What Is Measured - And How - Holm HOLMFIR User Manual

Get Ready to Measure - What is Measured - and How?
9.6

What is Measured - and How?

HOLMFIR measure the impulse response and thereby also the frequency response. If the
speaker/drivers where ideal they would play the electrical signal received, but this is not
the case.
Often only the amplitude is represented in plots of the frequency response, but HOLMFIR
goes further by measuring the phase. The phase response reflects the meachanical prop-
erties of the speaker. If the phase response is zero, then all tones at different frequencies
arrive to the ear at the same time. An uncorrected driver/speaker will typical have that
lower tones arrive later than the higher.
Below diagram illustrates this by the blue curve not being identically with the green curve
(for technical details refer to Appendix D).
HOLM Acoustics
36 of
HOLMFIR User Guide v0.4.4
65