PRESONUS HD9/HP4 PACK With HP4 Headphone Amplifier+ (4) HD9 Studio Headphones

The HD9/HP4 Pack sets up a four-person monitoring station in a single purchase: four HD9 closed-back studio headphones and one HP4 four-channel headphone amplifier. It is the practical answer for tracking a band, running a podcast table, or handing headphones to students and clients without hunting for spare cans and splitters. The HD9 headphones use 45 mm dynamic neodymium drivers in a closed acoustic design, with tailored frequency response from 10 Hz to 26 kHz, accurate low frequencies, and high power handling of 900 mW per channel into 40 ohms. Cups rotate 180 degrees on two axes for one-ear monitoring, and each pair includes a gold-plated 1/8-inch to 1/4-inch adapter and a 10 ft single-sided cable with a 1/8-inch connector. Sensitivity is 96 dB, plus or minus 3 dB. The HP4 amplifier supplies four very loud stereo headphone outputs at 150 mW per channel, each with its own level control and mono summing switch, so a drummer can run hotter than the guitarist and a bass player can collapse the cue to mono. Two balanced 1/4-inch line-level inputs accept the cue feed, and two balanced 1/4-inch line-level monitor outputs with their own level control and mute switch feed speakers or daisy-chain another headphone amplifier when the session grows past four people.