1. Yes, for two type E Alpine 12" subs, a true 600 watt rms amplifier will have them sounding good. Type E subs need little power.
2. Do NOT ever series your subwoofers unless you need to add the ohm loads together to get proper impedance.
First, determine what type of amp it is, and determine whether it's a single (mono) channel amplifier, or a stereo (two channel) amplifier, because, most (99%) of the two channel amps on the market are 4 ohm mono, or 2 ohm stereo capable. That 2 ohm, stable sticker means 2 ohms into two channels. Mono amps vary from 2ohm or 1 ohm most of the time. From here we have to determine if your subwoofers are dual voice coil or single voice coil, and what the ohm loads on those voice coils are. That will decide how your subs need to be hooked up. Post the information here. What brand and type of amp (model number if you have it) and if the sub woofers are single or dual voice coil. Single voice coil subs have only one set of speaker inputs. Dual Voice subs have two sets of speaker inputs. Once we know these factors, the hook up part is easy.
Grabber Blue "Betty" 2012 V6 Six Speed, 3.55, BBK cai/throttle body, longtubes, x-pipe, axle back w/oem tips, Lugo Performance Dynotune, Zex 100 dry. I need factory v6 foglight housings, and the stock 11/12 gt grill with the light housings.