I can get either 2 L7's in 8" size or a single 10" for the same price. I was wondering which would be better in terms of sound or SPL?

 

2 8 inch speakers will move more air

 

2 8's will probably weigh down the car more since you'll need a bigger box to hold them. If it were 2 different types of sub companies, I would of said the 10" L7 would be better than 2 8's. I have a 10" L7 and it sounds amazing!

 

Two 8's by a small margin. I would spring for one 12 though personally even though it's a bit more.

 

I run a single 12 Alpine Type R and it pumps hard!! Though, from past experience, i'll say that2 in any size will pretty much hit better than 1 of the next size up.

 

8's are pretty small. If I were you I would try and save up a little more and get 2 10's or a single 12. You'll be much happier.