ZX82 2.1ch Subwoofer & Satellite Loudspeaker System

This great sub-sat system requires a print area of 200x200mm for the subwoofer, and slightly less for the satellites. These use sealed speaker modules from Tang Band; the full range T1-2121SD in the satellites, and the T2-2181SA subwoofer module. It's a very user friendly build, no external circuitry or tuning is required and the quality of the 3D Print is not critical to the sound quality. The usable frequency range is 50Hz to 16kHz. I've attached a frequency response curve, measured in my office, not under controlled conditions.

At the time of writing, the modules are about $30 USD each, and are available from parts express:
https://www.parts-express.com/tang-band-t1-2121sd-speaker-module-5-7-16-x-2-3-16--264-948
https://www.parts-express.com/tang-band-t2-2181sa-2-subwoofer-module-6-7-8-x-2-3-4--264-940

The satellites print in three parts; the stand, the back cover and the decorative trim. The back screws into the stand (2x M3 screws), clamping the module in place. The trim can be glued to the front, or held with bluetack, allowing you to swap out colors. The speaker cable feeds through a channel in the body and out of a hole at the back. To avoid any rattles, use a few blobs of bluetack between the speaker and the stand, and the speaker and the back cover. You need to solder the wires to the terminals on the module. Some support is needed for the "stand" component. Make sure your slicer does not put support in the cable channel!

The subwoofer prints in two parts which screw together, clamping the module (6x M3 screws). You need to unscrew the existing mounting tabs from the module. Use bluetack between the module and the frame to prevent rattling, there is a clearance of 1mm for this purpose. Use enough bluetack to fill that gap. You will need to either put some additional weight inside the top of the subwoofer, or use bluetack to hold it down, otherwise it will dance about on the table. (There are some M3 holes inside the top surface to fix things there if needed.) You need to solder the wires to the terminals on the module.

I recomend a standard 2.1 channel class D amplifier with the crossover around 150Hz. The subwoofer powerhandling will increase if you also use a high pass filter at about 50Hz, but this is not essentail.

These speaker modules are really pretty good for the price and very good for their size. They also have a very uniform sound distribution, making them great for desktop use. The full range units have a peak in response around 14kHz, this may sound either crisp or a bit tinny, depending on your point of view. Use your equalizer to push the response down slightly above 10kHz, and you'll find they can sound very natural.

For an amplifier, you might try this:
https://www.amazon.com/Nobsound-TPA3116D2-Amplifier-Independent-Adjustment/dp/B074J9X3P5/
or this:
https://www.parts-express.com/21-hi-fi-class-d-audio-amplifier-board-2-x-15w-30w-10-18-vdc--320-608

Category: Audio