The cylindrical, black HD77 measures 7.3 inches in length and 3.0 inches in circumference and features two LED strips, one at each end of the speaker. They light up when in use, but generally appear to have only one color. Most of the speaker is covered with a black cloth grille. Underneath are two 12.5-watt drivers that deliver a frequency response of 80 Hz to 16 kHz. Passive radiators at both ends round out the sound. The cylindrical, black HD77 measures 7.3 inches in length and 3.0 inches in circumference and has two LED bands, one at each end of the speaker. They light up when in use, but generally appear to be only one color (blue when on, red when off, and green when charging, though these colors do not change during playback). Most of the speaker is covered with a black cloth grille. Underneath are two 12.5-watt drivers that deliver a frequency response of 80 Hz to 16 kHz. Passive radiators at both ends round out the sound. The bottom has a covered USB-C charging port as well as a 3.5mm aux input – cables for both are included. In addition to these cables, the HD77 comes with a carabiner. The speaker has an IPX6 rating, which means it is rain and splash resistant and can even be rinsed under the tap, but it cannot be submerged. It should be suitable for most outdoor situations where it might get wet. Treblab estimates the HD77’s battery life to be around 20 hours, but results will depend on volume. The HD77 is compatible with Bluetooth 5.0. On tracks with strong sub-bass, such as “Silent Shout” by The Knife, the HD77 has trouble reproducing low frequencies even at low volumes. There is clear distortion at high volumes, but beyond that we hear something like tape hiss, which becomes noticeable between beats and then recedes. This doesn’t sound good and is an example of DSP not working.
