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Manual written and edited by Calvert Dayton and Rob Wenig. Manual design by Rob Wenig. Cover design by Martin Lindhe. ©2007 EAW Software Company, Inc. All rights reserved worldwide. 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. EAW Software Company, Inc.
EAW Smaart 6 Operation Manual Table of Contents Chapter 1: Getting Started............................................................................................9 1.1 1.2 Hardware Requirements ............................................................................9 1.1.1 Computer.....................................................................................9 1.1.2 1.1.3 1.1.4 1.1.5 Measurement Microphone ........................................................
EAW Smaart 6 Operation Manual 2.1.10 2.1.11 Coherence..................................................................................30 Signal Alignment ......................................................................30 2.2 Glossary of Terms ...................................................................................31 2.3 Selected Bibliography .............................................................................34 Chapter 3: Analysis Modes and Display Types ...................
EAW Smaart 6 Operation Manual 3.9 External Device Control ..........................................................................66 3.9.1 3.9.2 External Device Control Interface ............................................66 Configuring External Devices...................................................67 3.10 The Locked Cursor ..................................................................................68 3.11 Smaart 6 Screen Capture ..........................................................
EAW Smaart 6 Operation Manual 5.3.7 5.3.8 5.3.9 5.4 Help Menu .............................................................................................102 5.4.1 5.4.2 5.5 Instantaneous...........................................................................101 Reseed Averages .....................................................................102 High Contrast View ................................................................102 About...........................................................
EAW Smaart 6 Operation Manual List of Figures 1-1 Audio I/O tab of the Options dialog ..................................................................................14 1-2 Input levels: too low (left), correct (middle), and too high (right) ....................................15 1-3 Smaart 6 main window ......................................................................................................16 1-4 Menu bar ..............................................................................
EAW Smaart 6 Operation Manual 4-2 Default RTA spectrum display (1/12th-octave).................................................................73 4-3 Spectrum parameters..........................................................................................................73 4-4 Spectrograph and SPL displays .........................................................................................74 4-5 Analog EQ measurement setup.....................................................................
EAW Smaart 6 Operation Manual Chapter 1: Getting Started Since its initial introduction in 1996, Smaart® has firmly established itself as the most comprehensive and widely used software product in the pro audio industry for real-time sound system measurement, optimization, and control. Smaart performs dual-channel, FFT-based audio measurement in an intuitive, accessible interface that integrates measurement, analysis, and data logging.
EAW Smaart 6 Operation Manual Getting Started Computer Sound Hardware Smaart does not address computer sound hardware directly. Since audio data is obtained through platform-native or third-party audio APIs, Smaart should work with virtually any audio I/O device compatible with the Windows and Mac operating systems.
EAW Smaart 6 Operation Manual 1.1.2 Getting Started Measurement Microphone A measurement microphone is necessary to measure anything other than an electronic device. Since the measurement mic must accurately convert acoustical pressure into voltage, we recommend an omnidirectional mic with the flattest possible frequency response. Condenser microphones are most commonly used for measurement applications. These require phantom power, either from the mic preamp or an internal battery.
EAW Smaart 6 Operation Manual 1.2 Getting Started Smaart 6 Software Installation Respect the License Agreement Notice that when you install EAW Smaart 6, the installation requires you indicate your acceptance of the terms of the End User License Agreement. In doing so, you are agreeing to be legally bound by the terms of this agreement.
EAW Smaart 6 Operation Manual Getting Started 2. If you have Internet access from this computer, click Unlock Online (this example). Otherwise, click Unlock with Keyfile to obtain the necessary information from another computer that can connect to our website. Be sure to copy the Machine Number before going to the other computer. 3. Enter your existing EAW account information or create a new account. This will enable you to log onto my.eaw.com and view your Smaart installation information.
EAW Smaart 6 Operation Manual Getting Started 1.3 Smaart 6 Signal I/O This section discusses how to recognize your hardware and adjust signal levels. 1. Make sure your computer recognizes your sound card. 2. Connect any external audio devices. 3. Start Smaart 6. Do not disconnect an external audio device while Smaart 6 is running. 4. Select the proper audio input and output device(s) and channel(s) by choosing Options->Audio I/O.
EAW Smaart 6 Operation Manual Getting Started 5. Select input and output devices from the Input Device and Output Device area’s Device drop-lists, respectively. The drop-lists displays your soundcard’s inputs/ outputs and those of any connected external I/O devices already added. 6. Select the desired input channels for your measurement and reference signals from the Meas in and Ref In drop-lists. Typical assignment for a stereo input device is Meas In = Left, Ref In = Right. 7.
EAW Smaart 6 Operation Manual 1.4 Getting Started Introduction to the User Interface The Smaart 6 interface is designed to put the most frequently used functions for most sound system optimization applications within a single mouse-click. Almost everything in the main program window functions as a control. The readout fields for the primary measurement and display parameters are drop-lists that display available options when clicked upon.
