View Full Version : 4 channel amp ... settings ?

04-07-2008, 06:40 PM
i have a V12 Alpine amp (MRV-F250 model) and was going to tackle the install myself. i've never done this before and notice it has all these settings and dials on one side ...

i'm hooking it up to my sony deck (MEX-5DI) and don't know what i should have the amp settings set at so i don't blow or mess up anything.

if anyone here is familiar with amps and how they should be set at please lend your input so i can be comfortable doing this. i would elect to have a stereo shop do it for me, but it's a straight forward thing to run the wires and what not so don't feel it really warrants having someone do what i can already do myself .... i just need help with the amp.

here are the switch/dial settings on the amp :

input mode : 1 ST 1+2
filter: off HP LP
crossover: 50 - 200 (it's a dial that goes from 50 to 200)
gain: min - nom. - 0.5v - max
input mode: 3 ST 3+4
filter: off HP LP
crossover: 50 - 200 (another dial that goes from 50 to 200)
gain: min - nom. - 0.5v - max

input channel: 1/2 3/4 (1+3 2+4) <-- the last one there is just one choice

the way this setup works is that my sony deck doesn't have a built in amp to power the speakers, so i have to have an external one (hence the alpine amp) so i have to run the amp to the deck and then i would run the speakers off the amp ?? or straight off the deck ?? ... (that one is a simple one to figure out, if it doesn't work off the deck then switch to the amp)

it's the settings i don't get .... umm i don't have a crossover as i was told i would only need that if i was adding a subwoofer to my setup, which i will add later on. right now i can make due with just the factory speakers just so i have sound and can listen to cd's (the car has a factory tape deck).

thanks !

04-07-2008, 07:27 PM
If the amp came with a owners manual they usually give an outline of what all the switches and dials are for, and where to set them.

I went on the alpine site and if you go under amps you can download the owners manuals for the amps, i couldnt find yours there but maybe it can help.

When i was installing my amps, i emailed JL audio with my set up, and they sent back a picture of how the amp should be set up. I know youur using alpine, but maybe alpine will help you out.


04-07-2008, 07:31 PM
i have the pdf version of the manuals for everything .... i will take a look and see if it gives guidelines as to what i should have everything set at for a basic (non-subwoofer) install.

one person at the audio/visual shop said if i still have the factory speakers in don't expect them to sound good nor last more than a week if i'm going through the amp. that's expected, but i'm not going to be cranking it to high volumes ...

will source out some nice speakers later this summer. i just want the ability to listen to my mix cd's and not always the radio. it's wearing on me .....

04-07-2008, 10:23 PM
yea the stocks wont last long if you amp the signal. They'll blow soon enough or start popping very quickly.

the pdf manual will have what the settings are for. If anything take it after your install to a local shop and get them to tune it or find a friend whose good with audio and get him to tune it. Thats what i did.

Mickey Knox
04-07-2008, 11:55 PM
there is really no point to upgrade ths system and keep the stock speakers in a bimmer, unless its a newer one but it doesnt sound like it.

04-08-2008, 11:25 AM
i see your point, but right now the car is taken apart so i can clean it up and remove what i don't want. so while it's like that i would like to run the wires and get that out of the way.

04-08-2008, 05:26 PM
there is really no point to upgrade ths system and keep the stock speakers in a bimmer, unless its a newer one but it doesnt sound like it.

Kinda agree, my 94 E36 has stock speakers all the way around, including my mids and tweets. Running a Jl 500/1 amp with a RBC and 2 10" subs and it sounds good in my opinion. I know it would sound 100X better if I upgraded my mids and tweets but it's good enough for now.

04-09-2008, 01:00 AM
i was just reading the pdf i have on my amp and it's only 25 watts per channel .... so it's not that powerful of an amp. i can boost the wattage if i choose to only go 2 channels. but then i would have to get another amp to make up the difference. so i think i might be good with the factory speakers and not end up blowing them. and if i did .. really i wouldn't care. i'm gonna be putting in better ones at some point.

i just noticed i screwed up .... when i bought the amp i also bought the hook up kit and read that the kit is for a 2 channel amp and not 4 like i need ... well ain't that just awesome.

04-09-2008, 08:57 AM
Wow I just looked up the specs on your deck and honestly I think that's the first time I see a radio without a built in amp. So basically the amp is for your speakers and no subs? What about using your BMW amp to power your deck, is that a possibility?

04-09-2008, 03:50 PM
my car doesn't have the HK setup .... just basic stuff. i have the mids and tweets in the doors, the speaker by the kickplate and the rears in the back windows. i think i might lose the mids and tweets when i do this hookup unless i can figure out the harness wiring to get them working.

i just got a harness from the wreckers that was used for a pioneer deck. so i will have to cut off the pioneer connector and then solder on the connections to my sony harness and cross my fingers that it works. if not then it's just the two main speakers in the front and rear run off the amp. the good thing about this i find, is that the battery is located in the trunk so i won't have as many wires being run from the front as i thought. and no drilling to hook up the power to the battery through the firewall.

i'm new to the whole amp stuff ... before i had the audi (had a kenwood already in it) i had a domestic car and just did the typical deck hook up only.

if anyone has some suggestions for my install please let it be known. i always appreciate the help you guys give ...

