A powerful sound source designed for building acoustics measurements per ISO 16283-1:2014 (replaces ISO-140/4 Annex A (Field measurements)).



The source provides uniform sound radiation. When used with the power amplifier Nor280, the high sound power level ensures accurate descriptors in measurement conditions that include high background levels, high sound insulation properties and large room volumes.

Nor275 is designed for placement on the floor and uses the floor as a mirror for emitted sound.

The loudspeaker is designed to operate at full power for more than one hour continuously.

The Nor275 is designed to be used with the Nor280 power amplifier only. Using other amplifiers may damage the speaker and will void the warranty.

Typical sound power level vs. frequency of the hemi-dodecahedron loudspeaker Nor275 when used with the pink noise source and equalizer included in the power amplifier Nor280.


  • Nor275 fulfil ISO 140-4 Annex A standard for airborne insulation measurements in field.
  • Powerful – 120 dB Lw
  • Lightweight (6 kg / 13.2 lb), portable and rugged design for field use.


Physical design: Hemi-dodecahedron
Sound power output: Using the Nor280 with pink noise, and equalisation: 120 dB (Lin)
Speakers: 6×6”
Power (broadband): 100 WRMS (max), Peak 500 W
Impedance: 5.3 Ω
Diameter: 355 mm (14”)
Height: 195 mm (7.6”)
Weight: 6 kg (13.2 lb)

Accessories incl. : – Speakon NL4FC plug replaced by a 5m assembled cable, if ordered with Nor280


  • Product Data: Noise excitation for Building Acoustics