Serving the Acoustics Community Since 1994
Cross-Spectrum Acoustics Inc. offers Sound & Vibration Consulting Services
Starting today Cross·Spectrum is offering a new service: Microphone Frequency Response Measurements. The primary purpose of this service is to address the needs of DIY’ers who have purchased low-cost capsules, and want to know the response of their individual microphone. I think it will also be useful to organizations who may want to check the responses of their precision microphones for diagnostic purposes.
Please take note that we in no way, shape or form claim that service represents a NIST-traceable calibration. In particular, our measurement procedure is similar to the “substitution” method, and there will be some inaccuracy at higher frequencies where the acoustic wavelengths begin to approach the size of the microphone diaphragm. Also note that the phase response is determined via Hilbert Transform - the Hilbert Transform is only valid for minimum phase systems, and unfortunately, many microphones are not minimum phase devices. However, we believe this service will help to diagnose problems with microphones at a much lower cost than hiring a calibration laboratory.
The process is pretty simple - send us your microphone and pre-amp, and we’ll run it through our test suite which compares the performance of your microphone with a NIST-calibrated mike. We’ll then send you a summary report that documents the measurement results. We may also be able to give you a calibration file for use with programs like WinAudioMLS, provided we can figure out the file format.
Price for the service is $30US, including return shipping (continental US only), and we accept checks or credit cards via PayPal. We can also make arrangements for oversease shipping. In most cases we should be able to turn around your microphone in 24 to 48 hours. Please contact us for more details.
Update, February 22, 2007: