Headroom and Padding in the DPS Algorithm

We are often asked about the difference between DPS on and off. In some cases, the effect of DPS is so dramatic people think we are somehow “degrading” the audio in “off mode”. We understand this concern and welcome the opportunity to describe our approaches.

Here are a few key points:

  • The Bongiovi DPS application decreases the volume by 3.5dB before any audio is processed.
  • This feature is similar to other software products in this category.  It is an industry standard.
  • Only volume is changed (no audio processing occurs when DPS is off).
  • The 3.5dB pad is also in place when DPS is on.
  • This feature is completely optional for final product implementations.

During development of the Bongiovi DPS consumer software, we analyzed the methods used for several existing solutions such as SRS, Dolby, and others.  All system-wide plugins for audio must contend with the headroom limitations of digital audio.  In our research, all existing solutions create new headroom by turning the overall level down before audio processing. In our case, we decided upon -3.5dB. 

Here is why:
If the improvement for an audio device requires increased bass, the level of the bass frequencies must be louder than the rest of the signal. Since there is no room to increase the overall level, we must turn down the entire track to make room for the new bass levels.

When most normal consumers of our software hear an overall decrease in volume (even if the bass and other features are improved over the original) the effect is perceived as weaker and undesirable. This is because our perception of sound changes just by hearing the same signal at different volume levels. By decreasing the overall volume by 3.5dB we allow ourselves 3.5dB of headroom to provide a good user experience. When turning DPS ON, the apparent volume level will increase or remain the same.

For OEM integrations, this is not necessary. We are delivered the specifications for the amplifiers and drivers and we get maximum performance from them using our algorithm. There is no OFF mode to compare to.

We have the ability to enable or disable the headroom padding with the DPS Profile Creator tool.