TBI subwoofers

Getting good bass is surprisingly challenging yet essential for true high fidelity sound.

Local Georgia company TBI audio systems produces subwoofers that are very fast and generate totally natural sounding bass quite different from the usual driver in a box. By really quite ingenious design, TBI subwoofers couple to the air in the room with very good impedance matching, and pass non-resonant low frequency signal energy in prodigious amounts via a high pressure/velocity port. Normal subs "boom" because the driver is allowed to more freely resonate. With TBI subwoofers, the main resonance peak is deliberately moved up to over 100Hz (verified by impedance plots) so the driver is always under control of the bass note signals below this frequency.
This is immediately apparent on listening. Natural sounds are much more "true to life". Low frequency cycles, rich harmonic overtones, sub-harmonic beating, can all easily be heard. Everything starts and stops on a dime. Synthesized dance music is brilliantly articulated with rapidly changing bass notes clearly differentiated perfectly following the recording. The band sounds together and on beat.

Many high end subs claim to have these desirable characteristics but when trying to augment a good 2-channel stereo system they rarely ever entirely satisfy.
For most subwoofers, as sound level is increased, the sub becomes more & more localized and separated, partly because it always has a difference resonance to the main speakers. Subs which claim to "move vast amounts of air" are worse; the inertia of the cone & motor assembly, and the time it takes to move over an inch back and forth can't keep up with the sound signal. The appearance of a second resonance to the main speakers compounds the problem - it is not just a matter of speed - so they never fully integrate or sound right. They flap around loosing their "grab" on the "fluid" air particles and fail to fully vibrate the air in lock with the sound signal.

You don't hear sound "coming" from TBI "subs" at all; they neither add nor subtract anything from the main speakers. If the bass from your main speakers sounds tight - it still will. If it sounds full bodied - it still will. TBI "subs" seamlessly extend the bottom octaves while preserving the characteristics of your main speakers. CDs do deep bass better than vinyl or reel to reel tape - and without compression - and capture all sorts of concert hall infra sonic information; even foot taping on stage! The sense of "being there" is enhanced
The non-resonant room coupling of TBI "subs" has other benefits. By stabilizing the air in the room to support rather than confound the loading on the main drivers, cone breakup from room interaction is reduced enhancing midrange clarity, presence, 3-dimensionality, and spaciousness.

Being more compact, locating a TBI sub centrally between the main speakers is possible. This is often the best location for room acoustics. With little external cabinet energy one can even be placed on a shelf in the equipment rack.

TBI audio systems makes one active subwoofer that has a built in amplifier, the rest are passive designs requiring one of the TBI external high quality amplifiers. Once incorporated into a system TBI subs will remain on all the time!

These subs are a bit of a "sleeper" product that don't get a lot of press coverage. They work well with electrostatic speakers. Contact kemela for a home demo (local Atlanta area customers only)

TBI Audio subwoofers


  • 20Hz-200Hz(-6db) freq response
  • 100W RMS power handlind 90db 1w/1m efficiency
  • 6.5" Low mass aluminum cone 8 ohms nominal impendance
  • 14.5"W x 14.5" D x 5.5" H (spikes add 1.5") 15 LBS


  • 18Hz-150Hz(-6db) freq response
  • Built in high quality 120Watt amplifier
  • RCA line and 5 way speaker binding post inputs
  • 14.5"W x 17.5" D x 5.5" H (spikes add 1.5") 20 LBS


  • 12Hz-160Hz(-6db) freq response
  • 175W RMS power handling 87db 1w/1m efficiency @ 25Hz
  • 8" Low mass aluminum cone 8 ohms nominal impendance
  • 17.5"W x 17.5" D x 6.8" H (spikes add 1.5") 26 LBS


  • Recomended where higher cross over point is required
  • 22Hz-200Hz(-6db) freq response
  • 200W RMS power handling 90db 1w/1m efficiency @ 28Hz
  • 17.5"W x 17.5" D x 6.8" H (spikes add 1.5") 28 LBS


  • New ISOteric™ design - custom order only call for details
  • 15Hz-250Hz(-6db) freq response
  • 250W RMS power handling 93db 1w/1m efficiency
  • 120db @30Hz maximum sound pressure
  • 14"W x 14" D x 19" H 40 LBS

TBI 200 su Power Amp

  • High quality 150Watt 8 Ohms 200Watt 4 Ohms amplifier
  • 4-way Binding posts/RCA line inputs
  • Adjustable level and crossover with phase switch
  • 6.25"W x 8" D x 6.75" H 6 LBS

TBI Majestic Diamond II

  • Minimum compression design for even response
  • Works well close to the wall where other speakers excite room resonances
  • 40Hz-23KHz(-6db) freq response in room at 3m
  • 75W RMS power handling 87db 1w/2m efficiency
  • 7"W x 7" D x 10.25" H 8.5 LBS


Magellan VI su
Magellan VIP su
Magellan VIII su
Magellan VIII xu
Emperor su

Power Amps

200 su

HDSS® Speakers

Majestic Diamond II