Probs with farting/squeaking sub

[Batesyboy]

OK - got a problem with my new setup; Im getting a farty noise from my sub (only really noticable at low volumes).

Got an Alpine headunit/MRD-M300 digital mono amp and 10"sub box. I can alter the noise by altering the Subsonic filter from 200Hz (sub farts) to 30Hz (Sub squeaks).

Think my earth is OK. Only thing I can think of is that Im using the central core of my phone leads (part of a kit) as the remote turn on for the amp. Ive considered removing this and linking the +12v to the remote on connector but dont know if this will damage anything.

Anyone got ay ideas? Mail-order company said its unlikely to be a faulty amp, more likely a dodgy RCA or maybe the sub pre-out of the head unit.

Dont really fancy taking the dash out again but might have to!

 

[Tom]

try

changing the phaze on the amp

what sub is it (this helps trust me)

 

[Batesyboy]

Ive tried this, both on headunit & amp.

Sub is an Alpine SWR-1041D Type-R 10"

Its really embarassing!!!

 

[Tom]

might be the box is it sealed up properly

 

[Batesyboy]

Yeah... when I alter any settings on the amp (ie press a button) it momentarily stops until the new settings kick in.

Flumoxed.

 

[Tom]

i have this problem when my boot is open

but when its shut its ok

strange

 

[Batesyboy]

Wheres your earth point then? Maybe we both have dodgy earths?!

I drilled a hole and am using star washers to break the paint... might need some sanding or something? Maybe your earth is better when the boots shut?

Jeeze what am I on about; Im talking sh1t... must be tired - hometime!

 

[Tom]

my earth is the bolt ont that brace thingy in the boot

 

[Colin_S]

The sub is not sealed inot the box properly. There is nothing else that would cause those type of sounds.

 

[coolspot007007]

Mine did this, i took it out of the box, used fibreglass filler around the face of the box and in the screw holes.Then i sanded it flat, then applied some tiger bond (spoiler/panel adhesive) all round the edge and screwed it up tight, problem solved.

 

[Flying Scotsman]

Firstly, check that you are not over driving the amp input causing distorsion, failing that secondly check the speaker in your sub box is not mechanically distorted, causing the voice coil to rub against the magnet. Try running the sub woofer speaker at the same low volume when it is removed from the sub box. If the sub box mounting face is not true then it could flex the speaker frame. Thirdly, try running the sub woofer from someone elses known source. If the problem is the same, the speaker is goosed!

 

[Batesyboy]

Thanks for all the tips but... just had the amp & sub out and powered it up on a bench at work and it still farts even with no source attached!!

Talked to Alpine UK and they said its definitely effyouseekayed and to return it to the dealer (whos also agreed to it).

When I phoned Alpine they put me through to a guy whos done "lots of testing on the MRD-M300" which suggests to me theyve had some teething problems with them. He didnt seem too surprised at when I told him the problem.

Thanks guys... keep you informed as to progress!