Mouth Equalization - BRUEL & KJAER HF HATS 5128 User Manual

Fig.2.3

1/4 microphone with
preamplifier in the
holder that positions
them at the MRP,
25 mm from the
equivalent lip plane
(Type 4128-C/D shown)
Some 1/4 microphones (for example, Brüel & Kjær Type 4938, which is 6.25 mm wide) require
that adapter DI-1058 is mounted in the microphone holder, see Fig.2.4
Fig.2.4
Microphone holder
with adapter DI-1058
fitted (shown before

1/4 microphone is
located in position).
Type 4128-C/D shown
Before calibrating the mouth simulator, the microphone and audio analyzer should be calibrated
using Sound Calibrator Type 4231, along with adapter for 1/4 microphones DP-0775.
2.3.1

Mouth Equalization

Most applications require that the actual frequency response of the mouth simulator is equalized.
The equalization or compensation at a particular test position (for example at the MRP) can be
accommodated in two ways:
CHAPTER 2
7
Operation