i got 2 single q-logic boxes for my two 12" infinity reference series sub woofers. then i have 2 rear infinity reference 6" x 9" three way speakers. then i have a infinity reference subwoofer amplifier . Also i have a v-power alpine amplifier 2 channel also i have a alpine head unit . How good is that ?
it sounds like a good set-up. it is also good to try and keep your system all the same brand as well. i see you only have 2 different brands.
i know people with expensive subs and crap amps, and a crap head unit, it was loud but that was about it.
keep in mind that an alpine amp was designed to be used with an alpine head unit, and infinity subs were meant to be used with your infinity amp. this is what i like about your sound system it isnt a mix and match sound system.
keeping everything the same brand isn't really always a good idea. some companies are far better at certain product lines than others. example, Alpine is graet at head units and signal processing. acceptable at amps and speakers but far from the best. Zapco makes awesome amps and signal processing, but they don't even make speakers or head units. RE and Adire only make speakers, etc.
you get the idea.
my present system consists of alpine, orion, resonant engineering, dynaudio, optima, knukonceptz, compustar, and audiocontrol. not all one brand, but I challenge you to design a better system using everything from one company. the entire reason amplifiers have input sensitivity adjustments is so that you can match the line voltage to the amplifier input stage. Take alpine, Clarion, or Pioneer for example. Even Eclipse. All of the companies are considered high end. All of them make both head units and amplifiers. None of them make all of their haed units with the same line out voltages. they all range anywhere from 2 volts to 16 volts for pre-outs. now how does that match up to any single product line? Speakers.. speakers don't care who makes the amp driving them as long as the power output is matched to the speakers, and even tehn you can't say "oh so and so makes an amp just for these speakers" since most times the power required for a sub will depend entirely on the enclosure the sub is in, and for components it'll depend on how much output is desired from them compared to the rest of the system.
the only reasons anybody uses all one brand of products to build a system are: 1: they don't know any better 2: they're stalinistic about brand loyalty 3: it looks pretty together (?) 4: it was all given to them by a sponsor.