Here, for your consideration, is a complete Rythmik Audio 350 watt DirectServo powered subwoofer kit. This was Rythmik’s original design back in 2004, when Brian Ding was first getting into the direct-to-consumer audio business, and before Rythmik actually started putting their logo on some of their products. The sub is in good working condition (please use the photos to serve as a more detailed description of its physical condition).  There are a couple of scuffs, but no dents or dings in the wood.

The complete assembled kit includes a GR 12” long-throw polypropylene woofer, a 350 watt rms amplifier modular with variable active crossover, speaker and amp module gasket material, acoustic polyester stuffing (for damping), and a Rythmik constructed enclosure.

The enclosure is a sealed design comprised of a combination of MDF and particle board totaling 1 1/4” thick. The cabinet is in its raw state, covered with a nice veneer and 1/4” round molding. The cab is sanded to perfection and ready to be stained and finished (or left in all its natural beauty!). Cabinet dimensions are approximately 22" x  20" x 15"

The amplifier is 350 watts rms. Here are some of the features in the amp design:

Thermal-coupled MOSFET differential input stage for the power amplifier

● No electrolytic caps on signal paths, nor feedback paths

● Adjustable bass extension control (with both frequency and damping)

● Audiophile grade MIL current sensing resistor

● Integrated 3/16" thick one-piece aluminum back plate and heat sink for better heat dissipation.

● Dimension: (W)10-3/8" x (H)12-7/16" x (D)4".

● Cutout Dimension: (W) 9 1/8" x 11 1/8"; 4" clearance in depth.

The amp has been optimized to work either in a sealed enclosure or in a vented design. By a simple flip of a switch on the amp (inside), the circuitry selects the optimum feedback control for the box design you've chosen. The amp is very flexible in terms of connection options and variable output. There are four sets of speaker level outputs as well as two pairs of L/R line level outputs. There is a volume control, variable crossover, as well as a 180° adjustable phase controller. The amp also has an auto on/off power switch, which automatically turns on the amp when a signal is detected. Bass extension is adjusted using the frequency and damping toggle controllers. Frequency settings are 14 Hz, 20 Hz, and 28 Hz. The damping can be set to low, medium, or high. Setting the damping to low provides a 3 dB gain, and the medium gives you 1.5 dB gain. This adjustment is most useful when fitting the sub into your existing system and room. For example, if your room has a lot of gain and the sub sounds too boomy, you can set the damping to medium or high to reduce this artifact. If you want maximum bass, the low setting works best.

For your information, I took some measurements using both the medium and low damping settings and have included them in photos 13 and 14.

An almost identical kit (their current version of the kit) just auctioned off on eBay (driver and amp only with no cabinet) for $568.00.

This subwoofer is pure vintage Rythmik that started it all! The rest is history!

I explain my sale items with as much detail as possible to try and avoid any surprises, but if you have any questions, feel free to message me BEFORE buying. If you would like to see additional photos, contact me, and I'll be glad to send them. In order to allow for additional photos if requested, I will pack up the speaker well once sold. Please allow up to 3 business days.

This sale is for US buyers (lower 48 states) only. No international offers will be accepted. I will ship only to an eBay confirmed US address, with a SIGNATURE CONFIRMATION REQUIRED upon delivery. I will ship the cabinet via UPS using the eBay discounted rate, so you pay what I pay (this sub is a beast weighing about 60 lbs!).

Buyer must have a minimum feedback rating of 10, or the order will be canceled.

Thanks for looking!