Networked Amplifiers for Live SoundPOWER, CONVENIENCE AND TOTAL CONTROL 1/01/2006 7:00 AM Eastern
These days, just about everything from your DVD player to your coffee machine can be remote-controlled, so why not your power amplifiers? Networked communication for power amp management can make life a lot easier when configuring and tuning industrial sound systems, touring P.A. systems and club/stadium/theater installations. Initially, network communication circuitry was offered as an add-on, but many amplifier manufacturers are now designing their amps with onboard data communication.
Most amplifier networks route control data, but several can route both audio and control information. Many manufacturers use Ethernet hardware, providing a familiar, off-the-shelf interface, with straightforward cabling requirements. The PC can be located anywhere in a venue, yet still allow adjustment of functions as simple as muting or gain, or as complex as multi-band equalization, delay and DSP. As network communication is two-way, amps can “report” various operational data back to the computer in real time, such as input/output clipping, thermal status, output voltage and status of protection circuitry. Complex amplifier networks can support hundreds of power amps (each with a unique identity), all under the control of any number of computers. Typically, the PC can be disconnected once the system is configured, preventing inquiring minds from making unauthorized tweaks or “improvements.”
Listed alphabetically, here's a look at the latest top-of-the line networked amplifiers for live sound applications. We've also included a synopsis of current offerings in network protocols — both proprietary (company-specific) and general-purpose approaches supported by several amp manufacturers.
The Ashly Audio (www.ashly.com) Protea
All amplifiers in Ashly's PE Series accept Protea DSP option cards ($900 each) with a SHARC 32-bit/96kHz processor, enabling 24-bit AD/DA, and analog and digital (AES-3) inputs. Ashly's DSP library includes EQ, filters with slopes up to 48 dB/octave, delay, compressor/limiter, gate, signal generator and matrix routing.
The VX880 ($2,745) is the flagship model of a new contracting series of amplifiers from BGW (www.bgw.com). The VX880 is capable of putting out 900W per channel into 8 ohms (2,450W bridged) and 1,400W at 70 volts (no transformers required). In addition to balanced XLR and Euroblock inputs, the rear panel features barrier strip output terminals, precision 1dB stepped attenuators for each channel and a switched 30Hz highpass filter (12 dB/octave). Safety features of the VX880 include quiet turn on/off, short protection, and independent DC and thermal-overload protection on each channel, which automatically protects one channel while allowing the other to continue operation (even if one channel is down). A rear panel FaastLink port allows the VX880 to be used with a CobraNet interface for audio routing and amplifier control.
Camco Audio's (www.camcoaudio.com) Vortex Series uses a switched-mode power supply to deliver extremely high power levels while reducing weight and dimensions. The two-space Vortex 6 ($4,905) has a rated output level of 2,300W into 4 ohms/both channels driven and 6,600W into 4 ohms/bridged. Protection features include emergency shutdown in case of extreme malfunctions, overvoltage protection of up to 400V, thermal protection for the transistors and hum-free operation in case of extreme undervoltage. Front panel LEDs show operational status and functions; all indicators and controls are available for adjustment via a remote-control network.
Camco's new UCA DSP-Module allows Vortex amplifiers to become a Universal ControllerAmp with 99 network addresses that are accessible by using the amplifier's volume controls. Parametric EQ, delay, filters, crossover and limiters are implemented via the Camco WinCai application. The UCA module is fully integrated with the amps, and data exchange is achieved via internal interfaces.
The Crest Audio (www.crestaudio.com) CMi 2208 amp works with the company's Nx CobraNet-8
Crown's (www.crownaudio.com) I-Tech 8000 ($7,685) is a 2-channel amplifier employing patented Class-I (BCA
Distributed by TC Electronic, Lab.gruppen's (www.labgruppen.com) C 68:4 ($4,895) provides four channels of amplification, each with a maximum output of 1,700W at 4 ohms. The amp may be configured for use in low-impedance or 70V and 100V applications via rear panel DIP switches, and permits individual channel adjustment of maximum voltage peak output and gain. The C 68:4's four channels may be bridged in pairs of two for increased output (2,400W at 4 ohms, two channels driven). Balanced input is on 3-pin Phoenix connectors, while output is on terminal strip connectors. Lab.gruppen's patented Class-TD and regulated switch mode power supply enable the C 68:4 to combine efficient high-power output with reliable operation.
As with all Lab.gruppen C Series amps, the C 68:4 incorporates an integrated interface for use with the company's NomadLink
The MC1250 from MC
At the head of the Digam K Series from Powersoft (www.powersoftaudio.com) is the K 10, a 2-channel amplifier with a max power output level of 4,000W into 4 ohms/stereo and 12,000W at 4 ohms/bridged mono. Intended for touring and installations, the K 10 employs an advanced switch-mode power supply for high performance in a single-space rack chassis. A front panel interactive LCD shows amplifier status, including load impedance, output power, mains voltage and current, and temperature. In addition to digital gain control, the K 10 features built-in (defeatable) clip limiters, user-defined maximum output power per channel and input sensitivity. An optional PowerControlModule interface card mounted inside the unit provides an RJ-45 on the rear panel for connection to an RS-485 network.
