need a little help here please. have a 10" DVC sub, 4 ohms per coil. want to run a single sub setup in my car. have a 2 channel kenwood amp rated at 50W x2 (4ohm), 150W x1 (4ohm bridged), and 75W x2 (2ohm).
question: do i run the amp in mono mode and hookup the L output to one voice coil and the R output to the other voice coil (for 4ohm operation) OR bridge the amp, hookup just the L output and run the sub in parallel (for 2ohm operation).
there's no good way to run what you have, and your best bet is to get rid of that kenwood amp. what you want is an amp like the JBL BP150.1 or BP300.1 (about $130, and $160 respectively) to drive a mono 2 Ohm load for that sub. when the kenwood is bridged, it can only handle a 4 Ohm load, which you can't get from that sub. if you put one coil on each channel, you only get a 4 Ohm load and half the power to each coil. no good way to do it. if you insist on keeping the kenwood, use it for components instead.
thank you glasswolf, excellent suggestion. after buying a nice sub (subwoofers.cc) and building a matched box with the "unibox" program, i shouldn't cheese out on the amp.
bought a barely used bp150.1 off ebay for $30, wow what a deal.
question: i have a stock ford mach460 system that i am tapping into to run my jbl amp and single sub box. i am tapping into a data cable (comprised of 4 wires, two positive, two negative, the equivalent of 2 line level rca jacks) that goes into the rear mach460 amps.
so the question is this: on the jbl amp is there any fundamental difference between the speaker level inputs and rca jack inputs. i want to be lazy and not run a remote lead and i saw in the amp manual that the speaker level inputs sense power automatically but the manual was hazy about the rca input jacks. all i want to run is a power cable to the battery, the rest are splices in the trunk. thanks.
yeah input impedance is very different. don't be lazy. just run the remote line to any ignition +12 line so the amp turns on with the car. That should be fine. you may want to check around for an adapter for that Mach system. I think there may be one to split off of those amp harnesses for a line level output for an additional amplifier.
Metra does make an adapter for the mach series systems. the complaint you have about running a remote wire is an easy one to fix. The amp for your mach system is in the trunk and has a remote turn on wire coming from the radio in the front, just tap into that and run it to your additional amp. That way whenever the factory amp turns on your sub amp turns on as well.