CLIOwin 7 PCI User's Manual - Audiomatica

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11.4 DISTORTION AND SETTINGS Sinusoidal stimuli allow CLIO to evaluated distortion in its single harmonic form. If not Set in Impedance Mode, CLIO always evaluates harmonics from second to fifth and allows the display of each one separately via its own push buttons. While it is simple to obtain meaningful distortion figures of electrical devices, measuring Loudspeaker distortion in normal environments (without anechoic chamber) is not easy. We will only give some advice here, relying on examples, as the topic is far beyond the scope of this User <strong>Manual</strong>. To do this we will use CLIO’s FFT Menu in quite an advanced way. Distortion evaluation is adversely affected by several parameters, two of which are the most important. Noise 50 dBSPL of ambience noise, a common figure, usually does not affect Amplitude evaluation which is usually carried out at an average level of 90dBSPL. This is particularly true using CLIO Sinusoidal Analysis capability which, by means of DSP filtering, allows exceptional S/N Ratio. Unfortunately evaluating 1% distortion means looking for signals that are 40dB lower than the 90dBSPL mentioned above, in the same order of magnitude as environment noise. Gating Effects Device settling time, non perfect delay removal and reflections arriving within the sampling time (Meter On) seriously affect distortion measurements, creating artifacts. It is advisable to perform a noise evaluation using FFT Analysis. Fig.9 shows two curves, the first (red) is obtained with the Max Hold function, the second (black) with Min Hold. 80.0 CLIO dBSPL 60.0 40.0 20.0 0.0 -20.0 20 100 1k Hz 10k 20k Figure 11.8 The first, a sort of worst case, should be taken as the reference lower distortion floor once raised 10dB at least. The second is useful to identify pure tones in the noise spectrum; these are likely to produce both distortion increase as well as cancellation artifacts. In our case these tones are caused by more than 20 different computer fans, spread everywhere in the room. Supposing we carry a distortion analysis at an average 90dBSPL, residues below 1% are difficult to evaluate up to 600Hz, things are much better at higher frequencies. Remember that the frequency axis should be referred to the harmonic we are looking for, not to the fundamental. The obvious solution to overcome noise is to increase the level. One way is to put more voltage at the Loudspeaker terminals; unfortunately this increases distortion by itself even if it provided important information regarding the device. The second way is to narrow the 140 Chapter 11 - Sinusoidal
Microphone to Loudspeaker distance. The next figures, dealing with Gating Effects, refer to a Microphone at 11.5cm (4.5") in front to a good quality tweeter. FFT size is set to 512 points, the equivalent of about 10ms Meter On at 48000Hz sampling rate. Fig.11.9 shows the effects of a wrong delay in capturing a 2kHz 10ms tone burst. All harmonics are buried below the effects of this wrong setting. 120.0 CLIO 10.0 CLIO dBSPL Pa 100.0 6.0 80.0 2.0 60.0 -2.0 40.0 -6.0 20.0 0.00 2000 4000 6000 8000 10000 12000 14000 16000 Hz 18000 20000 -10.0 0.00 1.00 2.0 3.0 4.0 5.0 6.0 7.0 8.0 ms 9.0 10.0 Figure 11.9 Fig.11.10 shows the effects of the device settling time as the delay is now correctly set to 0.35ms. 40dB down the harmonics (1% distortion) should be visible now. As the tweeter performs better than this what we see is the second harmonic canceling the broad spectrum caused by the device settling time. 120.0 CLIO 10.0 CLIO dBSPL Pa 100.0 6.0 80.0 2.0 60.0 -2.0 40.0 -6.0 20.0 0.00 2000 4000 6000 8000 10000 12000 14000 16000 Hz 18000 20000 -10.0 0.00 1.00 2.0 3.0 4.0 5.0 6.0 7.0 8.0 ms 9.0 10.0 Figure 11.10 Fig.11.11 shows the spectrum when the delay has been set to 1.5ms. The third harmonic, 64dB (0.06%) below the fundamental is clearly visible. 120.0 CLIO 10.0 CLIO dBSPL Pa 100.0 6.0 80.0 2.0 60.0 -2.0 40.0 -6.0 20.0 0.00 2000 4000 6000 8000 10000 12000 14000 16000 Hz 18000 20000 -10.0 0.00 1.00 2.0 3.0 4.0 5.0 6.0 7.0 8.0 ms 9.0 10.0 Figure 11.11 Chapter 11 - Sinusoidal 141
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ELECTRICAL & ACOUSTICAL TESTS User'
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CONTENTS 1 INTRODUCTION ...........
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7.10 SIGNAL FILES .................
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14.1 INTRODUCTION .................
