I am doing a complete re-new of an 1983 Dodge D-150,, long story on why......
back in the early 2000's when my sons drove this truck they had a local car audio shop upgrade the sound system
Alpine deck (with a removable face plate that is now AWOL)
4 alpine SPS 170A round 6.5 inch speakers, two in each door
2 Alpine SPS 100A round 4 inch speakers in the top center of the dash where the OE mono speaker was.
with all that, when the vehicle was on the road,, the sound was never good,,, a lot of road noise infiltrated the cabin.
during the vehicle tear down found out why, there was just about no sound insulation,, I have added two layers of of dyna mat to the floor, firewall and cab back, a single layer in side the doors, the tranny tunnel got an extra layer of foam and the carpet package has extra padding,The inside of the dash was also insulated. I also plan to add sound deadner and upholstery to the inside roof. since I have the 4 inch Alpine speakers I plan to re install the two in the center dash, probably not an optimum location, but I don't want to hack in additional holes
For the 6.5 speakers, does anyone think I really need two in each door?,, I am thinking of going with one in each door.
I also picked up out of a salvage yard D-150 a set of mid 80's Chrysler "premium speakers" these would mount in the rear door jam crevis behind the seat back. Would that be a good speaker location???, in addition to a speaker in each door,, or should I reinstall the double speakers in each door.
here are some photos of the equipment and sound insulation..
https://www.flickr.com//photos/13718356@N02/sets/72157633545764897/show/
and one more question,, is it possible to get a replacement face plate? if not, would that unit have any use?
thanks
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DadTruck
Apparently you can get Alpine faceplates - they are not security coded (info from others on the12volt).
I was considering replacing mine which had blown due to a chassis/engine ground drift, but bought new CDE121 with aux, mp3 & USB for $99 (RRP $199) instead. A faceplate would have cost $45 or more.
IMO one speaker should be fine. I have a 1965 ute complete with metal finish floor (with crack, no carpet nor insulation etc) and my 6 inchers are more than capable of covering high-speed road and window rubber noise. (It would be nice if they were more angled to the ear, but adding tweeters would overcome that...)
I also have pairs of speakers (2"?) in each headrest but these tend to be down of off (fader biased to the front = doors).
I'd recommend against the center speakers if good stereo is your aim, though they could be on the rear channel as per my headrest speakers, else maybe between the front left & right + outputs (ie, a "difference" signal - typically higher/treble frequencies).
FWIW, my former Alpine was newer than yours. It has the same spec as my current CDE121 (ie, 2nd lowest/base model; better frequency response etc then the base/lowest model). But IMO it sounds much better, and it plays formerly un-playable CDs.
FYI - if you want a dimmable display, don't get the CDE121. (That's a mod I'm considering as well as a tap into its USB port.)