EAW Smaart 6 Operation Manual 1.4.1 Getting Started The Menu Bar Smaart’s most frequently used functions and commands are available as on-screen controls or keyboard shortcuts. Pull-down menus in the Menu Bar provide an alternate method of selecting many of these same functions, in addition to providing access to some less frequently used features. Figure 1-4 Menu bar A menu command followed by “...” opens a dialog box.
EAW Smaart 6 Operation Manual 1.4.5 Getting Started Measurement Mode Buttons The Measurement mode buttons provide one-click access to Smaart’s three primary measurement types: • Spectrum: See Spectrum Measurements on page 38. • Freq. Resp.: See Frequency Response Measurements on page 44. • IR Analysis: See Delay and Impulse Response Measurements on page 52. Figure 1-6 Display mode (left) and Measurement mode (right) buttons 1.4.
EAW Smaart 6 Operation Manual 1.4.8 Getting Started Signal Generator Figure 1-8 Signal Generator and Delay controls Click the button to activate the signal generator; the square indicator on the button illuminates green when active. To configure the signal generator: 1. Click the arrow to the right of the Signal Generator button (labeled with the current signal generator type). The Signal Generation dialog opens. Figure 1-9 Signal Generation dialog 2.
EAW Smaart 6 Operation Manual 1.4.9 Getting Started Internal Delay Control The Delay control (Figure 1-8) provides access to Smaart 6’s internal signal delay. The internal delay can provide up to 750 ms of delay (in 0.01 ms increments) for one of the two input signals, intended primarily to provide signal alignment for Frequency Response measurements. The delay selected and corresponding distance are displayed on the Delay control.
EAW Smaart 6 Operation Manual 1.5 Getting Started How to use this Manual EAW has dedicated substantial time and resources to the Smaart 6 documentation. We recognize that our customers comprise a diverse range of experience and have strived to write and organize this manual to be accessible to everyone. Of course it is more fun to use Smaart 6 than read about it but we are confident that your time spent reading this manual will be rewarding.
EAW Smaart 6 Operation Manual Getting Started How to Use the PDF The Portable Document Format (PDF) version of this manual is a valuable learning tool, providing effective online help while using Smaart 6. We have included some useful amenities to aid your learning and exploration process. NOTE: We assume Windows users will use Acrobat Reader and Mac users either Acrobat or Preview.
EAW Smaart 6 Operation Manual Chapter 2: Concepts, Glossary, and Bibliography This chapter defines the concepts and terminology used in Smaart 6. These definitions are accurate with regard to Smaart 6 but are not intended to be mathematically comprehensive. A bibliography is provided at the end of the chapter for those wishing to pursue a more rigorous study of these topics. 2.1 Concepts 2.1.
EAW Smaart 6 Operation Manual 2.1.2 Concepts, Glossary, and Bibliography • At frequencies where the measurement signal has more energy than the reference signal, the transfer function is a positive dB value; when the measurement signal has less energy, the value is negative. • With respect to the input level meters and the default Full-Scale calibration reference, 0 dB (or 0 dBFS) means the maximum possible output of the A/D converter on the selected input device.
EAW Smaart 6 Operation Manual 2.1.3 Concepts, Glossary, and Bibliography Averaging When using asynchronous test signals such as music or random noise in FFT measurements, it is often beneficial to average data from a number of FFT frames.
EAW Smaart 6 Operation Manual 2.1.5 Concepts, Glossary, and Bibliography Frequency Resolution The frequency resolution (Q) of an FFT is equal to the sampling rate divided by the FFT size. The frequency data points in an FFT are distributed linearly along the frequency axis at intervals of Q Hz, from 0 to the Nyquist Frequency (1/2 the sampling rate). For example, with a sampling rate of 44.1 kHz, an FFT size of 4096 (4 k) yields a frequency resolution of 10.77 Hz.
EAW Smaart 6 Operation Manual 2.1.6 Concepts, Glossary, and Bibliography Pink and White Noise Pink and white noise both contain random (or pseudorandom) broadband energy. They are commonly used as signal sources in audio measurement applications. Pink Noise Pink Noise has equal energy in each octave band when averaged over a period of time. This means that when pink noise is displayed on an octave band plot, its spectrum appears flat.
EAW Smaart 6 Operation Manual Concepts, Glossary, and Bibliography Choosing a Noise Source The distinction between pink and white noise is not important in Frequency Response measurements. The transfer function compares the two input signals over a given frequency range point-by-point. This is a concern when looking at a single channel RTA noise measurement. If it appears flat in narrow band resolution, it is white.
EAW Smaart 6 Operation Manual 2.1.8 Concepts, Glossary, and Bibliography Impulse Response An impulse response is the response of a system under test (SUT) to an impulsive stimulus. The SUT could be an electronic device, a sound system and/or an acoustical environment. In Smaart the impulse response is the time-domain representation of the system’s transfer function, or system identification.
