8 replies to this topic

[lebspec_liberty]

Hey im usually alright with this kinda stuff but ive ran into a problem.. in my gen2 liberty i have been running a pioneer head unit and a mono block fusion amp powering 2 12" fusion subs and the bass was really good and all.. but now ive hooked up another amp to run 2 6x9"speakers for extra trebble dont really want bass out of them. but connected the power and remote wires from the mono block to another amp which is a 2 channel and ive lost pretty much all bass out of the subs. tere is still a bit but only when it is up all the way i am using 2 different earths.. whats the best way?? use the 2 channel for the subs and the monoblock for the 6x9"? or have i just wired the second amp up wrong? another thing is when i have my head lights on i get engine noise and it doesnt happen with just the parkers on.. any explanation?? any help would be appreciated as its got me stumped as usually i could figure out some sort of solution.. thanks in advance

[Hypnotic]

how is it wired? what gauge power and earth cable are you running? how many rca outputs from the back of h/unit? using the mono for 6x9's will not work as its only a single channel amp thats designed for low frequencies (subs)

[Delete This Account]

fusion subs

Theres your problem




You shouldnt run the power for the 2nd amp off of the 1st amp, it should be wired to the battery as well

[lebspec_liberty]

so if i ran a second power wire through the car the problem should be fixed?

[Delete This Account]

Yes, connect the 2nd amp straight to the battery, this should stop it stealing power from the 1st one

[SUBARU]

It would really help if we knew what gauge wire you are running and wheree your power and signal wires are running through the car.
Quite frankly, that setup sounds like a bit of a dogs breakfast.

Running 2, 12 inch subs off a monoblock isn't ideal, but it will work in a haphazard way, but will sound kinda messy. As stated, don't splice power from one amp to the other, the second amp will suck the first one dry. You need to have a direct power source for both.

Run at least an 8 gauge power wire from the battery to the amps. Run these power wires down the right hand side of the car.
Next run your remote wires from your HU to the amps down the centre of the car, along with your signal (RCA) wires. Does your HU have seperate RCA's for your sub and for your 6x9's?
If you run your wiring this way, you will have minimal noise interferance.

Now, as for the alternator whine when your lights come on.... This is something that Pioneer HU's are known for. They have a bad earth on the RCA outputs, which runs down the signal cable and through your speakers.
To test whether this is the problem, start the car, turn on the stereo and the lights and then unplug the RCA's from your amps. If the whine goes away, then your problem is most likely a bad RCA earth. If it stays, there might be a problem with the grounding of the HU itself.

In order to fix this you need to do two things:
1. make sure tht your HU is properly grounded. Quite often grounding a HU to the OEM ground wire is not enough.
2. Ground your RCA outputs. It's a bit of a ghetto looking fix, but it works and is recognised by Pioneer as a remedy.


BTW, there is no need for 6x9's if you are already running two subs. If you are after more mid range and highs, you'd be better of getting a good set of splits. Come to think of it, there is no need for 2, 12" subs. Your car isn't massive and doesn't require that much bass.

I'd recommend doing away with your two amps and just running one 4 channel amp. Run one 12" sub from bridged channels on the amp, leave the rear speakers connected to the HU and then run some nice splits up the front off the other two channels on the amp. That will sound so much clearer and responsive than the current
You can get ground loop connectors to "fix" the problem, but it's only a band aid fix.

[lebspec_liberty]

Thanks "SUBARU" big thelp there and yeah im already running 8 gauge wire and the power wire is going down the battery side of the car and the other 2 are goin down the other side i know all the basics just wasnt 100% sure how to wire up the second amp but its all good now cheers.. ill give this a crack on saturday and hopefully ill have the system set up to how i want it.. oh and the monoblock amp actually came suited to the 2 fusion subs in the same box so it sohould be addequate for the application.. ill let you guys know on how it goes

[alexGT]

+1 for getting rid of the 6x9's. if you already have a sub then just get a decent set of splits for the front and some rear 6". 6x9s are an attempted "all round" speaker.

[lebspec_liberty]

hey guys. the new power wire worked a treat and so did earthing the rca outputs behind the head unit thanks for the help..