My speakers cut in and out. When it’s damp they cut out, when it’s very dry they work. What’s the issue? When they aren’t working I get only one speaker and can’t hear the door locking chimes. When they work I get it all back.
My guess is that moisture is getting on the speaker cone and creating a path from one lead of the coil to the frame of the car grounding the speaker coil. Are the speakers in the door of the car? The drain holes in the door may be plugged up.
Are you sure the speakers are at fault and not the amplifier or other electronics?
I have a 2010 Cobalt which I believe is the same platform as the HHR. I’ve replaced the driver’s side speaker twice so far. This is the speaker used for the door chime and the turn signal. Today I was driving it and noticed the right front door speaker isn’t working. Use your balance and fader controls on the radio to determine which speaker(s) are bad.
Take the door panel off and check the speaker wiring to see if it’s loose or corroded first. I’ve had good experiences ordering from Crutchfield. I will check the speaker connections on the Cobalt before I order new speakers, besides a bad speaker I’ve had trouble with the speaker connections before.