Ok here goes so the formula you want to be using is
V = the square root of RMS power x Speaker ohm
So for your 704 is 70w rms x 4ohm = 280. square root of 280 =
16.73 your desired voltage
The 4505
Towers are 130w x 4ohm = 520. Square root of 520 =
22.8
Sub is 500w x 2ohm = 1000. Square root of 1000 =
31.62
Remeber it is imperative that you disconnect ALL speakers while tuning. Turn your head unit up to 75% volume. Turn off any bass boost, trebble, mids, bass all need to be set at 0. You will want to ensure that your amps to high level sensitivity switch for your mids/highs and of course to a low level sensitivity for your sub. I also would set your frequency on your mids/highs around the 120hz and your sub around 60 to start. You can always adjust these once your amps are tuned for better quality of sound on your preference. Start with the gains all the way down, plug your multimeter into each terminal respectively and start to slowly turn up the gain as you watch the multimeter. Once you have your gains set, turn down the volume all the way, TURN OFF batteries, reconnect all speaker wires accordingly, turn batteries back on and enjoy!!
For your towers and other coaxial speakers you want to use the 1khz track and the 50hz track for the sub.
Both tracks can be found here