IVIE IE-10A, Owner'S And Operator'S Manual

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TEST STEP
d B C a l i b r a t i o n
I n s e r t i o n L o s s
T e s
t
Figure 12
5 .
The i n s e r t i o n l o s s can now be measured by c a l c u l a t i n g t h e dB difference
between t h e two s i g n a l l e v e l s .
6.
Again, as i n t h e f i r s t example, any -d e v i a t i o n .from amplitude f l a t n e s s
on t h e
d i s p l a y w i l l be due t o t h e frequency response of the
audio device. The manufacturer's s p e c i f i c a t i o n
w i l l
be met
if
i n s e r t i o n l o s s a t a l l frequencies i s l e s s than 10 dB.
ROOM RESPONSE TESTING
A v e r y s i g n i f i c a n t p o r t i o n o f p i n k n o i s e and r e a l - t i m e analyzer t e s t i n g
i s measuring t h e frequency response o f speakers, microphones and other
a u d i o devices i n t h e i r o p e r a t i n g environments
.
Speakers and m i crophones
a r e c h a r a c t e r i z e d f o r frequency response i n anechoic chambers,
and y e t few o f these devices a r e ever used i n anechoic chambers.
Anechoic
chambers do n o t r e p r e s e n t t h e t y p i c a l " r e a l w o r l d " environments of
speakers and m i crophones. Temperature, h u m i d i t y
,
room s i z e , room shape,
room m a t e r i a l s and myriads o f o t h e r f a c t o r s p t o shape t h e o v e r a l l
frequency response.
There i s a t y p i c a l response p l o t o f t h e microphone i n t h e s p e c i f i c a t i o n s
s e c t i o n o f t h i s manual. The microphone has a f r e e - f i e l d response and
was designed t o be p o i n t e d d i r e c t l y a t t h e sound source being' analyzed.
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