Applies to

Studio

Origin

Audirvāna Remote

Operating System

macOS

Windows

Linux

Two upsampling algorithms are available in Audirvāna. Each of them has differences, but they both rely on the capabilities of your DAC (e.g., they can't upsample to DSD1024 if your device supports DSD512 at maximum)

Setting up upsampling in Audirvāna

In this article:

• Step 1: Set the operating rule
• Step 2: Choose your algorithm

Step 1: Set the operating rule

By setting up this command, you activate upsampling (please read this article to know more about it) :

• Power of 2 of the native track sample rate. This will be the highest frequency the audio device allows for a track natively at 44.1 kHz, 88.2, 176.4, or 352.8 kHz.
• Maximum sampling rate of the audio device
  
• x2 only: Twice the track's native sample rate (if acceptable to the audio device)
  
• By frequency: Specific sampling rate for each track natively (selection made by clicking on "Settings by frequency")
  
• DSD: this option is only available with a DSD-compatible DAC and can go up to DSD 1024 if your DAC supports it. 
  

Note: To avoid problems caused by oversampling of DSD, which can cause interruptions during audio playback, it is advisable to reduce the sound volume. 

Step 2: Choose your algorithm

You can choose between two upsampling algorithms in Audirvāna:

• SoX algorithm:
  
  • Bandwidth: This indicates the limit of the low-pass filter as a percentage of the Nyquist frequency (half the sampling frequency). The filter's slope is low at 74% and very steep at 99.5%. Make sure that this does not induce too much brightness (i.e., highs are too aggressive).
  • Maximum filter length, i.e., the amount of memory and CPU load, used by the oversampling filter. The default value is sufficient in most cases. It can be increased to achieve better quality when oversampling to very high frequencies (e.g., DSD oversampling)
  • Anti-aliasing: the level of suppression of the signal in the cut band of the low pass filter. Any frequency still present in the cut band gives artifacts from harmonics that end up in the output signal. Higher values of this parameter give better quality at the cost of a higher CPU load.
  • Phase: All low-pass filters have some level of overshoot. The steeper the filter slope, the greater the overshoots.
    
    
    
• SoX algorithm:
  
  • Bandwidth: This indicates the limit of the low-pass filter as a percentage of the Nyquist frequency (half the sampling frequency). The filter's slope is low at 74% and very steep at 99.5%. Make sure that this does not induce too much brightness (i.e., highs are too aggressive).
  • Cutoff Band Attenuation: this is the setting of the slope of the low pass filter expressed in dB per octave. With the maximum slope (218 dB), there may be too much brightness (i.e., the highs are too aggressive)
    
  • Phase: All low-pass filters have some level of overshoot. The steeper the slope of the filter, the greater the overshoots. There are two types of overshoot: pre-oscillations and post-oscillations. The former are audible as a "pre-echo" arriving before the signal and are the least natural to hear. You can choose between a filter setting with linear phase but with an equal level of pre-and post-oscillation or a minimum phase filter with no pre-oscillation but non-linear phase distortion.