AS3460
ALC Characterization
Demo Kit Manual
• PUBLIC
UG000480
• v3-00 • 2021-Nov-08
126
│ 115
Figure 127:
D2E Measurement for Different Acoustic Leakages
The figure above shows the D2E response for different leakages. It can be seen that the bass
response decreases with increasing leakage. The range in between the lowest and highest leakage is
the leakage range that the ALC can compensate. The highest leakage that can still be compensated is
physically limited by the acoustics of the headphone and the speaker that is used. As a rule of thumb
the difference between lowest and highest leakage should not be more than 25 dB at around 100 Hz.
For In-ear headphones with silicone ear-tips this difference should be slightly lower (around 15 to
20dB) since typically smaller speakers are used compared to leaky type In-ear headphones.
Figure 128:
LMA Measurement Setup
The headphone characterization front end (black box lower left corner) is used to drive the headphone
speaker (any analog linear headphone amp will do) and as a preamp for the reference mic signal
