linking alarm to audio system

first a little background about the build. Vehicle: 1994 GMC sierra extended cab Subs: 2 Sundown Audio Nightshade 18's (don't rape my pm box there is no more for several months) Sub amps: 2 Sundown Audio SAZ-3000d's 1 per sub Mids and Highs: Active 4-way setup (drivers undetermined most likely dls) Mids and Highs amps: 2 Sundown Audio SAX-100.4's (1 per door) Other Mids and highs:(part of alarm not audio) CDT HD-42 2-way Other Mids and Highs Amps:(part of alarm not audio) Sundown SAX-100.2 Alternators: 2 250 amp Ohio generator Batteries: 8 Powermaster D3100's Wire: all KnuKonceptz 10 runs of 1/0 gauge (5+ 5-) Sound Deadening: 290 Sq feet of Cascade Interior: Custom door pods for the 4-way setup, fiberglass dash and center console. Model of subs, amp rack and box at bottom of post ok here is were I would like some other people input. My alarm will be linked to my audio system. Speakers will be playing either a high tone or something that will gather peoples attention like my truck saying (rape or hes got a gun etc etc) the subs will be playing a 50hz tone which would make it hard as hell to concentrate. I am just trying to figure out the best way to hook into the alarm. I think the best way would to have a second headunit in the truck somewhere with my disk that contains the 50hz and the high frequency (have not decided what will hurt the ears the worst) I can put both frequency's on the same track. Do to the fact that after sound processing the subs will only get the 50hz and the mids and highs will only get the high frequency. The CDT 4" comps will be in the rear c-pillar facing toward the front of the cab (purely to fill in the rear with the high frequency and because I have had them laying around.) I could come off the alarm remote wire or siren wire to the remote going to the second source units 12+ ignition wire. Which will turn everything in my audio system on and at full tilt. The thing is how could I go about getting around a 15 second delay so that it takes the thief by surprise? I apologize for the drawn out post and my poor grammar and punctuation.

i am aware of the piezo sirens. and there are a few (5) in the truck already. honestly i dont find them to be bothersome

If you have 5 DEI 513T placed inside your cab correctly and wired correctly,i don't know how you can sit in there.You may want to look at there placement and try repositioning them.Or did you just get 513T knockoffs? I know they sell em on ebay,but their output is only something like 100db."ole blake"