Klein + Hummel O 300 Operating Manual page 7

Uncompressed PCM AES3, AES3id, and S/P-DIF digital signals generally contain two audio channels (called
"subframe A" and "subframe B") on one cable (single-wire mode). A clock input is not required because
loudspeakers are not audio sources and the clock signal is locally regenerated from data contained in the bit
stream. The four-way signal selector switch on the rear panel allows selection of:
• "ANALOG" (XLR input connector only).
• "R" (digital subframe B)
• "L" (digital subframe A)
• "MONO" (mono sum of subframe A and subframe B with a 4.5 dB attenuation)
There is no digital output from the BNC connector when the XLR input is presented with an analog signal,
therefore the O 300D cannot be used as an analogue-to-digital converter.
Always use good quality cables with the correct impedance and appropriate termination to achieve these
maximum cable lengths:
An AES3 signal (applied to the XLR connector) is point-to-point and may not be looped, so the BNC connector is
used to connect additional monitors to the AES3 signal. The signal selector switch on the first loudspeaker should
be set to the "L", "R", or "MONO" setting. This outputs an AES3id signal from the BNC connector for connecting
additional monitors to the original AES3 signal. The BNC connector is not internally terminated so a single 75 Ω
termination is required at the end of the BNC transmission line. This can be realized using T-piece and a 75 Ω
terminator (not supplied).
An AES3id or S/P-DIF signal (applied to the BNC connector) can be looped using a T-piece connector (not
supplied) for connecting additional monitors to the input signal. The signal selector switch on the first
loudspeaker should be set to "L", "R", or "MONO" setting. An appropriate setting should be made on the rear
panel signal selector switch depending on the signal channel order and loudspeaker position. See picture below:
O 300 (D) Operating Manual
Format Impedance
(Connector)
75 Ω
S/P-DIF (RCA)
110 Ω
AES3 (XLR)
75 Ω
AES3id (BNC)
XLR digital input connections on the O 300 D
Cable Length
up to 10 m (30')
up to 100 m (300')
up to 1000 m (3000')
Klein + Hummel
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