Crestron audio: amplifiers, DSP and speakers

Which Crestron amplifier do I need?

Work out how many zones you need and whether the speakers are 4 or 8 ohm, or on a 70 V or 100 V line.

• Single rooms: the AMP-X50MP gives 2 x 25 W, or 50 W for a 70 V or 100 V line, with volume, bass and treble controls, and mounts without a rack. The AMP-X75 gives 2 x 35 W, or 75 W bridged or on a 70 V or 100 V line.
• Flexible zones: the half-rack AMP-X300 splits 300 W as 4 x 75 W, 2 x 150 W or 1 x 300 W bridged.
• Larger systems: the AMP-X500, AMP-X750 and AMP-X1000 have two, three and four channels, each set for 250 W at 4 or 8 ohms, 500 W at 8 ohms or 500 W at 70 V or 100 V, within a total of 500, 750 or 1000 W. All X-Series models are fanless.
• High power: the AMP-4600 gives four channels of 600 W, and the AMPI-8150 gives eight channels of 150 W at 4/8 ohm or 100 V on 220 to 240 V mains. Both can be monitored through Avia Audio Tool or a Crestron control system.

Which speakers suit my project?

• Saros: in-ceiling, pendant, surface mount and low profile speakers for commercial and residential projects. The SAROS IC6ULPT needs only 61 mm of mounting depth, and several models have built-in 70/100V transformers.
• Ultimate: made by Origin Acoustics for demanding residential systems, with carbon fibre woofers on many models and IP66 all weather in-ceiling speakers. The ULTIMATE IC8-DT gives single-point stereo from one speaker, and the IWLCR62 is an in-wall LCR speaker for home cinema.
• Reference: also made by Origin Acoustics, for luxury residential projects, with steerable Silk tweeters in the IC6 and IC8 in-ceiling models, plus the IW4X8 in-wall speaker.
• Outdoor: the Reference OD4 and 4.1 landscape kit, the Ultimate OD6T and the Saros SMT6T and SMT8T surface speakers.
• Bass: in-ceiling, in-wall and in-ground subwoofers, plus the ULTIMATE ASUB10 active subwoofer with a 200 W amplifier.

The Ultimate and Reference IC6 and IC8 share a 222 mm cutout, which helps when mixing ranges on one ceiling.

How do amplifiers, DSP and speakers work together?

In a meeting room or venue, microphones and sources feed an Avia digital signal processor, which mixes, processes and routes the audio before it reaches the amplifiers and speakers. The DSP-860 is 8x6, the DSP-1280 is 12x8, and the DSP-1281 adds Dante audio networking with AES67. All are set up in Avia Audio Tool, live over Ethernet or USB or offline, and integrate natively with Crestron control systems.

Speakers can run at low impedance, which suits hi-fi and home cinema zones, or on a 70 V or 100 V distributed line, where many speakers share one amplifier channel and each is set with a transformer tap. The AMP-X500, AMP-X750, AMP-X1000 and AMP-4600 can be set for either, channel by channel.

In multiroom homes, the amplifiers sit in the equipment rack and the control system handles sources, volume and grouping from touch screens and keypads. 1Install's owner holds Crestron's audio and DSP certifications.

What should I check when replacing an amplifier or speaker?

• Load: note whether each channel drives 4 or 8 ohm speakers or a 70 V or 100 V line, and add up the transformer taps against the channel rating.
• Mains: the AMPI-8150 is the international model for 220 to 240 V AC. The AMP-4600 and X-Series models run from 100 to 240 V AC.
• Rack space: the AMP-X300 is half-rack width and the AMP-X75 and AMP-X50MP quarter width. The RMK-AMP-X kit gangs half-rack products, and a plenum kit is listed for X-Series amplifiers.
• Cutout and depth: check the ceiling hole and void. Ultimate and Reference IC6 and IC8 use a 222 mm cutout, and the Saros IC6VLPT needs 102 mm of depth.
• Ordering: Saros in-ceiling speakers are sold as single units but must be ordered in multiples of 2.
• Settings: save the DSP file and amplifier settings so a replacement can be loaded with the same tuning.