recently got the m4, does it support aptx HD, since im thinking to get a fiio btr 30 pro, it supports only aptx hd not adaptive? thanks.

Thanks for the suggestion buddy. But is it useful if i buy amp for CAL to cover bass ?

Hello,   After searching & gathered information from here. Recently i bought a CAL for £40 on amazon which is a discounted price.am happy with the headphones sound & build quality. But i feel the bass is not enough. Now, i want to buy another pair mainly for bass with good quality. We must...