Fully tested and verified the speaker channels that are present with the Alpine OEM stereo system (8.4). Basic setup for my truck is as follows (note: I have upgraded the speakers as shown or am planning to where noted).
Some quick notes about the system:
The Amplifier is an Alpine - supposedly a model 506W. I have found almost ZERO info on it (capabilities/specs). Much of what is known is educated guesses. I do know it has 12x channels. I used AlphaOBD to test each channel. The only channel I don't know about (where it is tied to) is channel 12. AlphaOBD reports that Channel 10 is Channel 0 IF you are doing short testing - but it is channel 10.
The original speakers are all junk made in China - as well as the Alpine Amp. They are 2-ohm speakers as verified by using a mulitmeter to test across the connectors.
You WILL get better sound with the setup below - though I can't swear to the three speakers shown in Orange as they haven't arrived yet.
The SUBWOOFER is amazing. They don't make that model anymore (find the comparable updated one with DUAL voice coils) as I bought it back in 2019. Tips/tricks for HUGE bass (w/o distortion):
1) If you have a 2-Ohm dual voice coil sub, wire your sub's dual voice coils in series. Plug the pigtail for channel 7 into the (+) positive of either one of the voice coils on the sub, and then run a wire from the (-) negative of THAT voice coil to the (+) positive on the other. Run the other pigtail to the (-) negative of the other voice coil. Your sub will be running 1x channel @ 4-Ohms across both voice coils, but the thump - well, you'll probably have to tune it down using your EQ.
2) If your bass sounds HOLLOW to you (which it most likely will if you haven't uprgraded your subwoofer's box), get some fiberfill (most Hobby Lobby's have this) for pillows, and LOOSELY fill the subwoofer box with it. Put your sub back in the box and test. Too much boom or muddy? Remove some fill. Still too hollow - add some fill. I use the stuff that looks like shredded foam fill, but you can also use the actual fiberfill that looks like threads/string - just try to keep it out of the sub's frame.
3) Note that the FRONT DOOR speakers only play sub 5000 Hz - meaning buying three-way speakers is almost a waste there - that's why there are three 2-way speakers in your dash (if you're still running OEM). They fill in for the lack of highs on the front doors.
4) OEM configuration uses five 2-way speakers: 1 in the center dash (channel 8) , 2 in the corners (channels 1 & 2), and 2 in the headliner (channels 9 & 11). The doors use some type of 6x9 woofers (channels 3 - 6), but you can put three ways in the back doors and they'll play ful range.
I don't know the OEM specs for the Subwoofer either, but it is a dual voice coil running @ 2-Ohms/channel, and uses channels 7 & 10.
5) Channel 12 is not used anywhere from what I can see/have been able to find. If you were in a higher end car, it might be a rear-dash center channel.
6) Put some sort of sound dampening in your doors - you'll need about 48 square feet of dampening material to properly seal off the doors, but you can get away with using just 12 sq. ft. if you're on a budget. Just follow the directions. If you're going to go all out, it'll take about 160 sq. ft. of material to do your roof, doors, floor, firewall, and engine hood. If you're going to do a bit at a time, Do the doors. Later, do the rear firewall behind your rear seats. Then do your roof. Lastly do the front firewall and the floor.
7) If you're using tweeters in the dash corners, make sure you can adjust their angle! They are meant to "reflect" their sound off the front windshield at the front seats. Test the sound and adjust incrementally till you get the sound you want from both the driver's seat and the front passenger seat. Same goes for rear tweeters - aim them at the rear passengers for best sound.
8) I recommend tweeters that come with some sort of passive attenuator - that way, if they're too loud, you can move the (+) wire over to the next connector on the crossover (see the Rockford Fosgates below) and reduce the volume by 2dB or 4dB. Other tweeters can do -3db, or even -6dB. The front ones won't probably need this, but for the passengers in the rear, you'll find it's good to have options if they're too loud!
9) If you lose a channel, you can use AlphaODB to connect to the Radio and amplifier and run the tests to see which channel is acting up. If it says "open" for that channel, pull the associated speaker and use an ohm-meter/multi-meter to see how many ohms it's got. If you don't get a reading close to the rated ohms (it'll probably be VERY HIGH in that case) for it - i.e.: 4-ohm impedance on a speaker should give 4-ohms (+/- 10%). Anything else is suspect. If your ohms are good, check your wiring harness. Shorts to ground are no-bueno either. You can check by connecting the negative lead on a multi/ohm-meter to ground and testing the + and - wiring leads at the speaker site.
10) Use Metra connectors when putting in aftermarket speakers. It'll save you from having to cut the OEM connector out. They're also correctly configured for +/- on the speaker and in the harness.
Hope that helps!
Here's my setup:
View attachment 532280