Sub and amp problem

[brodie2906]

If someone could help me with this would be much aprreciated, so basically i've got 2 kenwood subs in a box and im trying to run them off a sony xplod 4 channel amp. I've connected the 12v+ and ground no problems there, and even the remote to my pioneer head unit, thats all fine the amp is receiving power fine, even the rca's are connected fine. I've attempted to connect the speaker cables from the subs to the amp but nothing, no sound or pulsating, before you all say there could be problems with the subs I've checked the subs by connecting them to the pos and neg from the power and they pulsate so there no problems there? also theres no problem turning the amp off and on on the headunit, I just cant figure out where i'm going wrong, earlier when I was playing around with it the offset light came on if that helps? Maybe im doing something wrong anyone know? :S

 

[not260]

Hard to tell without seeing it, some times you need to turn the pre outs on, on the head unit. Have you got dvc subs and wired them like single coils. You sure everything works. You may have to mess around with the gain/input level. You sure you've plugged the rcas in to an output and not an aux in?

 

[not260]

Plus be sure you've got a good earth.

 

[brodie2906]

Thanks for the reply my old sub had a built in amp so never had any of these problems but didn't have to do anything with the head unit, although I did find a function menu on there with settings but that didn't do it. I think there dvc but could you give me more info on how I should be wiring them? Everything seems to be working is there any more ways to check? Ill have a play around with the amp settings tomorrow, but the amp has 2 white right rca's and 2 red ones I've tried all of them but no luck so far mate, will let you know how I get on tomorrow.

 

[Dink]

you might need a y adapter for the rca cables as you will want to bridge the output to give you 2 bridged outputs

also you never want to apply anything more than about 1.5v dc (i.e an AA cell) to a speaker as you can push them way past their Xmax

is the an option on the head unit to switch off sub output?

as for wiring you would need to know the voice coil impedance to find out how to wire it

 

[l33th3tr33]

As said, make sure you have a good earth, don't just drill a hole and screw it down.

Are the subs definitely connected to the inputs on the box? And the right way round?

 

[not260]

You will need to know the impedance of the subs, probably best to take one out and flip it round. If you've only got one half of each coil wired it won't work.

As as pointed out above could also be RCAs in the wrong place at the amp end. If your amp is stable at lower impedance there could be better ways to wire it.

Running 2 subs off separate channels usually doesn't work well, one always conflicts with the other.

 

[brodie2906]

you might need a y adapter for the rca cables as you will want to bridge the output to give you 2 bridged outputs

also you never want to apply anything more than about 1.5v dc (i.e an AA cell) to a speaker as you can push them way past their Xmax

is the an option on the head unit to switch off sub output?

as for wiring you would need to know the voice coil impedance to find out how to wire it

I have a y adapter at home somewhere but cant understand how that would help, There are sub control options on the head unit but there all switched on fine mate. I'm fairly new to all this so how would I find out the voice coil impedance?

As said, make sure you have a good earth, don't just drill a hole and screw it down.

Are the subs definitely connected to the inputs on the box? And the right way round?

The earth is fine mate used it for my old sub no problems there, its earthed to my back light there a good earth point there. I checked the subs and they are connected fine to the inputs on the box and pos and neg are in the right places.

You will need to know the impedance of the subs, probably best to take one out and flip it round. If you've only got one half of each coil wired it won't work.

As as pointed out above could also be RCAs in the wrong place at the amp end. If your amp is stable at lower impedance there could be better ways to wire it.

Running 2 subs off separate channels usually doesn't work well, one always conflicts with the other.

Could you explain how I would check the impedance for the subs? and how would be a better way to wire the amp? I'm going to take a picture of my amp so you can see and help me get it wired up correctly.

 

[l33th3tr33]

I'd move the earth from the light, mine had a s**t connection there and the sub didn't work until I relocated and made a decent earth point.

 

[brodie2906]

Theres the picture of my amp I tried my best to get a clear one, am I wiring it correctly?

 

[brodie2906]

I'd move the earth from the light, mine had a s**t connection there and the sub didn't work until I relocated and made a decent earth point.

No mate theres no problems with the earth, I rawed my contact point earlier and its got a good earth.

 

[l33th3tr33]

The lines above the speaker connections shows how to bridge them. I'd get some thicker cable for the subs as well IMO.

 

[Dink]

where is the other sub connected?

i'd connect both rca's to the white ones on the amp (think it says BTL in brakets) which is short for bridge tied load

then connect a sub on either side also marked BTL as shown by l33th3tree

set the filters to LPF and the dial screw so it's at about where 80Hz would be then set the level to min and low boost to 0dB

then try and see if you get anything out of the subs

 

[brodie2906]

Thanks guys for the help much appreciated ill give it a try tommorow and see where i'm at.