USING THE LEVEL REFERENCE:

1. SET THE LEVEL REFERENCE ALL THE WAY UP. (+3DB)
2. START WITH THE LOWEST ( 25HZ SLIDER). THIS IS THE TEST SLIDER.
3. SLOWLY MOVE THIS SLIDER UP UNTIL THE  REFERENCE AND THE
    LOWEST  SLIDER ARE EQUAL IN VOLUME.  MARK THE POSITION OF BOTH
    SLIDERS ON THE SETUP TEMPLATE WITH PENCIL TO SHOW THEIR   
    POSITIONS. USE THE SPACE JUST TO THE RIGHT OF THE SLIDER FOR
    MARKING ITS POSITION.
4. MOVE THE FIRST TEST SLIDER BACK DOWN AND REPEAT FOR THE NEXT
    HIGHER (31.5HZ) YOU WILL DISCOVER THAT THE FILTERED PINK NOISE IS   
    EASY TO USE IN THIS COMPARISON METHOD.
5. REPEAT STEP 4 FOR EACH OF THE SLIDERS REMEMBERING TO
    CLEARLY MARK THE POSITION OF ALL THE SLIDERS.

NOTE: 

YOU MAY USE ANY OF THE SLIDERS AS REFERENCES AFTER THEY HAVE BEEN MARKED. IT MAY BE DIFFICULT TO COMPARE A 20KHZ SOUND WITH A 25HZ SOUND SO SIMPLY CHOOSE A REFERENCE CLOSER TO THE TEST SLIDER. THIS METHOD IN THE, OPINION OF HARRISON LABS, ACHIEVES THE FREQUENCY RESPONSE THAT SOUNDS THE BEST AND CORRECTS FOR HEARING DEFICIENCIES. THE ANALYSIS GRAPH SHOWN ON THE CALIBRATED SLIDERS ALSO SHOWS THE COMBINED CORRECTION RESPONSE OF THE LISTENING AREA AND YOUR HEARING.

IASCA OR USING INSTRUMENTS

YOU MAY USE A LOW COST HAND HELD SPL METER INSTEAD OF YOUR HEARING TO ACHIEVE THE CURVE NEEDED FOR IASCA SOUND-OFF CONTESTS. IN THIS METHOD, ONLY 1 SLIDER AT A TIME IS MEASURED AND NO REFERENCE SLIDER USED.

THE SOUND PRESSURE LEVEL METER SHOULD BE LOCATED BETWEEN THE CENTER OF THE VEHICLE FRONT SEATS AND FACING THE FRONT. FOR HOME USE, THE SPL METER SHOULD BE LOCATED WHERE YOU MOST OFTEN LISTEN TO YOUR SYSTEM.

EACH SLIDER IS RAISED (ONLY ONE AT A TIME) SO THAT THE SPL METER READS THE SAME FOR EACH SLIDE POSITION. DON'T FORGET TO MARK THE TEMPLATE AT THE POSITION OF EQUAL LEVEL FOR EACH SLIDER. FOR INSTANCE 90DB MAY BE THE LEVEL CHOSEN AS THE REFERENCE ON THE SPL METER. EACH SLIDER SHOULD BE MARKED FOR THIS LEVEL.