Turbosound TQ-445DP ユーザーズマニュアル

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user manual 
QLight™ DP series 
QLight DP series manual 
page 18 
Limiting Functions 
The amplifier modules are equipped with accurate limiters for both high frequency and low 
frequency sections. Because the HF and LF limiters work independently of each other, there is no 
possibility of either section compromising the performance of the other as is the case with a single 
broad-band limiter. Furthermore, each limiter has its attack and release time constants 
independently set and optimised according to the operating frequency range. These allow 
transient delivery whilst preventing overheating or over excursion of the transducers. 
Limit LED Functions 
At switch-on the power LED will illuminate and the red limit LED’s will flash in unison for 
approximately 5 seconds as the unit performs an initial diagnostic self-test. Audio will be 
automatically muted during this period. 
After initialisation, the limit LED’s extinguish and the unit will now pass audio. During operation if 
either of the red limit LEDs flash this indicates that the DSP is taking corrective action by applying 
the limiter to that channel in order to avoid damage to the drive unit. You should reduce the signal 
accordingly so that the limit LED’s light only occasionally. Both LED’s flashing in unison under 
regular operating conditions indicates that the DSP is activating a protection feature, taking two 
possible courses of action: the input will either be attenuated to stop the unit being overdriven, or 
in extreme cases will be shut down. 
Status Condition 
Action 
Both Limit LED’s flashing 
System initialisation 
 
Both Limit LED’s flashing 
Protection activated 
Reduce input level 
Limit high LED flashing 
DSP  applying  limiting  to  the 
high frequency channel 
Reduce input level 
Limit low LED flashing 
DSP applying limiting to the low 
frequency channel 
Reduce input level 
 
1
 WARNING 1
 
The limiters are designed to allow short-term transients in program material in order to preserve 
sufficient dynamic headroom, while at the same time optimising component life by protecting 
against long-term heating effects. DO NOT allow the loudspeaker to constantly run into limiting; 
this will not only degrade your sound quality by reducing the available dynamic range, but also in 
extreme cases may increase the risk of damage to the drive units.