04-09-2008, 08:39 PM
For your amp, I don't have the HK setup either, but if you look behind your C-Pillers one side will have the antenna booster, and the other should have a factory amp..

04-09-2008, 11:10 PM
i have no clue what C pillars are .... well i know what they are but don't know what the C one would be. the haynes manual was showing the antenna booster on the back window pillar on the passenger side i believe. i don't know how i would wire the bmw amp into my deck though ... sounds like extra wire ran and more time tearing things out to run it. i would be better off tapping into the harness and seeing if i get lucky with the mids and tweets. so far it looks like i only have to run the inputs to the amp from the deck, since the battery is in the trunk the power and ground will be right there as well.

i just got to figure out this aftermarket harness and figure out which wires are the constant power and speakers .... i don't need the illumination since the screen is powered off the main line. the yellow lead on my deck is for constant so i'm thinking i just match it up with the yellow on the harness.

trying to track down the company that made the aftermarket harness so i can get the diagram of the wires.

04-10-2008, 09:49 AM
the haynes manual was showing the antenna booster on the back window pillar on the passenger side i believe.

That's your C-Pillar, behind the other one should be your amp.

04-10-2008, 10:52 AM
nascar318is, did you do the hook up with the bmw amp or used an aftermarket one ?. if you used the bmw one do you know the wiring details at the harness ? i think i could just use that in the meantime and then if i can figure out the speaker wires then i'm set.

one question i have though ... the wires coming off the sony only have 4 speaker wires (2 fronts, 2 rear) so is it safe to put the mids and tweets on the same line for the fronts without it overloading anything ?

since i have the ground,power and constant figured out i guess i can't hurt anything really by touching the speaker wires together... they would either work or not work.

trial and error ...

04-10-2008, 12:59 PM
The way I helped Identify my wires, was by using a 9v battery, hook up a wire to it and you will hear a hum in one of the speakers, then you know that wire goes to that speaker, and the ground or positive wire is usually the same colour but with a stripe in it. I have a sony deck and bought a $12 harness too hook up from the Stock harness to the sony, plug and pray type deal. As for my amp, I left it hooked to my deck to help my mids and tweets and speakers. For my subs I ran my rca cables to the trunk to my amp.

As for the mids and tweets in your situation.. I don't think it will go over board, but you never know. Seeing it will be the amp powering the deck, then the amp fuses would blow(should) before anything else.

But like I mentioned before, after you install the harness from the stock to the sony and you do have a bmw amp, then it will work or should at least.

So start by installing the harness and see if you have sound, and then work on the Alpine amp.

04-12-2008, 12:52 PM
ok, spent the better part of yesterday afternoon tearing open my C-pillars and both sides only had the antenna amp. from the bentley manual it shows that the radio amp should be in my trunk. but i spent way too long trying to get the C-pillars back in correctly to check that out.

had a bitch of a time getting the deck in all the way ... had to cut out that piece that's at the back and trim off some of the side lip, but it's finally in.....

now i'm going to tackle the amp and see how that goes. funny thing .. when i had my door panel off and the dash apart the cops roll by and decide to come over and pester me about what i'm doing. after showing them my ownership and drivers license they tell me to take it to a shop and not do that stuff in the open as it catches peoples attention and then they get calls from people thinking i'm trying to steal a car ..... yeah because we all know that a car thief likes to remove stuff before making a getaway with your car. what a couple of retards .....

04-13-2008, 09:14 PM
Interesting about removing your C-Pillars. You should just be able to pop the light off and detach the wire to the light and then remove your C-Pillar, unless someone decided to put some cocking back there.

That's pretty funny about the cops(in a way lol)

Hope everything works out for ya with the amp.

04-13-2008, 09:22 PM
ok, i located the amp .... in the trunk. i have a question .... the original wires that ran to the back of the factory deck do they loop .... what i mean is even if the amp wasn't there would it still be powered off itself ?

cause i was thinking now that i have the sony hooked up. there aren't any speaker wires off the sony , the reason i need a separate amp ..... BUT i was thinking i could just use the wires coming off the bmw amp and run them over to the alpine amp i have and not need to run speaker wires since it looks like they run back to the speakers and then deck.

does that sound do'able ? or just run the wires myself and be sure.

just trying to look for some short cuts

04-14-2008, 10:20 AM
Running amps in Series or parrallel I have no Idea about. So I'm not going to give you any ideas and wreck something.

04-14-2008, 11:49 AM
i think i my have to run new speaker wires ... because there are no speaker wires coming from the sony harness .... just front and rear outputs for the amp. so i guess it's going to need to go to the amp and then feed the front and rear speakers.

i just looked and the wiring diagram and it's not some easy hook up. the way i was thinking i could have done it was like this :

i thought the speaker wires coming off the bmw deck fed into the bmw amp... then back out to the actual speakers. what i was wanting to do was tap into the bmw amp and use it instead of having to install the alpine .... but there doesn't look to be rca input/outputs on the bmw amp. it's all through the smaller wires. and after inspecting the aftermarket harness i only see the blue remote wire and the speaker wires that are left to hook up. so that blows my plan out of the water.

so i think i'm going to take the bmw amp right out and then strip out all the bmw factory wiring for the sound system and then run my own stuff so that there aren't any crossed lines.