User manual EAW SMAART V6

[. . . ] v. 6 FOR MICROSOFT WINDOWS® AND MAC OS® X SOUND SYSTEM MEASUREMENT, OPTIMIZATION AND CONTROL SOFTWARE USER GUIDE Manual written and edited by Calvert Dayton and Rob Wenig. No part of this publication may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language in any form by any means without written permission from EAW Software Company, Inc. Smaart performs dual-channel, FFT-based audio measurement in an intuitive, accessible interface that integrates measurement, analysis, and data logging. Smaart 6 has been rebuilt from the ground up in a modern, object-oriented architectural design. [. . . ] The calibrator must be fitted to the capsule of the measurement microphone with an airtight seal. NOTE: If the calibrator doesn't come with an adaptor that fits your microphone snugly, check with the calibrator and/or microphone manufacturer. The calibrator manufacturer may offer additional adapter sizes not included with the base unit or you may be able to purchase an adapter collar from the microphone manufacturer that will fit the microphone to a standard calibrator cup size. 1. 4. Select the RTA display to perform the recalibration procedure and click the Start button. Set the RTA display to a fractional octave frequency resolution. Set the gain of the microphone preamp and sound card input controls to a useful level then insert your microphone into the calibrator and turn it on. When the peak on the RTA display stabilizes at the calibrator frequency, click the Options/Units button above the Signal Level/SPL Readout to open the SPL/ Calibrations Options dialog and select Calibrate Using Peak. Smaart 6 automatically finds the magnitude of the highest peak on the RTA plot. The Amplitude Calibration dialog appears with the magnitude of the peak frequency. 58 EAW Smaart 6 Operation Manual Analysis Modes and Display Types Figure 3-13 SPL/Calibrations Options and Amplitude Calibration dialogs 5. The Set this value to field in the dialog should already be highlighted so all you have to do is type in the correct value for the calibrator's output level, typically 94, 104, or 114 dB (consult the calibrator documentation if necessary). Click the OK button to apply the change and exit the dialog. 6. When the dialog box closes, all Spectrum mode displays automatically re-scale to the new calibration offset and the Signal Level/SPL Readout now displays SPL. Smaart 6 now provides accurate SPL metering for Spectrum and Frequency Response measurements, although Impulse Response mode always uses Full Scale calibration. NOTE: Changing the gain of the microphone preamp, mixer channel, or the voltage swing of the A/D converter requires recalibration. Also note that since Smaart 6 uses an "engineering units" calibration scheme, this procedure can calibrate to virtually any signal of known amplitude. SPL Calibration Without a Calibrator If you do not have a microphone calibrator but do have a standard sound level meter (SLM), you can calibrate Smaart 6 to provide relatively accurate SPL readings. The following simple procedure for "quick and dirty" SPL calibration takes only about a minute. Click the Options/Units button above the SPL Readout to open the Amplitude Calibration dialog and click the Calibrate Using Peak button. Set the Calibration Offset value to 1 dB, then click OK to set the change and exit the dialog. 2. 59 EAW Smaart 6 Operation Manual Analysis Modes and Display Types 3. Click the Options/Units button above the Signal Level/SPL Readout again and set the Weight and Speed settings for the readout to match those on the reference SLM. Slow time integration (Speed) will make the steps that follow easier. Click OK to set the change and exit the dialog. Place your measurement microphone and SLM very close together at the same distance from a loudspeaker then send a steady-state signal (e. g. , sine wave or pink noise) through the speaker. Run Smaart and the SLM and note the SPL readings on both. Subtract the Smaart reading from the SLM reading, then add 1 to the difference. Open the Amplitude Calibration dialog again (see Step 1) and enter the new calibration offset found in step 7. Run Smaart and the Reference SLM again and check the SPL readings. They should now match each other very closely. [. . . ] The Fast and Slow exponential averaging options also consume relatively small amounts of memory. 6. 5 Font and Display Problems Title and Label Font Problems Smaart normally uses the Arial (TrueType) font family for graph titles, labels and legends. (A Windows font family typically consists of four typefaces: the normal base font plus bold, italic, and bold italic. ) These fonts are normally installed on your computer with the operating system. Of course they can be removed just like any other TrueType font, but many applications (including Smaart) expect them to be available and can behave somewhat erratically if they are not. While Smaart 6 can operate without these fonts, the appearance of on-screen controls and graphs may suffer if they are not available. [. . . ]