Common Instrument Format
The CIF format is based on the same principles as the CLF format but is
for the directivities of natural sources such as musical instruments,
talkers, singers, and noise sources
, or in short anything but loudspeakers
that can essentially be seen as a point source.

The CIF Format was released Oct 27, 2020
Latest software updates Oct 27, 2020

Latest available CIF-files update Oct 27 2020

The same principles as for CLF hold: those having measured suitable data
and want to share them can register as CIF authors and create CIF distribution
,and prediction software developers that want to support the CIF format
can register for the binary format description via

End user and Trial Authoring kits

Item Contents Comment
End user kit

Viewer, Viewer help file and sample distribution binary files.

Views distribution files
(.CI1, .CI2)
News v1.0a

Initial release

(no update yet)
For an already installed End user kit.
Trial Authoring kit

Reader/viewer trial, viewer, editor, help files, CIF text-format specification, sample text-format and distribution binary files.

Reads CIF1 and CIF2 text-formats

Views distribution files
(.CI1, .CI2)

The Trial reader/viewer reads, verifies, and displays the contents of a CIF text-format file. This enables authors to
fully test the procedure before deciding on offering their data in the CIF format. To create actual distribution files requires registration (free).

(no update yet)
For an already installed Trial Authoring kit.

Note: registered CIF authors can also install this update and will receive info on an updated licensed reader via e-mail. If you have not received an e-mail you need to
contact and update your contact details.

CIF files currently available:

CIF-file content


Legacy data from ca. 2001.
Further background in embedded Info-files.

A set of 13 CI1 files:
trumpet, tuba, trombone, horn, bassoon, oboe, flute, clarinet, violin, viola, cello, contrabass, and a singing

PTB instruments as

Oct 27 2020

Prediction software that currently can use the CIF format:

CIF format utilization

CATT-Acoustic from v9.1f

CI1 at given resolution
at given resolution
Source 3D Visuals
A direct link in the Directivity Module to an installed CIFViewer

Oct 30 2020