Popping sound on power down.

I was wondering if anyone could shed some light on this issue. When I have my stereo on and working fine, and power off the vehicle and then once I open the doors as my stereo has the delay or until a door is ajar it shuts off. Once it does shut off the speakers give a horrible POP and then all shuts down. I have rewired the amps and checked the cables but I think its something to do with the Amp. This is my thinking since the deck powered speakers when used do not do this annoying POP. Anyone have an idea??? Thanks Alpine 7830 HU-4X100 W McIntosh -2X110 W McIntosh-MB Quart Q's Mid Tweets-4X10" Phoenix Gold Subs-Phoenix Gold EQ215ix-AC Epi-PG Line Driver-Phoenix Gold 1 Farad Cap -Clifford Avantguard 4-2 Ear Plugs

I have not installed the subs as of yet since I am still fibreglassing the box. I HAD this all installed at one point working perfectly until I decided to do some fibreglassing in my trunk area. Now the popping is here. I think the suggestion of the relay would be a good one. Do you know what size of a relay I would most likely use best? Thanks for your quick reply prior.Alpine 7830 HU-4X100 W McIntosh -2X110 W McIntosh-MB Quart Q's Mid Tweets-4X10" Phoenix Gold Subs-Phoenix Gold EQ215ix-AC Epi-PG Line Driver-Phoenix Gold 1 Farad Cap -Clifford Avantguard 4-2 Ear Plugs

Any other ideas would be appreciated if anyone else has had this issue. Also the relay type needed would be a plus. Like make or model number and the relay time frame needed like 3 sec or so??? Thanks again for the replies in advance.Alpine 7830 HU-4X100 W McIntosh -2X110 W McIntosh-MB Quart Q's Mid Tweets-4X10" Phoenix Gold Subs-Phoenix Gold EQ215ix-AC Epi-PG Line Driver-Phoenix Gold 1 Farad Cap -Clifford Avantguard 4-2 Ear Plugs