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AUDIOMATICA’S WARRANTY Audiomatic
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12 Chapter 1 - Introduction
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2.1 THE PB-4281 PC BOARD AND SC-01
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2.2.3 THE MIC-01 (OR MIC-02) FREQUE
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2.4 THE QCBOX MODEL 4 AMPLIFIER & S
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2) 2 x Stereo mini jack to two RCA
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3.3 HARDWARE REGISTRATION WITH WIND
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3.3.2 HARDWARE REGISTRATION UNDER W
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3.3.3 HARDWARE REGISTRATION UNDER W
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Figure 3.21 Let's now verify that t
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3.4 SOFTWARE INSTALLATION This para
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3.6 RUNNING CLIOWIN FOR THE FIRST T
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3.7.1 CALIBRATION VALIDATION Figure
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3.9 TROUBLESHOOTING CLIO INSTALLATI
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4.3 CLIOWIN DESKTOP The CLIOwin des
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4.5 HARDWARE CONTROLS TOOLBAR 4.5.1
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4.5.4 MICROPHONE CONTROL Switches C
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4.6.2 CONTROLLING A TURNTABLE Fig.4
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4.7.2 ANALYSIS MENU The Analysis me
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Fig. 4.16 Sinusoidal Submenu Fig. 4
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4.7.3 CONTROLS MENU The Controls Me
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4.8 BASIC CONNECTIONS In order to c
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4.8.3 CONNECTING THE CLIOQC AMPLIFI
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T&S parameters data files. Wow&Flut
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Invokes the Autosave Settings dialo
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5.3.4 PRINTING Enters the Notes dia
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customize up to 6 different color s
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5.7.1 SAVING MEASUREMENT SETTINGS M
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6.3 BUTTONS AND CHECKBOXES Moves (s
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6.6 THE MLS TIME DOMAIN DISPLAY Whe
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The following figure shows a 1031.2
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7.4 MULTITONES It is possible to ge
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7.6 MLS It is possible to generate
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7.8 The following figure shows a 20
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The following figure shows the same
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For comparison with Pink noises the
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The following figure shows a msampl
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84 Chapter 7 - Signal Generator
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8.2.1 TOOLBAR BUTTONS Starts the me
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This is substantially the measureme
Page 90 and 91: With the Multi-meter running, fit t
Page 92 and 93: 8.6 INTERACTION BETWEEN THE MULTI-M
Page 94 and 95: 9.2.1 TOOLBAR BUTTONS, DROP DOWN LI
Page 96 and 97: 9.4 FFT SETTINGS DIALOG Fig. 9.2 Th
Page 98 and 99: A better approach is to center the
Page 100 and 101: it is necessary to remove the fligh
Page 102 and 103: 80.0 CLIO dBSPL 70.0 60.0 50.0 40.0
Page 104 and 105: 9.10 “LIVE” TRANSFER FUNCTION A
Page 106 and 107: Another factor of maximum importanc
Page 108 and 109: The last obstacle you may find whil
Page 110 and 111: 10.2.1 TOOLBAR BUTTONS Starts an ML
Page 112 and 113: Amplifier & SwitchBox Model 2,3 and
Page 114 and 115: 10.4 MEASURING FREQUENCY RESPONSE I
Page 116 and 117: 150.0 CLIO 180.0 150.0 CLIO 180.0 O
Page 118 and 119: speaker we are testing is a gloriou
Page 120 and 121: 10.4.4 PHASE & GROUP DELAY We used
Page 122 and 123: etween true phase, as in Fig.10.22,
Page 124 and 125: 10.5 OTHER TIME DOMAIN INFORMATION
Page 126 and 127: utton. Any process you execute can
Page 128 and 129: 10.7 MLS Vs. LOG CHIRP As anticipat
Page 130 and 131: 10.8 RELATED MENUS The dual domain
Page 132 and 133: Display fifth harmonic distortion,
Page 134 and 135: Gating (Acquisition) Settings Gated
Page 136 and 137: 11.3 A BRIEF DESCRIPTION ON SETTING
Page 138 and 139: 11.3.3 GATING Enabling Gating allow
Page 142 and 143: Finally Fig.11.12 shows the distort
Page 144 and 145: 12.2 WATERFALL AND DIRECTIVITY CONT
Page 146 and 147: 12.3.2 WATERFALL OPERATION As alrea
Page 148 and 149: Figure 12.5 One powerful way to ins
Page 150 and 151: 12.5 DIRECTIVITY SPECIFIC CONTROLS
Page 152 and 153: 12.6 MEASURING AND REPRESENTING LOU
Page 154 and 155: 12.6.4 REPRESENTING POLAR DATA To r
Page 156 and 157: 156 Chapter 12 - Waterfall and Dire
Page 158 and 159: If you are a novice in using CLIO,
Page 160 and 161: life harder even if more interestin
Page 162 and 163: 13.4 I SENSE This requires Audiomat
Page 164 and 165: 0.0 CLIO 180.0 dBV Deg -10.0 108.0
Page 166 and 167: CLIO INPUT A INPUT B OUTPUT A OUTPU
Page 168 and 169: 13.7 THIELE & SMALL PARAMETERS 13.7
Page 170 and 171: L 1kHz L 10kHz Inductance at 1kHz I
Page 172 and 173: We can now save our complete result
Page 174 and 175: The graphs refers to a linearity me
Page 176 and 177: DIN measures Intermodulation distor
Page 178 and 179: 15.2.1 TOOLBAR BUTTONS AND DROP DOW
Page 180 and 181: 15.3 ACOUSTICAL PARAMETERS SETTINGS
Page 182 and 183: RTU [s]. Reverberation time evaluat
Page 184 and 185: 184 Chapter 15 - Acoustical Paramet
Page 186 and 187: 16.2.1 TOOLBAR BUTTONS AND DROP DOW
Page 188 and 189: 16.3 Leq SETTINGS Time resolution S
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17.3 FEATURES Figure 17.2 Aside a s
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192 Chapter 17 - Wow & Flutter
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[20] D. Clarke, “Precision Measur
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196 Norms
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