I'm about 10 years behind on car audio tech and need some help with a rather tricky install.

The car is a 1931 Plymouth street rod project. Here's a link to some pics, check out "progress 3-30-09" for interior shots to help understand my dilemma.
Street Rod pictures by lsrx101 - Photobucket

The wiring is done except for some minor glitches, so now we need a sound system before the interior is installed. The issue I'm having is that there is no good place to mount a regular head unit that won't cause appearance or operational issues. I have the speakers and cabling worked out.
Most usual mounting options won't work. Mounting in or under the dashboard is not an option, there is no clearance beneath or between the seats, no clearance for roof mounting and not enough space for a floor console. The only feasible place for equipment is behind the rear seat, and the space there is limited.
Radio operation is not a necessity, most listening will be pre-recorded. The system doesn't need a ton of power, just something comparable to a modest OEM system. I'm thinking 30-50 WPC or thereabouts.

The initial thought was to mount a typical head unit behind the rear seat, face up, and use a remote. Unfortunately, a CD player won't work in that position and the remote needs to be in line of sight. A marine unit with tethered remote would solve that issue, but not the CD issue.

Right now I'm thinking an amp behind the seat fed by an I-Pod or other MP3 device tucked into a pocket in the driver seat. From an installation and operational standpoint, that would be perfect. Problem is, opinions are all over the map on whether it will work or not.
Some say it will work fine, others say it won't, it will sound great, it will sound like crap, it will distort, it won't distort, will need an EQ, won't need an EQ............ad nauseum.

I'm looking for suggestions, opinions or ideas for other alternatives. Any thoughts?
I'm especially interested to know if anyone has used an MP3 device feeding an amplifier with no head unit. I'm not totally married to that idea, so If I'm missing another good option, please toss it out there.

 

Somebody here may well be able to help you out. But, you might also try hotrodders.com. ( They call it a bulletin board, not a forum, over there). Lots of discussion about various rod projects.

 

It depends on the amplifier. In most cases, car stereo amplifiers are used to amplify low frequency signals because they drive subwoofers. You'd want to use an amplifier with a frequency response that covers the majority of the audible range. You'd also want to make sure your speakers are rated to handle the output power of the amp, since most amps are intended to drive subwoofers that can withstand a decent amount of power.

My advice is, if you want to use a common amp, you'd need to investigate the frequency response and output power. You could also look into audio amplifiers that aren't originally intended for automotive use, but household use. The only issue would be powering it, since consumer electronics not intended for automotive use rarely run off a 12 volt rail. The answer to your question is yes it's possible, you just need to research the equipment you're using.

 

Yes, I've been doing that for years. If anyone tells you it won't work, smile politely, change the subject, then run far away. In my Mustang, I ran a Discman directly to a power amp and 6.5" two-ways at first, then changed to a 4 channel amp with a separate electronic crossover, and a 10" subwoofer. I later added a Sony CD changer, again without a head unit. That's another option that would work for you: an add-on CD changer which has a small wired remote with display and player controls. They generally come with an RF modulator, but there should be RCA outputs as well. This setup would require a volume control somewhere... just a passive stereo volume control should work. This could go someplace like under the seat or on the dash. Pretty much the same amp setup is in my panel truck now, except it's been MP3 Discman or a flash player; battery life is so good that I don't worry about trying to power them from 12V. I'll be installing a more compact 4 channel R-F amp that has built-in crossovers real soon.

If you would like the option of playing cassettes or the radio, mounting a head unit under the seat isn't the craziest idea ever. I did that for a while. It was a twin-shaft deck, and I got completely used to operating it by feel. Newfangled DIN decks don't have real ***** to turn. But... Sony had (maybe still has) a wired remote called the Remote Commander for some models of head unit that resembles a joystick. It should run most of the functions of the head unit by feel, once you get used to what to push or twist.

[edit] Whoops, no room under the seats? Well, the Sony Remote Commander, or the changer with wired remote could still work for you. On the other hand, a $20 2 gig flash player from Wal-mart or Staples holds more music than the CD changer, and is much smaller than the changer remote, and did I mention it's only $20? Only problem: tiny display and tiny buttons to operate it. I'd advise going with a real volume control between the MP3 player and the amp, for safety and convenience.

Another option: put a remote sensor on the dash that transmits the signal back to the hidden head unit. They're sometimes used in home theater installations where the electronics are hidden inside cabinets. Places that deal in "home automation" may carry them, if a serious home theater dealer won't help you out. Going with the Sony wired remote is probably cheaper and better.

 

do you have some interior pics?

 

Right here:
Progress 03-30-09 pictures by lsrx101 - Photobucket

 

Another sort of MP3 player works like that add-on CD changer, with a box containing a small hard drive that stashes someplace, and a small remote display. The Omnifi DMP1 is one example; it was being liquidated really cheaply a couple of years ago; I picked one up then, but still haven't installed it. There's one on eBay at the moment, new-in-box, for $160. You can transfer music to the hard drive over WiFi without having to schlep the drive caddy back and forth. Although the manufacturer dropped support, a user community sprang up and there's even alternative software for it that's added features and fixed bugs, and the stock hard drive can be upgraded if 20 gigs isn't enough.

Is a console above the windshield possible? The control/display modules for the Omnifi or CD changer need less than an inch of mounting depth, if you can get the cable up there.

 

You can run the setup angus was talking about but use a Microsoft zune or an apple ipod as the source. With both you have the option of prerecorded music and the ability of listening to the radio.

 

Well, we came up with a working system.
A 200W (50wpc) amp, a line booster and an MP3 device. The amp and booster are behind the rear seat with a heavily shielded RCA cable up to the driver seat area. I would have preferred to put the booster closer to the source, but this seems to work well. I split the stereo output of the line booster to the 4-channel amp.
The owner will be shopping for an I-Pod, MP3 player that he likes, so I used a Sony PSP for testing.
There's no insulation, sound deadener or interior, so it sounded rather tinny. A few well placed towels behind the speakers temporarilyand it sounds pretty darn good. I think we have a winner!