Mackie TH-15A Benutzerhandbuch

10

•  If the internal temperature again gets too hot,

    the shutdown process repeats. Should this    
   happen, make sure that airflow to the rear of the
    cabinet is not restricted. If the ambient air    
    temperature is very warm, try pointing a small  
   fan toward the rear panel to increase the airflow
    through the fins.

Each driver has its own compression circuit, which 

helps protect them from damaging transient peaks. The 
compressors are designed to be transparent and are not 
noticeable under normal operating conditions.

You should use high-quality, shielded cable to 

connect the signal source to the INPUT jack on the  
TH-15A. 

•  High quality microphone cables work well. 

•  Foil shielded cables are commonly used for audio

    wiring. 

•  The better the shield, the better the immunity

    from externally induced noise (like EMI and   
    RFI). Route the cable away from AC power cords  
    and outlets. These are common sources for hum  
    in an audio signal. You can purchase quality    
    cables from your Mackie dealer.

The TH-15A loudspeaker is designed to sit on the 

floor or stage. It can be pole-mounted via the built-in
socket on the bottom of the cabinet. Be sure the pole is 
capable of supporting the weight of the TH-15A. 

WARNING: The cabinet has no rigging 
points and is not suitable for rigging.  
NEVER attempt to suspend the TH-15A by 
its handles. 

As with any powered components, protect them from 

moisture. If you are setting them up outdoors, make 
sure they are under cover if you expect rain.

There are several protection mechanisms designed 

into the TH-15A to safeguard the loudspeakers and 
amplifiers from inadvertent damage. 

CAUTION: The protection circuits are 
designed to protect the loudspeakers under 
reasonable and sensible conditions. Should 
you choose to ignore the warning signs 

(i.e., frequent OL LED indications, excessive distortion), 
you can still damage the speakers in the TH-15A by 
overdriving them past the point of amplifier clipping. Such 
damage is beyond the scope of the warranty.

A 12 dB/octave high-pass filter at 40 Hz just prior 

to the low-frequency amplifier prevents very low 
frequencies from being amplified. Excessive low-
frequency energy below 40 Hz can damage the woofer by 
causing it to “bottom out,” also known as overexcursion, 
which is equivalent to a mechanical form of clipping.

All amplifiers produce heat. The TH-15A is designed 

to be efficient both electrically and thermally. 

The amplifier module is mounted on a large 

heatsink, which is cooled by convection where cool air 
is drawn over the rear panel, carrying the heat away. 
In order for this convection cooling to work efficiently, 
it is important to provide adequate airspace behind 
the loudspeaker. When you position the TH-15A, we 
recommend leaving at least six inches of air space 
behind it. 

•  If for some reason the internal temperature  

    gets too hot, a built-in thermal switch activates  
    and turns off the amplifier. This protection    
    operates independently for the low-frequency and  
    high-frequency amplifiers. Therefore, it is possible  
    for only the low frequency or high frequency    
    amplifier to shut down while the other remains on. 

•  When the amplifier cools down to a safe

    temperature, the thermal switch resets  

 

    and normal operation resumes.