FuzzMeasure Pro is an easy-to-use acoustic measurement program for Apple Mac computers. In this app note we will show you how to get started with the UMIK-1 and FuzzMeasure Pro.
- 1. Get your calibration file
- 2. Get connected
- 3. Configure system and software
- 4. Calibrate SPL
- 5. Test and measure
- What's next?
1. Get your calibration file [Top]
On the UMIK-1 page, enter your microphone's serial number to download its unique calibration file. The calibration file ensures that measurements made with your microphone are as accurate as possible.
2. Get connected [Top]
Mount the UMIK-1 into the small stand supplied with it, or if you like, you can use any other microphone stand. Connect the UMIK-1 to your Mac using the supplied USB cable.
You will also need to connect your Mac to generate audio output through your system. There are several options:
- The inbuilt analog line output with a 3.5 mm to RCA adapter cable
- Your Mac's optical digital audio output connected to a DAC or A/V receiver
- A USB cable to an external DAC
- An HDMI connection to an A/V receiver
This photograph shows the UMIK-1 connected to a MacBook Pro and a Mini DisplayPort to HDMI adapter cable for audio output:
3. Configure system and software [Top]
Start up FuzzMeasure Pro. The toolbar across the top has several handy buttons that we will use below:
Click on the Capture Settings button. Here are two examples:
Set the output device under Playback Settings to your chosen output device. In the example above, at the left the inbuilt analog or digital output is selected. At the right, the HDMI output device is being used. Select one or more output channels to send the measurement signal to.
Also set the input device under Record Settings to the UMIK-1 and select Channel 01.
Click on the Configure button for the output device to open it in the Audio MIDI Setup program. Set the output device to operate at 48000 Hz (48 kHz), the same sample rate as the UMIK-1:
Finally, load the calibration file for your UMIK-1 into FuzzMeasure. From the Window menu, select Microphone Calibration. Click on the "+" icon and select the calibration file you saved in step one above to add it to FuzzMeasure's list of calibration records. Then near the top of the window, select that calibration file from the drop-down menu.
4. Calibrate SPL [Top]
SPL calibration is optional. Without performing the SPL calibration step, the measurements will be correct but the absolute SPL readings in FuzzMeasure's Sound Pressure Level frequency response display will not be correct. In that case, you may prefer to use the Magnitude Response graph instead to avoid confusion.
If you decide to do SPL calibration, you will need to generate an acoustic signal of 94 dB at the microphone tip. If you have a microphone calibrator, then of course you will use that. Otherwise, place the microphone and an external SPL meter close to a loudspeaker driver. Generate pink noise and increase the volume until the SPL meter reads 94 dB.
(To generate pink noise, you may be able to play a test disc through your system. There are also some nice Mac applications for generating audio test signals, such as SignalSuite.)
Once you have a 94 dB signal at the microphone, click the Level Meter button. Then click on the small "C" button so it lights up green. From then on, FuzzMeasure will take that SPL to be equal to 94 dB.
5. Test and measure [Top]
Before proceeding, turn down the volume on your preamp or A/V receiver to a fairly low level. Position the UMIK-1 where you want to take the measurement, and point it towards the speaker being measured.
Click on the Sweep Settings button and set the parameters as follows:
Then click on the Measure button. You should hear a faint sweep from low to high frequencies through the selected speaker. Turn up the system volume until the sweep is loud enough to halt a conversation, but not so loud as to be uncomfortable or to sound distorted. If you have done the SPL calibration, an average SPL of about 75 dB is generally considered suitable for home measurements.
You can now run as many more measurements as you like! FuzzMeasure Pro allows you to save all current measurements as a "project" and reload it again later. You can view multiple measurements at once by Command-clicking on them.
FuzzMeasure provides a lot of analysis tools, accessible from the menus. Explaining them all is beyond the scope of this app note, but you should be able to quickly find the options to set the amount of smoothing, to display harmonic distortion, and to change the frequency and SPL range displayed on the graph. To share your graphs online, right-click on any graph and select Export Image File.
Now that you have the ability to run acoustic measurements with FuzzMeasure Pro, you can proceed to optimize and equalize your system. The following app notes contain information that you may find helpful in your journey:
- Loudspeaker measurement with UMIK-1 and REW explains the principles of loudspeaker measurement (but you would use FuzzMeasure instead of Room EQ Wizard.)
- Building a 2way crossover and Stereo 3/4 way Crossover describe the basics of setting up a loudspeaker with an active crossover.