6" or 8" Sub

I have a regular cab and I want to add some components and a small sub behind the seat. I was looking at some subs from Elemental Designs their 6" and 8" subs. I have heard good things about both. I was wondering which I should get. I will give you my goals of the upgrade. I want to have more detailed music. I want great sound quality and not outrageous spl. I like bass but I want my music to be balanced. I will not be getting the sub to show off merely to hear as much of the audible range (20hz-20khz) as possible. Therefore, I want quality over quantity. I will be cutting the components off at 80hz and channel the rest through the sub.

SO WHAT DO I NEED??

 

So no one wants to give an opinion?

 

I would go with the 8" more low level sound. If its unbalanced turn it down. Whereas if you went with a 6" you can't/won't be able to go as louder if you wanted too.

 

I have a single 8" in my system and it sounds great. Just make sure to get a good amp and balance the system using the amp gains and you'll have what your looking for.

 

Thanks for the opinions guys