Measurement Microphone Capsules, Preamplifiers & Accessories
Class+ Microphone Capsules

Cirrus Research plc provides a range of measurement microphones, preamplifiers, power supplies and microphone accessories.
The Class+ Microphones are a range of high performance ½” Pre-polarised Electret condenser capsules designed for use on Sound Level Meters and Noise Measurement Equipment. The range also includes a wide range of accessories that enhance the performance of the Class+ Capsules.
Key features of the range include:
- Pre-polarised Electret Condenser Technology
- International Standard ½ Capsule with Type 1, Type 2+ and Type 2 versions
- Long Term Stability & Reliability
- High Accuracy
- Ideal for OEM Specifications & Replacement
- Wide range of variants & accessories
- Compatible with Brüel & Kjær Type 4155 & 4189
All of the Class+ capsules are based on the same technology, with all of the capsules being mechanically compatible.
At the top of the range, the MK:224 capsule is fitted to several leading brands of Sound Level Meters as well as PC based instruments and Noise Monitoring Systems. In many applications, the use of the most accurate microphone capsule is excessive, and a lower specification can be accepted. In these situations, the Class+ microphone capsules are ideal replacements for existing units at significantly lower cost, often less than 50% of competing units in OEM applications.
The MK:224 is the most accurate and stable of the Class+ Microphone capsules and is used on the Cirrus Research plc Type 1 Sound Level Meters, Noise Analysers and Noise Monitoring Systems. The excellent long term stability and temperature stability allow the capsule to be used in long term outdoor monitoring applications, and has been in use in Cirrus Research plc Airport Noise Monitoring systems over periods of many years.
The Class+ Microphone Series includes three other microphone capsules, the MK:226 Class 1, MK:216 Class 2+ and the MK:215 Class 2.
These capsules are produced using the same design and technology as the leading MK:224 capsule, but have reduced specifications.
At the top of the range, the MK:224 capsule is fitted to several leading brands of Sound Level Meters as well as PC based instruments and Noise Monitoring Systems. In many applications, the use of the most accurate microphone capsule is excessive, and a lower specification can be accepted. In these situations, the Class+ microphone capsules are ideal replacements for existing units at significantly lower cost, often less than 50% of competing units in OEM applications.
The MK:224 is the most accurate and stable of the Class+ Microphone capsules and is used on the Cirrus Research plc Type 1 Sound Level Meters, Noise Analysers and Noise Monitoring Systems. The excellent long term stability and temperature stability allow the capsule to be used in long term outdoor monitoring applications, and has been in use in Cirrus Research plc Airport Noise Monitoring systems over periods of many years.
The Class+ Microphone Series includes three other microphone capsules, the MK:226 Class 1, MK:216 Class 2+ and the MK:215 Class 2.
These capsules are produced using the same design and technology as the leading MK:224 capsule, but have reduced specifications.
Would you like more information about our Microphones?
NoiseTools support videos now available
Sound Level Meter Calibration – UKAS Calibration for your sound level meter & calibrators
We’ve updated our Knowledgebase – Visit our new Wiki
Support Noise Action Week and enter our Noise in Action Photo Competition
Windows 7 USB Connectivity with Cirrus noise measurement instruments
What are Octave and Third Octave Band Filters on a Sound Level Meter?
Sound Level Meter Calibration – UKAS Calibration for your sound level meter & calibrators
We’ve updated our Knowledgebase – Visit our new Wiki
Support Noise Action Week and enter our Noise in Action Photo Competition
Windows 7 USB Connectivity with Cirrus noise measurement instruments
What are Octave and Third Octave Band Filters on a Sound Level Meter?

