Impedance tube
Mecanum’s conventional impedance and transmission tube measures the key acoustic indicators of a wide range of materials using 2, 3, or 4 microphone methods. Available in 29 mm, 44.4 mm, and 100 mm diameters, with custom sizes on request, it follows ASTM E1050, ASTM E2611, and ISO 10534-2. Its small-sample format makes it well suited to rapid prototyping, quality control, and teaching.
Performance
Frequency range
29 mm impedance tube: 50 Hz to 6600 Hz
44.4 mm impedance tube: 45 Hz to 4300 Hz
100 mm impedance tube: 35 Hz to 1800 Hz
Hard wall measurement (zero absorption)
All ⅓ octave until 4 kHz < 4 %
⅓ octave 5 kHz and above < 10 %
Dimensions & sample thickness
Dimensions
29 or 44.4 mm impedance tube: 800 (L) x 200 (W) x 200 (H) mm
100 mm impedance tube: 1200 (L) x 200 (W) x 200 (H) mm
Max sample thickness
2 microphones absorption: 250 mm
3 microphones transmission: 220 mm
4 microphones transmission: 125 mm
Measured properties
Tube-X
Tube-X guides you through normal-incidence absorption and transmission loss measurement in a single, intuitive window, clear enough to be productive from the first use. It supports all 2, 3, and 4 microphone methods alongside advanced research features, and lets you save raw data to run your own post-processing. Built-in tools take measurements further, averaging, smoothing, merging curves across frequency ranges, adding an air cavity, comparing projects, and a one-click, ISO/ASTM-ready Excel report turns results into professional documentation.
Coming soon.
Automotive industry
Characterize trim, foams, and sealing materials at normal incidence to feed cabin-noise models early in development.
Aerospace industry
Evaluate engine and silencer liners under grazing incidence, and qualify lightweight absorbers against tight weight budgets.
Material manufacturers
Validate absorption and transmission loss on small samples to support datasheets and incoming quality control.
Building
Screen porous absorbers and multilayer materials before scaling up to full partition or room testing.
Laboratories
Run fast, standards-compliant absorption and transmission loss measurements on small samples for rapid prototyping.
Universities
Teach absorption, reflection, and transmission hands-on, with a compact setup that introduces measurement and signal processing.
Optional accessories, available with your impedance tube or separately.
Circular knife
The circular knife lets you cut clean, repeatable sample geometries from porous materials, so each specimen fits the tube precisely and edge effects stay minimal. Consistent sample preparation is one of the simplest ways to improve measurement repeatability.
Material slicer
The material slicer holds a porous sample firmly in place while you cut it to thickness, giving you flat, parallel faces and a controlled height. It removes much of the guesswork from preparing soft or compressible materials that are otherwise hard to slice evenly.
Grazing incidence sample holder
With the grazing incidence sample holder, the impedance tube evaluates liner performance under grazing conditions that mirror real operating environments. Using the four-microphone transfer matrix method, it derives impedance and transmission loss for aircraft engine liners, muffler coatings, and pipe treatments.
Weather station
The weather station measures the ambient temperature, pressure, and humidity at the moment of testing, the atmospheric conditions that influence the speed of sound and, in turn, your acoustic results. Logging them alongside each measurement keeps your data accurate and traceable.
Square add-on
The square add-on adapts a circular tube to measure square specimens such as metamaterials, whose periodic geometry does not fit a round cross-section. It extends the tube to non-conventional samples without requiring a dedicated square instrument.
Fabric sample holder
The fabric sample holder ensures a sealed, repeatable installation of fabrics, resistive films, and other thin materials that would otherwise leak air around their edges. A proper seal is essential for these materials, since even small leaks distort the measured absorption and impedance.
Muffler adapters
The muffler adapters connect mufflers and similar components directly to the tube, so you can measure their acoustic indicators as complete assemblies rather than as material samples. They open up transmission loss and impedance testing on real exhaust and silencer parts.