Handbook for Sound Engineers

Computer Aided Sound System Design 1345

(35-5)

where,

Ts and Td or Tr are given in Pa/V.

The sensitivity level, GS, is defined as the logarithmic
quantity of sensitivity:

The reference sensitivity T 0 is preferably 1 Pa/V. If

another value is chosen, it has to be indicated.

The graphic representation of the sensitivity level as

a function of frequency is called frequency response.

One of the quantities most frequently used in sound

reinforcement engineering is the rated or characteristic

sensitivity. In combination with the nominal load

capacity it serves, among other things, to ascertain the

maximum achievable sound pressure in the main refer-

ence axis of a loudspeaker or a loudspeaker system.

According to the definition given in the Standard DIN

45570,^8 also AES2-1984 (r2003),^7 it is the ratio

between the sound pressure pd averaged over a deter-

mined frequency range (mostly 250–4000 Hz) and

measured on the reference axis at a distance of 1 m from

the reference point of the radiator—usually the point of

rotation during measurements, and the square root of

the power supplied. By the standard, this power is

referred to the nominal impedance Zn of the radiator as

Figure 35-7. Directivity pattern of a natural source and an instrument.

A. Female voice.

B. Horn instrument including his player.

350 Hz 880 Hz 2500 Hz

590 Hz 1050 Hz 6300 Hz

Ts p

̃

u ̃

---=

GS 20

TS

T 0

= log----- dB