What is the Common Loudspeaker File Format (CLF)?

By Pat Brown

The Common Loudspeaker File Format provides well-defined loudspeaker specifications and platform-independent data for acoustics modeling software applications.

Sound system designers need a base-line set of loudspeaker specifications to locate suitable loudspeakers for their projects. The problem is that there are numerous metrics that can be used to describe loudspeaker performance, and different manufacturers may use different ones or even different versions of the same ones. The long-term solution to this is an industry standard for loudspeaker specifications. In the mean time, a group of interested individuals have agreed on a common set of specifications and their presentation.

The Common Loudspeaker File Format is a loudspeaker data format that serves two purposes:

  • 1. To provide a common set of well-defined loudspeaker specifications to aid in the selection of loudspeakers.
  • 2. To provide platform-independent data for acoustics modeling software applications.

We think that sound system designers and end-users alike will benefit from the CLF and the uniformity that it brings to the sound reinforcement industry.

Since the CLF is currently under development, this page will be used to keep those interested up-to-date on its progress. The most current information can always be found at


Free Software!!!  – Download the End User Kit

A Windows™- based CLF Reader/Viewer can be downloaded from www.clfgroup.org/clfdocuments.htm. This is your virtual spec sheet that puts loudspeaker data at your fingertips.

Screenshot from Common Loudspeaker File Format