EAW Smaart 6 Operation Manual 2.1.10 Concepts, Glossary, and Bibliography Coherence The coherence for any two FFT frames The Smaart 6 Coherence display represents a complex mathematical function used to determine the coherence between the two signals. Smaart displays coherence values as a percentage from 0-100, rather than as a number from 0-1 because we have found that many people find it more convenient to think of it as a score than as a probability.
EAW Smaart 6 Operation Manual 2.2 Concepts, Glossary, and Bibliography Glossary of Terms Analog to Digital (A/D) Conversion: The process of sampling the amplitude of an analog signal at regular intervals to create a digital representation of the signal. Amplitude: The size of a real number (e.g., a number of Volts), in either the positive or negative direction.
EAW Smaart 6 Operation Manual Concepts, Glossary, and Bibliography FFT Time Constant: The amount of time it takes to collect all the samples required for a single FFT frame of a given size at a given sampling rate. The time constant of an FFT, also called the time window, can be calculated by dividing the FFT size by the sampling rate. For example, a 4k FFT sampled at 44.1k samples/second has a time window of 0.09 seconds.
EAW Smaart 6 Operation Manual Concepts, Glossary, and Bibliography Propagation Delay: The time it takes for sound to travel from one place (typically a loudspeaker) to another place (typically a microphone). Reverberation Time: The amount of time required for audio energy introduced into a system (typically a room) to diminish, or decay a specified number of decibels. Often expressed as an RT60 value. RT60: Reverberation time.
EAW Smaart 6 Operation Manual 2.3 Concepts, Glossary, and Bibliography Selected Bibliography The following is a list of publications suggested for readers who want to expand their understanding of the physical and theoretical concepts and mathematical procedures underlying Smaart 6, sound system design, and acoustics. Badmaieff, A. & Davis, D. How to Build Speaker Enclosures. Indianapolis: Howard W. Sams & Co., 1966. Ballou, G. ed. Handbook for Sound Engineers - The New Audio Cyclopedia.
EAW Smaart 6 Operation Manual Concepts, Glossary, and Bibliography Knudson, V. O. & Harris, C. M. Acoustical Designing in Architecture, New York: John Wiley and Sons, Inc., 1950; reissued by the American Institute of Physics for the Acoustical Society of America, New York, 1978. Lubman D. and Wetherill E., eds. Acoustics of Worship Spaces. New York: The American Institute of Physics, 1983 McCarthy, B. Meyer Sound Design Reference For Sound Reinforcement. Berkely: Meyer Sound Laboratories, 1998 Olson, H.
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EAW Smaart 6 Operation Manual Analysis Modes and Display Types Chapter 3: Analysis Modes and Display Types Smaart 6 has two analysis modes: Real-time and Impulse Response (IR Analysis). These run in separate windows. Real-time mode processes incoming data continuously and offers four display types: RTA, Spectrograph, Magnitude, and Phase. RTA and Spectrograph displays are considered Spectrum measurements, where each data set displayed is based directly upon FFT data from a single signal.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Click the IR Analysis button to open the Impulse Response window. Impulse Response mode collects and stores a limited amount of data and then offers two display types: Time and Frequency. Clicking the IR Analysis button does not override the selected View. Figure 3-2 Impulse Response Window 3.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Press the Start button in the real-time window to begin all real-time measurement operations. When the RTA display is active, time-domain audio data from the A/D converter of your sound hardware is continuously transformed into the frequency domain using a Fast Fourier Transform (FFT). The FFT data can be plotted on the RTA display in real time, either in raw narrowband form or processed into octave or fractional-octave bands.
EAW Smaart 6 Operation Manual 3.1.2 Analysis Modes and Display Types Spectrograph The Smaart 6 Spectrograph is a second type of RTA display that shows an input signal’s frequency content over some period of time. Instead of showing just one FFT measurement at a time (whether averaged or instantaneous) like the RTA display, the live Spectrograph displays a record of the most recent 100 or more RTA updates.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Figure 3-4 Spectrograph dB Range The frequency scale of the Spectrograph is set by clicking and dragging a rectangular area, which becomes the new displayed range. Click on the frequency axis numbers to return the scale to normal. 3.1.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Averaging Averaging is used in RTA, Spectrograph, and Frequency Response measurements to increase the effective signal-to-noise ratio (S/N) of the measurement and reduce the influence of transient events. This stabilizes the display and makes overall trends easier to see. Spectrum measurements use RMS averaging but several integration schemes are available: linear first in, first out (FIFO), Infinite, Fast, Slow, and Exponential.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Spectrum Mode FFT Parameters The FFT parameters for Spectrum, Frequency Response, and Impulse Response are in their respective tabs in the Options dialog. Sample Rate – Each time Smaart 6 starts or a new input device is selected, the computer’s sound hardware is queried to determine which sampling rates are supported. These options appear in Sampling Rate drop-list in the Audio I/O tab of the Options dialog.
EAW Smaart 6 Operation Manual 3.2 Analysis Modes and Display Types Frequency Response Measurements Smaart’s real-time Frequency Response measurement capability is an extremely useful tool for setting up sound system equalizers and crossovers. Frequency Response measurements compare the input and output signals of a device or system under test, using a mathematical calculation called a transfer function, to determine the difference between them.
