OSD BK-100W70T 70V commercial transformer

Name: OSD BK-100W70T
Brand: OSD Audio
SKU: 452BK1HW70
Price: 65.39 USD
Availability: InStock

Item # 452BK1HW70

This transformer lets you convert an 8-ohm speaker for use in an indoor 70-volt distributed audio system.

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This transformer lets you convert an 8-ohm speaker for use in an indoor 70-volt distributed audio system.

Item # 452BK1HW70

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Convert 8-ohm speakers to 70-volt use

The OSD BK-100W70T indoor transformer allows you to convert standard 8-ohm speakers into 70V speakers for use in a commercial-style custom-installed sound system. With taps at 20, 40, 60, 80, and 100 watts, it allows you to daisy-chain the 8-ohm speaker together with multiple additional 70V speakers, all driven by a single amp. It is rated for indoor use only.

Product highlights:

lets you convert a standard 8-ohm speaker for use in a 70-volt distributed audio system
selector for choosing 20, 40, 60, 80, and 100-watt taps
color-coded, in-wall rated 18-gauge wire leads included
4"W x 2-3/4"H x 2-1/2"D
weight: 1.8 lbs.
warranty: 2 years
MFR # BK-100W70T
Item # 452BK1HW70
California customers: Please click here for your Proposition 65 WARNING.

What's in the box:

OSD BK-100W70T owner's manual

70V Transformer with 7.5" wire leads and attached mounting bracket (adhesive backed)
Wiring & Specification sheet

Researched by Crutchfield's Stacey B.

Product Research

Features

Overview: The OSD BK-100W70T line-matching audio transformer lets you power 4- or 8-ohm speakers from a commercial 70V amplifier, letting you deliver high wattage over long speaker wire runs. Featuring taps at 20, 40, 60, 80, and 100 Watts, the BK-100W70T lets you connect speakers up to 2000' away using 14 AWG wire, making it an ideal solution for commercial installations where distance is an issue. The transformer has a frequency response of 20Hz-20kHz with little insertion loss and no effect on sound quality.

Mounting: The OSD line-matching audio transformer is pre-attached to an angled mounting plate for installing it on the back of a speaker magnet. An adhesive pad on the the mounting plate allows it to be attached to the speaker without the need for mounting hardware.

Wiring: The BK-100W70T features six input wires for connection to a 70V commercial amplifier, offering five wattage options for your connected speaker. Each wattage can be selected by using a color-coded input wire. Three output wires are used for connection to either a 4- or 8-ohm speaker.

70V Amplifier Input (Primary):
- Black: Common negative
- Brown: 100W (50Ω)
- Red: 80W (62.5Ω)
- Yellow: 60W (83Ω)
- Blue: 40W (125Ω)
- Green: 20W (250Ω)
Speaker Output (Secondary):
- Black: Common negative
- White: 4Ω
- Red: 8Ω

Specifications:

Primary Voltage: 70V
Power Rating: 100W
Primary Taps: 100W, 80W, 60W, 40W, 20W
Secondary Impedance: 4- and 8-ohms
Insertion Loss: 1dB
Frequency Response: 20Hz-20kHz (± 1dB)
Dimensions: Width = 3.91", Height = 2.71", Depth = 2.48"
Weight: 1.8 lbs.

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1 question already asked

this article, "Convert 8-ohm speakers to 70-volt use". Will these transformers also convert a 8ohm amp signal to 70v for running 70v speakers?

reynold Jan 31, 2023

1 answer

These transformers will not allow allow you to use 70V speakers on an 8-ohm compatible amplifier.

zachary Feb 01, 2023 (Staff)

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OSD BK-100W70T 70V commercial transformer

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