Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Sub broken?? Or is it the Amp? What's going on?

jazza15

Jarryd
Joined
Jun 3, 2008
Messages
511
Reaction score
5
Points
18
Location
Eltham North, VIC
Members Ride
1999 VT II S
So I've been having a problem where the rear parcel shelf speakers and the Sub randmomly cuts in and out (doesn't seem to have anything to do with frquency).

I bought my car with this system already installed. It has tweeters, all door splits, the parcel shelf speakers and the Sub all upgraded/installed. All running through the amp. So i don't know a whole lot on the matter.

So checked the wiring and it seems fine. Today I disconnected the Sub and the rear parcel shelf speakers no longer randomly cut out (and back in again).

So my question is what's going on there. Does the problem lie in my sub? They are usually working or blown (not working) aren't they. Is it the amp? Settings?
I switched it (the amp) to 'full' after d/c the sub and testing, which didn't really seem to make a difference but the guy (who wired it up) i bought it (the whole car) off said to do that if i was gunna d/c the sub.
 

holdenboy

Custom Car Stereo Systems
Joined
Aug 31, 2008
Messages
2,330
Reaction score
16
Points
0
Age
39
Location
Nelson Bay NSW
Members Ride
VR Wagon
So let me get this straight...youve got the front speakers (splits), rear speakers and subwoofer running off the amp?

Could you provide the model number / brand of the amp? Unless its a 5 channel amplifier then the amp has been wired up wrong. You cannot run 5 speakers (be it speakers or subwoofers) off an amp that has only 4 output channels. Hence the reason why when you disconnect the subwoofer the speakers work fine, by the sounds of it your amp is going in and out of protection.

You have a few options here......you could disconnect the subwoofer altogether and just keep the fronts and rears connected, disconnect the rear speakers and "bridge" the rear channels to run the sub and run the rear speakers off the head-unit. Your only other option is to buy another amplifier / wiring kit and use this to run your subwoofer.....leaving the other amp to run your speakers.
 

jazza15

Jarryd
Joined
Jun 3, 2008
Messages
511
Reaction score
5
Points
18
Location
Eltham North, VIC
Members Ride
1999 VT II S
OK, so I went an had a decent look at what wires were going into and out of the amp.
The amp has the rear parcel shelf and (had) the sub speakers running out of it. Which means the tweeters, front splits and rear splits are running from the head unit.
Previous owner did mention that protection mode, showed me how it works by progressivly turning the stereo up until the speakers cut out. However this problem started occuring this year. I got the car early last year. It happens regardless of volume.
Some details of setup:
Amp is a Power Acoustik (PA 400)
Rear parcel shelf speakers are Sherwood 6X9's 160W, 4 ohm's Impedence
Sub is a Cobolt 400W
 
Last edited:

holdenboy

Custom Car Stereo Systems
Joined
Aug 31, 2008
Messages
2,330
Reaction score
16
Points
0
Age
39
Location
Nelson Bay NSW
Members Ride
VR Wagon
The protection mode shouldnt just "come on" at a certain volume level....its there to protect the amplifier from killing itself.
The amp has definately been wired up wrong (too many speakers running off it), and has more than likely caused damage to the amp or protection circuit over that period of time.

If the amp works fine with just the four speakers connected (not the sub) then leave it like that.....or do as i said in my first post.
 

stated vr v6

New Member
Joined
May 18, 2009
Messages
20
Reaction score
0
Points
0
Members Ride
vr statesman
Protection mode should not come on till ya have it cranked up or in really bad heat, other from that it is wired up wrong just like holdenboy sez
 

holdenboy

Custom Car Stereo Systems
Joined
Aug 31, 2008
Messages
2,330
Reaction score
16
Points
0
Age
39
Location
Nelson Bay NSW
Members Ride
VR Wagon
Protection mode should not come AT ALL, unless you have a major problem, regardless of the volume level......the speakers should distort badly before protection kicks in.
 

jazza15

Jarryd
Joined
Jun 3, 2008
Messages
511
Reaction score
5
Points
18
Location
Eltham North, VIC
Members Ride
1999 VT II S
So i have looke dinto the problem more. Pre-tinned the sub wires just in case they were going a bit dodgy.
I think it's a 4 channel amp (PA 400), with the rear parcel shelf 6 x 9's bridged? across 1 & 2 and the sub across 3 & 4.
Now aross to the other side of the amp and, this is were i did all the fiddling.
I currently have the sub crossover on 'low' (as opposed to 'full' or high') and the rears on 'full'. Now both have a min to max knob, with the rears being at min and i think heres the problem, the sub not being able to operate much past min.
Now originally, (or unless i fiddled with this knob, not noticing what I've done andf then 'why do I have a problem?') the sub crossover knob thing was set at about half way between min and max, which was a good level for it, otherwise the rear speakers overpower it, volume wise.
Now for the amp to operate without the power light turning off (cutting out) i have ther knob turned to about half of what it used to be at (half way round). I'm sure on a song with some 'kicking bass' it could be even less, but didn't have time to be changing music. If it cuts out, it is at the low frequencies that the sub uses, bot the full/higher freq's that the rears use.
So what is wrong?
I have read all of your responses, a lot being 'it's wired up wrong' but I previously never had this problem before. Haven't fiddled with the wiring up until now and I'm sure i put it all back the way it was.
 

holdenboy

Custom Car Stereo Systems
Joined
Aug 31, 2008
Messages
2,330
Reaction score
16
Points
0
Age
39
Location
Nelson Bay NSW
Members Ride
VR Wagon
Do you have the front speakers running off the amp, or is it just the 6x9s and the subwoofer?
Might be an idea to take a photo of the amp wiring and point out which wires go where.
Also in the pic get the size of the wiring cable used for power/earth.

In all honesty mate the gear your using isnt the best of quality, which may be half the reason why your having troubles.

But just take a pic of the amp wiring and get back to me. Filters and gain settings a irrelevant at the moment untill i can verify that the wiring on the amp is up to scratch.
 

Jaso88

New Member
Joined
Jun 1, 2009
Messages
2
Reaction score
0
Points
0
Location
Wollongong
Members Ride
VS V8 5 Speed Ute
if the wiring wasn't write than bits and peices wouldnt work at all
electricity flows if it can and doesnt if it can't
i'd lean towards dodgy connections possibly causing too much resistance in the circuit
or the amp is just getting too hot, whether it be from use or positioning
 

camstatic

I'm back babeh.
Joined
May 19, 2006
Messages
327
Reaction score
4
Points
18
Location
Regional SA
Members Ride
VZ SS
Just something worth checking into:

A lot of older/cheaper woofers have a problem where if you use them aggressively, over time the tinsel leads:

can wander away from their usual position, and begin to earth out on the frame of the woofer at higher volumes, forcing even the most solid amplifier into dc protect mode or worse.

Definitely worth checking in to.

6x9s running off of channel 1/2 would be fine on 'high' filter, sub bridged on 3/4 running on 'low' filter, then adjust gains accordingly.

Good luck. :)
 
Top