EAW Smaart 6 Operation Manual 3.2.2 Analysis Modes and Display Types Frequency Response Overview In Frequency Response measurements, Smaart 6 compares the reference and measurement input signals in real time to find their relative magnitude and phase differences, frequency by frequency. The mathematical technique used to compare the two signals is called a transfer function.
EAW Smaart 6 Operation Manual 3.2.4 Analysis Modes and Display Types The Phase Display Clicking the Phase display button shows the phase shift t(ime difference) in the measurement signal relative to the reference signal across frequency. All phase values are plotted within a 360° range of +180° to -180° (0° in the center). This 360° range represents one complete cycle at a given frequency.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Note that because the time dimension of the data window function used by the time windowing routine is actually double the size of the specified window time, the maximum window is equal to half the time constant of the FFT size/SR selected in the Frequency Response tab of the Options dialog. NOTE: When FPPO is selected from the FFT menu, the Time Window controls are disabled because it is incompatible with this feature.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Vector averaging works directly with the complex data FFT data from the transfer function calculation. Vector is more effective at rejecting uncorrelated noise and reverberant energy and tends to correlate better to the intelligibility and accuracy of signal reproduction. Vector is more sensitive to wind and speaker/source movement and other time-variant issues, so it is better suited to indoor venues and/or calmer, more controlled conditions.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Smoothing Smoothing, an averaging technique available only for Frequency Response measurements, can reduce the jaggedness of the Magnitude trace, making trends in the system response easier to see. Smoothing averages each data point with a number of adjacent points on either side of it determined by the Smooth setting below the Freq. Resp. button. The Smooth settings available from the drop-list are none, 3, 5, 7, 9.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types The Coherence Trace The Coherence trace displays as a second trace in red in the upper portion of the frequency/magnitude response plot if the Show Coherence Trace checkbox is selected in the Frequency Response tab of the Options dialog. The Coherence trace is normally plotted in the upper half of the Magnitude display using the center line as zero and the top of the graph as its maximum value (100% = perfect coherence).
EAW Smaart 6 Operation Manual 3.2.8 Analysis Modes and Display Types Magnitude Thresholding Magnitude Thresholding is another way to limit undesirable data from Frequency Response measurements by setting a threshold for the reference signal level, below which incoming measurement signal data is rejected on a frequency-by-frequency basis.
EAW Smaart 6 Operation Manual 3.3 Analysis Modes and Display Types Delay and Impulse Response Measurements In Impulse mode, Smaart 6 measures and displays the impulse response of the SUT. The impulse response is used primarily to find the time offset (delay) between the two input signals. The Impulse mode plot displays energy versus time rather than energy vs. frequency as in the analyzer modes (RTA and Frequency Response). The result of the impulse response measurement can be stored as a Windows .
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Figure 3-10 Impulse Response window NOTE: FFT Frequency Resolution (FR) is not displayed in Impulse mode since the impulse response is a time-domain display. Type Select the desired type: Log, Lin, ETC. FFT Select the FFT size, from 128 to 512k points. Note that changing the FFT size also affects the time constant (TC) below. TC Displays the time constant for the selected FFT size.
EAW Smaart 6 Operation Manual 3.3.2 Analysis Modes and Display Types Working with Impulse Response Data Enter impulse response analysis mode by clicking the IR Analysis button in the main real-time mode program window. The Impulse Response window opens but the measurement does not start until you click the Start button.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types The first large peak on the impulse response or ETC trace is usually the highest in magnitude and corresponds to the initial arrival time of energy in the impulse response measurement. The time from the beginning of the measurement to this peak provides the total propagation delay time (electrical and acoustic) through the SUT.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Figure 3-11 Delay auto-locator buttons Default settings for the Auto Sm and Auto Lg yield time windows of approximately 300 ms and 3 s, respectively. The Auto Sm default is appropriate for measuring delays through electronic devices or acoustic measurements in small and medium rooms.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types The Signal Level/SPL readout tracks the channel designated as SPL Source in the Audio I/O tab of the Options dialog. When Smaart 6 is calibrated to SPL, the readout can be set to display an A-weighted, C-weighted, or flat (unweighted) SPL value based on the current FFT frame (only) or an average of the data from some number of the most recent frames.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types The default Full Scale internal display calibration shows all magnitude values in terms of dB down from the maximum input level of 0 dB. The Signal Level/SPL Readout above the input level meters always shows a negative value and dB Full Scale appears in the field immediately above the numeric readout. When Smaart 6 is calibrated to SPL, this notation changes to SPL, and the dB value is normally positive.
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). 6. Click the OK button to apply the change and exit the dialog.
EAW Smaart 6 Operation Manual 3.5 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. 4. Click OK to set the change and exit the dialog. 5. Place your measurement microphone and SLM very close together at the same distance from a loudspeaker then send a steady-state signal (e.g.
