[Plasar]

SomeGeoffGuy:

• I'm glad you asked your question - it prompted me to look up what a PAC Audio interface was.
• I went to Crutchfield as a first step - Crutchfield is really a great resource for car stereo upgrades.
• I would be tempted to give Crutchfield a call and get their advice.
• If you were going to buy your equipment from them, they will also send you their installer instructions for the Camaro - seems very helpful for DYI.
• Take this feedback with a huge grain of salt, but... I would be hesitant to take a subwoofer signal off of ANY of the standard Camaro speakers. Who knows what equalization curve they send to each speaker. Who knows how they roll off the bass to the stock speakers - which are lame.
• I think I learned there are 2 types of DSP interfaces: 1) interfaces with the factory stereo on the digital bus to get audio signal as a flat signal pre-equalization/processing (ex. Helix DSP.3); 2) interfaces with the factory stereo off of a speaker signal and then recreates a flat signal by sending a test audio signal sweep thru the factory stereo and then applying a post-equalization/processing adjustment to recreate the flat signal (ex. JL Audio Fix 86). I believe the PAC interface is like the FiX 86. Option 2 devices seem to be a lot less expensive than Option 1 devices. To add just a sub, Option 1 seems like it would work fine. If you wanted a significant improvement of sound, and were going to replace other speakers, Option 1 sounds like the way to go, as the Bose equalizations would not apply well to any new speakers, and rather than "undoing" whatever the Bose has baked in, Option 2 gives you a nice, flat, pure audio signal with all of the car tones and phone features integrated.