This is an electronic crossover that has 2 sub outs- one output has phase control for 0 to 180 degrees to fix room placement issues and is infinitely variable from 30Hz to 170Hz . It has 3 high pass outs- the first is 50Hz the 2nd is 80Hz and the 3rd is 120Hz. There is a 70 db scale for adjusting sub-woofer level as well. This is a great piece for bi-amping or use in a home theater.
The X-30 measures only 1.85"H x 7.25"W x 5"D and uses a 24-volt wall-wart power supply that plugs into its rear panel.
The X-30 employs high-quality active circuitry. The high-pass section topology is third-order active Sallen-Key, implementing a Butterworth transfer function. Butterworth is claimed to give the best compromise between attenuation rate and group delay. The X-30 uses 1% metal-film resistors and 5% metal/polyester-film capacitors. The low-pass section also uses a third-order, 18dB/octave slope.
The X-30 is a line-level device, made to work in conjunction with a stereo preamplifier’s main outputs. It will also work with receivers or integrated amplifiers that have variable preamp line outputs -- not tape outputs. .
I found the variable phase control to be a particularly useful feature. When the sub-woofer is not located in the same plane as the main speakers, as will be the case in many installations, time-delay errors will occur and result in cancellations and suck-outs of other bass frequencies. Use of the variable phase control and level output can really fine-tune a system more so than the bass management found on most home theater gear.
Includes crossover, power supply and an approx 15 foot mono to RCA cable for sub-woofer to crossover- some lettering is a bit worn but perfectly functional- pm for pictures. Manual extract included - This really is one of the great audio bargains in active crossovers and has only been equaled by my Audessey set up. Price is fair and firm as this is one that- for any less you keep in the "rainy day" drawer. Price includes parcel post shipping in Canada/US. Payment by EMT , PayPal or international postal money order. Lots of feedback on other sites -audiogon, ebay, canuckaudiomart-same id