Which gauge wire do I need?

Here is a list of stuff i have already

It's all Alpine

HU - CDA - 9815

Front Speakers - SPR-136A

Rear Speakers - SPR-694A

Amp#1 - MRD-M500

Amp#2 - MRV-F540

Subs - *still not sure (need sugestions)

Which brand should I get? And what size/gauge? Any help is appreciated.Thanks!

You'll want a single 2-gauge fused power cable from the battery to a distribution block, and then either 4 or 8 gauge to each amp.

That 4 channel amp is actually a 5-channel amp, cuz it has a separate mono subwoofer channel.  But since you have a separate sub amp already you might as well use that for the subs.  I bet you could run this amp at 1 ohm if you're careful with it, and once you get a 2nd sub you're gonna want to be able to give the amp a single 2-ohm load for maximum efficiency.  So basically you should get the subs with the 2-ohm voice coils.  And for the time being you can either take the risk and hook up the two voice coils in parallel for a 1 ohm load, or be safe and get less output and wire them in series for a 4-ohm load.   Regardless, once you get the 2nd sub you'll wire it up so that you'll give the amp that single 2 ohm load.

12 or 14 gauge wire for the subs is fine; i'd go for 16 or 18 for the speakers, though you can usually use the factory speaker wiring with good results.  Just remember the power and signal cables need to be run down opposite sides of the vehicle to avoid any noise problems.

Those alpine type R subs are awesome and I think you will be very happy with the way they sound. Just make sure you get the proper enclosure for them or else they'll sound horrible (as would any sub).

Your head unit has separate front/rear/sub preamp outputs so you will use those for each amp, and this way you'll be able to get proper fade/balance control as well as change the volume of the sub from up front at the head unit.

Just out of curiosity, has any of this been installed yet?  or have you just purchased it yet but not gotten it in your car yet?  and what kind of car do you have?

If you've got the directions for disassembly and use the proper harnesses and kits, neither the radio nor the speaker installation will be that difficult.  Especially if you're willing to work slowly and carefully, you will have nothing to worry about.  Hondas are pretty tough little cars and the plastics they use are very hard to accidently break.  they include the instructions for removing the factory head unit with the honda dash kit (see below), but you'll need to know how to get to the speakers as well.  email me and I'll send you the dash and speaker panel removal instructions if you need them.

If you REALLY wanna do everything the right way and not mess up your car at all, you'll need some install parts: 01-up civic dash kit (recommend metra's: HONK809); a wiring harness for the head unit ( metra 70-1721 or equivalent ("98-up honda")); speaker harnesses for each pair of speakers if using the factory speaker wiring ( Metra 71-012 or equivalent ("90-up honda")).

to get the absolute best sound you should run all new speaker wiring from the 4-channel amp directly to each aftermarket speaker.  With the rear speakers this is obviously easy as cake but with the door ones it's a little more tricky--have to run the wire through the factory rubber "boot" between the doorjamb and each front door.

Also don't worry about directly connecting the head unit to the battery as it might instruct you to do in the owners manual. This is only when you're using the head unit's internal amp.  Since you have the 4-channel amp powering all the speakers you're not even gonna be using the internal amp so the radio will draw FAR less power.  The wiring harness from metra will be able to EASILY hand the power demands of the head unit.

In my experience it doesn't really matter what brand wiring you use as long as it's one of the major brands.  The amount of effort taken to ensure that cables are routed properly throughout the vehicle has a much bigger impact on your overall sound quality than if you use, say, Monster RCAs instead of RF RCAs or whatever.

A lot of the main brands are really overpriced and I think it was bberman1 who introduced us to www.knukonceptz.com.  I was skeptical at first but I guarantee you will love these cables.  They look slick and they perform very well--probably better than the main brands.  And they don't overprice their stuff so you can get really good deals on quality cables.  I highly recommend getting your amp wires from here.

You will not need a special kind of battery post because you're just going to have a single ring terminal connected to the single 2-gauge power cable running from the battery.  This will easily fit onto the positive battery post.

I already have a Scosche dash kit (HA 1567). I ordered it before I posted this. Why would I need a wiring harness if i'm not using the factory speaker wires? I was thinking about using Stinger products. Can you tell me exactly what I would need? Would I need a capacitor also? Is 1/0 the same as 2 gauge? Sorry for all the questions but if I bring it to a shop i just don't want to get ripped off. Besides if I do it  this way I can lean something from it.

Tell me if / where I went wrong:

Step 1:  I run a 2(g) power wire from the battery (+ terminal) to an inline fuse holder (80-100amp).

Step 2: From the fuse holder I run 8(g) power wire to a distribution box. (Should this also be fused?)

Step 3: From the distribution box I run two 4(g)(or 8 gauge) power wires. One wire to EACH of the amps.

Step 4: From the Subwoofer amp(MRD-M500) I run 12(g) speaker wire.(Sub is wired in parallel because I'm only using 1 for now)

Step 5:    From the other 4 channel amp (MRV-F540) I run 16(g) speaker wire to the rear(6x9's) and the front(components).

Did I forget anything?  

Thanks for reminding me about the ground from the amps.  I forgot about them. I was looking on www.SoundDomain.com and found some amp wiring kits. Would I be able to use any of these?

Lightning Audio  - Storm SQ1/0

Lightning Audio  - Strike SXPK2

RockfordFosgate - Type RF CP2POS

Stinger - Custom Pro SWKO

Stinger - HPM SWKHO