Should I worry if the speakers crack/pop everytime it's powered on or off, even if it's not connected to the PC?

I thought it was normal for them to do that.

well mine makes noises (thats not the music playing) when ever its on, when you adjust the volume and when you throw it on the floor with rage.

My old (and first and only) speakers don't, lol.

It (probably) won't hurt anything, aside from your ears. Of course, it also depends on what sort of speakers you have - if they are $40 cheapies, don't worry.

It's not.

Well, it was on the discount rack, lol. I guess I have nothing to worry about...

You tend to get that with cheaper speakers.

Basically (and I'm not a technician or electrician) the problem arises when power / a signal is fed to the speakers when you turn them on - that initial jump is the cracking sound you hear. As Dr D mentioned, it happens a lot more with cheaper speakers.

Its most likely due to an influx of current (electricity). Too much current will cause a sound distortion. Cheap speakers won't account for the spike in current when power is connected (or disconnected). More expensive speakers and sound systems usually have something to dampen the current spike, for example a capacitor and/or discharge relay.

This can also happen when a connection is loose (or not completely seated), for example when inserted a headphone or line-in plug it will cause a sound distortion until the jack is completely seated in the jack.

This power spike can damage the electronics within the sound system over time.

The audio equipment world relies heavily on good design (especially car audio) so its certainly not uncommon to get weird noises or something from cheaper equipment.

The CPU and other equipments won't be harmed?

Will it be better if I just leave the speakers constantly on. (I would have done so sooner had it not for the irritating LED lights that cannot be disabled without powering the whole speakers down.)

I've got some cheap speakers and they 'pop' every time I turn them on, it's happened with all the cheap one's I've had.

No, not your CPU. I meant components inside the speaker (for example: transistors, resistors, capacitors, etc...) may be damaged. Any "dirty" power will be cleaned before it gets to the CPU, that's what the MOSFET array is for... Now this array won't protect against everything. The only thing at any risk would be the audio chipset (or a front panel I/O), as its directly connected to the speaker.

I didn't mean to worry you. The spike isn't that great (usually). Just trying to state that cheaper speakers usually wear out faster.