Help hooking up the amp?

[Oldsmann 10+ year member]

Hey, my friend let me borrow his brand new jenson amp and earthquake sub because he doesnt have a car right now, i hooked it all up, and it appears to be correct to me, i have the red wire running to the battery, the ground wire grounded, and the blue wire running to the head unit, then i used the wires for the rear 6x9's and put that into the amp as channel A&B, then i have the "A Channel" on the amplifier running to the sub. When i turn it on, the sub moves but it doesnt make any real sound at all, my 3.5" speakers go louder right now, i tryed adjusting the settings but nothing happened, please help me, any ideas are appreciated..

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[Savant 10+ year member]

Does the amp support high-level inputs? Meaning, does it support taking a signal that is supposed to go to speakers, and amplified signal? Also, does the amp have a crossover built into it? maybe it's set too high and the woofer can't play the lows very well cause it trying to run mids and highs...?

Knowing the model of the amp might help (someone might know about that particular amp).. Knowing more about how the amp is hooked up would help too.. When you say the red wire is running to the battery, is it really to the battery or just on some power wire in the car.. maybe the amp isn't getting enough juice? Where is the ground wire grounded to, some ground wire in the car or to the body/chasis, etc etc...

make sure all your connections are solid and tight.. make sure the amp is ok with the high level inputs.. Oh, if there is no crossover in the amp, you speaker is definately getting a full signal (not just lows).. you will need to clean the signal before the amp (low pass filter or a crossover or somthing)...

Hope that helps..

 

[Oldsmann 10+ year member]

here is the amp... http://www.jensen.com/mobile/prod_mobile_yes.asp?product=129 im gonna go check everything out, if anyone has any other thoughts please let me know, thanks.

 

[Savant 10+ year member]

My guess is you aren't giving it enough power.. if you only have the sub hooked up to 'channel A' then you are only getting 50 watts RMS to it (pretty low).. You should see if you can 'bridge' 2 of the channels, you will get 150 watts RMS if you do that (according to the product description)..

Hope that helps..

EDIT: Oh, and make sure you have the crossover/filters set so that only low frequncies are going to the sub as well..

 

[Oldsmann 10+ year member]

i went out and bought some RCA wire to run from the HU to the amp, i hooked that up, now it makes no sound out of the sub, i should hook the wire up to the "Rear audio out" on the headunit, Correct?? then what should i hook it upto on the amp?? i know im doing bad at explaining this, its because i am new to this, so bare with me, also how do i bridge 2 channels??

 

[Oldsmann 10+ year member]

one more stupid thing, could a poor ground not let the sub make sound, because i am not sure if the ground i am currently using is that good, but the 'JENSEN' light comes on on the amp when power is being suplied... we grounded the ground wire to the hood hinge bolt. should that be good or should i drill a hole into the floor and ground it like that??

 

[Savant 10+ year member]

Originally posted by Oldsmann one more stupid thing, could a poor ground not let the sub make sound, because i am not sure if the ground i am currently using is that good, but the 'JENSEN' light comes on on the amp when power is being suplied... we grounded the ground wire to the hood hinge bolt. should that be good or should i drill a hole into the floor and ground it like that??

Where is the amp?? the ground from the amp should be as short as you can make it.. and yeah, if the ground isn't all that good you won't be able to flow the current you need.

The RCAs from the HU go to the input (RCA) on the amp.. It's a 4 channel amp so you might have to supply signal to all 4 inputs on the amp if you are gonna bridge it.. you can just get some splitters if you need to.. front to both front, rear to both rear.. if you only have one set of pre-amp outs, you will have to split the RCAs to all 4 channels... To bridge, you run from the + on one channel to the - of the other channel (one + and one - will be unused).. There should be something on the speaker outputs on the amp that show which posts to use to 'bridge'..

Hope that helps..

 

[mgaidica 10+ year member]

(not trying to make you feel dumb, but be safe and use a fuse if you dont have one) Make sure to sand off , or clean very well the grounding area.

 

[Oldsmann 10+ year member]

thats for all the feed back, i regrounded it to the body, i throughly cleaned the area i was grounding to, then i finally decided to check to see if the sub was working okay, i didnt even bother before all this because my friend said it worked fine, but the voice coil was blown, just shows you that you need to take the time to check everything out! god i feel dumb thanks alot though