70V Line Speaker Wiring - Revision history

Daveallen at 20:25, 6 September 2019

2019-09-06T20:25:36Z

← Older revision		Revision as of 20:25, 6 September 2019
Line 6:		Line 6:
	Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant voltage system is used to save money on speaker wire.		Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant voltage system is used to save money on speaker wire.

	The reason the audio industry settled on 70 Volts is so all audio wiring can be installed without conduit. Many electrical codes of the time stipulated that voltages of 100 or more Volts must be installed in conduit. Modern codes break audio and signaling voltages into various classes. Class 2 covers typical speaker wiring installations. The main implication is that primary wiring and Class 2 wiring must never be placed in the same conduit or junction box. Note that the voltage is not ''constant,'' as its name seems to imply, but does actually fluctuate with the audio signal. The tapped transformer Power to the speaker voice coil reaches its rating when the speaker line Voltage reaches 70.		The reason the North American audio industry settled on 70 Volts is so all audio wiring can be installed without conduit. Many electrical codes of the time stipulated that voltages of 100 or more Volts must be installed in conduit. Modern codes break audio and signaling voltages into various classes. Class 2 covers typical speaker wiring installations. The main implication is that primary wiring and Class 2 wiring must never be placed in the same conduit or junction box. Note that the voltage is not ''constant,'' as its name seems to imply, but does actually fluctuate with the audio signal. The tapped transformer Power to the speaker voice coil reaches its rating when the speaker line Voltage reaches 70.

	== Loudspeaker connection ==		== Loudspeaker connection ==

Daveallen: constant?

2019-09-06T20:25:11Z

constant?

← Older revision		Revision as of 20:25, 6 September 2019
Line 6:		Line 6:
	Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant voltage system is used to save money on speaker wire.		Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant voltage system is used to save money on speaker wire.

	The reason the audio industry settled on 70 Volts is so all audio wiring can be installed without conduit. Many electrical codes of the ~~50s and 60s~~ stipulated that voltages of 100 or more Volts must be installed in conduit. Modern codes break audio and signaling voltages into various classes. Class 2 covers typical speaker wiring installations. The main implication is that primary wiring and Class 2 wiring must never be placed in the same conduit or junction box.		The reason the audio industry settled on 70 Volts is so all audio wiring can be installed without conduit. Many electrical codes of the time stipulated that voltages of 100 or more Volts must be installed in conduit. Modern codes break audio and signaling voltages into various classes. Class 2 covers typical speaker wiring installations. The main implication is that primary wiring and Class 2 wiring must never be placed in the same conduit or junction box. Note that the voltage is not ''constant,'' as its name seems to imply, but does actually fluctuate with the audio signal. The tapped transformer Power to the speaker voice coil reaches its rating when the speaker line Voltage reaches 70.

	== Loudspeaker connection ==		== Loudspeaker connection ==

Daveallen at 19:50, 6 September 2019

2019-09-06T19:50:35Z

← Older revision		Revision as of 19:50, 6 September 2019
Line 6:		Line 6:
	Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant voltage system is used to save money on speaker wire.		Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant voltage system is used to save money on speaker wire.

	The reason the audio industry settled on 70 Volts is so wiring can be installed without conduit. Many electrical codes of the 50s and 60s stipulated that voltages of 100 or more Volts must be installed in conduit. Modern codes break audio and signaling voltages into various classes. Class 2 covers typical speaker wiring installations. The main implication is that primary wiring and Class 2 wiring ~~should~~ never be placed in the same conduit or junction box.		The reason the audio industry settled on 70 Volts is so all audio wiring can be installed without conduit. Many electrical codes of the 50s and 60s stipulated that voltages of 100 or more Volts must be installed in conduit. Modern codes break audio and signaling voltages into various classes. Class 2 covers typical speaker wiring installations. The main implication is that primary wiring and Class 2 wiring must never be placed in the same conduit or junction box.

	== Loudspeaker connection ==		== Loudspeaker connection ==

Daveallen: wiring class

2019-09-06T19:49:36Z

wiring class

← Older revision		Revision as of 19:49, 6 September 2019
Line 5:		Line 5:

	Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant voltage system is used to save money on speaker wire.		Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant voltage system is used to save money on speaker wire.

			The reason the audio industry settled on 70 Volts is so wiring can be installed without conduit. Many electrical codes of the 50s and 60s stipulated that voltages of 100 or more Volts must be installed in conduit. Modern codes break audio and signaling voltages into various classes. Class 2 covers typical speaker wiring installations. The main implication is that primary wiring and Class 2 wiring should never be placed in the same conduit or junction box.

