installing amp with stock HU
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=41126
Printed Date: May 14, 2025 at 1:47 PM
Topic: installing amp with stock HU
Posted By: peterw244
Subject: installing amp with stock HU
Date Posted: October 18, 2004 at 12:37 PM
My friend Mike is getting Two Rockford P3s and wants to put them into a sealed enclosure. The only problem is that he wants to keep the stock HU for now, speakers the same b/c they are BOSE and it comes with an amp to that. my only problem is which Rockford amplifier would work the best for 800RMS and how can you go about putting this in? Thanks in advance.
Replies:
Posted By: forbidden
Date Posted: October 18, 2004 at 1:44 PM
What vehicle is this in? List the exact model # of the subs please. ------------- Top Secret, I can tell you but then my wife will kill me.
Posted By: peterw244
Date Posted: October 18, 2004 at 4:19 PM
sorry I forgot, its a 1995 Mazda Mellina, stock bose speakers and amp....wanting to put in two Rockford Model: P310D4 in an enclosure in the truck, need an appropriate amp and wiring to make it work right
Posted By: hurtado_roberto
Date Posted: October 18, 2004 at 6:57 PM
You can either wire them in 4 ohm or 1 ohm. I think amplifiers capable of running at 1ohm bridged are a bit expensive so you should wire them for 4ohm like this if bridged. 
You can also wire them in stereo; one on each channel like this to give you a 2ohm load. 
With these configurations you will need an amplifier rated at 800x1 @4 omh bridged RMS or 400x2 @2ohm. The newest Rockford Fosgate amp which provides this is the P8002. I have one of these but it's pushing a pair of pentagon sony's. It sounds too loud for me sometimes but I think I'm going to upgrade to P3 someday soon. I had last years model and it sounded pretty good as well (801s I think). You can get these from e-bay provably around $300. I bought mine from best buy because of their great extended 4-year warranty which is pretty liniant. If anything goes bad you can return it to them and they will send it to the manufacture and you can get a brand new amp. I hope this helped. I'm not too experienced but I generally like to match my subs brands and series with the same type of amp. I think they were designed with respect to each other and diffrent brands might under rate or over rate their products. ------------- Poly Dollies
Posted By: peterw244
Date Posted: October 18, 2004 at 10:02 PM
alright thanks a lot, also...I heard that you cant change the headunit that easily to aftermarket and do any rewiring because of bypassing the stock amp anybody have anything on that before i begin to take a look at the vehicle in two weeks. how to go about that
Posted By: boxmaker85
Date Posted: October 18, 2004 at 10:15 PM
Changing the stock bose to an aftermarket isn't easy but can be done. Hooking up an aftermarket amp to a factory hu is rather simple. Just check to see if the amp has speaker level inputs and hook it up (splice into the speakers' wire). If not get a LOC and splice into you're speaker wire and hook that up to the LOC and then that up to the amp. As far as amps: Kicker KX850.2 and the already mentioned rockford would be my first of choices. Good luck
Posted By: peterw244
Date Posted: October 18, 2004 at 10:20 PM
thanks, i appreciate the help
Posted By: stevdart
Date Posted: October 18, 2004 at 10:37 PM
You may need something like this PAC to add an amp to that bose stuff. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: hurtado_roberto
Date Posted: October 19, 2004 at 11:45 AM
Where is the best or usuall place to install a line output converter? Is it a good Idea to stuff it behind the HU?
------------- Poly Dollies
Posted By: peterw244
Date Posted: November 05, 2004 at 8:54 PM
if i do it like that bottom one, 1 (4ohm) sub=2ohm load, and in two channels how would you go about wiring the subs themselves? get 18ga speaker wire, wire both of the negatives wit neg n pos on the wire n going to negative on the terminal, wire both positives on the sub wit neg n pos on the wire then to the positive on the terminal?? please reply i jus wana make sure
Posted By: stevdart
Date Posted: November 05, 2004 at 9:31 PM
1 (4ohm) sub=2ohm load...................how would you go about wiring the subs themselves? . I could not understand what you just said... What do you have, one sub or more than one? Wire according to the diagram, coil A gets wired to coil B first. Speaker wire is fine, whatever you're using to connect the sub(s) to the amp After the coils are wired together in parallel as shown in the bottom diagram, then you connect a wire to one of the coil's positive and send it to the amp. The other wire connects to the other coil's negative, then to the amp negative. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: forbidden
Date Posted: November 05, 2004 at 9:35 PM
Correct, wire like diagram A if you have two 4 ohm dvc subs.
------------- Top Secret, I can tell you but then my wife will kill me.
Posted By: peterw244
Date Posted: November 06, 2004 at 1:23 PM
no i mean that if I wire it like diagram B, in two seperate channels.....then as i am doing the coils (dual voice coils), like positive to positive (on the sub)n then to positive on the terminal of the box using the speaker wire, I use the positive and negative wires of the speaker wire when connecting the coils rite? not just negative or just positive part of the speaker wire I may be a little confusing, sorry about that
Posted By: stevdart
Date Posted: November 06, 2004 at 7:26 PM
peterw244 wrote:
I use the positive and negative wires of the speaker wire when connecting the coils rite? not just negative or just positive part of the speaker wire
I see what you're getting at. Wires are not positive or negative. They are just wires. You would rip a speaker wire length along where the two wires are connected and use each one to connect coil terminals. Or you can leave them stuck together, it doesn't matter. A regular double speaker wire is just two separate wires with the insulation stuck together and marked for ease of installation. (Some speaker wire isn't marked at all and you have to check the ends with a meter to make sure...) ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: bumpingjeep
Date Posted: November 06, 2004 at 11:41 PM
hurtado_roberto wrote:
Where is the best or usuall place to install a line output converter? Is it a good Idea to stuff it behind the HU?
generally behind the headunit is fine...but in cases with bose amplifiers if you are using a normal LOC after the factory amp is where the signal needs to come from
Posted By: hurtado_roberto
Date Posted: November 07, 2004 at 11:59 AM
Connect all positives together and all negatives together. I'm not sure if an 18ga wire will sufice. What does everyone else recommen for wire size if it's a short run?
------------- Poly Dollies
Posted By: jeffchilcott
Date Posted: November 07, 2004 at 2:19 PM
I typically run 16 or 12 depends on how much power they are running
------------- 2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: peterw244
Date Posted: November 07, 2004 at 8:29 PM
yo guys, to run the remote wire..do i tap into the yellow ignition wire behind the HU and it'll work from there also..the line output converter has 4 inputs positive n negative for both right and left, coming out of the amplifier I saw I think 6 wires, im not sure which ones are what, wat should I do...or can you connect them to the 6x9s? (the LOC i mean)
Posted By: stevdart
Date Posted: November 07, 2004 at 10:47 PM
Yes, the yellow for switched. But I would check it with a meter first. Your LOC is a two channel, correct? Two of the wires have a stripe and connect to the negative leads, the other two are the positive. You can connect to either the front or rear OEM speaker wires, although I prefer the front connection in most cases.
------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
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