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SIA Smaart Live for Beginners

An earnest attempt to explain SIA Smaart Live concepts and implementation in a fashion easily digested by the beginner.

By Doug Fowler May 1, 2008

The Windows Audio Mixer
Unquestionably, the most common problem encountered by Smaart novices is failing to set up the Windows Audio Mixer properly.

Access the Windows mixer via the Control Panel. Go to Multimedia and in the audio portion of this control check the box labeled “Show Volume Control on Taskbar”. Apply this change and you should see the loudspeaker icon in the system tray.

Double click the Volume Control icon and the Windows Audio Mixer is displayed.

Your computer may/will display a slightly different window, depending upon the sound card capabilities.

Select Line In, and lower the input level using the fader. Due to the fashion in which some sound cards implement gain controls, it is possible to lose bit resolution when increasing the gain using the Windows mixer. Set this control to a lower position and get appropriate gain by increasing it with your measurement mixer.

After starting Smaart, the signal level on the Smaart meters should read about –12 dB. This provides the optimum operating level for Smaart. Note that after starting the Smaart Live program it is necessary to push the “On” button to actually start it and display audio input levels.

Microphones and Mixers
It is tempting to use a condenser microphone you already own, but most likely it is inappropriate for measurement use. There a good chance the frequency response is not flat enough to take a respectable measurement. Additionally, a measurement microphone should be omnidirectional. Why? The construction techniques used to create non-omnidirectional pickup patterns (cardioid, hyper-cardioid, or super-cardioid) cause the phase response of the microphone to become skewed.

Use a microphone built for the task. There are several relatively inexpensive measurement microphones which work fine for basic measurements. After you get some experience and want to move on to more serious measurement work consider one of the “better” microphones. It is not necessary to spend thousands of dollars on a laboratory grade microphone. Suitable microphones are available for under $400 U.S.

Inexpensive measurement microphones are manufactured by Audio Control Industrial, Audix, Behringer, and others. “Pro” models are manufactured by Earthworks, Josephson, and others with the Earthworks model currently the preferred microphone in Smaart Live circles.

You may use any mixer which has phantom power for your measurement microphone and the ability to pan left and right. In fact, in many applications it is possible to do a basic system measurement without a “measurement mixer”.
1. Use a matrix output or Y-Cable to get one channel of the console output into the computer sound card. If you use a Y-Cable consider using a high quality line level 1:1 isolation transformer in order to keep the console output from “seeing” the sound card input.
2. Use a channel on the console for your measurement microphone. Engage phantom power and send that input channel to the computer sound card’s left channel by:
a. Using the channel direct output
b. Assigning the channel to a subgroup, taking the subgroup output to the computer
c. Using an aux send, taking the aux output to the computer

You may now use the direct output level, subgroup fader, or aux send to control the measurement microphone level. Controlling the console (reference signal) level is a bit trickier if you do not have matrix outputs. You may have to use the Windows mixer to control the line input level to get the reference (console) signal within a reasonable operating range (-12 dB is optimum). Once this level is established for the reference channel you may use the direct output, aux send, or subgroup to match the measurement level.

CAUTION: be absolutely positive your microphone channel is not assigned to the mix bus lest you get a huge surprise.

Starter Kits
Audio Control Industrial manufactures an excellent starter kit for Smaart, the MP-200. The MP-200 kit contains a calibrated measurement microphone and a small mixer, powered with either a “wall wart” or internal battery power. The mixer provides both microphone and line inputs, plus an internal pink noise generator. If you choose to use pink noise for measurements the MP-200 (and its big brother MP-400) can internally monitor the pink noise it sends to the system. This means “no Y-Cable required”, and for quick one-offs this can be very handy.

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zolkifli bin sam says

i need a free basic software for eq thank you

Give A. Shit says

Very good information, but why stop there? I’d love a case study where you actually use this in a real life senario.

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