Well, after having the car for almost 4 years and the stereo system for what was probably 3.5 years, it's time for a bit of an overhaul. Here is what I have so far:

- Nak MB-75 6-disc changer
- a/d/s/ P840.2 8-channel amp
- a/d/s/ 335is.2 fronts
- JL Audio Stealthboxes

The original writeup that I did is:
http://www.geocities.com/chester_p_wong/car_audio/stereo_upgrade.html

I find myself not even using the stereo system because, well, the engine with an AA exhaust and BTG Racing's LTW flywheel just kicks butt. Also, even though the Nak has 6 disc capacity, I still find myself wanting more. I want MP3 playback capability!

So, I'm at the crossroads where I'm going to replace the head unit. I'm leaning heavily towards the Alpine CDA-7897 and perhaps the MP3 capable Alpine 6 disc changer.

So, here are a few regrets from the first time around:
- I should have run power *and* ground from the head unit to the trunk. I ran power only and got alternator whine. I then ran a ground, but only to a ground point somewhere behind the dash.
- Although my amp bracket is nice and it keeps the amp out of harm's way, it's a pain to adjust crossover points, etc.
- I ran RCAs but I cut off the ends at the head unit side and crimped on terminals to plug directly into the back of the head. I thought it would make for a cleaner install, but I kinda regret cutting the ends.

I will be running 3 sets of RCAs (even if I don't use all of them). The alpine head has 3 sets of outputs: 1 - fronts, 1 - rears, 1 - subs. I will be running power and ground...any recommendations on wires? Last but not least, I'll probably make the amp and/or sub box removeable...for track days, etc.

So...I appeal to you experts for advice and recommendations. The amp has crossovers built in, but so does the head unit. Which should I use? How would you configure the a/d/s/ separates? Bi-amped or regular? Should I ditch the stealthboxes for rear channels and go with a single or double 10" sub arrangement? Recommendations for patch cables? Does brand really make a big difference?

TIA!!!
Chester

I've got some info for you but I don't have time right now. I'll get back to it later.

Jay

Stereo whine can be picked up from several places. I would be willing to bet that you are not picking it up from not grounding your head unit with the amps. With the battery being in the trunk, there are a lot of power wires running to the front of the car. If some of these power wires gets close to the RCA cables, or you ran the power wire to the radio with the RCA, that could be causing the noise. I get it through the Factory CD changer in the rear but not the radio. It is mostly likely because the signal from the CD changer combines with several power wires right in the trunk and it is picking it up right there. That may save you one step, but you really want to run power and ground from the radio to the trunk, go ahead. I just see it as extra work.

Using crossovers in the head unit would make for easy changing, and not messing around with the amp that is difficult to get to anyway. Also, I would suggest to not cut the RCA’s to make them exact length. That could let some whine in too if it was not crimped perfectly and shorted it a bit. Get good patch cables, that will help with the whine too. You may be looking at $50 a set, but it will be worth it. You get what you pay for, but don’t even think about the $1000 set for RCA’s, you will never notice a difference. I kept the rear speaker in the stock location and went with a single 10. With a good sub and amp, it will add just enough low end. I have people in back every now and then and wanted them to have speakers. Good luck.

I am in the same dilemma.

I currently have:
Clarion AutoPC 310C
GPS Unit
CD-ROM/Changer
Stock speakers up front
JL stealths in the rear
4x50 old school alpine amp

I have in my possession now ready to install:
Clarion VRX925VD/MP3 in-dash unit
Clarion DVH920 DSP 5.1 processor
Clarion CD changer
Clarion TV tuner.
McIntosh MC440M 4x50 and 2x100 6-channel amp
MB Quart 325I 3-way components

Still need to buy 2 TOSLink digital cables.

So I also need some expert advice.

Should I invest in some better front components up front, like focal, Diamond Audio, Boston Acoustics, or A/D/S?

