The EMB II Series was essentially engineered to address a common problem with all subwoofers - distortion at low frequencies. The inherent challenge of any driver in reproducing sound is to generate the requisite diaphragm excursions linearly and accurately. At very low frequencies, such excursions are substantially greater than at higher frequencies, so the probability for error increases dramatically. The end result is usually some harmonic distortion, for which multiples (or harmonics) of the intended (or fundamental) frequency are produced in small amounts (relative to the fundamental). One way to address this is to use two active drivers, which share a common enclosure. By wiring them out of phase, and orienting them appropriately, the harmonic distortion is dramatically reduced through internal cancellation. The EMB II Series subwoofers employ a unique approach to address harmonic distortion. The passive radiator has been tuned such that its resonance frequency is at around 35 Hz. The active driver has been tuned at a different resonance frequency, and also has been strategically equalized. The key is to engineer the frequency response of the active driver, such that when combined with the passive radiator, the resultant output is linear and flat in frequency response. Theoretically, lower distortion and more accurate performance of the active driver is achieved, simply by producing smaller cone excursions, and the passive radiator generating the bulk of the acoustical output. Because the radiator has been tuned with its acoustical peak in the region of frequencies where bass energy in music and movie soundtracks tend to be greatest, the active driver can operate at the frequencies within its linear cone excursion range, and rely on the passive radiator to simply "amplify" its output. There are two other beneficial consequences of the EMB II Series design. The first is that a relatively small sized cabinet is possible, or equivalently, a subwoofer can be designed with a more compact size, to produce the same output as a more conventional, considerably larger subwoofer. The second is that greater efficiency in terms of required amplifier power can be realized. EMB21 features (1) 21" Internal Active Driver and (1) 21" EMB Passive Radiator. Sealed non-resonant aluminum enclosure, matching aluminum grille. Standard finishes include Satin Black or Gloss White - custom colors and finishes are also available.

Product Documents

• CAD drawings

  • EMB21 CAD Drawing (PDF)
  • EMB21 CAD Drawing (DWG)

• Datasheets/Cutsheets

  • EMB21 Datasheet

Related Documents

• Brochures

  • Full Line Brochure
  • Hidden Subwoofer Brochure
  • Interior Product Brochure

• Color Samples/Finishes

  • Standard Powder Coat Finishes

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