View Full Version : Subwoofer 'motorboating'

06-09-2014, 04:12 PM
I think the truck has it out for audio and does not want any type of audio in it at all :-\

Recently (as in the past 3 months) the subwoofer has been acting strange. It's not fast, but whenever I turn on the truck and the head unit comes on (either ACC or engine) the subwoofer pulses like a heartbeat in & out about once a second for 5 seconds then it stops. I get no audio out of the speaker at all either.

As far as diagnostic, I've disconnected both RCA's from the amplifier. Turned the truck back to the ACC and it does the same thing.

I haven't had any time to diagnostic test it at all. I'm thinking it may be a bad ground or signal wire? Amp in question is a MTX6152

06-09-2014, 06:47 PM
It is picking up interference.

david in germany
06-12-2014, 02:08 PM
Sounds like the ground is loose. make sure the contact is clean and tight.

06-12-2014, 04:13 PM
Haven't had time to look at it again :( Damn life..

Anyway I was at the DMV yesterday and sure enough, it started working again but then cut out. I'll dig into the wiring this weekend when I'm under there (I ran the ground through a grommet to the frame rail).

The Captain
06-15-2014, 11:16 AM
http://www.celicatech.com/gallery/files/5/7/2/1/motorboating-o.gif (http://www.celicatech.com/gallery/showimage.php?i=23811)

06-16-2014, 01:56 AM
Could be. Though it honestly sounds more to me like the driver is getting pushed a DC signal. May be that the source for the power was not drawn direct and fused. Also could be an amplifier issue.

But yeah, check grounds first. Always have a solid ground.

06-16-2014, 06:28 AM
My vote is for ground. If it doesnt go away by RCA disconnection, the unit is either generating that noise as it charges up its capacitors and shit, OR its picking it up by improper ground.

If you dont fix it soon, that type of shit could damage both the amp and the sub.

david in germany
06-16-2014, 08:47 AM
Haven't had time to look at it again :( Damn life..

Anyway I was at the DMV yesterday and sure enough, it started working again but then cut out. I'll dig into the wiring this weekend when I'm under there (I ran the ground through a grommet to the frame rail).

Why not ground it to the body? When you send it to the frame it is exposed to the elements and corosion can/will happen. Find a good solid point like a seatbelt mount or something similar. Also make sure your engine to body grond is in good condition as well as body to frame.

06-16-2014, 05:14 PM
I checked the ground wire again. The ground wasn't exposed to any elements (up high enough & behind shielding). I pulled it off and re-attached it to the seatbelt bolt after removing all paint from the contact points and tried again. It worked fine. Took a quick drive down to the parts store to dump some oil and came back with it working all along.

This morning I jump in to drive off to work. Nothing. I feel the speaker moving in & out until it slowed down to a stop. I pulled the fuse and once I arrived at work I turned it all off, put the fuse back in, disconnected the RCA leads and turned it back on. It did the same thing (slow pulse). I'll move the woofer leads to the other one (it's bridged right now) and see if it does the same thing.

06-17-2014, 04:35 PM
All has been tried..and no dice. I'll head in to the store and get something new after they test it.

06-17-2014, 06:34 PM
Power issue with amplifier.

We had a tower subwoofer do this. It was powered, and the power supply went bad, making it pulse loudly. Eventually it stopped making sound, and just moved in and out. Test your amplifier.

david in germany
06-18-2014, 09:14 AM
What amp are you running?

06-18-2014, 03:40 PM
Pioneer 10" with an MTX 6152 in bridged mounted to box.

06-19-2014, 12:49 AM
Dont mount your amps to your boxes without dampening them first guys. The vibrations can kill circuitry. Ill bet you have rattled something on the mainboard and you have a dry solder joint. Ive seen it happen several times before.

The Captain
06-22-2014, 01:03 AM
Amp is toast.

06-26-2014, 05:29 PM
Could be Amp, could be out of phase as well. did it ever work? if so, did you ever disconnect wiring at any time? if so, check phase.
easiest way would be to only hook up one speaker, does it work? Yes, unhook, check other speaker, does it work? Yes, hook both up but put one pos on neg and vice versa on only ONE sub. Does it work? Yes, out of phase.
hope that makes sense.
it happened to me when I swapped out sub boxes, some assclown hooked up the terminals internally wrong. Both subs would move but no sound (very low). Swapped the pos and neg terms on one speaker and just about went deaf until I turned the deck and amp down :)

Oh almost forgot, check your ohms as well if it is bridged. make sure you are within limits of your amp depending on how your amp works for speaker hook ups in bridged mode.
My MTX was setup like + - - + instead of + - + - (I don't use this amp anymore). My Infinity is a mono amp but has 2 sets of + -. In the end I think I ran it in parallel only using one set of + - terminals and out of phase for the 2nd sub in the box. God what a nightmare day that was trying to figure out what the hell went wrong LOL.
Good luck!

06-26-2014, 05:54 PM
It was working just fine for a while. Not sure when it started freaking out to be honest. I'm starting to think maybe it was rattled to death. I had it on when I was driving out to go 4 wheeling with the quad. There's only 1 speaker attached to it. I'm pretty sure it's toast though. Never messed with the power to it. I'm going to take it into a shop to have it tested.

I've been browsing new amps and I am liking the Kicker CX3001 amp paired with the Kicker 10" in the box.

06-28-2014, 04:51 AM
infinity basslink. Will suit your needs pretty well from what David says about them. And you're in a truck, so yeah, use that option. Cheap+Reliable = WIN

david in germany
06-28-2014, 06:32 PM
Yes, I have both round and square versions of the Basslink in the garage. Both are VERY capable but the Square version aka Basslink ii is a more versatile setup.

Sent from my iPad using Tapatalk HD

07-07-2014, 03:53 PM
Went out over the weekend and got a great deal on some Kicker equipment. Picked up the little CX3001 D amp and some 5.25 speakers for the rear (one of them is blown). Threw it all together and it sounds great now. Only problem I have now is windows up = no bass. Windows have to be at least 75% down to have the subwoofer work. Opening the doors and it works amazing.

07-08-2014, 01:07 AM
pressure differential bro. lots of installs have that issue. Nothing to stress on. At least it works now. Did you use a new source to pull power from? (Like direct with an inline fuse I hope ;) )
If you don't have any Vdrop issues or odd behavior, then I am happy if you're happy.

07-08-2014, 02:37 AM
Using the same power feeds and everything. Nothing is different aside from the amp. The power is a direct feed off the battery with a fuse 8" from the battery. I replaced the ground cable with a new one and cleaned up the ground, that's about it though.

This pressure differential thing blows ass though. Windows down in AZ summer monsoon season really isn't an option :-\

07-09-2014, 01:14 AM
Try aiming it in a different direction. Not joking.

And the reason for it is that being in such a small cabin, there simply isn't room for the wave to develop.

Try the aiming thing and see what it does for you.