Remastero's Audio Spectrum Analyzer (RASA)

[Zaphod Beeblebrox]

Remastero's Audio Spectrum Analyzer (RASA)

I am happy to announce that I just released a free app RASA (v1.0.42), you can get it here. Available for both Mac and Windows. 

 

RASA was born out of my own need to analyze resampling and noise shaping performance and I often found existing tools did not quite get me what I needed. The recently released PGGB v5.2.42 uses the same analysis engine for its plots too. I welcome suggestions and constructive inputs and of course any bug reports.

 

Objectives:

The primary objective of RASA is to provide you with an easy to use tool to analyze your audio tracks, but there are other objectives too:

• To also provide you with a tool to compare performance of your favorite resampler(s)/upsampler(s).
• To help you compare what various options and filters within a resampler do to your tracks.
• It can also be used to check if Hi-Res versions of the tracks you purchase are truly sampled at the higher rates or if they were just upsampled!
• It can be used to analyze tracks to see if there is true music content beyond 20kHz or if it is mostly noise from ADCs noise, shaping which in turn may help you decide if you want to use HF filtering when available. (RASA does not have an in-built logic to tell you this, so you have to use your own judgement for now)

Features:

• RASA is a free and a very easy to use tool to help you analyze the frequency spectrum of audio tracks.
• It supports most common formats .wav, .aif, .aiff, .flac, .m4a and .dsf.
• It allows you to (optionally) perform the analysis using 128 bit precision.
• Other than the commonly used Hanning window, it provides an option to choose between Remastero's own proprietary windowing and an optimized flat top window which are both more accurate and better suited for analysis of resampling and filtering performance.
• RASA does not use power of 2 FFTs, instead it computes FFT over a one second window. This is advantageous as it has a fixed resolution (1Hz/FFT bin) and makes it very easy to compare the same track sampled at different rates.
• It will trim digital silence from beginning of tracks before analysis (can be turned off)
• You can analyze up to three tracks and overlay them, you can customize the color of the plots and add text title sand change legend text for each track.
• You can export the lot in most common image formats (.jpg, .png, .tiff, .gif, .pdf, .eps and .emf).
• You can optionally export animated gifs where the tracks are plotted one at a time and loops for ever.

 

Here is an annotated example comparing the three windowing options in RASA, but you can find a lot more information on the companion site.

 

 

[GoldenOne]

I've been using the beta of this for a while (Thank you very much @Zaphod Beeblebrox) and it's been brilliant.

I do a fair bit of analysis in the digital domain and it's surprising how difficult it is to find tools that offer even just features like extremely high FFT bin counts that aren't either flawed in various other ways or extremely clunky to use.

I'd been using DeltaWave for some time which for many applications and in particular comparing differences between files in various ways is excellent, BUT it does get extremely slow and eat up over 64GB RAM if you try to do stuff with 768khz files.

RASA has been lightning fast and offers brilliant performance. Huge thanks to Zaphod for making this AND for making it free!

[Zaphod Beeblebrox]

I just released a new version of RASA v1.0.43 here. 

 

Based on request from @GoldenOne , I have added an option to use logscale for X axis.

 

The legend now uses smart positioning to minimize interaction with the plot.