DSC260 Preliminary Owners Manual Revision 0.9
7.4.1 Limiter Level Calculations: The DSC260 comes from the factory with suggested limiter settings for various
JBL systems. These limiter settings are guidelines for use with specific JBL power amplifiers. There
are two primary uses for these limiters: One is for prevention of amplifier clipping and the second is to
limit the amount of power transmitted to the transducers. When using JBL MPA and MPX power
amplifiers consult the tables in Appendix B for recommended settings for specific amplifiers and power
levels. For other amplifiers or transducers, the method for setting the limiting threshold is given by the
Limiting Threshold (dB) = Transducer voltage limit (dBu) - Amplifier gain (dB)
As an example, we first convert a transducer power rating into dBu. Our example transducers has a
continuous power rating of 600 watts. With an impedance of 8 ohms, this corresponds to a voltage of:
Voltage = (600 x 8)0.5 = 69.28 Volts
Expressing this in dBu:
20 log (69.28/0.775) = 39.03 dBu
Next you find the amplifier gain from the published specification in the spec sheet or owner’s manual.
For this example, we will use an MPA1100 amplifier which has 38dB of gain and use the formula:
Limiting threshold = 39dBu - 38dB = 1dBu.
This would be the limiter threshold for 600 watts continuous output into the 8 ohm transducer.
7.5 Variable Output Delay 0 - 635ms: The Plus and Minus buttons accelerate in their effect the longer the buttons are held by increasing
the size of the steps. To return to the small increment settings release the key then press again to begin with 21 µs steps again.
At no time can there be more than 635.417 ms of delay on any input to output path. Delay units are set in the Utility section from a
list of Milliseconds, Meters and Feet/Inches using the parameter keys in the Utility “Delay Units” section. These are displayed as
ms, m and ft, respectively.
Output 1 delay:
OUT 1 Subs
Outputs 2 and 3 stereo linked:
OUT 3&4 Mid
Output 1 delay in feet and inches:
OUT 1 Subs
Delay 11' 12.9”
Output 1 delay in meters:
OUT 1 Subs