AKG Acoustics WMS 4000 manual Akg Wms Glossary, Definitions From A To Z

AKG WMS GLOSSARY

GLOSSARY

DEFINITIONS FROM A TO Z

Antenna Cable

Cable specifically designed for RF signals. Used for connecting a remote antenna to a receiver. Antenna cables are typically coaxi- al and symmetrical. Signal attenuation de- pends on the frequency band of the signal as well as the length and quality of the cable and is quoted for a 100-m run of cable.

Antenna Splitter

Electronic network specifically designed for RF signals. Distributes an antenna output signal to several receivers. Powered anten- na splitters use an amplifier to compensate for cable attenuation while passive antenna splitters have no amplifier.

Balanced/Unbalanced Connections Microphones can be connected to an amplifier with either balanced or unbalan- ced cables. In a balanced cable, the signal is carried by the two inner conductors and the shield is not part of the signal path. Even with long cable runs, any external in- terference signal (such as power line hum) would be induced equally in both conduc- tors and thus be canceled. Unbalanced cables use only one center conductor as the “hot” wire, the shield being the ground (“cold”} lead. While this arrangement works well with cables up to 10 meters in length low-frequency,long-wave hum inter- ference may be picked up by longer cables which act as a long-wave antenna.

BNC

Connector specifically designed for RF lines.

Booster

Amplifier for RF signals. Boosters are connected between a transmitter output and the antenna in order to increase radia- ted power (custom product).

Condenser Microphone

The transducer element consists of a vibra- ting diaphragm (metalized foil) only about

a ten thousandth of an inch thick and a fixed metal electrode (back plate). The two electrodes make up a capacitor (condenser) charged by an externally applied DC volta- ge 1" polarizing voltage or carrying its own permanent charge. The sound waves dri- ving the diaphragm will vary the capaci- tance of the capacitor and consequently the microphone output voltage will vary in step with the sound waves.

Condenser microphones, also called “capa- citor microphones”, need an impedance converter (preamplifier) to match the very- high-impedance condenser transducer to low-Z inputs. Condenser microphones usually have a flat frequency response, high sensitivity, and good transient res- ponse. They require a power supply. All AKG condenser microphones are designated by the letter(s) “C” or “CK” in front of the model number.

Connecting AKG Microphones

All handheld microphones listed in this catalog are low-impedance 1200 to 620 incorporating a balanced output on a 3-pin male XLR connector. Conforming to IEC 268-12, pin 1 is ground, pin 2 high, and pin 3 low. The output is compatible with all mixers, tape recorders, etc.

To connect an AKG microphone to an input jack, wire the microphone cable as follows: connect the sleeve of the jack plug (ground) to the cable shield and the shield to pins 1 and 3 on the XLR connector. The center (“hot”) wire connects pin 2 to the jack plug tip (see diagram1).

If your installation uses pin 3 as “high” or “hot”, bridge pins 1 and 2 for unbalanced connections and make sure to follow the same convention for all cables in order to avoid phase reversal problems.

Very old sound systems sometimes have high-impedance microphone inputs.

Should the signal of a low-impedance mic- rophone be too weak, insert a 1:10 step-up transformer at the amplifier input. Long cable runs used with high-impedance equipment cause high-frequency loss. The same applies if you connect a microphone to a high-impedance guitar amplifier input.

Connecting Condenser Microphones Condenser microphones - except for the battery powered C 1000 S - require an ope- rating voltage that needs to be fed through the microphone cable (phantom powering). This can be done in several ways:

1.From a mixer with built-in phantom power (9 to 52 V).

2.By modifying the mixer or tape recorder to provide phantom power: find a regu-

lated DC voltage between 9 and 52 V in the power supply. All modern AKG con- denser microphones accept any voltage within this range. Wire the input(s) as shown. Current consumption of the phantom circuit is negligible (about 1 mA per mic). Replace the input jacks with XLR sockets if possible. While ste- reo jacks will work as well, there may be a risk of mistaking them for send/returns or the like.

Use the following standard resistances (IEC

26815) for Rv:
Voltage	Resistance
12 V (±2 V)	680 Ω	+10%
24 V (±4 V)	1.2 kΩ	±10%
48 V (±4 V)	6.8 kΩ	±10%

Make sure to use resistor pairs whose com- bined actual value is within 0.4 % of the specified value!

3.By inserting N 62 E or N 66 E AC power supplies between the mixer and micro- phones.

4.By using the B 18 battery power supply which is ideal for outdoor recording.

Unbalanced Input jack

Balanced Input

XLR Socket

➀

Modified Input with	Modified Input (XLR) with
phantom powering	phantom powering
➁	➁

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