Marantz HD77

Marantz HD77 with woofer replaced, radically changing its sonic characteristics

Box the speakers were packaged in; showing foam grille

HD77 is a model name of Marantz 4-way high-fidelity loudspeakers which were produced during the mid-1970s. They were bass reflex speakers, but came with a cylindrical piece of foam which fit into the bass-reflex port of the enclosure if the listener preferred the more accurate bass response provided by airtight speaker boxes. However, they were not fully airtight this way, but rather what is known as aperiodic.

Technical details

Weight: 49 lb (21 kg)

Power handling: 250 watts RMS, 330 Watts peak

Impedance: 8 ohms

Physical dimensions

Marantz HD77s had a total volume of 2.8 cubic feet (79 L) each. The cabinet dimensions are:

Depth: 12 inches

Width: 15 inches

Height: 28.5 inches

Drivers

The four drivers of the Marantz HD77s were a woofer, mid-range, tweeter and super tweeter. The given frequency responses are what the crossover circuit fed to each speaker, not what each speaker would respond to with no crossover circuit. The mid-range, tweeter and super tweeter have controls for switching between a laboratory flat and neutral response and a room EQ response.

Woofer

The woofer was 12 inches in diameter with a frequency response of 30 to 500 hertz.

Mid-range

The mid-range was 4.5 inches in diameter with a frequency response of 500 hertz to 3 kilohertz.

Tweeter

The tweeter was a soft dome-type. The tweeter's frequency response is from 3 to 8.8 kHz Linear Polyester Film Dome

Super-tweeter

The super-tweeter responded from 8.8 to 23 kHz, which extends 3 kHz above the nominal range of audio frequencies which can be heard by the human ear. Linear Polyester Film Dome

References

• Classic Audio. Marantz HD770