I have installed a helix dsp pro mk2. I highly recommend installing a good solid dsp, it will get you a great bang for your buck. Like unbroken said the install price is very high. How are you installing your subwoofer? Are you going to be using the factory location or just making a box. Here is what my installer did for me for my box. It's 2 8 inch db drive g5 subwoofers.