LM3886 ics per channel, but 67w
That requires a +/-28V power supply. With a +14.4V power supply the theoretical maximum maximum power you can get from a bridge amplifier into 4 ohms is about 26 Watts (twice that into 2 Ohms). With a real-world amplifier, you'll be lucky to get 20W (less if your voltage drops to 12V). (With a standard non-bridged design, you can only get 1/4th the power.)
Car stereo manufacturers use voltage-boosting switching power supplies[/b] to get higher voltage. These power supplies re not easy to build. So, so I agree with CrossRoads... Buy a car amplifier from someone who has the design nailed and builds them in bulk (at least the subwoofer amp).
...and then the amp would split the audio up into 5 channels FR FL BR BL sub.
That's complicated shtuff!!! If you have a DVD, Blu-Ray, or some other true-discrete 5.1 channel source, then you have 6 channels of audio to begin with. And of course, you need the appropriate Dolby AC3 or and/or DTS decoders.
Usually, those decoders come with DVD/Blu-Ray player software such as PowerDVD or WinDVD, or the decoders are built into your home theater receiver. (I have no idea what's available for the ODROID.) You can get a 5.1 channel (or 7.1 channel) soundcard, but you need the software decoders to drive it.
There is also the old "analog" Dolby Surround (i.e. Pro Logic), but you'll only find that on VHS tapes and some DVDs. It doesn't work properly with FM radio, CDs or MP3s., etc. For that you also need a Dolby Decoder
(or decoder software).
For regular 2-channel stereo sources CDs, MP3s, etc., there are Dolby Pro Logic II "soundfield" options
for sending reverb to the rear channels, etc. Some soundcards come with similar (non-Dolby) surround-sound effects for "spreading around" 2-channel stereo.
Typically, a home theater receiver has "bass management" to filter the bass out of the 5 surround speakers and send it to the subwoofer. With a DVD or Blu-Ray, the "point one" channel is called the LFE channel (low channel effects
channel) and it ONLY contains "booms and explosions", with the other 5 channels containing the normal bass. (Bass management is used to re-route all of the bass to the sub when you have 5 small surround speakers that can't put-out bass.)
I forgot to mention I was looking at the PT2322 IC for splitting the audio into channels, is that any good for it?No.
That's NOT a surround-sound decoder. It's a dual active crossover chip for tri-amplified systems with separate amplifiers for bass, mids, and highs. A traditional speaker (passive) system has a passive 2 or 3-way crossover to send the lows to the woofer, (mids to the midrange if you have a 3-speaker), and highs to the tweeter. Active crossover filters the line level signal before it's amplified. Many car amplifiers have a crossover built-in so the amp can be used as a subwoofer amp, or tweeter amp, etc., so you don't need a separate crossover.