AMI NGX MINI 2, Installation & Owner'S Manual

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22022623 Rev B 14 NGX Mini 2 Jukebox
Sound System Set Up
The NGX Mini 2 jukebox sound system is powered by a 1000 Watt S-Pro2 Class 2 power amplifier manufactured
by Pascal. Speaker terminals are provided to connect extension speakers directly to the amplifier. An Audio
Output Transformer Kit (part number 22180806) is available if your installation uses 70 volt speakers or you need to
connect extension speakers using various power taps.
Extension Speaker Operation
To avoid poor sound quality, care must be taken when adding extension speakers. The following requirements
must be met:
•
Speakers connected to the amplifier must be wired so the power consumed by the extension speakers
does not exceed the amplifier power rating of 500 watts per channel.
•
Complete the Extension Speaker Worksheet (
Table 1-1
) for each channel and verify it does not exceed
the 500 watt amplifier channel rating. After wiring the speakers, perform the Amplifier Overload Check
immediately following
Table 1-1.
•
All speakers must be connected with the correct polarity (see
Figure 1-A)
.
•
Do not bridge output channels.
Low Impedance Speakers
Low impedance speakers (16, 8, or 4-ohm) can be used when the connecting cable is less than 100 feet. Keep
the following two things in mind when wiring your speakers:
1. No more than one 4-ohm speaker should be connected to a speaker line. If several 4-ohm speakers are to
be used, each speaker should have its own line.
2. The loss in 100 feet of 18-gauge zip-cord feeding on an 8-ohm speaker is 15%. The loss for two 8-ohm
speakers is 30%.
Selecting Speaker Power
General Instructions
This section will lead you through the power and speaker selection process. This process consists of three
major steps and several smaller steps. The major steps are:
1. Identify the extension speakers and compute the speaker power
for speakers connected directly across the
amplifier.
2. Make the extension speaker connections.
3. Perform an amplifier overload check (see instructions immediately following
Table 1-1
).
Selection Procedures
•
Use a pencil (you may want to revise your figures) to fill in the Extension Speaker Worksheet on the
following pages.
•
Use the
Table 1-1
Worksheet to help you calculate the amount of power consumed by the extension
speakers.
•
An extension speaker RMS power rating should be at least 10% higher than the power it will consume at
maximum jukebox volume.
When RMS power to speaker
at maximum jukebox volume is:
Then recommended RMS power
rating of speaker is:
240 watts 300 watts
120 watts 150 watts
60 watts 75 watts
30 watts 40 watts