Even smaller meeting spaces often offer some kind of voice reinforcement for presenters and the ability to play recorded content. When it comes to the amps powering the audio; what influences user choices, what options are available and why is networking increasing in importance? Kevin Hilton reports.
All amplifiers do the same job: they take a sound and make it louder to cover a large area or long distance. While that fairly basic definition covers most kinds of amp, within it are different categories of device. Hi-fi models are designed for reproduction of recorded music. Those used for rock touring have to combine quality with power. In the middle are devices built specifically for meeting room installations, which require clarity at lower volume levels while being easy to use by non-technical types.
Many presentations these days incorporate some kind of AV material, from play-in and play-out music to voice or video clips. Presenters and delegates often use microphones. That makes the amplifier a key part of the AV set-up. And, despite the seemingly simple nature of such installations, choosing the right amp is not necessarily straightforward.
“In general, most conference applications are small rooms so the amplifier needs are pretty minimal - typically less than 100W per channel,” comments Dale Sandberg, senior product manager for QSC.
Sandberg adds that today’s digital technology makes it easier for manufacturers to produce specific amplifiers for a particular application while still having a core platform covering a number of different market areas: “As products get more technologically sophisticated, and applications become more specific, it makes sense to develop products to fit specific needs,” he says. “Sometimes, however, you can create a platform with similar functions but application-specific features. This can reduce the development time when there are sufficient similarities in applications.”
“As products get more technologically sophisticated, and applications become more specific, it makes sense to develop products to fit specific needs.”
Wolfgang Schulz, product manager at d&b audiotechnik, acknowledges the requirement for lower outputs in education and corporate meeting environments but observes that this does not mean the amplifiers used are unsophisticated. “Applications like these also require high level features on the amplifiers,” he says. “Preconfigured set-ups for different scenes or changing the configuration of a room can make a real difference to the people ultimately responsible for operating the system.”
While there is generally the view that there is no need for high power sound in meeting/ presentation areas and classrooms – Keith Stouten, marketing manager with Audac, suggests an average of 40W a channel - there is also the argument that amps should have a little more capacity so there is no distortion if they are turned up loud on some occasions. “A key point about an amplifier is how it handles being over-driven,” says Justin O’Connor, product manager for Biamp’s Tesira range. “You’ve always got to over-spec an amp because then it won’t clip. If it’s going into a small conference room you can always keep the level down.”
Biamp produces four amplifiers as part of the Tesira range, which also includes servers and DSP (digital signal processing) units. “They cover a lot of AV installation needs,” O’Connor comments. “They’re not for big venues but houses of worship, small hotel meeting rooms and even small ballrooms, as well as education and corporate.”
Budget often has an influence, which is why manufacturers such as Vision Audio Visual produce 12W per channel products. In most cases, particularly for education projects, company director Stuart Lockhart says the choice tends towards 30W per channel amps. The traditional configuration for professional installations over the years has been a standalone amplifier connected to loudspeakers usually mounted nearby to reduce the amount of cabling, because long cable runs can - depending on the material used in the cables - result in a reduction in signal strength.
A way round this is to use powered, or active, loudspeakers, which have amplifiers and controls built into the enclosure. There is clearly a space-saving advantage to this, plus the benefits of fewer pieces of equipment to install. “We’re seeing a move away from separate amplifiers and speakers to powered loudspeakers,” confirms Lockhart. “Some people prefer them because of the way they wire everything up. Others prefer separate amplifiers.”
“We’re seeing a move away from separate amplifiers and speakers to powered loudspeakers.”
Keith Stouten comments that active loudspeakers are ideally suited to a standalone meeting or presentation room that is not intended to connect to any other facility in a building. Stouten’s colleague, marketing manager Tom Van de Sande, adds that while compact systems are becoming popular for the education and corporate sectors, customers are appreciating the connected features of amplifiers, with web capability allowing use of remote control wall panels.
Networking is now a serious consideration for any type of AV installation, with Dante, AVB and general IP technologies leading the way. But such technical networks date back over 20 years, with amplifiers being among the first components in a system to be connected for control and operational purposes. Stouten says that in this new era of networking it is becoming more important by the day: “It gives the installer the possibility to check the end-user’s system at the moment the customer is calling him about a problem. And while audio systems are becoming more complex the IT side is growing in a similar way but these days you cannot plug a device into a LAN socket and just hope it will work.”
QSC produces the Q-Sys IT-based platform for connectivity. This is based on Layer 3, the network level of the Open Systems Interconnection (OSI) model, which forms the basis of IP set-ups. Sandberg observes that many integrators “like the idea of a networked solution” because it can simplify both the installation and operation of a system: “They already have a network switch in the room so adding one more device to that network is no big deal. If the facility already has a standard Layer 3 network infrastructure then adding other Layer 3 network amplifiers and other peripherals is simple and almost an afterthought. If, however, the network is something else then a separate network must be pulled, which can be painful as it may not be in the budget.”
Wolfgang Schulz at d&b agrees that integrating audio over an existing IT infrastructure is a “logical step”, saving time and money while simultaneously making integration easier. “Networked audio is the easiest way for people working in education and corporate applications to operate and monitor the status of the amplifiers,” he says.
Despite the ongoing discussion about networking, these are still relatively early days in the mainstream adoption of the technology. Stuart Lockhart at Vision sees the distribution of emergency messaging as the field where networked audio will grow initially but that it will eventually move into areas such as education and corporate for controlling and monitoring amplifiers.
Biamp’s Tesira range has a foundation of AVB. From this base Tesira products are also able to connect to networks using the Dante and CobraNet protocols but O’Connor makes a distinction between networking and integration.
“The digital age of audio means there will be a number of ways to have digitally connected amps over something like Cat5 but that doesn’t mean you have a fully integrated network,” he says. “You can connect devices over Dante but that doesn’t mean they’re integrated with each other if they’re not using the same DSP. What is upstream of the amp is important and that will become a vector of differentiation for manufacturers and provide benefits to the customers.”
DSP has already added sophisticated levels of control and monitoring to the humble but still very necessary amplifier. Greater networking capability is likely to increase what these devices can do beyond their core task of amplifying a sound source. As Tom Van de Sande says, an amplifier is not just an amplifier any more.