When I first tried out EPs (more than a year ago), I went string by string. With a Spiro Mittel E and A and EP D and G I thought that the bass sounded pretty darn good. There was a tiny bit of tension difference, but it seemed negligible. The main thing, to my ear, was what seemed to be a drop off in mids on the lower 2 strings and a strong fundamental on the top 2. Imagine the bottom 2 strings kind of "mwahing" all day and the top 2 smacking you in the chest with fundamental alot more quickly. Volume-wise the set worked for a while, but particularly in the studio I could really hear the difference between the 2 string brands on my bass. . . Hope this helps.