Questions about LOC's and keeping factory headunits

[crashprime 10+ year member]

I have a late model Camaro. It is equipped with a factory head unit that powers the front 6.5" components, and rear 6x9 2(3?) way coaxials.

To be completely honest, I think the sound it produces is actually pretty reasonable at lower listening levels. If I want to get speakers moving, as expected, it turns from pretty decent to pretty much garbage. In addition, at peak volume (100%) it still isn't what I would consider "loud" on all sources. XM for instance really leaves a lot to be desired for headroom.

I am trying to figure out the best way to amp some new speakers, while maintaining the factory head.

I've read about a number of things to accomplish this. They are:

1) Generic install bay LOC slap 2 on for front/back. Cheap.

2) Specific LOC harness designed for Camaros from PAC (AA-GM44). Even cheaper, because it includes a T-harness that I'll need anyways.

3) Multi-channel LOC's. Some with built in EQ. Things like: Kicker SUM8, AudioControl LC7i.

4) Expensive EQ/LOC processing units like Rockford Fosgate 3SIXTY.3, and JBL MS-8.

5) Use the speaker level connection input on a multi-channel amp.

I am looking for the best end result without spending a total fortune on overkill (let's be honest, when keeping a stock head unit, it's hard to justify spending outrageous amounts on upgrades).

Things that I am concerned with would be any distortion/hiss/engine whine. I want as clean a signal as I can given my limitations. I am also concerned with the bass attenuation that occurs on the stock HU. I know the LC7i claims to deal with this using something called "AccuBass" but I have no idea how effective it is. I've also read about the MTX RE-Q5 that also deals with bass restoration. However, the RE-Q5 seems to have fallen off the planet as it's not for sale anywhere on the internet. I've never had anything other than the stock speakers hooked to the HU so I have no idea how much of a problem it is, or will be. I've just read about it.

I am planning on installing Polk Audio DXi speakers all around.

DXi 6500 components in the doors

DXi 690 6x9 coaxials in the rear

Most likely would use a Polk Audio 660.4 (PA 660) to power them. 75w x 4 @ 4ohm AB. Seems pretty well matched in price and quality to the speakers I've chosen.

They sound good for their price, but I want everyone to understand I'm not working with Focals, or Helix, or even JL audio stuff. It's decidedly consumer grade. My budget will top out at right around $700 for a 4-channel amplifier, and whatever I need to get the signal to it. In an ideal world, closer to $300 would be more like it.

Finally, if going with the cheapest solution, using speaker level inputs on a 4-channel amp, will the amp send an RCA line level output? This would be helpful, as the mono amplifier could be fed these RCA's without worrying about where to grab an audio source. I'm just not sure if the RCA output circuit on most 4-channel amps are just a "y" adapter of sorts for the RCA input.

I'd appreciate any help on this that I can get. Keeping a stock head unit is a real son of a gun, but in the camaro, aftermarket head units just kill the look of the dashboard.

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[trumpet 5,000+ posts]

It's not a big deal to keep the factory head unit if you have the right supporting hardware. The entire car audio industry has been shifting toward supporting this emerging market, so you're covered. Let's talk about some of the ideas you listed.

AudioControl still is known for really good hardware for specific purposes, but they've fallen behind in terms of technology. DSP is not their strength, in your case meaning the way it handles a factory signal and manipulates it to sound better. Since you know you have bass attenuation in your head unit that should immediately rule out any one-size-fits-all LOCs. I've not worked on a Camaro, but you may need to use a processor that has you set the factory head unit to a determined volume and then use the processor to change the volume of the music. This would completely avoid the bass attenuation.

If you don't mind sharing your true location I would be happy to help you find a good shop near you to meet with to discuss your goals.

 

[crashprime 10+ year member]

Sure, I am located in Chippewa Falls, WI, about an hour away from the WI/MN border.

 

[trumpet 5,000+ posts]

It's not the easiest to verify by Internet and phone which shops are worth a hoot, but Sound-N-Logic looks like they may be worth a visit. The web site looks straight out of 1997, but they're on Facebook too. http://www.soundnlogic.com/

 

[crashprime 10+ year member]

Well, thank you for the pointer trumpet. Stopped in and got some advice from the shop, and ended up deciding AGAINST the Polk's. Instead I am going with JBL's which I've been a LONG time fan of. I got setup with an MS-A1004 amp which takes speaker level inputs (eliminating the need for LOC's) and will do a lot of the same DSP the MS-8 handles. To run off those I am going with:

JBL GTO608c 6.5" components

JBL GTO938 6x9" 3-way coaxials

I am not totally decided on my subwoofer choices. I am split between going with a JBL BassPro12 with the built-in amp, and going with a more elaborate system utilizing the MS-A5001. To me the MS-A5001 seems like an expensive 500w amp at $550, but the MS stuff looks like it works really well with factory integration, and I already have the money going into the MS-A1004 to match. And who doesn't love more power?

 

[trumpet 5,000+ posts]

Do they stock the MS-BassPro SQ? It's a newer powered subwoofer that really has impressed me.

Yes, the MS amplifiers have some very good DSP built in. It's an either/or situation going with MS-8 or MS amplifiers, as there's no point in running both. I personally would have recommended the MS-8 with different amplifiers, but they seem to have gotten you sorted out.

 

[crashprime 10+ year member]

They do carry the MS BassPro SQ, but I decided to go for 2 12" JBL GTO drivers instead. Going for the MS-A5001 amplifier to match up with the rest of the system. JBL claims 500w @ 4ohm with that amp, but also lists only 500w @ 2ohm. I've seen tests on the A1004 that show the reduction in impedance does increase the power output, so I figure I'll get closer to 6-700w out of it which is the sweet spot for those GTO drivers.

I've given up trying to be budget friendly. I found out after more conversation that the MS amplifiers don't do EQ like we thought, and so I said screw it and grabbed an MS-8. I've spent money on worse, and this will get the job done properly.

Now to try and figure out the most effective way to mount this insane amount of kit... that's for another thread.

 

[mclerico83 5,000+ posts]

N-RHL2 - BEST LOC IN THE WORLD!! - $24.95 : Zen Cart!, The Art of E-commerce

4 the price pretty hard to beat