I don't have the DSP sound so I will be adding the sub and an amp. What are the stock speakers like.. anywhere near as beefy as these? Could you post or send a picture of the stock woofers? The amount of bass is going to be a function of the speaker motor (magnet and voice coil) and the surface area of the cone. I'm assuming these are much stronger motors than the stock speakers. The surface area would be 2x113 sq in. While that is smaller than 10" it is bigger than a 8". Do you know what the box volume is? I thought it was only something like .4-.5 ft^3 .. Seems like a 10" might be a bit much for that small of a box. I'm also planning to add something like a JL 250/1 which I assume is a much better amp than stock. I think 75 W of clean bass will be more than enough for this application. It takes a lot of money to get really good sub bass.. my home sub is about 4K.. I'm not looking for booming bass, and I don't think real sub-bass is possible without a bigger box... I'm just looking for fuller bass.

Thanks
Bruce