D-Box SD20AS Mini Monitors, Metal Cabinets and Grills

D-Box SD20AS Mini Monitors, Made in Canada, Metal Cabinets and grills

The D-Box SD20AS is a compact Canadian-made 2-way bookshelf/satellite speaker from Synthedata, designed as a heavy-duty mini monitor for use with a subwoofer-based music or home theater system.

Each SD20AS uses a 3.5-inch woofer and a 1-inch metal dome tweeter with diffuser in a dense die-cast metal enclosure, giving these small speakers surprising heft and a very solid, resonance-resistant feel for their size. They are reminiscent of the famous Realistic Minimus line of mini speakers, but with cabinets that feel at least as substantial and arguably even more solidly built in the hand. Frequency response is approximately 90 Hz–20 kHz, with bass rolling off sharply below about 100 Hz, so they are intended to be paired with a subwoofer to handle true low-frequency duties. With an 8-ohm impedance, modest 10–40 watt RMS power rating, and real-world sensitivity in the mid-80 dB range, they are best matched with quality receivers or integrated amplifiers rather than very low-powered tube gear.

In use, the SD20AS excels at clean mids and crisp, focused highs, making dialogue, effects, and acoustic instruments easy to follow even at moderate listening levels. Their compact footprint and rear spring-clip terminals make them a practical choice for surround, height, or compact stereo duties where space is tight but rugged build and clarity are still priorities. Cosmetic condition on this pair is very good, with only light signs of use and no major marks, and the heavy cast cabinets still present as purposeful, understated industrial design.

Passive 2-way bookshelf/satellite speakers (pair)

Made in Canada by Synthedata/D-Box

3.5-inch woofer

1-inch metal dome tweeter with diffuser

Approximate frequency response: 90 Hz – 20 kHz

Intended for use with a subwoofer (steep bass roll-off below ~100 Hz)

Power rating: 10–40 watts RMS

Nominal impedance: 8 ohms

Estimated sensitivity: ~84–86 dB @ 1W/1m

Heavy-duty die-cast metal cabinets, very dense for their size

Rear spring-clip terminals for bare speaker wire

Very good cosmetic condition

Dimensions (Width x Height x Depth): 4.5 x 7 x 4.5 inches (11.4 x 17.8 x 11.4 cm) per speaker

Weight: 4.1 lbs (1.9 kg) per speaker

This Canadian-made pair of D-Box SD20AS speakers offers rugged, high-density construction and clear, focused sound in a remarkably compact package, ideal as surrounds, satellites, or desktop monitors when combined with a capable subwoofer. Their very solid build, easy amplifier load, and tidy cosmetics make them a smart, space-efficient option for buyers looking to upgrade from plastic satellites or soundbar add-ons without sacrificing clarity.

A matching pair of metal adjustable wall mounts sized for these speakers is available for an additional $30, perfect for clean, flexible placement in surround or height-channel roles.

Backed by Radique Audio’s 90-day Bumper to Bumper Warranty and our Perpetual Trade-Back Policy, you can purchase with confidence; asking $95 or $125 with the matching Metal Wall-Mounts.