EAW Smaart 6 Operation Manual 3.5.2 Analysis Modes and Display Types Loading a Reference Trace A modified Open file dialog appears with the *.ref files in the folder last accessed. A field for the file Description has been added to make finding the desired file easier.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Files can be saved in ASCII format so they can be imported to a spreadsheet or any other program that accepts ASCII input. Select the desired file and choose Save ASCII from the “>>” list. Change the vertical offset (amplitude) of the selected trace by using the dB +/- up/ down arrows. Load additional traces from this dialog by clicking the Load button.
EAW Smaart 6 Operation Manual 3.6 Analysis Modes and Display Types Internal Delay Smaart 6 can provide up to 750 ms of signal delay internally for one of the two input signals. This feature is primarily intended to provide signal alignment between the reference and measurement signals in Frequency Response measurements. Delay properties are set from the Delay tab of the Options dialog box, accessed by choosing Options->Delay or by clicking the Delay button.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Figure 3-17 Signal Generation dialog Select the following test sources from the Signal list: • Pink Noise: Pseudorandom noise with equal energy per octave. • Sine Wave: Use the slider to adjust the frequency or type a value in the range 20 Hz - 24 kHz. Use the Level1 up/down arrows or type a value in the field in the range -96-0 dB. The Level2 and Freq2 controls are disabled.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types Synchronous Stimulus Signals The synchronous noise and sweep options (Pink Sync and Pink Sweep) in Smaart 6’s signal generator construct repeating sequences of pseudorandom noise or logarithmically swept sinusoidal signals that are the same length (in samples) as the current FFT size.
EAW Smaart 6 Operation Manual 3.9 Analysis Modes and Display Types External Device Control NOTE: There is currently no external device control for the Mac. 3.9.1 External Device Control Interface Smaart 6’s External Device control interface allows direct control of supported, remotely controllable equalizers (EQs), system processors and other devices.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types You can cycle filter selection through all displayed filter markers using the Tab key (Shift + Tab cycles in the reverse direction). When a filter is selected, its center frequency (Hz), bandwidth (Oct), and cut/boost value (dB) are shown in the top three edit fields on the external device control panel. Filters set at 0 dB cut/boost are considered unused.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types To operate a selected EQ device: 3.10 1. Drag the filter handles to set the filter or use the Filters controls in the dialog. 2. Set this filter or all of the device’s filters to flat by clicking the Flat or All Flat buttons, respectively. 3. Select the Show Inverted option to invert the filter’s boost/cut display.
EAW Smaart 6 Operation Manual Analysis Modes and Display Types 3.11 Smaart 6 Screen Capture 3.11.1 Windows Windows has a built-in feature that allows capturing a bitmap image of the entire screen, or more usefully, the active window. This is an easy method to include Smaart 6 data displays as illustrations in reports and other documents. Press the PrtScn key to capture the entire screen as a bitmap image. Press Alt+PrtScn to capture the active window only.
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EAW Smaart 6 Operation Manual Chapter 4: Applications This chapter discusses four typical applications, presented in order of increasing complexity, that use Smaart 6 to measure audio systems and components. Since each example builds from those preceding it, we recommend reading all four, even if you are only interested in the later exercises.
EAW Smaart 6 Operation Manual 4.1 Applications Real-Time Spectrum Analyzer (RTA) Two-channel real-time spectrum analysis is Smaart 6’s most basic function. Spectrum measurements are similar to a hardware RTA: incoming signals are divided into frequency regions and displayed dynamically as magnitude vs. frequency. The default display shows each channel as a real-time bar graph of energy vs. frequency, each bar representing a 1/12-octave wide band of energy, although many other displays are possible. 4.1.
EAW Smaart 6 Operation Manual Applications Figure 4-2 Default RTA spectrum display (1/12th-octave) Experiment with the settings that affect the appearance and behavior of the RTA display. Frequency scale has the most immediately visible effect. Select the following options from the Scale list to the right of the main plot: Log, Lin, Oct, 1/3, 1/6, 1/12, 1/24. The Oct and fractional options result in an Octave or fractional octave band display, represented as a bar chart.
EAW Smaart 6 Operation Manual Applications The Spectrum tab of the Options dialog contains additional display options (page 93). Spectrum measurements can identify feedback frequencies, analyze room noise, and study the spectral content of music. When properly calibrated, the RTA display can be used for real-time, banded SPL metering and is used to calibrate Smaart’s broadband SPL metering functions as well (see page 57).
EAW Smaart 6 Operation Manual 4.2.1 Applications Measurement Setup Connect all the components as shown in Figure 4-5. The computer’s line level output drives both the equalizer’s input and the sound card’s reference input. The equalizer’s output is routed to the computer through the sound card’s measurement input.
EAW Smaart 6 Operation Manual Applications Figure 4-6 Signal Generation screen control (left) and dialog (right) 5. Click the Start button to start the analyzer. 6. Adjust input signal levels using external hardware level controls or software sound card controls so the reference and measurement channels are approximately equal and remain in the range –9 to –12 dBFS (see Smaart 6 Signal I/O on page 14). 7.