Designed for permanent installs where space is at a premium, QSC's (www.qscaudio.com) CX168 ($2,450) is an 8-channel amplifier delivering 90W/channel at 8 ohms. Each pair of channels may be bridged to configure the amplifier as a 4, 5, 6 or 7-channel unit. Like the entire CX Series, the CX168 includes DataPorts for remote amplifier management or signal processing, as well as QSC's PowerWave technology for reduced size and weight. Selectable highpass filters protect speakers and prevent speaker transformer saturation with minimal effect on program material, while front panel LEDs indicate signal, clip, bridged mono and parallel input status. The CX168 accepts audio input via rear panel Euroblock or DataPort connectors. An RS port connects the CX168 to a CM16a amplifier network monitor for remote control. The DataPort enables using the CX168 with a variety of QSC expansion modules such as the DSP-3, which adds two channels of independent signal processing.
The PC9501N ($1,699) is the top of Yamaha's (www.yamaha.com) PC-1N Series of networked amplifiers. The PC9501N provides stereo, parallel and bridged-mono output modes, delivering 925W/channel into 8 ohms/stereo and 4,600W bridged mono at 4 ohms. Weighing less than 29 pounds, the PC9501N employs a switching regulator that yields a more stable and balanced supply of voltage and current, and eliminates fluctuations in output level. Each channel features a 31-position input attenuator, highpass filter and 10-segment LED meter. Rear panel input is via balanced XLR and Euroblock connectors with binding post and Speakon output connectors. Dual RJ-45 terminals are included for networking the PC9501N via CobraNet with Yamaha's ACU16-C amplifier control unit and NetworkAmp software.
In addition to contributing to Mix magazine, Steve La Cerra is an independent engineer currently mixing front of house and tour-managing for Blue Öyster Cult.
UNDERSTANDING NETWORK PROTOCOLS
Networking and interfacing amplifiers is still a relatively new topic to most audio pros. The following are capsule summaries of control protocols used in live sound amplifiers. All companies listed here will provide more detailed information such as specs, white papers and other technical data on request.
Ashly Audio Protea: Running on any PC, Protea Software allows setup, control and monitoring of PE Series amplifiers and Protea processors using standard Ethernet hardware and manual or auto-IP configuration. Monitoring and control functions include input attenuation, mute, channel polarity, output voltage, clipping, temperature and power on/off. PE Series amps accept Protea DSP option cards, which use SHARC processors to operate from 48 to 96 kHz with a 24-bit AD/DA.
Aviom A-Net Pro64: Designed for use with Aviom's (www.aviom.com) distributed audio products and peripherals, as well as OEM products to other manufacturers, A-Net
Camco Adaptive Intelligence (CAI): Camco's amplifier networking and remote control can run from any Windows PC using an Ethernet network card. The company's WinCai software communicates with an EtherCai Interface, supporting connections for up to 32 amplifiers. Connection is via CAI protocol and RS-485, fully compatible with all CAI-equipped amplifiers and Nexo NX241/2 controllers.
Crest NexSys: NexSys
Crown TCP/IQ: Crown's IQ
EtherSound: Invented by DigiGram and supported by numerous manufacturers, Ethersound (www.ethersound.com) provides bidirectional, low-latency transmission of synchronized audio channels and control data over standard Cat-5/6 Ethernet. Up to 64 channels of 24-bit/48kHz PCM audio, plus embedded control and monitoring data, are transported via a single cable.
Harman HiQnet: HiQnet
Lab.gruppen NomadLink: This closed-loop network facilitates control of up to 60 amplifiers. The NLB 60E serves as the bridge between Lab.gruppen's C Series amps and Ethernet using standard Cat-5 cable for communication of up to 1,000 feet. Local monitoring and control of the amplifiers are possible via the NLB 60E's front panel or via PC. DeviceControl software facilitates setup, monitoring and control of C Series amps, automatically generating a list of networked amps and channels.
Peak Audio CobraNet: Peak Audio's (www.peakaudio.com) CobraNet is open to any manufacturer that wishes to license the technology for use in its gear. CobraNet has the capacity to carry 64 channels of 48kHz/20-bit audio, plus control data over a single Cat-5 cable. CobraNet is currently supported by Crest, Crown, Peavey, QSC and Yamaha.
Peavey MediaMatrix: MediaMatrix
Powersoft PowerControl: The PowerControl System is designed for monitoring and amplifier control in real time. Main system components include PowerControl Manager software (running on any PC), a PowerControl hub unit and a PowerControl board installed inside the amplifier. A single PC can manage up to 99 units with the provided software.
QSControl.net: This is QSC's latest network for control, processing and amplifier monitoring of the company's BASIS and next-generation RAVE and DSP products from a single graphic software interface. Multiple networked computers can control and monitor all devices simultaneously. QSControl.net supports amplifier and loudspeaker control, monitoring and protection, as well as CobraNet for up to 32 channels of audio I/O.
Yamaha NetworkAmp Manager: NetworkAmp software for Windows combines with Yamaha's ACU16-C amp control unit to instantaneously relay and handle a variety of crucial data concerning the connected amplifiers and speakers through the network using the DATA ports on each connected unit. A single ACU16-C can control up to 32 separate PC-1N Series amplifiers. Adding the optional NHB32-C network hub/bridge facilitates monitoring and control of the entire system via CobraNet.