User:B137/Marantz HD77

Marantz HD77 is a model name Marantz 4-way high-fidelity loudspeakers which were produced during the mid 1970's. They were bass reflex speakers, but the came with a cylindrical piece of foam which fit into the bass-reflex port if the listener prefered the more accurate bass response provided by airtight speaker boxes. HD in HD77 stands for high definition.

Technical details
Weight: lbs

Power handling: 250 watts

Impedence: 8 ohms

Physical dimensions
Marantz HD77's were fairly large speakers, with a total area of 2.8 cubic feet. The cabinet dimensions are:

Depth: 12 inches

Width: 15 inches

Height: 26.5 inches

Drivers
The 4 drivers of the Marantz HD77's 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 literally respond to with no crossover circuit. The mid-range, tweeter and super tweeter have controls for switching between a lab flat and a room EQ response.

Woofer
The woofer was 12 inches in diameter with a frequency respnonse of 30 to 500 Hertz.

Mid-range
The mid-range was 4 inches in diameter with a frequency response of 500 Hertz to 3 Kilohertz.

Tweeter
The tweeter (and super-tweeter) were dome-type. Their diameters cannot be acceptably measured. The tweters frequency respnose is from 3 to 8.8 kHz

Super-tweeter
The super-tweeter responded from 8.8 to 23 kHz, which extends 3 kHz above the accepted range of audio frequencies which can be heard by the human ear.