Anybody running Stock HU and Speakers with a DSP?

I'm thinking about running the base audio system in a 2012 and just adding a DSP with a sub/mono amp behind the rear seat. Has anybody tried doing this? How much better did the stock HU and speakers sound with just these minor tweaks?

The write ups on the JBL MS-8, the JL Clean Sweep, and the Helix PP50-DSP sound pretty good. But I find it hard to believe they have enough magic to really make the stock equip sound any good.

I'm looking closest at the PP50. Marketing specs say they have a sound profile imaged from a DCSB Taco they can load into flash memory on the unit. I'd rather listen to someone with real live experience than a marketing piece.

 

I'm not a fan of just using someone else's EQ. I didn't see where the Helix would allow you to do your own thing, the guy in the video I just watched just talked a lot about dumping settings into it... not what I would want.

 

I used the stock HU and added two JL 10" W0 Subs + 1000W HIFONICS amp and the iPod hookup.

This had extremeeee power and sounded so crisp. It's all for sale too. If you need any info or have any questions, let me know!

http://www.tacomaworld.com/forum/buy-sell-trade/213581-selling-2x-10-jl-audio-subs-amp-more.html

 

What did you use between the HU and the amp? Did you use the amp just for the subs or for the door speakers as well?