Turbosound LMS-A6 Speaker User Manual


 
user manual
LMS-A6
LMS-A6 user manual
Page 11
When this switch is up (on) the Left and Right Band 1 signals are summed together and fed in
mono to both Band 1 outputs.
When the switch is down the Left and Right Band 1 signals remain independent from each other.
Level Trims
Band 1 and Band 3 have independent gain trims for fine adjustment of the system frequency
response. If the internal preset band gains have been specified correctly these controls will
nominally all be set central at 0dB. The +/-6dB range should be more than sufficient to balance
your system in any realistic situation. Band 2 gain is taken as the reference level, and the Band 1
and Band 3 controls will be adjusted for correct spectral balance.
Phase Adjustment
In a theoretically ideal speaker design the drive units for adjacent bands would be in perfect
alignment and their signals would combine to give perfect summation at the crossover point.
However, realistically this seldom occurs and shifting the phase of one of the signals in the
crossover region will improve the summing, and therefore the frequency response of the system.
Each phase control gives nearly 180 degrees of adjustment. Used in combination with the POL
Switch we can achieve continuous adjustment over a full 360 degrees.
There may be some interaction between the phase controls in each channel, especially if the MID
Band, Band 2 is fairly narrow, so it is advisable to further fine tune the phase by repeating the
above process a second time.
LIMITER SETTING AND OPERATION
The limiters should be set to a level that affords protection to the speaker drive units. The time
constants for the limiters are set internally and are preset to be optimum for each frequency band
being protected.
Limiter Threshold setting
The limiter threshold switches are located behind a security cover on the rear of the unit. Each
Band has an independent 10 position switch to accurately set the threshold. The switches are
calibrated in 1dB steps from +1dB (Pos0) to +10dB (Pos9)
In a high powered system where the amplifier output power is below or equal to the rating of the
speakers the limiter thresholds will nominally be set to 1dB below the clipping level of the
amplifier. This prevents severe clipping from driving the cones with square waves but does not