Astell&Kerns T9iE earphones are made in conjunction with renowned German headphone manufacturer Beyerdynamic - the T9iE uses their patented high-efficiency Tesla Technology and are manufactured by hand in Germany satisfying the highest standards. The T9iE is the next generation of earphone with them using a newly designed acoustic vent that helps with better bass response over the T8iE and T8iE MKII. The T9iE has been acoustically matched to the Astell & Kern range of portable players and it has an extremely neutral sound signature with soft treble linear midrange and slightly elevated bass.