Sonic Visualiser is an open source application available for Windows, OSX, and Linux which allows the user to view and analyze audio files. It is extremely useful as-is, and is extendable with Vamp plugins.
A valuable use for Sonic Visualiser is to create a spectrogram of a section of audio to see how deep the bass plays. Having an easy to use ability to quantify this data can make you more effective at organizing your subwoofer test tracks. It's also a handy way to demonstrate why a song is awesome to people who place a high value on objective data.
Culture Shock - Have It All ft.Raphaella
After downloading the software and installing, you're ready to start making spectrograms immediately, although I'll suggest a few settings tweaks to make your spectrograms more easily readable.
Before loading up an audio track, go to the File menu --> Preferences. Go to the Session Template tab. Select "Waveform and Melodic Range Spectrogram", and hit Apply. This template is a good starting point for creating your own template. Before dismissing Preferences, go to the "Other" tab and uncheck "Show splash screen on startup" for faster loading. Hit OK, and close and reopen the application for the settings to take effect.
You can load an audio file through the File menu, through the second toolbar button, or by dragging and dropping a file onto the window. With an audio file loaded, you'll see the waveform pane and the melodic range spectrogram pane. X out the waveform pane.
There are zoom controls in the lower right corner of the spectrogram. The vertical wheel increases and decreases the frequency range on the Y axis, while the horizontal wheel changes the measures per inch, expanding and contracting the X axis. Incidentally, rolling the mouse wheel also changes the X axis, and you can double-click the wheels or the vertical range slider to enter values manually. For analyzing bass response, I like to set the vertical range from roughly 10 Hz to 200 Hz. You can drag the spectrograph up to reveal lower ranges, and play with the vertical roller control until you get the range the way you like it. The wheels can be hidden or revealed through the View menu, or by hitting Z on the keyboard.
To the right of the spectrogram are the property boxes, where you can further tweak the behavior of your spectrogram.
- Firstly, on Tab "3", change the amplitude range to 20dB by messing with the dial on the right edge of the "Sunset" color drop-down. Click the dial and drag straight up to rotate it clockwise, or down for counter-clockwise. You can watch the value change in the status bar on the bottom edge of the window.
- The value of the Window size changes the level of focus for the spectrogram. Larger values make the blobs skinnier for greater accuracy, but at the expense of CPU usage. A value of 16384 focuses the fundamentals to a width of only a few Hz while still allowing for reasonably acceptable scrolling motion during playback on my 6th gen Core i3. You can further focus the fundamentals by changing the normalization on the "Scale" line, but that can also add puddles of blue to other parts of your spectrogram while de-emphasizing the fundamentals. Try it both ways and see what you prefer.
- The Window Overlap setting blurs or sharpens the blobs. There seems to be no appreciable CPU hit for leaving the Window Overlap set to its highest setting.
These are the settings I used to generate the spectrogram above:
Next, go to the View menu --> Show All Overlays to reveal a dB color legend to the left of the frequency axis.
After you get the spectrogram tweaked the way you like, go to the File menu --> Export Session as Template. Name it something recognizable, such as "bass spectrogram", and check mark the box to have this template applied by default to all the audio files you load. This template will also store the song position, so be sure to rewind your song if you want all songs to start at 0:00. Or if you most often measure Drum and Bass tracks whose bass lines typically don't start in earnest until a minute into the song, pause your song at 1:00 before exporting the session.
To export a screenshot of your spectrogram, go to File --> Export Image File. Choose a name and location, then tell it to export the visible area only. You can then upload it to
Imgur or similar to show off to a bunch of strangers you met on a forum. Achievement unlocked: bragging rights.
