Limiter Settings Notes; Vt4887 & Vt4881 Transducer Complement - JBL VerTec VT4880 Applications Manual

NOTES REGARDING LIMITER SETTINGS
• The recommended limiter threshold settings provide 3 dB of headroom before the
component or bandpass peak voltage is reached.
• The component or bandpass peak voltage is 6 dB above the voltage used at
continuous maximum power.
• These settings assume the use of a Crown MA-5002 in stereo mode with input
sensitivity of 1.4V for a voltage gain of 37 dB. Amplifier limiter and Offset
Integration switches are set to the off position.
• If a different amplifier is used or if the input sensitivity is changed, the limiter
threshold must be re-calculated.
• Not all DSP controllers behave the same way. Please study your unit accordingly.
• Users must take into consideration that the digital controller gain outputs are not
all "0" dB, i.e. for VT4889/4880, the VLF is at +6 dB, the LF is at 0 dB, the MF is
at -2.5 dB and the HF is at - 4 dB. Hence, the actual headroom before limiter
threshold is effectively greater than it may seem from the above charts.
• Users should carefully test these settings, and lower or raise the thresholds for a
given type of program material as required.
VT4887 & VT4881 Transducer Complement:
Speakon NL8
Model
Terminals
HF 2407H
MF 2104H
LF Pins 3±
2168J
VLF 2256G Pins 1± & 2±
1
PASSIVELY CROSSED OVER MID/HIGH FREQUENCY SECTION.
2
LF SECTION HAS TWO 8" COMPONENTS WIRED IN PARALLEL.
3
SINGLE COMPONENT WITH TWO VOICE COILS INDEPENDENTLY WIRED.
Nominal
Per Impedance
box
Transducer
Pins 4± x 2
1
Pins 4± 1 x 4
2
x 2
3
x 1 2 x 8Ω
Nominal
Impedance
per per
Passband
8Ω 8Ω
8Ω 8Ω
16Ω 8Ω
8Ω + 8Ω
AES Power Peak
100 HR Power
Rating per Rating per
Transducer Transducer
25W 100W
50W 200W
350W 1400W
600W 2400W
Recommended
Power per
Passband
450W
450W
1000W
1200W
Page 5