Car Stereos: Focal K2 165 KBE, pioneer avic d3, alpine amplifier

Question
Hello Brian,

Thanks again for your thorough explanation of my last question regarding my 'tri-mode' amp.

While at a charity auction raising money for children I, somewhat accidentally, purchased a audio system for my car (thought I'd get outbid and didn't). My reward was a Pioneer Avic D3, a set of Focal 100KP and a pair of Focal 165 KBE.

I have the 100KP up front and have purchased a pair of Focal 690 CA1 for the rear. I want to add the 165 KBE to the front, but have lost the crossovers that came with them. and I want to run it all off my Alpine MRP-600 (which is powering my current system).

Can I add the 165s without adding power? If so how do I isolate the proper frequencies?

I'm thinking of adding an Alpine MRP-M500 to power the planned JL Audio CS110RG-W3v3... Bad Idea?

Any tips or suggestions for how I can better set up what I have?

Answer
Hi Shane,

While it's possible to run all three sets of speakers from the Alpine amplifier, there are (again) some disadvantages in doing so--or, more precisely, you won't be able to take advantage of the crossover feature of the amplifier.

It looks like the 165KBE originally came with a 300Hz, low-pass filter.  I think you could run the speakers from a full-range output; you wouldn't be likely to damage them, but it would be better if you could limit them to the frequency range they're designed to play.  Similarly, the 100KP could be run with a full-range signal; but since they're 4" speakers and have a limited low-frequency range, it would be better if you could use a high-pass filter to cut out the deep bass.  With both together, it would be ideal if you could limit the 165KBE to 300Hz and below, and let the 100KB pick up the audio above 300Hz.

Because they're both 4-ohm speaker sets, you could connect both to the the amplifier's front outputs, and use the rear outputs for the 6x9's.  However,  unless you want to build a passive 2-way crossover network, you'd have to let both sets of front speakers run full-range.

Here's another option:  You can use the amplifier to run the 100KB and the 165KBE, then use the  AVIC-D3's own speaker outputs to drive the 690CA1 in the rear.  I know your instincts are probably against using the head unit to run any of the speakers, but here's why I think it might be a good idea:

--The MRP-F600 has a pretty flexible crossover system, adjustable from 50Hz to 400Hz in high-pass or low-pass mode.  This would allow you to use the 165KBE with a 300Hz low-pass filter, just like the passive filter they originally came with.  It would also let you set a 300Hz high-pass for the 100KB set, so they're integrated seamlessly with the 165KBE set in the front.  You could also adjust the level of each set independently.  
--The rear 6x9's are the least important of all the speakers in your system.  They're really just there for a "fill" effect; giving you a bit more depth by putting a some sound behind you.  For realistic imaging, you wouldn't want the rear speakers to distract you from the front sound stage.  And you don't need them for bass, because you're also using a subwoofer.
--The 690CA1 is actually a fairly sensitive speaker, which means you should be able to get acceptable output even with the head unit's lower power.

Another option would be to pick up a second 4-channel amp, then use two channels to drive the rear speakers, and bridge the remaining channels for the 4-ohm subwoofer.  This would be an alternative to using a mono amp for your sub--because it's a 4-ohm sub, it can be used with a bridged amplifier if you wish.  (This assumes you're only using one subwoofer).

The MRP-M500 would be an acceptable choice to drive the JL subwoofer.  You'd need to be careful, because this amplifier is rated for 300 watts RMS with a 4-ohm load, and the sub is rated for only 250 watts RMS.  I don't think you'll have a problem, though, if you don't abuse it.

Hope this helps!

Brian