EAW Smaart 6 Operation Manual Applications Figure 4-7 Sample measurement of an analog parametric EQ filter 4.3 Measuring a Loudspeaker This example uses IR Analysis mode and the real-time Frequency Response display to measure a loudspeaker in a room.
EAW Smaart 6 Operation Manual Applications Measurement Microphone Microphone Preamp Reference Signal Loudspeaker Amplifier Computer Measurement Signal Line Out Figure 4-8 Speaker/amp measurement setup 4.3.1 Adjust Signal Levels 1. Position the measurement microphone about 1 meter (3.3 ft) from the loudspeaker. As the mic’s distance from the loudspeaker increases, it becomes more difficult to discern the loudspeaker’s direct sound from the room’s reflections. 2.
EAW Smaart 6 Operation Manual 4.3.2 Applications Impulse Response Measurement 1. Click the IR Analysis button. The Impulse window opens. 2. Click the Start button. SmaartLive measures the system impulse response and displays it as a time domain plot.
EAW Smaart 6 Operation Manual Applications The additional energy shown in the impulse response after the arrival of direct sound is due to room reflections and the noise floor, which has a relatively constant average level. The accuracy of the measurement depends on an adequate S/N between the direct sound and noise level. Impulse response measurements are used extensively in room acoustics work.
EAW Smaart 6 Operation Manual 4.4 Applications Measuring a Loudspeaker and Setting an Equalizer This example combines the techniques used in Measuring an Analog Equalizer and Measuring a Loudspeaker. We will measure the frequency response of a loudspeaker then configure an equalizer to optimize its performance. Connect the following components as shown in Figure 4-10: • Signal source (e.g.
EAW Smaart 6 Operation Manual Applications The following steps assume knowledge acquired during the previous example: 1. Set the mixer controls so that input signal A (in Figure 4-10) is routed to Smaart’s reference signal input on your computer and C is sent to Smaart’s measurement channel. The output of the equalizer (input signal B) is not used for the first measurement and should be muted or turned all the way down.
EAW Smaart 6 Operation Manual Applications 11. If you were using noise for the initial measurements you may want to switch to music as your source signal for this step. Start by matching cut filters on the EQ with the (now-inverted) bumps on the stored system response trace. You may also want to add a boost filter or two to help out in areas where there were dips in the system response, but remember that boost filters should be used judiciously.
EAW Smaart 6 Operation Manual 4.5 Applications Measuring and Optimizing a Sound System Before measuring a sound system it is critical to answer the question, “What am I trying to measure and why?” Sound system performance is qualitative and quantitative.
EAW Smaart 6 Operation Manual Applications Step 1: Evaluation Listening Before measuring a sound system, we strongly recommend listening to it! Attempt to qualitatively answer all the questions on page 84. Activate each subsystem separately, move around, and assess whether each serves its intended area. Explore the boundaries of the coverage patterns to look for holes.
EAW Smaart 6 Operation Manual Applications NOTE: If you cannot avoid a bad floor bounce, put the microphone on the floor. This creates a short enough reflection time that the resulting comb filter is above the audible spectrum. Step 4: Compare Positions It is important to make acoustical measurements from different microphone positions to avoid being fooled by something that affects only one location, such as a reflection. Move the microphone around and observe the effect on frequency response.
EAW Smaart 6 Operation Manual Applications Step 7: Stability Testing It is vitally important to explore the stability of a sound system that includes one or more microphones before it goes into service. Otherwise, the engineer may be in the uncomfortable position of exploring the system’s instability—finding and fighting feedback frequencies—during a live performance. This is every engineer’s worst nightmare but can be easily avoided.
EAW Smaart 6 Operation Manual Applications Stabilizing a Sound System Stabilizing an unstable system means giving it more GBF, primarily by reducing the gain at the feedback frequencies. Although not a panacea or a substitute for good system design, EQ is one of the most powerful tools to stabilize a sound system. Smaart 6 can help identify feedback frequencies and apply precise EQ. But before you start turning knobs, remember that EQ affects the overall frequency response of the system.
EAW Smaart 6 Operation Manual Applications Stabilizing a System with EQ Feedback is most commonly solved using EQ to remove or attenuate offending peaks. Carefully run the system into feedback, identify problem frequencies, and set up filters (i.e., EQ stages) to reduce gain at those frequencies. We strongly recommend using parametric equalizers. 1. Connect the system as shown in Figure 4-10. This allows using the EQ without switching the input signals to the computer. 2.
EAW Smaart 6 Operation Manual Applications How Much EQ Is Enough? Remember that using cut filters to increase system stability reduces the gain, even though only at specific frequencies. In most cases, the feedback frequencies have too much gain anyway so the system’s frequency response has probably improved at operating levels while simultaneously increasing stability. It is possible, however, to use too much EQ.
