Ever hear the "Maggie Scream"?


Ok, so I got a bit dramatic in my title. However, the phenomenon is real. It's happening to my Magnepan 1.6's, which are biamped at 200 wpc. So, 400w into each speaker.
When I power down the system, about 20 seconds later, there is a pronounced, but not loud, electronic sound, which starts out high pitch and slowly drops until very low, then dies. Like the speaker itself is powering down.
The sound is from the SPEAKER (I know someone is going to say, 'are you sure it's the speaker, and not some other piece of electronics?') Has anyone else encountered this phenomenon, and what is it? Is this the amps powering down?
I'm assuming I'm not hurting the equipment this way; I've had this sound in the speakers for months.
douglas_schroeder
It's the amp some "scream" some make a soft thump and some are quite. And unless it's very loud it's nothing to worry about.
I UNPLUGGED THE SPEAKERS, AND THEY'RE STILL DOING IT! THEY ARE POSSESSED!!!! HAHA maybe that would be true if they were Polks!

Everyone, thanks for your input!
I should have mentioned, the high to low pitch sound is quite soft. Not remotely close to the "tearing speakers in half" problem mentioned above. In fact...it's almost cool!

It makes sense that it's the amp discharging, since with many amps you get a similar effect; kill the amp while music's playing and the music fades away.
Here's the interesting thing. With the Outlaw 5 channel, when I used only two channels (200 right speaker and 200 left speaker) there was no "scream", but when I biamped the speakers, doubling up on wattage, they made the sound.
Possibly the amp still discharged, but since the power was low enough, it was inaudible until I doubled it?
Now, about that alien "beep" sound the Rega Planet 2000 makes...