The Nor276 is a high power loudspeaker with omnidirectional characteristics.

It fulfils the following standards; ISO 140-3 Annex C (Laboratory measurements), ISO 140-4 Annex A (Field measurements) and the ISO3382 Annex A (Reverberation Time measurements).

The output power level is up to 120 db re. 1pW for a pink noise signal.

The Nor276 has been designed for continuous operation for more than one hour at full power. It is designed to be used with Nor280 Power Amplifier only. Using other amplifiers may damage the speakers and will void the warranty.

The dimension is 332 mm (13”) diameter.

Geonoise Noise registration instruments and software

Geonoise Thailand Co., Ltd.
Address: 6/54-56 Poemsin Soi 42,

10220 Sai Mai, Bangkok, Thailand

Phone: (+66) 02-1214399

Noise Excitation Equipment for Building Acoustics Measurements

Nor276 Dodecahedron Loudspeaker

Typical sound power level vs. frequency of the Dodecahedron Loudspeaker Nor276
when used with the pink noise source and equalizer included in the Power Amplifier Nor280.

Maximum and minimum directivity indices in different directions
according to the requirements in ISO 140-3 and ISO 140-4 compared to the tolerance limits.

Maximum and minimum directivity indices in different directions
according to the requirements in ISO 3382-1 compared to the tolerance limits.

Sound power in different directions for Nor276. The measurement is done in a horizontal plane through the centre of the loudspeaker. The graph shows the response for a sinusoidal signal at 100 Hz, 315 Hz, 1 kHz and 3,15 kHz.  

Nor277 Tapping Machine

For making footfall noise transmission measurements in buildings as set out in International and National Standards

– Impact sound transmission testing according to ISO 140 part VI, VII and VIII, ASTM E-492 and ASTM E-1007
– Determination of single number quantity index Ln,w, in accordance with ISO 717-2 and ASTM E-989
– Remote operation from hand switch or PC
– Mains or battery operation
– Powered from 85-264 volt AC main supply. Built in Lithium Ion rechargeable batteries.
– Battery capacity: Typical 1 hour with intermittent use and 45 minutes of continues operation.
– Battery de-rating: <5% loss in capacity per 100 discharge/charge cycles.
– Charging time: 2 hours
– Compact
– Low weight 10 kg (22 lb) incl. battery and wireless remote option
– Rugged construction
– Five hammers each having a mass of 500 g falling from a height of 40 mm (adjustable)
– Tapping sequence of 10 impacts per second, rpm controlled via servo feedback loop
– Built in self check of hammer fall speed, and tapping sequence.
– Retractable feet
– Dimensions feet retracted: 165 x 230 x 495 mm (6,5 x 9,1 x 19,5″)
– Dimensions feet extended: 265 x 230 x 495 mm (10,4 x 9,1 x 19,5″)

Nor280 Power Amplifier

Our aim is to take the latest technology available to help our customers complete their measurements faster but without loss of precision. With the Nor280 we have again met this objective.This power amplifier is the 4th generation of specially designed units for building acoustic measurements from Norsonic. It is less than half the size and weight, but twice as powerful as its predecessors; it replaces the Nor260 as the preferred amplifier to drive the Norsonic range of full and hemi dodecahedron instrumentation loudspeakers.


– Specially designed for Building Acoustic measurements
– Lightweight and rugged construction
– Self contained noise generator
– 500 Wrms output power
– Emits 120 dB sound power level in the 50—5000 Hz frequency range when used with Norsonic dodecahedron loudspeakers types Nor275 or Nor276
– Wireless remote control of noise generator (optional)
– Equalization network to optimise acoustic output from speaker
– Balanced signal input for low noise and limited cross talk problems


– Sound insulation measurements
– Reverberation time measurements
– Absorption coefficient measurements

Download Brochure Norsonic Noise Source