cobymedic

This thread should be moved to the how to section. I think alot of people wod find this very usefull. Great job!

Black Betsy

It's been awhile since this was posted so I'm not sure I'll get any response but I've got a question for the OP or I guess anyone really who has done anything like this. I'm putting pretty much the same setup in my truck, but it's been about 15 years since I've done this so I'm a little foggy on some things.

My question is how is the sub run on its own channel when there are only RCA inputs to the amp for the front L&R and rear L&R speakers? My amp has gain adjustments for front, rear and sub but if the sub has no input to the amp from the HU, how can it use its own gain adjustment and channel? Like I said, it's been awhile so I could just be missing something here but any help would be appreciated.

jbone14

Old thread but im just reading through now. The radio turns on via Can-Bus

Black Betsy

OK so I've made up a little diagram so you can see exactly what i'm asking. I realize it's pretty basic and doesnt have everything on it but it pretty much shows what i'm trying to figure out.

After watching the OP's videos a couple times, I will be doing everything exactly the same, aside from using an LOC to convert the door speakers to RCA's going to the amp, instead of the RCA converters he used. From watching the videos, he does not have an RCA going to the amp for the subwoofer inputs. He runs the two RCA's from the harness for all 4 door speakers and has each of the 4 door speakers running off a separate channel on the amp. Then talks about running the 5th channel to the sub, but never mentions an RCA to the amp for the input.

Does anyone understand what i'm talking about? Like I said, it's been a while since i've done this but this isn't making sense to me.
Thanks

jbone14

The amplifier takes the the stereo input and internally sums the signal for a sub output. You don't necessarily need a sub input into the amp so don't worry. What amp are you using? Make sure it gives you the ability to use input A/B as sub input.

Black Betsy

Thanks for the reply. The amp I'll be using is a Rockford Fosgate Prime. R600-5 is the actual model I believe. The reason I ask is because it has separate gain and other adjustments for the front and rear speakers and for the sub. My concern was that with no input, I would lose functionality of these adjustments for the sub. I'm not sure what you mean by A/B inputs.

jbone14

A/B inputs are simply a "label" for left/right - front/rear RCA inputs on an amp. The Prime is an entry level amplifier and does not have the ability to use the Front/Rear RCA inputs for internal summing to output to the sub channel. It also does not show anywhere in the documentation that there is any internal summing. Your solution would be to use an RCA splitter from the rear rca output of the headunit and use that to get your sub input to the amp. My brain is working a little slow today as I had an incredibly busy morning lol so I cant think of any other method at this time. Most mid-level and even entry level amps have the option to use A/B inputs for the sub but there's always an odd duck! Great amp for the price though to say the least.

93Cobra#2771

iTrader: (2)

Nice vids!

Black Betsy

Thanks man. Never thought of using an RCA splitter. I'll probably use it at the amp instead of the HU just so I don't have to run an extra set of RCA's to the back. Yeah it's a cheaper amp. I wasn't looking to spend a ton of money. Just gonna throw 2 pairs of Polk db571's in the doors and run a 10" sub under the back seat. Should be around $600 all said and done and will sound a hell of a lot better than stock. Thanks again for the help.

jbone14

Heck yah, that will be an awesome system! Also I agree to split at the amp as its always best to have the shortest run possible when splitting.