Expert: Cleggsan - 3/5/2009

Question
Hi, i run a full sony eplod system, HU, 1200w 4ch Amp as well as 2 1200w 12" subs. I am simply asking you what would be my absolute best settings for the HU and Amp. I am looking for some pumping bass but also clear. My question is specifically about the LPF, HPF , and gain settings on my amp and also the LPF, HPF and EQ settings on my HU. I know this is a very vague question but ive been tinkering for a long time and cannot rest without knowing an expert opinion. Thank you in advance for your help

Answer
First, make sure you have the subs matched to the amplifiers (for best power transfer and impedance matching).  This will get the maximum power to the 2 subs.  If you have any question about the wiring, go to the crutchfield.com wiring guide for the best connections.  See:

http://www.crutchfield.com/S-WiVw1qNrdup/learn/learningcenter/car/subwoofers_wir...

and choose from among the variations that match your amp rating and speaker impedance configurations.

The crossover (LPF) settings should be set for the best range AND the lower capability of the full-range speakers you are running in the system.  If the lower end of the full-range speakers is 80Hz, then the subs should crossover near that point, and so on.  If you are uncertain as to what the best crossover point is, then I would suggest you start with 60Hz - which is a very good selection for most automotive sub setups.

Next, you must set the level of the subs to match the audio level of the full-range system.  This is a trial-and-error procedure.  Best way to do this is to take your favorite musical selections of a female voice, a male voice, a band or group and one with good bass (such as pipe organ or any music that you want to showcase the bass sound output.   By experimenting with the various reference tunes you should come to a setting that gives a good, well balanced sound for clean and natural sounding music.

Last comment; you must make sure the subs are in phase with the rest of the speakers. This is done by  making sure that all the plus terminals are connected to plus terminals on each speaker throughout the car.  This will ensure the speakers cones are all moving outward or inward at the same time.   For example, if the sub cones are out of phase with the full-range units you could have a big cancellation around the crossover frequency.  

Hope this helps!
C