subwoofer cracking and popping noise

[jimboraver77]

hi all, been having trouble with my subwoofer, as in it makes a load cracking and popping sound, this happens randomly so is very intermittent and annoying. Any suggestions would be appreciated thanks. james

 

[Karadjgne]

Usually indicative of voice coil burns at specific areas. Any higher demand in that frequency resulting in cracking as it basically shorts out the coil.

 

[jimboraver77]

Usually indicative of voice coil burns at specific areas. Any higher demand in that frequency resulting in cracking as it basically shorts out the coil.

sounds terminal ! thanks for your reply though, would this also happen when the sub isnt receiving a signal, ie, when only the power is turned on but no audio signal ?
thanks

 

[Karadjgne]

No. The coil is a mile of copper wire wrapped by a huge magnet. When you send a deliberate signal to the coil, it moves in response to the magnetic field produced. Without a signal, the coil doesn't move as there's no frequency to make it move.

If the speaker is emitting cracks/pops without a signal from the deck, then there's something else interfering and creating a signal. Usual suspect is a bad ground on the amplifier creating backfeed, abraided/ungrounded/unshielded signal wires allowing certain frequencies to enter etc.

Usually it is a burned voice coil, but only usually. Sometimes it is something else. Check all wiring, move any signal/speaker wires away from power cords etc. If it's a household powered sub, check the outlet it's plugged into, the plug should be tight, not loose to plug in. Check the deck power outlet too.