Where it all began. Well, not really – I’d done a number of designs with cheap components as I learned a ton. This was the first one I got right – partly becuse I decided I was done with the cheap stuff, and invested in quality components for the first time.

A simple MTM that works well just about any way you need, this design is offered with a number of variations on the theme, and with multiple tweeter choices as well. It revolves around the Dayton RS-150-8 (originally RS150S-8) and is a 4ohm design. It can be built sealed (ideal for movies – pair with a sub and cross between 80Hz and 100Hz) or ported (tune between 38 and 42Hz). Baffle step assumes near-wall placement. Target crossover is 1800Hz 4th-order Linkwitz-Riley. This keeps this design usable to about 20° off-axis when placed horizontally.

The original version of this won the budget category at the 2005 Chicago DIY gathering.

Box design

The ported tower will extend a bit deeper (it’s tuned to ~37hZ stuffed with about half a pound of poly or less). Both will peak out at around 1.5W and a max output level of ~92dB if there is any significant bass below 40Hz. The smaller cabinet ported has slightly more power handling with a ~42hZ port tuning (stuff with about a quarter pound of poly, or less). The sealed box fares a bit better on power handling and will peak out at about 98dB. I have run into this in a few instances at what should be well under max levels, but I was also not listening with my SPL meter running – and I may have just done the “ooh, this one is good… gotta crank it a little more” just a bit too much. Still, these are really best suited to use with a good subwoofer if you are into heavy bass at high levels. My normal listening level is usually peaking at 75-80dB but with normal playback 65-68dB (at 3 Meters) and the clarity and detail of these excels here.

Seas 27TDFC, 27TBFC/G, or 27TDFCTV

Bill of Materials

  • (2) RS150-8 (RS150-S8)
  • (1) Seas 27TDFC, 27TDFC/TV, or 27TBFC/G
  • (1) 10μF capacitor
  • (1) 12μF capacitor
  • (1) 35μF capacitor
  • (1) 18ga .22mH inductor
  • (1) 18ga .40mH inductor
  • (1) 18ga 1.0mH inductor
  • (1) 2Ω resistor (10W+)
  • (1) 6Ω resistor (10W+)


Dayton RS28A or RS28F

Bill of Materials

  • (2) RS150-8 (RS150S-8)
  • (1) RS28A-4 or RS28F-4
  • (2) 12μF capacitors
  • (1) 25μF capacitor
  • (1) 40μF capacitor
  • (2) 18ga .25mH inductors
  • (1) 15-18ga 1.2mH inductor
  • (1) 1Ω resistor (10W+)
  • (1) 6Ω resistor (10W+)