Hi, I intend to buy the M-Audio AV40, currently at $123: http://www.amazon.com/M-Audio-Studi...eakers/dp/B0051WAM64/ref=cm_cr_pr_product_top I remember having read that you get better sound quality using e.g. a Behringer audio interface: http://www.amazon.com/gp/product/B002GHBYZ0/ref=ox_sc_sfl_title_8?ie=UTF8&m=ATVPDKIKX0DER Or: I could connect them to the headphone jack. But: my headphone jack has a bad connection. Once I unplugged the headphones and the internal speakers of my iMac went dead. I had to plug the headphones in again, and wriggle, and then the sound was back on. So: what is better: using an usb interface or the headphone jack? Thanks!