mtm1502 wrote:

Hello, I was just setting up a new pair of speakers when I plugged the source's RCA connectors into the amp while the amp was already on. This produced some incoherent static - nothing too loud as the volume on the amp was only at moderate levels - but I'm still concerned this could have been bad for the speakers. The speakers are so new that I'm not familiar with the sound enough to know if it has changed. Could this have caused damage to them?

Thank you.

If it wasn't too loud, damage is very unlikely.

Always make sure the amplifier has been off for at least one minute before making any change in speaker connections, and everything is turned down.

mtm1502 wrote:

Thank you for your response! The amp was just at listening volume so I don't think it would have been too loud.

Looking into it a bit more apparently RCA cables won't be properly grounded as they're being plugged in, which is what caused the sound. Does that change anything?

Exactly.

The center pin contacts before the ground, which can cause a huge 60 Hz hum to be sent into the circuit, which can cause a lot of damage.

That is why you ALWAYS want the power amplifier turned OFF for one minute before changing any connections. That gives the power supply capacitors of the amplifier time to discharge, so the amplifier has no voltage to run off of.