This subwoofer is VERY TIGHT, MUSICAL, and defies its size! I run a pair of them and the construction is solid enough to serve as stands under my ADS speakers! Even with the lowpass filter extended all the way up, (just to test) there is no hint of boom or upper bass peakiness! The variable phase control is something that I won't listen without ever again! The front firing, bottom ported design is efficient and smart-- energy is emitted from two perpendicular planes-- makes integration easier! KEEPERS, small, big sound, TIGHT!! Integrates very easily!! I even went so far as to switch the LED color to white, took 10 minutes. I love these, and dont plan on getting rid of them anytime soon. RCA jack was finnicky due to factory glue seeping between grounding washer and jack on the inside. No problems otherwise. The woofer takes some time to completely break in. Mighty sub! Only complaint is the look of the volume knob on the front, nothing a little plastic paint cant fix, though.

Underrated.

This sub is essentially the same thing as the Mirage S8 (API) but with a continuously variable phase adjust, a slightly different rolloff filter, slightly different cone material, controls layout and enclosure design. Schematics and specifications are very similar. Woofer has an inert, vented, cast resin frame. It appears as though the output transistors are discrete, port is flared on both ends. Good.
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Again, very tight and size defying.