that's off the top of my head for now. i'm glad to answer any questions or go into more detail. like i said, this is likely to become a sticky.

 

i have to go to work. and did not get to read the whole thread. i thoroughly look forward to reading kha's post. it looks like a good read. so know this is coming from not having read his post. i dont know if he answered this or not.

but: this is exactly what i am doing right now but with a different budget. i am redoing my entire system keeping the stock deck.

i did:
two diamond d3 12" sub woofers in an enclosed box built to spec. (119 a piece for the subs. 35 dollars for boxes, built them myself) while sq is my overall goal i am a bit of a bass head too.
diamond m3 series 6.5's in the rear. (had them for a while, get comparable speakers now about 150)
mb quart onyx series 6.5's in the front. (100)
the diamond tweeters are going in custom tweeter pods in the sail pillars and the mb quart tweeters are replacing the stock.
lanzar 2000 watt mono block for subs (250, picked it up for 40)
pheonix gold 400 watt 4 channel for speakers (if i were to guess it was about $300, i didnt buy it)
tweeter pods and baffels for front i made.
wiring from knuconceptz.com (4 awg $1.55 a foot) two runs. about 35 feet total
speaker wiring monster 202 series ($20 for 25 feet, although if i were to go back i would get the 404 series) i used 50 feet of 12 gauge plus a little bit of 12 awg rockford fosgate i had laying around)
two 100 amp fuses (10.00)
equalizer (got a power acoustic off ebay for $50 bux. may replace it if it doesnt meet my needs)

so that is the whole system for a total of: just under $1200

 

Great information K_H_A! Thanks so much. Reading through a few times I have a couple more questions/thoughts.


I would love the flexibility/control over the system I could get out of adding a Processor but I don’t think it’s going to be in the budget. Are there any other cheaper alternatives to give me more control over the system with the OEM head unit? From Neo’s post I’m thinking just an EQ would be the answer?


The Accord Sedan has pretty large rear volume and I’m concerned with it just feeling empty if I don’t have any rear speakers. My catch is I don’t want multiple amps and I definitely want (1) 10” sub in the trunk (hence I figure (1) 4 channel amp to the fronts and bridged to the sub). What would you do in this scenario? Would you just leave the factory rears? Would it be worth the money to replace the speakers even though they are powered by the stock head unit? Add a bandpass filter?


Am I going to get pressurization distortion on the rears from that 10” sub in the trunk if I don’t put an enclosure on the rear speakers? I was thinking I’d use a sealed box on the sub if that matters.


This is likely a dumb question, but is there any way to bridge power from the stock head unit to just the rear speakers to get more power?


Sorry for all the questions! Thanks again!

 

No need to apologize for asking questions, that's why we are here!

You can add an EQ with high level inputs, and it may even give you sub level control. For some, that may be enough tweaking.

You cannot bridge a factory or aftermarket head unit.

You can stick with stock rears for fill and leave them powered off the head unit. That way you keep costs down and just have front components, a 4 channel amp, and a sub. In this case, use the front speaker outputs as your input to the amp (or input to the EQ). I like the idea of using an EQ with built-in sub level control for added flexibility. I always find myself adjusting the sub level control based on the album/genre.

The sub will pressurize the trunk and cabin - that's what bass is. you want a path for air between the trunk and cabin. the rear speakers are the weakest path. the pressure generated by the sub will actually move the rear speaker cones. This is why we like to enclose them. You can alleviate some of that pressure by leaving the ski-hole in the rear seat open.

Crutchfield is an excellent place to shop since they give you all of the necessary installation instructions and accessories. it will save you money and time. and you get a warranty and customer service. But try to listen to speakers before you buy them. I really like Hybrid Audio Technolgies for front components (at $200 they are hard to beat) in a budget system.

 

you can build a much nicer system for $1000 if you buy used gear. You forgo the warranty, free accessories, and instructions, but you get a lot more for your money. It takes longer, requires a lot more research, carries some risk, but can be quite rewarding. You can look to ebay, and also the classified section on DIYMA.

Used vs New is not an easy question and the answer is unique for everyone.

 

just be aware that in my situation at least. the eq has its own volume and sub control. i am running it off of an loc because it is a cheaper one and does not have high input. in this case when you adjust the volume to the rear speakers through your head unit you will be amplifieing the signal to the eq. this could cause clipping and would mean to turn the volume up two adjustments would be necessary. if leaving the rear stock i would suggest, as kha has already said, getting an eq with high level inputs.

also not mentioned in the earlier expenses. (i thought about them on my way to work)
fiber glass kit ($15)
bondo gold body filler ($12, the gold is specifically made for fiberglass adhesion)
rca cables (not sure but not too expensive.)
inddor/outdoor capret ($17 a roll at lowes, if you want to carpet the box)
loc ($30)
sound deadner. (i use milla mat. it is $130 for 100 feet. it is not as thick as dynamat or second skin but for that price it can be doubled if need be. i did one layer in my trunk and it made a noticeable difference)