Deeper Dive into 70v Audio - Speakers, Switchers, Streaming, Sweet Sound
In Part 2 of his 70-volt audio series, Capitol's Fred Harding expounds on 70v features, options and considerations, including timers, pagers, video conferencing, music licensing, and hybrid 8-Ohm + 70v amps.
Much of what was written about in that article, frankly, could have been written 50 years ago. What has many folks excited about the commercial audio market today, however, didn’t exist even fifteen years ago. This article will explore some of those items and trends.
70v loudspeakers have evolved and proliferated over the past few years. In addition to the traditional horns and pie-pan style ceiling speakers, you’ll find a wide range of newer form factors, including pendants for installations over large open floor spaces, better-looking and -sounding flush ceiling-mounted speakers, robust outdoor speakers in a variety of put ups, and a wide range of box-style of models.
As always, fit the tool to the job, and understand that some speakers are designed to have different coverage patterns than others.
That being said, it’s important to know that you can’t break the law when selecting a speaker. I’m referring, of course, to the laws of physics. If you are playing something in a noisy environment, you need to have speakers that are more efficient and/or able to handle a higher amount of amplifier power to succeed.
For higher-power applications, you’ll find compression drivers are deployed for high-frequency reproduction. These are more robust and can handle noise from microphones better than conventional tweeters.
Switchers, Amps, Paging
The next area of change has been at the head-end of the system. We’re now seeing audio matrix switchers that allow you to have multiple inputs and multiple outputs.
In a typical bar/restaurant complex, for example, it’s easy to have classical music playing in the dining room, soothing music in the waiting area and bathrooms, upbeat music on the patio and the game playing in the bar.
Priority switching can be programmed, so that if a juke box is in place, it can kick in when a fiver is inserted and knock the background sound off. Many offer timer functionality, where different sources can play at different times of the day at different volume levels.
CATCHING UP | Part 1: 70v Audio Fundamentals
Paging can be set to occur only in appropriate areas. You don’t need to tell folks eating dinner that a table for Jones is ready. These types of systems can be controlled by wall mounted controllers, or tablets, or at the face of the unit itself.
Installers simply choose how many different zones they need to work with, and how many sources they want to have available, understanding full well that extras are not a bad thing. From there, you choose your amplifier(s), with single-channel and multi-channel options available.
Some amps can be configured for hybrid applications, with one channel set to low impedance (8 ohm) and the other set to 70 volt. Such configurations facilitate easier installation of the hybrid subwoofer/high-frequency speakers mentioned in Part 1 of the 70v story.
Modern-Day 70v Options
Additional cool features in the matrixes can include ambient noise sensing, which monitors room noise and raises and lowers volume appropriately; AGC, which monitors music volume level from song to song and smooths it to a more uniform level; and parametric eqs for each zone, to provide tone control as each room requires.
The matrix type of design allows users to have preamp-level volume control as opposed to old-school attenuation. Preamp level is cleaner, and the installer can set maximum limits to prevent someone from turning it up to eleven. Attenuation chokes a signal back from the level that was predetermined, and can impact sound quality with better systems.
Further applications for audio matrixes can be found in video conferencing applications, where auto echo cancellation (AEC) is used to improve intelligibility for users at both ends. Essentially, the matrix allows the programmer to have remote sound only play in the board room, and the output of the microphones in that room only go to the remote node(s). By deploying automatic gating, whereby only microphone channels that are receiving a certain amount of signal are active, communication over the internet improves dramatically.
Some manufacturers are integrating streaming devices into their mixer amplifiers. Savvy installers who understand that music licensing is a potential pain point for venue owners are quick to point out when a commercial streaming service like Sirius/XM for business is built in.
Having a color display for control, in either tablet or touch panel configuration, allows staff members the ability to easily change sources as needed.
Getting Started with 70v Audio
Essentially, 70-volt audio has evolved from the old systems that were purpose-built for simple applications. Folks interested in knowing more would do well to research DBX, QSC, Symmetrix, BSS, Rolls, Crown, JBL Pro and Atlas Sound in the commercial domain, as well as a bunch of popular residential-centric vendors mentioned in Part 1.
(from JJ: or contact your favorite tech-sales guy at Capitol Sales … information below.)
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Fred Harding is in sales and technical support at Capitol Sales, a full service distributor of electronic installation hardware. He is a frequent contributor to CE Pro, writing hands-on product reviews and technical tips. Have a suggestion or a topic you want to read more about? Email Fred at firstname.lastname@example.org
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