JBL manual Project EVEREST DD66000, HF Level, LF Level, Change from LF1 level trim

Project EVEREST DD66000

HF Level

This switch adjusts the attenuation applied to the 476Be (high frequency or HF unit) by approximately 0.5 dB over the range of 1,000 Hz to about 8,000 Hz. The action is accomplished by trimming the main attenuation resistors.

Mid-range sound becomes calm by reducing level and brighter by increasing level. No addit ional parts are inserted in the signal path and there is no sonic deterioration by position or adjustment functions .

LF Level

There is a level trim available for each of the two woofers (LF1 and LF2). Moving a bar from Low to High will increase the drive level to a portion of the frequency spectrum over which each woofer operates. LF1 refers to the low range woofer (up to 150 Hz) and will affect the output level in the range of 60Hz – 150Hz by about 0.5 dB. LF2 refers to the main woofer and will affect the output level in the range of 150 Hz to 700 Hz. The purpose of these adjustments is to allow fine-tuning of the mid -bass and midrange response of the system to better integrate with varying room characteristics.

Normally, the control bars of LF1/LF2 are moved together to get the maximum effect (LF1 & LF2 = High or LF1 & LF 2 = Low). Depending on room environment, you may get a good balance by moving of them. In case speaker systems are placed close to corners of the room and the distance between 2 systems are great and you notice bass boost by reflections from walls , try to increase the LF2 level and decrease LF2 level (LF1 = Low, LF2 = High). These adjustments will not cause loss of series element from adjustments they are done by change values of damp ing resisters which are in parallel.

Change from LF1 level trim Change from LF2 level trim