Basic Measurement with DewesoftX Using Sound Card and Webcam

Course overview

The course guides users through a low-barrier entry into DewesoftX’s capabilities using only common PC hardware. After installing the software and activating a webcam (via DirectX) and sound card simulation (in Offline mode), you’ll access real-time measurement in Measure mode.

Analog input channels are then configured: set sample rates appropriately high for sound acquisition (10–40 kHz), assign Pa units for sound pressure, and calibrate using simple acoustic signals like a whistle to approximate 1 Pa levels.

In parallel, the webcam input is enabled, and camera settings such as resolution and compression are adjusted to integrate live video into the measurement screen (). Custom widgets—including recorder, scope, and FFT—are placed onto the interface to visualize both audio waveforms and frequency content.

During data acquisition, you’ll trigger and record live sound events, monitor display real-time signals, and record synchronized video. In Analysis mode, replay files with audio and video sync intact, use cursors to zoom into interesting sections, and explore waveforms and spectra.

Finally, the training shows how to export data using multiple formats (Excel, CSV, FlexPro), capture screen images for documentation, and generate comprehensive reports summarizing the measurement campaign .

By the end, you’ll be comfortable creating and analyzing simple audio-video measurements—perfect for educational demos, proof-of-concept tests, or demonstrations—using nothing more than a standard PC with a sound card and webcam.

This lesson will first demonstrate how to perform a simple measurement with DewesoftX. The hardware used in this example is a sound card and a webcam.

First, download the DewesoftX software from our website, then run the installer. To follow this tutorial, you will need a physical license (professional or trial .lic file) installed in Dewesoft, and the webcam connected. Once everything is set up, you can select the DirectX camera in the Settings.

You can download the Audio Card from our website (SB_v3_0.zip). Copy the .daq file to the DewesoftX installation folder (for example, if DewesoftX is installed on drive C, the path would be:
C:\Dewesoft\Bin\X2\Addons).

Next, run DewesoftX as an administrator.

You can activate the Audio Card in three simple steps under Device Settings:

1. Make sure the operation mode is set to Simulation.

2. Click on Simulated Devices.

3. Change the Simulated Channels mode to Sound Card.

In the DAQ Settings section, you will see your active audio devices.

Even though only minimal instrumentation is used in this example, it still provides a good demonstration of what can be achieved with DewesoftX software.

The following table lists the required hardware and software for completing this lesson:

In the upper-left corner of the screen, you will find two main tabs: Measure and Analyse. These are used to switch between Measure Mode, for acquiring data, and Analysis Mode, for processing the data.

You can view all available properties and adjustments for the analog channels.

Click the Ch. Setup button. This will open the channel setup screen, where you will see the Analog section with two analog channels (stereo), the Video section, and the Math section.

In the Storing section, you can enter the file name and choose the location on your computer where the files will be saved. In the Analog section, you can configure the sample rate.

The sample rate determines the speed at which data is acquired. This setting should be chosen carefully depending on the measurement type:

• For temperature measurements, only around 100 Hz (samples per second) or even less may be sufficient.

• If the chosen rate is unnecessarily high, disk space will be wasted without providing additional useful information.

In this lesson, we are measuring sound, so a minimum sample rate of 10 kHz (10,000 samples per second) is required to correctly capture audio. For good audio performance, a rate of 40 kHz or higher is recommended.

Next, select the appropriate channels. Since only a simple microphone is used in this example, one channel is sufficient. Users can enable it by clicking the on/off button. Note that Setup buttons are available on the right side of the channel list.

Even though this example uses a simple microphone, the importance of correct measurement should be emphasized. First, we need to define the units of measurement. A microphone measures sound pressure, expressed in Pascals (Pa). Therefore, Pa should be entered as the unit.

Next, we will perform a simple “calibration.” Sound can be calibrated using a sine wave. For this example, we can generate a sine wave by whistling. The RMS value of the signal will rise to a certain level, and we can use the Calibrate from RMS button to adjust the level so it corresponds to approximately 1 Pa.

A real microphone is calibrated in the same way as shown in this tutorial. However, with a proper microphone and calibrator, we can rely on the calibration value being exactly 1 Pa.

Here is an example of how to set up a web camera.

