Ultra compact passive fill loudspeaker


Ultra-compact two-way passive, infinite baffle loudspeaker

Astonishing LF performance for enclosure size

Signature EM Acoustics passive crossover for unprecedented frequency and phase response

5" LF drive unit, 1.1" diaphragm soft dome HF drive unit

An ultra-compact passive loudspeaker for use where compact size is as important as sonic performance. The EMS-51 is a compact two-way multipurpose loudspeaker intended for a variety of applications – either as a stand-alone product, or else with the incorporation of i-8 or EMS-112 subwoofers to make a truly fullrange system.

  • Gentle 12dB/octave low frequency roll off
  • 75° conical dispersion allows vertical or horizontal orientation
  • Premium 12mm multi-laminate birch plywood enclosure
  • Black or white textured paint finish
  • Optional weather protection or RAL custom colours
  • Multiple threaded rigging and mounting points
  • Perforated steel grille
  • Horizontal and vertical mounting yokes supplied

The EMS-51 is completely passive, yet outperforms many bi-amplified or DSP-processed designs. The enclosure contains a 5” (127mm) LF drive unit, linked via the internal passive crossover network to a 1.1” (28mm) diaphragm HF soft dome drive unit which produces a 75° conical dispersion pattern. Unusually for a loudspeaker of this size, it is an infinite baffle design which gives a smoother LF rolloff and a much more robust LF performance than would be expected from an enclosure of this size.

The robust enclosure is constructed from premium multi-laminate Birch plywood and is finished in impact resistant textured paint. Two NL4 connections are provided on the rear for input and enclosure link. The front of the loudspeaker is protected by a rigid steel grille. Various threaded fixings are provided in the enclosure for the included rigging hardware. RAL colour matching and weather protection options are also available if required.

The EMS-51 requires a single amplifier channel, and should be used with professional power amplifiers capable of delivering 300-500W RMS into an 8-ohm load. For optimum results, the EM Acoustics DQ Series Advanced System Amplifiers, or the AQ Series power amplifiers in conjunction with the DSC48 system controller (for loudspeaker protection) should be used.

Enclosure TypeTwo-way passive, infinite baffle
Components1 x 5" (127mm) LF drive unit
1 x 1.1" (28mm) HF soft dome drive unit
Dimensions (HxWxD), mm/ins250 (9.9) x 140 (5.5) x 175 (6.9)
Net/Shipping Weight4.5/5.3kg (9.9/11.7lbs)
Frequency Response80Hz - 20kHz ± 3dB
Nominal Dispersion75° conical (-6dB points)
Maximum SPL113dB continuous, 119dB peak
Power Handling200W RMS, 400W peak
Nominal Impedance8 ohms

YK-51v vertical yoke

YK-51h horizontal yoke

Case Studies


Top Billing at The Atkinson

We chose EM Acoustics products because we have been extremely impressed with them on recent projects. Simply put, we believe that there is little to compete with them at this price point.

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