Determine Car Amp Load, Designing System, 2003 Ford Mustang

Hey, all: My name is Kevin. I'm new-ish to the forum (was a member back in 2006-2007). I'm designing a new system for my 2003 Mustang, and finding myself unsure of my next steps. Mny original plan was to just install some 6x8's in the doors and put some 6" Massive Audio subs in the rear deck. Now I'm wondering if perhaps I should put my 6x8" speakers in the door, a pair of 6.5" speakerss in the rear deck (they will fit, I trimmed them big enough for the subs already). and putting the subs underneath the rear seat. Seems like a nice plan to me, but the problem is it would require more money for a mono or dual channel amp to drive the subs, having to buy some good 6.5" speakers, and cost for extra material. Also, I'm concerned if I have to add another amp whether that would force me to upgrade my alternator and battery too (which would be spendy). Right now I have a Pioneer DM-G8704 4channel amp that I was planning on using for the 6x8" speakers and 6" subs. Again, if I end up putting in some 6.5" speakers in the rear deck instead, that would force me to put in another amp. I haven't installed the amp yet either because I'm worried about overloading the system. How would I be able to determine if my car can handle the power draw of an amp before I install it? My alternator is only capable of handling 110amp max load, which seems really low to me, and my battery is some Duralast battery I purchased a couple years ago from Autozone. Also, how would I be able to know if adding another amp would require an upgraded battery or alternator? A few things to know is the Pioneer DM-G8704 has a max output of 1,200watts, of which I'd be pushing only about 100watts per channel for each speaker). Also, the 6" Massive Audio speakers can only handle 150watts RMS, so I was planning on only putting 100-150watts to each speaker, so the amp requirements are quite small. I'm just feeling overwhelmed about everything because 1.) I don't want to spend unnecessary money, and 2.) I don't to have to install and uninstall things a million times, eating up time and resources (and money). If you need more info, I'd be glad to provide it. Just ask. I know I'm asking for a lot, but any help would be greatly appreciated. Thank you all so much for your time.

I will get the discussion going by offering an opinion. 2 full range speakers in the front plus one or two subs in the rear are all you need for decent sound.

That's what I was originally planning on doing: 2 Cerwin Vega 6x8" speakers in the front doors and 2 6" Massive Audio Summo64 Subs in the deck. The reason i was going to do that was because my Chrysler Cirrus had a similar setup (though the speakers in the rear deck were more mid speakers than subs). I'm thinking what I may do is just follow this original plan and see how it goes. It wouldn't be too much work to switch out the speakers down the road if I want to put mids in there and move the subs under the seat (and want to spend more money). I think the main thing I'm concerned about is being able to determine if my car's electrical system can handle the amp before I install it, and being able to tell what sort of draw it has. I want to make sure I'm protecting my car's electrical system and the amp.

The Pioneer DM-G8704 has a maximum output of 600W RMS and is fused for 2x30A so I wouldn't worry about your alternator rating of 110A.

I was running through the manual for my Pioneer GM-8704 and saw this: Current Consumption: 29A (at continuous power, 4ohm) Average Current Consumption: 3.1A (4ohm for four channels) 4.4A (4ohm for two channels, BRIDGE) 4.4A (2ohm for four channels) What exactly does this mean? The Average Current Consumption makes sense but what does it mean to say there are 29A current consumption at continuous power?

That's a max rating. Make sure your power cabling can supply it.Support the12volt.com