The next step is to configure the video channel. Go to the Video section. In the Camera Options section, the webcam should appear if it is installed correctly. Click the Unused button to switch on the camera, and complete the setup by clicking the Setup button.

If the camera is not recognized, go to Settings in the upper-right corner of DewesoftX, press the Devices button, and then click the + button. The Add Device window will open, where you can add the camera you are using.

Here, you can adjust the frame rate, resolution, compression, and other camera properties. More details about camera setup will be explained later, but for now, we will keep the configuration simple.

We are now ready to take the first measurement.

You can add and adjust different widgets for signal input.

Click the Recorder button in the upper section. The system will begin acquiring data. You can now test how the microphone works by making some sounds. Use the plus (+) or minus (–) buttons in the lower-right corner of the display to zoom in or out along the time axis.

To view the data at a faster rate, switch to the Scope screen. In the Trigger tab, select the Norm trigger, then drag the L1 level with your mouse to about 10% of the full range. You can now tap on the microphone to create trigger shots. This will clearly show how different sounds create distinct patterns.

Next, the FFT screen can be used to perform frequency analysis.

The FFT screen can be added from the Widgets menu. As you will see, there are several visual controls available, including the FFT display.

A fine line resolution and a logarithmic scale are useful for better observing harmonics. For example, in the screenshot below, 4096 lines are used, giving approximately 1 Hz between each frequency line.

Here, you can try singing your best A note (A3 has a frequency of 220 Hz, A2 has a frequency of 110 Hz). If you have a piano or another musical instrument, you can also check how well it is tuned. It is interesting to compare the differences between a whistle, singing, and a musical instrument. In fact, the higher harmonics define the timbre, or the color of musical tones.

Now you can return to the Recorder, where all the previously captured data is still available. You can zoom out to observe the entire time period during which you or someone else interacted with the microphone.

The next step is to store the data. Click the Store button, and a red light will appear on it. In the upper-right corner, you will see the size of the stored analog data along with the video file size.

This chapter explains how to design a clear and transparent measurement screen.

In the previous example, we showed how to use separate instruments. In DewesoftX, it is possible to combine these instruments to create well-organized and visually appealing displays. In fact, any display can be customized according to the user’s needs. For this example, let’s modify the Overview display, which is intended for combining instruments.

First, locate the Design button, which is positioned next to Measure. When Design is enabled, a bar with available instruments appears. From here, you can add all the instruments that were used independently before. For instance, add a Recorder, Scope, and FFT. These instruments can be dragged and resized to fit your layout.

Don’t forget that video can also be included. Click the camera icon (Video) on the bar to add a video screen.

To zoom in or out, or to adjust trigger levels, exit Design mode by clicking the Design button again. This hides the instrument bar and restores the full functionality of the displays. You can now practice arranging and configuring these basic instruments to create a clear overview of your measurements.

Finally, remember that we are storing data. Click the Stop button to stop recording.

Explore all the possibilities for reviewing stored data.

The next step is to take a closer look at how we can analyze the stored data.

It’s quite simple—just click the Analysis button. Since we just stored a data file, DewesoftX assumes this is the file we want to review. If the user clicks Analysis in other cases (such as when launching DewesoftX or from the setup screen), the file explorer will open. There, you can browse subfolders of the main data folder, view the file list, and check detailed information about the selected file, such as size, start time, version, sample rate, number of channels, storage options, and video files (if available).

Double-click on the previously stored file to open it.

If subfolders are present, you can open them by double-clicking on the subfolder.

The top-level data folder can be changed by using the folder list drop-down and selecting any upper-level folder. You can also save a default folder by selecting Set as default project folder from the drop-down menu.

When a file is selected, it is pre-scanned to display important information about channels, events, and the data header. This information is shown in the General file information section and in the Channel info list below the file explorer. Note that Min and Max values are also available, and if a channel is overloaded, it will be highlighted in red.

 Now, we can open the file. The user can choose any display that was pre-built in Acquisition mode.

There are several ways to review the data file. In the upper-right corner, you’ll find the Play button. Clicking it starts playback—the yellow cursor moves through the data, FFT is calculated, the scope displays the current signal, and the video file is replayed. When playback begins, the Play button changes into a Stop button. Clicking it stops the replay.

