Matching Products AKG K240 MKIISemi-open studio headphones for accurate mixing and mastering. The sophisticated transducers provide solid bass, accurate mids and crystal clear highs. AKG K271 MKIIClosed studio headphones for monitoring, mastering, studio and live mixing. The K271 has an automatic cut-off and high external sound isolation. AKG K240 StudioSemi-open studio and hi-fi headphones. The sophisticated transducers provide solid bass, accurate mids and crystal clear highs.