I've been looking at the JBL speakers, but I need some input on which series to get. I'm looking at the N38 or ND310 of the Northridge series, and the S310 from the Studio series. Can anyone tell me the differences between the two, and if so, what preference one has? I plan on upgrading the center and surrounds with the same series, but for now I just need two good speakers for music listening. Thanks.