The Orion-4 analog signal processor (ASP), designed by Siegfried Linkwitz, has been developed over several years. It has evolved to an exceptionally high level of performance during years of testing and listening comparisons to live music. The ASP provides an active crossover function as well some driver parameter compensation, cabinet design compensation, and driver time alignment.
An active crossover offers multiple advantages over passive crossover circuits including higher efficiency as there is no signal loss as happens with passive components. The efficiency of the Orion-4 speakers is basically the efficiency of the high quality drivers used in the Orion-4 design. Active crossovers isolate the driver signals so that when a large bass passage places high current demands on the amplifier, the other signals are largely unaffected by this, assuming a good power supply is incorporated in a multi-channel amplifier or independent amplifiers are used, as the signals are driven by independent channels or amplifiers.
The inputs from the music source, usually a preamplifier or DAC with volume control, to the ASP support balanced or RCA (single ended) connections. The outputs are four RCA connectors for each channel. They are tweeter, midrange, upper woofer, and lower woofer. These outputs connect to four amplifier inputs. If the woofer amplifier output connections are wired in parallel, the Orions can be driven with six channels of amplification and use only a single woofer output from the ASP. When the woofers are driven independently, then eight channels of amplification are used for the speaker pair. If multiple amplifiers are used rather than a single or two multi-channel amplifiers, the gain of the amplifiers must be the same or adjusted to be the same. If needed, the output circuitry of the ASP can be modified to accommodate this gain matching function. The ASP design incorporates a universal power supply that operates at domestic or international power source levels.
The ASP includes a flat or cut switch and two LED indicators to show which position is active. The cut position activates a 6db per octave roll off starting at 30 Hz. This allows the playing of recordings with subsonic noise on the recording, while limiting the woofers extraneous cone movement. This circuit can also be activated for reducing the cone movement due to turntable rumble.