The Zircon is a loudspeaker-microphone probe for measuring in situ the absorption and reflection properties of surfaces. These may be indoor surfaces, such as in concert halls and gyms, or outdoor surfaces, such as road surfaces (ISO 13472-1), sound barriers installed in a free field (NF S 31-089) and traffic noise reducing devices (CEN/TS 1793-5).

Using the wall measurement stand, the Zircon can be rotated horizontally and vertically, and is provided with 10° step angle indications. When using the floor measurement stand, the Zircon can be rotated vertically over 360°.

The Zircon components are easy to dismantle and transport in their flight cases.

Zircon wall absorption setup

For wall measurements, a setup including the Zircon Probe and the Zircon W-stand is used.

Zircon connection setup

The Zircon is connected to an analyzer such as Dirac running on a notebook PC, with integrated sound device or external sound device such as the Triton, and using a power amplifier, such as the B&K Type 2734.

The analyzer generates an excitation signal, such as an MLS or sweep signal, which is fed to the loudspeaker. The microphone picks up the direct and reflected sound. From the sent and received signals, the analyzer calculates the impulse response. From the impulse response, a direct and a reflection part are extracted by windowing, subtraction and other techniques. By comparing these signal parts, the absorption and reflection properties of the surface under test are obtained.

Zircon signals

The low end of the usable frequency range is determined by the (limited) length of the time windows. The direct sound time window cannot be made so long as to overlap the reflected response, whereas the reflected sound time window is limited by the tail of the direct response, and the parasitic reflections. Both windows can be extended by using the subtraction technique as described by E. Mommertz in 'Angle-dependent in-situ measurements of reflection coefficients using a subtraction technique' (Applied Acoustics, Vol.46, 1995, pp. 251-263).

For floor (e.g. road surface) measurements, a setup including the Zircon Probe and the Zircon F-stand is used.

Zircon floor absorption setup


  • Optimal ergonomic design.
  • Wall measurement stand provided with 10º angle indication in 2 dimensions.
  • Floor measurement stand enables vertical rotation over 360º.
  • Tethered constructions ensure high stability and acoustic transparency.
  • Ergonomically placed grips for easy handling.
  • Easy to dismantle and transport.
  • High performance miniature microphone.
  • Includes light-weight protective flight cases.
  • Includes cables with connectors and lengths of your choice.



You can download the Zircon datasheet including all specifications as a pdf.



Zircon Probe
Parameter Condition Min Typ Max Unit
LS14 loudspeaker unit
Operating frequency range Third octave frequency bands 50 10000 Hz
Nominal impedance 8
Power handling Continuous
Sound pressure level At 1m distance in front, at 50 W applied power 104 dB
Microphone power supply PP3 battery 9 V
Connectors Microphone input
Microphone output
Loudspeaker input
3-pole XLR
Weight 9.5 kg
DPA 4060-B microphone
Diameter Prepolarized condenser element 5.4 mm
Operating frequency range -3 dB 20 20000 Hz
Sensitivity at 1 kHz 14 20 28 mV/Pa
Equivalent noise level CCIR 468-1 35 38 dB
MM14 microphone mast
Source-microphone distance Without microphone insert
With microphone insert
Weight including microphone insert 0.9 kg
FC14 flight case
Dimensions 45x45x45 cm
Weight Filled completely 20 kg
Zircon W-stand (for wall measurements)
Parameter Condition Min Typ Max Unit
WS14 stand
Horizontal angle of rotation 10° angle indication with optional snap function unlimited deg
Provided Zircon height Rotational center locable at 1.6, 1.8,2 . 2.2 m. Tensable at 2 m 1.5 2.2 m
Weight Without snap function 4.5 kg
VS14 vertical swivel fork
Vertical angle of rotation LS14 loudspeaker unit 10° angle indication with optional snap function 40 90 320 deg
Mounting screw distance 2 knurled M6 screws 45 mm
Bottom plate width 40 mm
Weight 2.5 kg
FC15 flight case
Dimensions 125x35x17 cm
Weight Filled 16.5 kg
Zircon F-stand (for floor measurements)
Parameter Condition Min Typ Max Unit
SW12 stand wheel units
Provided additional stand height 13 cm
Dimensions Each unit folded L x W x H 69 x 35 x 20 cm
Weight Each unit 8.5 kg
FS14 stand
Provided source height including SW12 units 1.25 m
Flight cases
Dimensions L x W x H FC16 (tubes)
FC17 (tripods, table, wires)
FC18 (stand wheel units)
110 x 17 x 14
123 x 37 x 22
73 x 39 x 39
Weight FC16, filled
FC17, filled
FC18, filled


The Zircon comprises 3 products.

  • Zircon Probe: LS14 loudspeaker unit, CA12 loudspeaker cable assembly, FC14 flight case, DPA 4060-B microphone, MM14 microphone mast, CA14 microphone cable assembly.
  • Zircon W-stand (for wall measurements): WS14 stand, VS14 vertical swivel fork, FC15 flight case.
  • Zircon F-stand (for floor measurements): 2 SW12 stand wheel units, FS14 stand, FC16, FC17 and FC18 flight cases.

Each product or component can be ordered separately. For pricing and other ordering information, please contact us.