Dayton-audio OmniMic V2 Precision Measurement System User Manual

1 | P a g e Software version 4 (c) 2013 Bill Waslo HELP MANUAL Jan. 31, 2013

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11 | P a g e Frequency Response - Advanced Functions Index Additional Advanced features are built-in and available in the OmniMic Frequency Respon

12 | P a g e directions. To use these, there must be at least three added curves in the main frequency response plot, each with different radiation

13 | P a g e Frequency Response: Waterfalls Index Waterfall plots are used by driver and loudspeaker designers for driver selection, to identify re

14 | P a g e "Toneburst Energy Storage" shows the effect that would occur if the loudspeaker were driven by short tonebursts of energy

15 | P a g e "Wavelet Spectrogram" shows a combined time/frequency representation of the impulse response. The Wavelet Spectrogram in

16 | P a g e The time resolution is more detailed at higher frequencies than at lower frequencies (because there are more "Hz" in an oct

17 | P a g e If you spread the time axis out to full length, you can also use the Wavelet Spectrogram for viewing room reflections and the frequenc

18 | P a g e Determining Z-Offset (depth offset) between speaker drivers Index A major advantage of Omnimic over other audio measurement systems i

19 | P a g e ________________________________________ How to use the Z-Offset Calculator:  1). Position your microphone at the design center po

2 | P a g e Index Contents  Using OmniMic V2………………………………………………………………………………….…pg. 3  OmniMic Adjustments……………………………………………………………………………….pg. 5

20 | P a g e Room Equalization with Omnimic Index Omnimic enables you to measure the frequency response of your room and speaker system at any numb

21 | P a g e If we equalized the response for flat at the Red position, then at 100Hz that would be fine for both Red and Blue around 100Hz. But B

22 | P a g e Obtaining your Typical ("Average") Response Measurement To make up your average curve, play one of the "Short Sine Swe

23 | P a g e The red curve above is an in-room measured curve, and the green curve is a generated EQ frd file (loaded as an "Added Curve"

24 | P a g e If you set any of the EQ sections to Auto, then the form will further expand to show buttons and limit settings that the Omnimic pro

25 | P a g e MiniDSP Equalizer Tuning Index The OmniMic v4 software MiniDSP Equalizer function allows you to configure parametric filter settings,

26 | P a g e In the form, you choose:  the frequency range over which you wish to have automatic optimization occur  the type of target curve:

27 | P a g e  1) Measure the frequency response (probably without windowing, using the "All" radio button above the plot) and perhaps 1

28 | P a g e Polar Displays Index Polar displays are an Advanced Feature, provided by a non-live postcalculation using multiple saved frequency re

29 | P a g e these patterns -- dipoles, omnidirectional, bipole, arrays, or waveguides. To see the response magnitude (dB) varying with both freque

3 | P a g e Software version 4 (c) 2012 Bill Waslo Using OmniMic V2 Index OmniMic V2 is extremely simple to use. You can be up and making meas

30 | P a g e these peaks appear. There is a set of example FRD files which can be loaded all at once by going to the Frequency Response menu "

31 | P a g e You can configure the base file name and the increment value (and starting value) by choosing "configure auto-increment".

32 | P a g e Polar Protractor Index Provided to assist in arranging OmniMic and loudspeakers when collecting responses for Polar Displays. Print t

33 | P a g e SPL/Spectrum Index Use the SPL Meter/Spectrum Analyzer type to see - The level of any sounds on the SPL meter face. Options:  Se

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35 | P a g e Oscilloscope Index Use the Oscilloscope to view any sound waveforms. These might include music, your voice, or waveforms played by l

36 | P a g e Signal Generator Index With most computers, Omnimic can be used to directly generate test signals such as the sweeps for Frequency Re

37 | P a g e Harmonic Distortion Index To properly measure Harmonic Distortion with OmniMic, you must measure only while the sound system is playi

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39 | P a g e Reverb/ETC Index Reverberation is a measure of how quickly sound reflections die down in a room, and will depend on the frequency ran

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40 | P a g e  Set the value of the "Integration time" to a value approximately equal to the expected RT60 of the room (around 500 milli

41 | P a g e comes from the speaker and reflects around the room. In other words, imagine the speaker sent out a sudden pulse rather than the sweep

42 | P a g e Bass Decay Index Use the Bass Decay analyzer to measure how bass notes decay in a room.  Use only the provided "bass sweep&quo

43 | P a g e At the bottom is a check box labeled "adjust for response". This affects whether the variations in relative bass strength

44 | P a g e Operating Notes:  when working with the "adjust for response" box checked, you would normally set the blue line (click in

45 | P a g e Scaling Graphs Index The various graphs and the SPL meter display can be scaled as suits the user. Or they can be set to automatical

46 | P a g e Adjusting Input Gain and Auto-Level Index For best results, the input sensing gain of OmniMic should be adusted approximately for the

47 | P a g e Freezing the Graphs Index By default, the OmniMic software runs, and the graphs and meters update, continually. At times you may wis

48 | P a g e Reading Values on Graphs Index You can position the mouse cursor on most graphs to read data values that would exist at the point tha

49 | P a g e Printing Graphs Index Print the current OmniMic screen image by clicking on the Print menu. You can select the printer that will be

5 | P a g e OmniMic Adjustments Index The accuracy of each individual OmniMic is enhanced in software to account for frequency sensitivity variati

50 | P a g e Saving Graph Pictures to Disk ("Snapshot") Index You can save a high quality picture file of the current graph by clicking

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52 | P a g e Saving Data Files to Disk Index Data files can be saved to disk by clicking on the File menu. It will be saved in an ASCII text form

53 | P a g e Playing OmniMic test tracks without a CD Index OmniMic test tracks can be "ripped" from CD using commercially available sof

54 | P a g e Instructions for special measurements not described on other pages Index How to... Splice two or more frequency response curves toge

55 | P a g e Optimally position speakers within a room Speaker and listener positioning within a room is probably the most significant factor dete

56 | P a g e Arrange and test whether a frequency response falls within a specified range The "Evaluate within" function (in the "Mat

57 | P a g e Turn any equalizer or tone controls off. You can then play the 50Hz reference tone tracks and measure or set the voltage level from th

58 | P a g e Troubleshooting Index Listed are answers to some questions that may arise. There is a message with a yellow background telling me &q

59 | P a g e levels of background noise or weak signal levels are indistinguishable from distortion. You can find the distortion "threshold&qu

6 | P a g e browse to where you stored your ".omm" file. Then click "Apply". Or if you are connected online with the computer

60 | P a g e response rolled off naturally before 20kHz (like human ears do), that would result in a phase response and delay which would prevent th

61 | P a g e Test CD Track Listing 1 Track 1: Monophonic Pseudo-noise sequence 2 Track 2: Monophonic Short Sine Sweep 3 Track 3: Monophonic Long

7 | P a g e Frequency Response Index Use the Frequency Response analyzer to measure the frequency response or the impulse response.of a sound sys

8 | P a g e show impulse responses, and you can select how much of an impulse reponse you want to analyzer to look at when forming a frequency respo

9 | P a g e can be included. In snapshot files, a text note can also be added. FRD files or properly formatted ".txt" files can be load