Weird Subwoofer Problem - Please Help Me!

[SnowCommando 10+ year member]

Searched hard and couldn't find a post with these symptoms.

Wired in the sub today and it just started acting weird.

4gauge power into distribution block. 2x 8gauge into 4 channel and mono amp.

Pioneer GM-D7400M mono amp into Kicker 8" sub.

Wiring seemed straightforward. + to + and - to -

The woofer didn't produce any sound and started pulsing in and out very slowly. The power indicator on top of the amp also pulsed with the woofer.

While I was trying to trace the problem, the fuse protecting the amp blew.

I have the ground wires from the Mono and a 4 channel amp meeting in a distribution block and then going to a ground point.

I have disconnected the mono amp til I know what to do.

Any help sorting this issue would be greatly appreciated.

Click to read more...

 

[fasfocus00 5,000+ posts]

i think you grouded the RCAs

 

[SnowCommando 10+ year member]

As in there is a split in the RCA's somewhere or the tips touched or are touching bare metal?

Are they screwed now?

 

[fasfocus00 5,000+ posts]

trace your RCAs and see if any are bare wire, if they are securely plugged in behind the headunit. also if they are plugged in behind the headunit if plugs are covered from grounding on something behind the headunit.

 

[SnowCommando 10+ year member]

How does that cause the amps power to fluctuate? And does that have a flow on effect to the sub making it pulse?

I like to understand the "whys" when I fix my screw-ups.

 

[SnowCommando 10+ year member]

Another detail that might help...

The manual for the mono amp specifies: Fuse (40A) x 2. Which I still don't really understand how you can fuse an amp twice at the battery. Anyway, I have a 100A fuse protecting the main 4gauge power wire at the battery, then a 30A fuse at the DBlock protecting the amp.

Is it possible the 30A fuse is strangling the power flow?

And what is the idea of 40A x 2?

Do I just stick a 40A fuse in the DBlock and that will free up the power?

Refer here: http://www.pioneer.com.au/Products/Car%20Entertainment/Amplifiers/GM%20D7400M.aspx for Instructional PDF in top right corner.

 

[iamamp3pimp 5,000+ posts]

hows the ground?

id run a seperate from the amp...sounds like a ground issue.

 

[fasfocus00 5,000+ posts]

Is it possible the 30A fuse is strangling the power flow?

And what is the idea of 40A x 2?

Do I just stick a 40A fuse in the DBlock and that will free up the power?

1. yes it is possible and probably is

2 is that 40x2 on the amp? if so that is the current draw of the amp

3 is your distro to different amps? if not just eliminate the distro block.

 

[SicAudio 5,000+ posts]

are you by chance running the amp at to low of an impedance? what vc does your sub have and svc or dvc?

 

[SicAudio 5,000+ posts]

if that sub is a 2 ohm dual voice coil sub thats the problem, your amp is only 2 ohm stable

 

[SnowCommando 10+ year member]

No, the sub is a 4ohm SVC. So that's not the issue and has been wired cleanly and carefully.

40A x 2 is shown on the amp wiring diagram at the BATTERY. The amp has two 25A fuses in it as per its specs.

And as for the grounds, can some clarify whether this thread: http://www.caraudio.com/forum/showthread.php?t=356580&highlight=ground+distribution+block is saying yes or no to the grounds going through a distro block?

 

[SnowCommando 10+ year member]

Well, mystery solved.

Got my hands on another amp to check the connections and the woofer.

It's the monoblock... it's a dud. //content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif

Anyway, off to the retailer to see what they're gonna do about it.

Thanks to everyone who chipped in to try and figure out the problem.