The speakers are making a crackling noise that is not effected by the volume

Get a meter and check the resistance on the speaker. Looks like a speaker may be blown but with the description of the crackle noise from the slide controls you might have a bad pot in the unit or the pot has come loose from the board. This could explain why the speaker blew out

Try spraying switch cleaner into the volume control and working it from side to side. It sounds like it may be worn, dirty or corroded.

If the speakers are making a crackling noise at high volume yes, you need to take them in for service. The main problem that I have found to cause this issue is faulty instillation from the factory or using the system at a high volume with music. If it were me, I would send them in to Bose. They are a great company and will work with you to fix the issue.

Crackling is usally one or two things my guess would be bad grounding of the amp or bad connection with the jacks or plug it self try to make it crackle on purpose by jiggling the jacks see if it has any effect on the crackling try to narrow your possibilitys

I have a Korg C-15s and also experiencing loud crackling sounds when I turn it on. The problems seems to be either the sliding volume control or the amplifier itself. Honestly though, I believe the issue is the volume control. I opened my piano to get a closer look and attempted to clean the contacts on the volume. Unfortunately after cleaning the contacts, the crackling sounds became somewhat worse. After I turn the piano on, the volume control is generally rendered useless......volume set to low volume and the noise is quite loud and other times the volume control is set high and get very low volume crackling noise. No real consistency. The noise does diminish after a few minutes but so does the piano sounds to an inaudible level. There were a couple of instances where I turned it on and surprising enough, no no noise and perfect sound. For these reasons I believe the issue is within the volume control and not so much the amplifier. I have an electronics background and noticed that the volume control is very unique in design and is not something that can be substituted with another volume control from other sources.

My recommendation is to check the sound quality of the audio from the RCA L/R audio outs on rear of the piano by connecting to a stereo receiver. If it sounds fine you're in luck. If the crackling sound does not diminish after a few minutes like mine does, I would suggest disconnecting the internal speakers and using the audio out only. You can connect a pair of studio monitors or high quality computer speakers, preferably with a small subwoofer to deliver the full audio range and deeper tone of a real piano. I'm currently using a basic pair of Logitech computer speakers and is quite acceptable until I can afford a high quality set of monitors or relocate my piano closer to my high quality Yamaha receiver.

I hope this info helps a bit.

Crackling is an unusual noise but typically indicates a bad capacitor in the amplifier board. This can be a rather costly repair but first we will go through basic trouble shooting steps.

Reduce the volume on the sub and see if the noise remains and changes with the volume.

Unplug the sub and disconnect interconnect cables. With both hands push softly on the speaker cone to move it in, let it back out and do this a few times. If you hear a scraping noise and some resistance your driver is misaligned and you need to recone or replace the driver.

Check all your interconnect cables, there may be a bad internal connection (usually causes pops and cut-outs).

Let me know how things workout. If it makes the crackling noise at all volumes and the driver seems fine then I would seek a professional to repair it, or replace.

Cheers,

Kevin

there is some problem with the speakers or u have got some electromagnetic field near to your speakers.
try keepng the cabinet, mobile,or any such eqiupment away from the speakers . the electromagnetic waves created by these stuff effect the magnet in the speaker

Your speakers need replacing or you could turn down the volume till it stops and use it like that if it's not too quiet.

The horn speaker is wearing out. Inside speakers, there is a magnet, the speaker part is attached to a cone that slides over the magnet, They tend to make crackling noises. Try very gently to apply pressure to the horn and then release. If you hear a scratching sound, the horn will need to be replaced

firstly check the cable, some times it may in loose contact
otherwise any radiation equipment is located near by the amplifier,
sol. replace the location of the amp. and check cable loose contact

other wise
it is due to its amplifier IC problem, it is weak due to over load signal, or temperature of IC make leakage
sol.replace IC