Should I ditch my JL stealth box subs for some rear fill and use some separate components and use (2) 10” subs in a aperiodic membrane setup? Or should I keep the JL stealths and screw rear fill. I don’t want to lose trunk space.

Any help is appreciated.

Dan

Chester, I just wanted to thank you for doing that write-up. I used it to base my system on in terms of how I wanted the install. Do you still have the spec's for the amp rack that you use to have a link to? I'm going to have the shop redo it like in that pic but with the amp facing back into the carpet side (carpet will be cut away) so I can have the EQ facing out.

What kind of RCA's did you run? The stuff I used was EXPENSIVE; it's called Encore II and is used for home audio. They actually add the RCA heads on after cutting the stuff so you should be able to put some RCA's back on. Just make sure it's quality twisted pair. BMW's are notorious for engine while. Also, sand down the ground location behind the dash for the head unit so you're down to the metal.
The 335is are nice speakers. I'd bi-wire them if you could. That would leave 4 channels to bridge for the subz. In terms of which cross over to use, pick the one with the steeper slope. I don't miss rear fill at all with my kick panels. Sorry for the poor pics.

http://images.cardomain.com/installs/193000-193999/193485_9.jpg http://images.cardomain.com/installs/193000-193999/193485_8.jpg
The mid-woofers are actually angled a bit up for better imaging.
I have two IDQ 10's in the rear deck (infinite baffle) and I'm very happy with it. It's not really loud but loud enought and it's tight. I also wanted the Stealth Boxes but my installer said it wouldn't hit enough with the Focals and I thin he may be right because I had to turn down the midbass with those things.
http://images.cardomain.com/installs/193000-193999/193485_11.jpg http://images.cardomain.com/installs/193000-193999/193485_10.jpg
Dan, you should consider getting the Focal subz. Even the Polyglass subz hit hard in infinite baffle if done properly. With that "mini" MacDaddy you got, you should consider some other (don't want to say "better") speakers. Depends on what type of sound you like but my favorites are the Focal Utopia's. If you like a mellow sound then the DynAudio. They have these new ones with these HUGE tweeter assembly's; it's almost as big as the 6" mid. The a/d/s sound in between, at least to me. You could bi-wire the fronts and still have plenty of power for some subz. Where are you having the install done?
Sorry for the long post, but you guys have some nice gear.

OK, here we go. The CDA-7897 doesn't have amber lighting. If you want the fantom face, go with the CDA-7998. It's more expensive and doesn't have internal power. But, it has a better display and amber lighting. If you don't need the fantom face, do the CDA-7894.

If you do CDA-7897, you'll need to power the deck from the battery. If you do the CDA-7998 or CDA-7894 you can use the power from the factory harness.

As far as ground goes, I'd do a source ground. Do not ground the deck to the factory harness or the battery. Instead, connect the deck's ground, along with any other components grounds to the ground wire(s) on your amp(s). The amp(s) should be grounded to bare metal chassis using a ground wire the same size as their power wire and less than 3' long. You can use 18ga wire to connect the components to the amp ground. The idea is to have the same ground potential for all components of the system. Engine noise is caused by induced noise from power wires and from a difference in ground potential.

As has been said earlier, don't run any RCAs on the right side of the car. That's where the battery cable goes from the battery to the front of the car. Don't use home audio RCAs. They aren't twisted pair and aren't designed with induced noise in mind. Use a quality twisted pair design. There are a number of good ones. We carry Phoenix Gold. Monster is another good brand.

When you run the RCAs, down the left side, you should also run the 18ga remote turn-on (blue) and the 18ga source ground (black). Also, run an extra wire for each of these. That way you have a wire in place if you ever need one. If you need to run deck power from the battery, do it on the other side of the car.

My tendency would be to use the crossovers in the amp. If you have good amps, they'll be 24dB/octave. But, your components should have their own crossovers. And, the stealthboxes will just be lowpass. Really depends on how you decide to wire it up and which component has the best crossovers. If you're really a tweak, you can always play with the deck's crossovers.

Good luck & Happy Tunes - Jay