PRESONUS PreSonus HD9 HeadphonesWhen 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 musicand your housemates hear nothing at all.