Configuration:The Orion-4 speakers use an active crossover that has RCA and balanced inputs plus four RCA output connections for each left and right channel. These outputs are Tweeter, Midrange, and two Woofer outputs. They can each be connected to an amplifier input in an eight channel amplification configuration or if the woofers are wired in parallel they can be driven with six channels of amplification. A multi-channel amplifier makes this an easily accomplished configuration.
Amplifier Specifications:The Orion-4 speakers are very efficient, as there are no passive crossover components to load the signal. The efficiency is basically that of the high quality SEAS drivers used in the Orion-4 design. The amount of power required to drive the Orion-4 speakers depends upon the playback level desired and the content of the music to be played. Bass frequencies require greater power than the midrange and tweeter drivers. The two woofers used in the Orion-4 speakers provide a minimum 4 ohm load, so if a six channel configuration is chosen, then the amplifier should be capable of driving a 2 ohm load. Due to the high efficiency and low Q of these woofers, this is a fairly easy load for most solid state amplifiers.
Due to the high efficiency of these speakers, they can easily be driven with 120 watt per channel amplifiers. Higher wattage amplification can yield better performance in bass response, though the VA rating of power supply is more important than the actual wattage output. The wattage requirements for the midranges and tweeters are much lower than those for the woofers. Most multi-channel amplifiers offer the same wattage for each amplifier channel, so a 200 watt per channel amplifier is fine for driving the woofers, but is much more power than is needed to drive the other speakers.
Multiple amplifiers can be used with different wattages to provide the appropriate levels of amplification to the different drivers. The gain of the amplifiers should be matched to work properly with the Orion-4 speakers. Many amplifiers multi-channel amplifiers are THX rated, so selecting amplifiers with the same gain is easily accomplished. If the amplifiers chosen to drive the Orion-4 speakers do not have equal gain, some amplifiers have individual channel gain adjustments that can be set to match the gain of a lowest gain amplifier. Alternatively, the Orion-4 ASP has circuitry to enable a modification of the output stage to match the gain of the signal fed to multiple amplifiers.
Orion owners have used a variety of amplifier brands to drive the Orion speakers. I have tested or heard the Orion-4 speakers with the following currently available amplifiers: (Listed with number of chassis and in alphabetic order).
(1) ATI AT-1806 - Six channels (180 w/ch. @ 8Ω) Two AT-1804 amplifiers will also work well for 8 ch.
(2) Bryston 9BSST2 - Available with four channels of amplification in each chassis. (140 w/ch. @ 8Ω)
(1) Marantz MM8003 - Eight channels in a single chassis. (140 w/ch. @ 8Ω)
(2) McIntosh MC-126 + Mc-122 Six and two channel amplifiers for eight channels (120 w/ch. @ 8Ω)
(4) Parasound A-23 Two channels per chassis (120 w/ch. @ 8Ω)
(2) Parasound A51 + A52 Five channels each (250 + 120 w/ch. @ 8Ω)
(3) Pass Labs X250.5 (one) and XA30.5 (two) 2 channel Class A amplifiers
***The X250.5 provides (250 w/ch. @ 8Ω) while the two XA30.5s provide (30 w/ch. @ 8Ω)
***Current Orion-4 demonstration amplifiers