An instrument equalizer provides the possibility to adjust the volume of an individual instrument in a recording without affecting the volume of the other instruments. On this website, we present recordings in a multitrack audio player with an individual track for each voice/instrument of No. 6 from "Der Freischutz". When studying a specific melody line of the violins and the flutes, for example, the instrument equalizer enables a user to raise the volume for these two voices and to lower it for the others. Note that, when recording orchestra music, the microphones for capturing the different voices are usually not shielded from each other. In practice, each microphone not only records sound from its dedicated voice or instrument, but also from all others in the room. This results in recordings that do not feature isolated signals, but rather mixtures of a predominant voice with all others being audible through what is referred to as interference. In [1], we presented a method for reducing interferences in multitrack recordings. A way to use multitrack recordings suffering from interference in an instrument equalizer is to apply an interference reduction first.

The following players present an excerpt of the multitrack data from the recording session of No. 6 of "Der Freischütz". The player on the left presents the unprocessed recordings, in which every voice is audible in every microphone. The player on the right presents an interference reduced version of the recordings which have been created by applying the algorithm presented in [1].

No. 6 (measures 124-129)

Unprocessed multitrack data	Interference reduced multitrack data
The following player presents an excerpt of the unprocessed multitrack data from the recording session of No. 6 of "Der Freischütz".	In this example, the interferences in the recordings have been reduced by processing them with the algorithm introduced in [1].

No. 6 (measures 127-132)

Unprocessed multitrack data	Interference reduced multitrack data
The following player presents an excerpt of the unprocessed multitrack data from the recording session of No. 6 of "Der Freischütz".	In this example, the interferences in the recordings have been reduced by processing them with the algorithm introduced in [1].

References

[1]

Thomas Prätzlich, Rachel Bittner, Antoine Liutkus, and Meinard Müller. Kernel additive modeling for interference reduction in multi-channel music recordings.
In Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP), Brisbane, Australia, 2015.