, will see a reduction in the output of the Tube, due to the simple fact that you are removing low bass information. HPF (High Pass Filter) will filter frequencies below the set point, for example, 120Hz will see everything below filtered off. LPF (Low Pass Filter) does the exact opposite, for example, set at 80Hz, everything above will be filtered off. And lastly, SW (Subwoofer) will filter everything above, for example, set at 90Hz, everything above will be filtered off.
If you are using a FAST-9999 with the RCA's, connect the RCA's to the Tube and take advantage of filtering out the low notes on the main speakers. If everything sounds good as is, you can always play around with the filters, but you will probably find leaving the system as is, will sound best.
Long winded post, for sure, but I do like to provide some details with every question posted! Post back with any other questions.