	== Loudspeaker connection ==		== Loudspeaker connection ==

Daveallen: /* Disadvantages of 70V speakers */

2019-09-06T19:43:11Z

Disadvantages of 70V speakers

← Older revision		Revision as of 19:43, 6 September 2019
Line 33:		Line 33:

	*Cost: The addition of transformers increases the cost of these speakers		*Cost: The addition of transformers increases the cost of these speakers
	*Frequency Response: Inexpensive transformers may have poor low and high frequency reproduction.		*Frequency Response: Inexpensive transformers may have poor low and high frequency reproduction. Primary applications for constant voltage systems are low fidelity paging and background music systems.
	*Insertion Loss: As much as 20% of the amplifier's power is wasted through the transformers. This figure should be accounted for and compared to when calculating the losses encountered through various sizes of low impedance wiring.		*Insertion Loss: As much as 20% of the amplifier's power is wasted through the transformers. This figure should be accounted for and compared to when calculating the losses encountered through various sizes of low impedance wiring.
	*Capacitance: To handle higher powers, transformers have to be scaled up in size. The added capacitance begins to attenuate high frequencies.		*Capacitance: To handle higher powers, transformers have to be scaled up in size. The added capacitance begins to attenuate high frequencies.

Daveallen at 19:29, 6 September 2019

2019-09-06T19:29:00Z

← Older revision		Revision as of 19:29, 6 September 2019
Line 4:		Line 4:
	This method of getting audio from amplifiers to speakers is similar in principle to power transmission methods used to distribute electrical power. The power company puts power on a line that carries it a long distance with thousands of Volts. The voltage is stepped down to hundreds of Volts at the building where the power is used. Because lower currents are required at high voltage, the resistance of the line does not cause a loss of power because of heat, and smaller diameter wires can be used.		This method of getting audio from amplifiers to speakers is similar in principle to power transmission methods used to distribute electrical power. The power company puts power on a line that carries it a long distance with thousands of Volts. The voltage is stepped down to hundreds of Volts at the building where the power is used. Because lower currents are required at high voltage, the resistance of the line does not cause a loss of power because of heat, and smaller diameter wires can be used.

	Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant ~~current~~ system is used to save money on speaker wire.		Similarly, we can apply a high voltage audio signal to a speaker line as long as there is a transformer at the speaker end to reduce the voltage to appropriate values for the drivers. Usually this system is used to distribute audio to a large venue with many speakers. In some cases, a constant voltage system is used to save money on speaker wire.

	== Loudspeaker connection ==		== Loudspeaker connection ==

Daveallen: /* Alternatives to constant voltage */

2019-09-05T14:53:20Z

Alternatives to constant voltage

← Older revision		Revision as of 14:53, 5 September 2019
Line 24:		Line 24:
	=== Low Impedance Speakers ===		=== Low Impedance Speakers ===

	Use of low impedance speakers connected directly to the outputs of a modern solid state amplifier generally provides the best sound quality. The length and size of the speaker cable must be carefully determined. For our typical 400 Watt systems, 14 AWG wire is generally suitable up to 100 feet. For longer lengths consider using 12 AWG. Always used '''stranded''' wire for audio.		Use of low impedance speakers connected directly to the outputs of a modern solid state amplifier generally provides the best sound quality. The length and size of the speaker cable must be carefully determined. For our typical 400 Watt systems, 14 AWG wire is generally suitable [[InSpire_audio_connections#What_size_wire_should_I_use.3F\|up to 100 feet]]. For longer lengths consider using 12 AWG or larger. Always used '''stranded''' wire for audio.

	=== Locate the amplifier near the speakers ===		=== Locate the amplifier near the speakers ===

Daveallen: /* Atlas PD-60AT 70 Volt Transformer wiring */

2019-09-05T14:44:57Z

Atlas PD-60AT 70 Volt Transformer wiring

← Older revision		Revision as of 14:44, 5 September 2019
Line 40:		Line 40:

	=== Atlas PD-60AT 70 Volt Transformer wiring ===		=== Atlas PD-60AT 70 Volt Transformer wiring ===
			[[File:PD60ATDrivers.jpg\|400px\|thumb\|PD60AT Drivers]]
	Internally mounted transformers Atlas PD-60AT drivers have the following color code:		Internally mounted transformers Atlas PD-60AT drivers have the following color code:
	Red - Voice Coil Negative		Red - Voice Coil Negative

Daveallen: /* Atlas PD-60AT 70V Transformer wiring */

2019-09-05T13:54:53Z

Atlas PD-60AT 70V Transformer wiring

← Older revision		Revision as of 13:54, 5 September 2019
Line 39:		Line 39:
	== Transformers ==		== Transformers ==

	=== Atlas PD-60AT ~~70V~~ Transformer wiring ===		=== Atlas PD-60AT 70 Volt Transformer wiring ===
	Internally mounted transformers Atlas PD-60AT drivers have the following color code:		Internally mounted transformers Atlas PD-60AT drivers have the following color code:
	Red - Voice Coil Negative		Red - Voice Coil Negative

Daveallen: /* San Ming 70 Transformer wiring */

2019-09-05T13:54:39Z

San Ming 70 Transformer wiring

← Older revision		Revision as of 13:54, 5 September 2019
Line 52:		Line 52:
	Brown - 2.5W input terminal		Brown - 2.5W input terminal

	=== San Ming 70 Transformer wiring ===		=== San Ming 70 Volt Transformer wiring ===
	Internally mounted transformers in San Ming drivers have the following color code:		Internally mounted transformers in San Ming drivers have the following color code:
	Top terminals - Voice Coil		Top terminals - Voice Coil