You can even listen to the sounds you recorded. Next to the Play button, there is also a Sound button marked with a red cross. Clicking it opens the channel list. By selecting the stored channel, the loudspeaker icon will lose the red cross. Now, click Play again, and you will hear the recorded sound through the speakers. To stop playback, click Stop, and to turn off the audio replay, select None from the loudspeaker icon menu.

While playing back the data, you may notice the yellow cursor moving through the timeline. You can also drag this cursor with the mouse to quickly move through the data file.

If the data file is very large, it can be useful to zoom in on a specific section. The recorder provides two additional silver cursors—labeled I and II—which the user can drag to select a region of interest.

Another way to select a specific area is to left-click and hold the mouse button on an empty part of the recorder (where no red events or cursors are present). This places cursor I at the clicked position. The user can then drag the mouse to a second location, which positions cursor II.

Once both cursors are set, the mouse pointer will change to a zoom icon within the region between cursors I and II. Clicking the left mouse button will zoom in on that region. This process can be repeated multiple times to reach the exact area of interest.

Additionally, the X-axis scale can be dragged left or right to fine-tune the position of the data. Right-clicking anywhere on the recorder will zoom back out to the full scale.

In DewesoftX, it is also possible to output the recorded signal.

A signal recorded with a microphone or any other sensor can be replayed and played through speakers in Analysis mode.

Under the Sound section, select the Output channel you want to replay. Note that only one channel can be selected at a time.

The de facto standard for sound replay is 44,100 Hz, based on the limits of human hearing and signal processing. Sound cards can replay files with the following rates directly (without software resampling):

• 11,025 Hz

• 22,050 Hz

• 44,100 Hz (default rate for sound reproduction in the Red Book standard, 1980)

• 88,200 Hz

• 176,400 Hz

• …

To replay recorded sound data in the best possible way, the acquisition sample rate must be set to one of these standard rates for sound reproduction. The formula to calculate the nearest rate in Hz is:

11025 × 2ⁿ (where n = 1, 2, 3, …).

Recorded sounds sampled higher than 44,100 Hz must be band-limited first. For this purpose, a low-pass FIR filter can be used (see the Filtering section).

If the sample rate differs from the standard rates, DewesoftX applies linear interpolation. However, linear interpolation is a poor choice for signal reconstruction and resampling because it is a non-continuous step function that introduces harmonic components in the frequency spectrum (multiples of the main harmonic).

This resampling effect can be heard to varying degrees:

• Less noticeable when:

  • the sound frequency is low compared to the sampling rate, or

  • the spectrum already contains many frequency components.

• Clearly noticeable when:

  • the sound frequency is close to the Nyquist frequency of the band-limited signal, or

  • pure tones are played.

Example: A test was made using a single-tone sweep signal from 5 kHz to 10 kHz.

 The green line represents the original signal, recorded with DewesoftX and SIRIUS.

This recorded signal was then replayed and recorded again with DewesoftX. The replayed signal clearly contains harmonic components because the original signal was not sampled at 44,100 Hz and was therefore linearly interpolated.

Conclusion: For the best sound quality in Dewesoft, it is recommended to use one of the standard sample rates (direct playback through the sound card at 11,025 Hz, 22,050 Hz, or 44,100 Hz).

What can we do with this data?

First, we can print the current page. Simply click the Print button, and the same page will appear with a white background to make it “printer-friendly.” You can select different print options in this menu and then click Print again to complete the process.

The next step is to export the data to other applications. DewesoftX is primarily an acquisition application, so for advanced analysis, the data can be exported to post-processing tools. This is done by selecting the Export button. From there, you can choose to export the data to MS Excel or FlexPro. You can also select a script, which generates measurement reports. Alternatively, you can choose File Export, which provides a wide range of post-processing options, although in this example we are only exporting the data file.

It is important to note that in this example we will export only a zoomed-in region. If MS Excel is installed on your computer, avoid exporting too much data when testing this feature, as Excel cannot efficiently handle large datasets. For larger data files, it is recommended to use FlexPro or MATLAB.

Another useful option is creating a video recording of the screen during replay. This can be done by selecting Edit → Export Screen to AVI. This will generate a video file showing the playback exactly as it appears on the DewesoftX screen.

This has been a short overview of what can be achieved using very basic hardware. With professional equipment, the possibilities are much greater. The upcoming measurement tutorials will demonstrate how to perform real measurements.