I currently have a shaker 1000 system. Have a different head unit, 1/2 din EQ, two alpine amps, assorted speakers and a different 10" sub ready to go in.

As I understand things, the factory amps only drive the 8" speakers and the rear subs, right? I was thinking about keeping the front ones. Does anyone know if the crossovers are built into the amps or the headunit or what? Any idea where they're set?

Current thought is to power the four 6x8 locations with my 4-channel amp, power the sub with the sub amp, and power the 8" locations with the factory amps.

I've found some strange conversation about voltage requirements for the factory amps, little confusing. Between the current HU & EQ, I have RCA outs available at 2.5 or 7 volts, or line level at 4x 25 watts RMS. Thoughts?

 

Actually with the shaker 1000 there are two sets of subwoofer amplifiers. The ones for the door 8" speakers are mounted in the driver's side kick area and the ones for your trunk subs are mounted on the subwoofer enclosure in the trunk.

The strange thing about the factory amplifiers is that they only require 5 volts to energize the remote turn on whereas your aftermarket deck will provide 12 volts. In order to get around that little issue, you will need to either use a Radio Shack voltage regulator or a 1.5K Ohm resistor on the remote turn on wire going to those amplifiers. You can get by without using either of those parts BUT you will have a horrific turn on and turn off THUMP from your 8s. Edit Warning: Connect the remote turn on lead going to your after market amplifiers BEFORE the resistor or the voltage regulator otherwise your aftermarket amplifiers may not turn on!

You are going to have to experiment with the pre-amp voltage a little. My stock Shaker 500 amplifiers did NOT like 4 volts of output and I had to keep the sub level down to keep them from distorting too bad. I'd imagine that 7 volts of pre amp output would be even worse.

 

Crap, I forgot to warn you about something else. The Shaker 500 subwoofers are phased weird via their amplifiers, somewhere between 0 and 180 degrees. I never figured out exactly where they were phased, but I encountered cancellation issues with the three different subwoofers that I used in my 2006 Mustang.

I've spoken with other installers and they told me this is an issue with just about every Ford and Mazda vehicle that has a factory subwoofer. I just wanted to throw that out there in case you notice that your bass doesn't sound right after adding your trunk sub. If it doesn't, try disconnecting the factory subwoofers and see if that makes a difference.

 

Thanks, this is very helpful! Hopefully gonna pick up the last wiring bits & pieces tomorrow & get to work over the weekend. Just wish secondskin/dynamat/etc weren't twice as expensive locally as they are online... sucks that I'm gonna have to open everything back up again later.

Any thoughts on the crossovers?

 

I really don't know about the crossovers and I never tried my factory amps after pulling them from the car to see if they had any filtering built in.

 

Okay, I haven't started the install yet because I'm still trying to work out the design kinks. What do y'all think of this plan? I'm concerned that it doesn't allow independent level control over the 8" midbass and I might have to step down the voltage from the EQ. Better to send a non-EQ'ed signal from the rear headunit outs? As I understand it the Memphis crossover is bi-amp, so that part is handled even though it isn't shown on this diagram (also I know there should be a green box labeled "trunk").

If y'all have other 3-way component speaker or 2-DIN Bluetooth-capable headunit recommendations, I'm all ears. My combined budget for these parts is $500.