Dynacord Stereo System User Manual

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The EVID C4.2 is just such a 4” speaker.  The effect of the C4.2’s wider dispersion  is indicated in 
the figure at the right. In applications where reverberation is not an issue, the C4.2 (shown with 
coverage pattern “A”) offers greater overlap and, thus, more uniform coverage than an 8-inch unit 
(coverage pattern “B”). When specifying a 
new system, you can take advantage of the 
C4.2’s wider dispersion to decrease the 
number of speakers required to cover a 
given area. This will result in even greater 
savings.  
Of course, a 4-inch unit will typically be 
somewhat less sensitive than a comparable 
8-inch: for equivalent motor assemblies, the 
difference is on the order of dB. The 4-i
will also have slightly reduced low-freque
capabilities. 
nch 
ncy 
A= C4.2 4-inch speaker @ 4000 Hz  
B=Typical 8-inch speaker @ 4000 Hz 
Neither of these factors is a significant problem in most distributed systems, however. The C4.2 is 
conservatively rated to handle far greater power than most standard 8-inch units so its continuous 
SPL output will be more than adequate. Moreover, its reduced output below 150 Hz actually gives 
it an edge in intelligibility, since low-frequency energy is most likely to excite ambient 
reverberation. For these reasons, the C4.2 represents a great way for you to improve the 
performance of your distributed systems while maintaining a competitive edge in price quotes. 
When Controlled Coverage is Needed 
In some installations coverage control is clearly essential to maintain intelligibility and listenability.   
In these cases a speaker which provides controlled coverage over as wide a bandwidth as 
possible is needed.   In live room environments the reflection of sound off of walls can be a major 
cause of intelligibility problems.  The two examples below illustrate the effect of speaker 
dispersion in a room.  The first example is the EVID C8.2 speaker with it’s 110 degree coverage 
pattern at 1kHz.  The next illustration is the controlled coverage EVID C8.2HC unit with it’s 75 
degree spec.  As you can see the effect of the controlled coverage in the C8.2HC has a dramatic 
effect on the energy spilled onto the walls.  The result will be a more intelligible installation using 
the C8.2HC. 
C8.2HC Speaker Coverage at 2kHz  
C8.2 Speaker Coverage at 2kHz  
The Use of Subwoofers 
Subwoofers are an important part of an outstanding business music system. Light background or 
foreground music might not require subwoofers; however, even in systems where the bass 
doesn't need to be a dominant factor, having clear low frequencies can make a big difference in 
the customers' enjoyment of the music. 
The number of subwoofers to use, where to position them, how to set the taps (on 70V/100V 
subs) and how loud to run them vary depending on the characteristics of each installation. Criteria 
  ElectroVoice/Dynacord BGM Guide 
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