When you need to do serious work without bothering anyone in your living space and without being distracted by outside sound, choose PreSonus HD9 headphones. Theyre clean-sounding, extra-comfortable, and offer a broad, transparent frequency response that ensures accurate mixing.The HD9s closed-back acoustic design provides superior listening isolation and reduces headphone bleed, so you hear nothing but music – and your housemates hear nothing at all.Its 45 mm dynamic, neodymium drivers and high power handling (900 mW per channel into 40 ohms