Profiling A Rotary Speaker Cabinet; Under The Hood - Kemper PROFILER Grundlagen Anleitung

22 KEMPER PROFILER

Profiling a Rotary Speaker Cabinet

The Profiler already ships with a Rig named "CK Rotary Speaker", captured from the real thing, but if you have
access to a different brand of rotary speaker, you can take your own profiles, too.
To do this, first set up the rotary speaker as you would in a normal recording situation. Next, connect the whole
chain to the Profiler, just as you would with a guitar amp. This time, however, two microphones should be used to
capture the cabinet - one for the bass rotor, and one for the tweeter horn.
Connect the microphones to a mixer, create a mono mix of the two, and send this to the Profiler's RETURN IN-
PUT. The idea is for both microphones to be captured at the same time, resulting in a single profile. Now, switch
your rotary speaker to high speed and start the profiling procedure. The profiling process will ignore the rotation
of the cabinet and only capture the typical sound character. The resulting Profile will probably sound weird and
uninspiring on its own, but when you engage the stomp "Rotary Speaker" in the Mod Module, you'll hear the rich
and animated sound of your original rotary cabinet.
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Tip: Although the Profile is captured in mono, you can use the "Rotary speaker" stomp in the Mod or X Module
to recreate the typical stereo movement of the signal. The Rotary Speaker effect will automatically separate the
bass rotor from the tweeter horn.

Under the Hood

In case you enjoy reading about technical details, below is a description of what the Profiler is doing during the
profiling process:
During the first phase, you will hear white noise with a rising amplitude. The Profiler is now collecting data about
the frequency response of the reference amp. The frequency response will change dramatically as the gain in-
creases. This is how the Profiler learns about the circuitry of the reference amp and the frequency response of
the cabinet. Also, the characteristic impedance curve of the speaker, including its feedback to the power amp, is
detected in fine detail.
In the next phase, slowly pulsating white noise is sent to the reference amp. The volume of the white noise is set
to a level at which the reference amp starts to distort. This is how the Profiler learns about the dynamic distortion
curve of the tubes in the reference amplifier. Using this information, the Profiler is able to recreate that curve with
the highest possible accuracy. This is also true for transistor-based, as well as digitally-modeled, distortions.