While not the first headphones to boast on-board digital signal processing, this closed-back design has an ace up its sleeve. TruNote technology uses microphones located within the headphone capsules to automatically correct the frequency response for the ears of any listener. There’s also active noise cancellation, a choice of three sound modes and a built-in DAC fed by a micro USB input, also used to recharge the internal battery. Open and neutral sounding, with particularly impressive bass, the AKG N90Q gets closer than most to achieving loudspeaker-like sound. Game-changing technology often comes at a price, but if you want to take your private listening to the cutting edge, the AKG N90Q is well worth the cost.