EAW Smaart 6 Operation Manual Chapter 5: Smaart 6 Commands 5.1 File Menu 5.1.1 Save Impulse Choose File->Save Impulse to save the Impulse Response as a file (.wav for Windows, AIFF for Mac). 5.1.2 Exit Choose File->Exit to close Smaart 6. 5.2 External Devices Menu NOTE: External device control utilizing the legacy SmaartLive device control driver is currently implemented in the Windows version of Smaart 6 (only). 5.2.
EAW Smaart 6 Operation Manual 1. Smaart 6 Commands Select the new device from External Devices->Add (left of Figure 5-1). The device’s Configuration dialog appears (right of Figure 5-1). If the device you want to control does not appear in the list of supported models, check our website for recently added device control drivers. If you cannot find it there, contact the manufacturer of that device directly. 2. Type a name for the device in the Device Name field.
EAW Smaart 6 Operation Manual 5. Smaart 6 Commands Select an input or output to control from the External Devices menu (left of Figure 5-2). A floating control dialog for the selected channel appears, like the one on the right of Figure 5-2. The position of all filters currently available on the selected device channel should now be indicated by markers on the Magnitude plot.
EAW Smaart 6 Operation Manual Smaart 6 Commands Choose Options->Spectrum or click the arrow to the right of the Spectrum button. The top line displays the current Sampling Rate, which is set in the Audio I/O tab. Window: Hanning, Hamming, Blackman, Blackman-Harris, Max Flat Top, Parzen, Welch. Set to Hanning unless you have a well informed reason to change it.
EAW Smaart 6 Operation Manual 5.3.2 Smaart 6 Commands Frequency Response Figure 5-4 Frequency Response tab in Options dialog Choose Options->Frequency Response or click the arrow to the right of the Freq. Resp. button. The top line displays the current Sampling Rate, which is set in the Audio I/O tab. Window: Hanning, Hamming, Blackman, Blackman-Harris, Max Flat Top, Parzen, Welch. Set to Hanning unless you have a well informed reason to change it.
EAW Smaart 6 Operation Manual Smaart 6 Commands Inputs Average: 1, 2, 4, 8, 16, 32, 64, 128, Inf, Fast, Slow, Exp Average Type: RMS or Vector Y+/-: Shifts the vertical offset of the traces up or down. Show Time Windowed Data: This box must be selected to access the Time Window Y+/- and Time Window controls. Note that all Time Window controls are disabled when FPPO is selected as the FFT option. Selecting this option displays time-windowed versions of the Frequency Response (Phase and Magnitude) traces.
EAW Smaart 6 Operation Manual 5.3.3 Smaart 6 Commands IR Analysis Figure 5-5 IR Analysis tab in Options dialog Choose Options->Impulse/Locator or click the IR Options button in the Impulse Response window. Choose Options->IR Analysis or click the IR Options button in the Impulse Response window. The top line displays the current Sampling Rate, which is set in the Audio I/O tab. IR Measurement Parameters Type: Select LogIR, LinIR, or ETC views for the impulse response time display.
EAW Smaart 6 Operation Manual 5.3.4 Smaart 6 Commands Audio I/O Figure 5-6 Audio I/O tab in Options dialog Choose Options->Audio I/O. Sampling Rate (Hz): The sampling rates vary according to the selected input device. Input Device Device: Select the input device from the drop-list. The list displays your soundcard’s inputs and those of any connected external I/O devices already added. Meas In: Select the desired input as the measurement input. Ref In: Select the desired input as the reference input.
EAW Smaart 6 Operation Manual Smaart 6 Commands Output Device Device: Select the output device from the drop-list. The list displays your soundcard’s outputs and those of any connected external I/O devices already added. Main Out: Select the desired main output. Aux Out: Select the desired Aux output. Bits per Sample: Select the bit depth for the output device (varies with device). Show ASIO Control Panel: See note on the preceding page. 5.3.
EAW Smaart 6 Operation Manual Smaart 6 Commands Delay Delay Time (ms): Type in a delay time (maximum = 750 ms). Assign To: Choose one of the A-E buttons to assign the Delay Time to that function key. The time appears in the key’s field in the Presets section below. Alternately, enter the desired delay time directly in the function key’s field. Channel: Select either the Ref->Meas (delay assigned to Ref channel) or Meas->Ref (delay assigned to Meas channel) radio button.
EAW Smaart 6 Operation Manual 5.3.6 Smaart 6 Commands Zoom Figure 5-8 Zoom tab in Options dialog Choose Options->Zoom or press Alt+z to display the Zoom tab to configure four zoom settings. Use Nyquist: Check this box to automatically set the Max frequency field to the highest frequency obtainable with the selected sampling rate (Nyquist Frequency = SR/2). The Max field in Figure 5-8 is set to 24 kHz (SR = 48 kHz) but is gray and inactive because this box is checked.
EAW Smaart 6 Operation Manual Smaart 6 Commands In real-time mode, averaging helps stabilize the live trace, making it easier to see trends in the data but slows down the display’s response to changes and can mask transient events.
