I have a 2001 BMW M5 with the factory M-audio setup which includes double DIN size GPS, 2 open air subs and a DSP (digital amp). I bought a Kenwood DNX9980HD 7" Double-DIN GPS Nav. I will have to cut the HVAC duct because the factory screen is not a true double DIN size. I also have 2 JL 10W3's in a sealed box.
Here is my plan, and I need suggestions/input. I have to delete the factory amp because it won't work with anything other than the factory head unit, and it's junk anyway. I will install the Kenwood head unit and JL W3's, with the intentions of later upgrading to 1 or 2 W6's or a couple of JL TW5's in a custom box. Besides the subs, I was planning on using the factory speakers until I could upgrade to some Focal components (not sure which model, but kevlar material around $700/pair retail).
I was thinking of getting a JL 900/5 amp, which would give me enough power for the Focals and W3's, enough for one W6, or maybe barely enough for 2 TW5's (probably on the weak side for 2 TW6's).
What I'm trying to achieve: good, clean, powerful sound in my daily driver, and good bang for my buck. Questions:
1. Does it make sense to upgrade in stages?
2. Can I run the stock speakers off an external amp safely? Should I instead run the speakers off the head unit until I upgrade the speakers?
3. Can I use the factory speaker wire and still get good sound or do I need to change it out?
4. What amp should I get to drive my 2 W3's if I want to get good, clean thump but go a little cheaper in the nearterm?
5. What other products would you recommend instead of the ones I list above. I don't understand all of the nuances of audio, but I do know that I returned some cheap Kenwood subs that sounded like garbage and fell in love with JL, and heard a very clear difference in speakers at an audio shop, hence the Focals. I'm not deadset on anything, even the equipment I already have if there are better options/cheaper options for sound quality/better options for the money. For example, if I can get 95% of the sound quality of the Focals for 1/3 the price, I would probably do that.
6. What kind of amp power kit do I need to get (brand, model).
7. Do I need a capacitor?
8. Anything else I'm missing?
9. My BMW is already fairly quiet (particularly compared to cars like my Honda), do I need dynomat? If so, how much and which locations?