It is true that in music production you should trust your ears. However, over time you get used to your studio up to a certain point, whether it’s acoustically treated or not. The truth is, after hours and hours of work your ears get tired, and your perception of the sound levels gets shifted. At this point, spectrum analyzers shine in their full glory. Good and trustworthy spectrum analyzers are not easy to find and usually, what costs more is worth more. There are few exceptions regarding this matter, and one of them is SPAN by Voxengo.


Voxengo SPAN


SPAN is a very flexible, accurate and FREE tool that everyone should know about when they start working with digital audio. There’s plenty of variables to tweak to get it performing and looking exactly how you need it to be. SPAN provides you with a very flexible “mode” system which you can use to setup your spectrum analyzer preferences.  You may specify Fourier block size in samples, FFT window overlap percentage, spectrum’s visual slope. Besides that, you can choose to display the secondary spectrum of the desired type (e.g., real-time maximum, all-time maximum).

Spectrum can be smoothed out visually for a more straightforward examination. SPAN supports multi-channel analysis. You can set the display spectrums from two different channels or channel groups at the same time. What’s more, you can choose the spectrum’s color. SPAN also features output level metering with adjustable ballistics and integration time, K-system metering (including calibration K-system metering). SPAN displays level metering statistics, headroom estimation, and clipping detection. Correlation metering is available as well.

Let’s add it on the master channel in our SoundBridge: DAW and go thru its functions.



The Interface


As you can see the more significant portion of the interface takes the spectrum analysis graph, which is very accurate and balanced. In the upper part, we can see a line of tabs and settings. If you click on the “?” mark, the Span will show you information of every part of it down in the bottom of the interface. Next, to it, we have presets menu, which contains some useful presets. After that, we have A/B comparison buttons which are also kind of handy.

The “Routing” tab is one of the more useful functions of SPAN. It offers an elaborate routing scheme where you can, analyze your group track, for example, separately from the kick drum & bassline and compare the waveforms together in the same window of SPAN set on the master bus.



In the same line, we have “Copy To,” “Solo” and “Hide Meters and Stats” which pretty much explain themselves.

In the line below we can see a few options:



The “Hold” button allows you to hold spectrum values temporarily for visual comparison. You can use to display the current channels group own spectrum. The “Underlay” is an impressive feature of the SPAN since it offers an ability to add additional underlying spectrum ( in specific color) from another channel group of the other plug-in instance.

Further to the right, we have a mode selector which offers several spectrum analysis, such as Hi-Res., 96 kHz, Average, to name a few. Next, to the mode selector, there is a button for opening “Spectrum Mode Editor” window. Here there are many options for furthermore tweak and fine-tune the settings of the analysis to your liking.



The bottom of the interface offers even more options but turned more to the metering statistics. You can see the “Max Crest Factor,” “RMS,” “Clippings” and so on. Besides this real-time metering statistics, you can set the mode of the metering and chose one of many different standardized types such as many variations of DBFS and K. Also; there is an accurate correlation meter that can be seen at the end of this line.





To summarize everything, this is a pretty useful analysis tool, which offers a wide variety of useful functions and features and best of all it comes as FREE!