EAW Smaart 6 Operation Manual Smaart 6 Commands 5.5 Keyboard Shortcuts Range, Scale, and Zoom Shortcuts Ctrl/Cmd means press the Control (Ctrl) key if you are using Windows, or the Command key (sometimes referred to as the “Apple” or “Flower” key) on a Mac. Similarly Alt/Opt refers to the Alt key on a Windows keyboard or the Option Key on a Mac. Left-Click refers to a Windows style two-button mouse and is equivalent to a regular mouse click on a Mac.
EAW Smaart 6 Operation Manual Smaart 6 Commands External Device Control External Device Mode = X Flatten Selected filter = Del Increase Boost = Up Arrow (S) Decrease Boost = Down Arrow (T) Increase Frequency = Right Arrow (X) Decrease Frequency = Left Arrow (W) Increase Bandwidth = Shift + Right Arrow (X) Decrease Bandwidth = Shift + Left Arrow (W) Select Next Filter = Tab Select Previous Filter = Shift + Tab Mouse Create New Filter or Grab Nearest (device dependent) = Shift + Left-Click plot Select Filt
EAW Smaart 6 Operation Manual Chapter 6: Troubleshooting 6.1 Installation Problems 6.1.1 Problems During Installation The single most common cause we have seen for installation problems with Smaart in general has been some conflict with automatic virus checkers, system monitors, and install monitors. Other types of programs can occasionally cause problems during installation as well. We therefore strongly recommend closing all other programs before installing Smaart 6.
EAW Smaart 6 Operation Manual Troubleshooting If Smaart 6 installed successfully and seems to run properly but you experience audio problems, it is likely just a configuration problem. Refer to the sections on Configuring Audio Input/Output Controls, Sound Hardware Problems and Measurement Input Levels later in this chapter to troubleshoot audio problems. 6.
EAW Smaart 6 Operation Manual Troubleshooting 2. In the Volume Control application, choose Options->Properties. 3. Click the Recording radio button, check the Microphone and Line-In boxes in the list below, and click OK to exit the Properties dialog box. Notice that the title of the Volume Control window changes to Recording Control. Make sure the Select box for Line-In is checked, confirm that the balance control is centered and the fader is set to a useful level.
EAW Smaart 6 Operation Manual 6.4 Troubleshooting Performance Issues If Smaart is running too slowly, the two most likely causes are not enough available CPU time and/or not enough RAM for the task. Two possible strategies are to free up more system resources for Smaart to use and/or decrease the amount of RAM and CPU Smaart is using. Close other applications to free more RAM for Smaart to use.
EAW Smaart 6 Operation Manual Troubleshooting Control Spacing You may have noticed that when changing video resolution or color depth in Windows you may also have the option of selecting “Small Fonts” or “Large Fonts.” Some driver sets provide additional choices. These options refer to the bitmapped screen fonts used in menus, dialog boxes, and other control areas.
EAW Smaart 6 Operation Manual 6.7 Troubleshooting Technical Support Information Maintenance updates for Smaart 6 will be posted on the EAW Software Company, Inc. web site as they become available. Smaart’s home page on the EAW web site is: www.eaw.com/smaart/. You can also find Application Notes, Case Studies, answers to frequently asked questions as well as product news and other information of interest to Smaart 6 users on our web site.
EAW Smaart 6 Operation Manual Index D Data Window 31 Data Window Functions 28 Decay Rate 31 Decibel 23, 31 Delay and Impulse Response Measurements 52 Delay Locator 55 Display and Font Problems 108 Dynamic Range 31 A Amplitude 31 Analog to Digital (A/D) Conversion 31 Application Notes Measuring and Optimizing a Sound System Evaluation Listening 85, 86, 87, 90 Attenuation 31 Auto Delay Locator Buttons 20 Automatic Delay Locator 55 Averaging 25 Averaging and Smoothing 47 Averaging Reference Traces 62 E EQ
EAW Smaart 6 Operation Manual I Phase Shift 32 Pink Noise 27, 32 Pink/White Noise 27 Plot Area 17 Propagation Delay 33 Impulse Mode Working with Impulse Response Data 54 Impulse Mode Measurement Parameters 52 Installation 12 Installation Problems 105 Installing SIA SmaartLive 12 Internal Delay Control 20 Internal Signal Generator 63 R Real-Time Spectrum Analyzer 38 Reference Signal 49 Restoring the Default Configuration 109 Reverberation Time 33 RT60 33 L Latency 32 Linear Scale 32 Loading a Reference
EAW Smaart 6 Operation Manual T Technical Support Information 110 Thresholding 49, 51 Time Constant 33 Time Window 33 Time Windowing 46 Transfer Function 29, 89 Averaging and Smoothing 47 Coherence 49 Coherence Blanking 49 Phase Display 46 Smoothing 49 Typical Measurement Setup 44 Transfer Function Measurement Setup 44 Troubleshooting Configuring Windows Audio Controls 106 Font and Display Problems 108 Installation Problems 105 Performance Issues 108 Sound Hardware 106, 107 Technical Support Information 11
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