Cal, you ought not place more value on my opinion than your own. I'm flattered, but take my opinions with a grain of salt. I generally get to a point where I've tried three or four options and listened to a lot of other people, and have spent 4x more money than I should have thinking I'm smarter than Apple or even Lambing Kenwood:) Kraco

Sparkomatic

I'd rather think of it that you'd rather learn from my humbling experiences screwing things up three times expensively and still not being completely happy with a system. I know you want to do it clean on the new rig, so i'll do a data dump on how I would set things up. Subs are easy, tower speakers, etc. Batteries, minimum 2, isolator/relay. The user interface of the Ipod/discs/satellite and the VoLUme control is where you suck or not. There's some new stuff out there......T You asked so tunerread it and hear me now and believe me later.
he HK thing is 25$, dirt cheap. You can mount it without drilling holes. The control knob and display are separate and have flexible, high quality mounting hardware. Unbelievable bang for the buck. GIT YOU SUM BOAH!!!! Three or five. On the new rig, if you are starting from scratch, I'd definitely look at the NEW HK version of the Drive+Play. It has a color display and does video. I'm going to put 2 7" screens in my SX, there's a perfect spot on each side on the 22' Vdrives. Its a pretty cheap super high quality interface, you really don't need anything more than your Ipod and some amps. Meaning, you don't need a receiver/tuner/cd player. If you are really good to go with your Ipod, well there you go. The thing has a pass thru aux input so you could stick a satellite radio or other MP3 player in there. Hell, if you don't need a head unit put ballast switches in there. Or a slot machine:0 pimp. The Drive and play 1 is pretty cool considering how much engineering was put into the display and button, for TWENTY FIVE DOLLAR BUY THREE RIGHT NOW!! model that I bought. Drop the 25$(shipped) and put one in your truck at least.
I like the idea that the HK unit emulates very well the user interface of a real Ipod. The ring and the four buttons, and simple white with black letter display with pulldown menus of the Apple products is the simplest most elegant user interface of any product out there with a transistor in it. Why try to fix it if it ain't broke? The HK thingy (old one, we're talkin') has a pretty nice display, very heavy duty and well engineered mounting, etc. The buttons and rotary control of the HK are very intuitive. i don't have the system fully installed in my boat, but the common complaints I've heard about the old one that I've heard are that the menus and displays are simplified from an actual ipod i.e. fewer controls. (shuffle, etc.) and that the tactile feel of the spring loaded ring is not quite as lineal, it's said to be just a little twitchy when navigating the menus as compared the the real Ipod interface with the touch ring. It looks and feels fine to me, Nattering nabobs of negativism. FOR 25$!! Screamin deal right now with the new one coming out.
OR
Choose not to reinvent the wheel. mount the ipod in a place where it is visible and accessible and won't get destroyed. The ipod interface is superior to all, in your hand. If you are gonna do it this way buy the best quality cable with a Dynex connector and get a simple slide in bracket that sticks somewhere convenient (to the driver, prolly) that plugs into an AUX input on your receiver. You can pull the ipod out of the bracket and hand it around for people to dink with your sheot. Or not. You can get really nice stick on billet aluminum "soap bar" type mounts on ebay for not too expensive
With such a setup, you can also go straight to the amps i.e no head unit though you might want to spend 60$ on a preamp or parametric EQ to help tune things. 300$ for top end stuff like Audiocontrol, cheap but high end stuff on the market for much less. Shittier manuals:) You could input a satellite receiver no problema.
If you want to do video, either buy the new HK thing or get this box from Alpine:
http://www.alpine-usa.com/US-en/products/product_acc.php?model=KCE-415iIt is a high quality black box made by Alpine that attaches to your ipod (good black connector) and outputs audio and video. It is cheap as hell, like 60$ right now.
VOlumE ConTROl
With a multiamped system with tower speakers, subs on a boat it's helpful to have a remote volume control. Most sub amps have a volume control. For the boat and tower speakers, you can use the faders on a head unit. This sucks to operate underway. Some head units use pushbutttons, dedicated rotary knobs are way more awesomer. A good preamp like the Audiocontrol 3.1 gives you front, rear and sub controls between your ipod and your amps. There are much cheaper options with similar performance, given some external control hardware.....
You can also make a simple but super high quality and cheap tapered audio control for each amp, for a couple bucks. I mean like a total of under 10$ in shipped parts from Mouser to build this control for three channels:) Careful not to set some shit on fahr with the soldering iron. I put them in 1x2 rectangular aluminum channel and I have plastic plugs that fit the ends. I get machined and anodized and filled aluminum faceplates for them. They can be totally custom, I can arrange the controls any way you want, put your team on there, whatever. That all costs bucks but it's a pass thru for me.It's like 30$ for a totally custom faceplate for the volume controls.
What I mean is just a knob for each amp. There's lots of not too intrusive ways to make a panel with 3 knobs on it. I'd hate to drill on any way on a new boat, there's no reason to have to do that.
I am going to try the HK Ipod interface right now, with my home grown audio controls for tower, boat and sub amps. I want video output soon so I may go to the new HK model, 300$ or do the 60$ alpine and 30$ HD cable and 30$ billet mount. I recommend that you get a hard shell case for your Ipod and stay away from the clamp style stalk windshield type mounts. I broke one video ipod by trying to clamp it too hard. Even in a hard shell, clamped it, it pops out on double ups. Holster style mount is best imho, with high quality cable and hard case.