Loudspeaker compensation

AN3340

18/24

Doc ID 18453 Rev 1

6.2.2

An example and verification

In this section the result achieved using Speaker Tune to compensate a speaker used in a

LCD flat-screen TV is described.

The first step is to measure the impedance and to identify the resonant frequency as shown

in Figure 17. The resonant frequency is around 232 Hz and the peak impedance is 12

Ω.

Figure 17.

Flat-screen-TV speaker impedance

The second step is the frequency response measurement. Figure 18 shows the frequency

response of the speaker under test. The curve shows a very poor response in the frequency

range above 10kHz. Indeed, above 5 kHz there is significant attenuation.

Figure 18.

Flat-screen-TV speaker frequency response

This frequency response data must now be imported into the APW Speaker Tune section.

10

2

10

3

10

4

5

10

15

20

X: 232.3

Y: 12.06

Frequency [Hz]

Speaker Impedance - Modulus

10

2

10

3

10

4

-40

-20

0

20

40

Frequency [Hz]

Speaker Impedance - phase

10

2

10

3

10

4

-80

-75

-70

-65

-60

-55

-50

-45

-40

-35

-30

Frequency [Hz]

Original condition