User manual SMART DEVICES SYSTEM 2000

[. . . ] INSTRUCTION MANUAL Instructions for System 2000 Polarity Checker with Auto-Off Circuitry Description: The Polarity Checker is a small hand-held audio testing tool. It is powered by a 9-volt battery and designed to determine the direction of cone movement of a dynamic loudspeaker. The device features an internal microphone, a red LED, a green LED and a push-on switch. A very low current circuit automatically turns the Polarity Checker off after approximately five minutes of non-use. [. . . ] Notice that approximately 5 minutes time has elapsed. This is how the auto-off circuitry works. Checking Polarity: Place the test software into a CD player, set the repeat track and then use the balance and fader controls so that only one speaker is playing at a time. It is always best to test one speaker at a time. The polarity pulses on the test software are recorded with two consecutive positive pulses immediately followed by a single, equal but opposite negative pulse. The software actually creates the electrical equivalent of the book's positive and negative directions of travel. The timing and duration of the specially recorded pulses makes it possible for the Polarity Checker to actually checks itself so as to accurately verify its readings. Following is the order of the recorded software pulses: Green Green Green Green Red Red etc. With that single speaker playing the test software, position the microphone of your activated Polarity Checker directly in front of the speaker's cone. Be sure to stay away from ports, passive radiators, and reflective surfaces. Adjust the volume of the speaker until the LEDs on the Polarity Checker synchronously blink with the sound of the pulses- Notice that you cannot easily hear the difference in polarity, but the Polarity Checker's circuitry measures the difference. Let's say that your Polarity Checker's LED's are blinking Red Red Green. Well, from your familiarization session, the reason for the reversed pattern is that your sound system is reproducing the exact opposite of the worded pulses. Actually your system is creating a mirror image reproduction of all software not just our test CD. The important aspect of this test is the repeatable pattern of either Green Green Red, indicating a faithful reproduction of the software or Red Red Green, indicating a mirror image reproduction If the LEDs are blinking randomly or all Red or all Green, then something is wrong with either the sound system, the Polarity Checker, or the way in which you are per- 2 INSTRUCTION MANUAL forming the measurements. Install a fresh 9-volt battery, get out your flat book and check out the Polarity Checker's readings, and repeat this section. Remember that the environment must be quiet and the Polarity Checker must receive the most direct energy from the speaker - no reflections!Relative Polarity: When all the speakers in a system are working together, we can say that the system is in relative polarity, This means that if all your speakers tested either Green Green Red or Red Red Green, then your system is in relative polarity. If one or more of your speakers tests opposite to the rest, simply reverse the wires on the speaker terminals and recheck the system. Absolute Polarity: When all the speakers in a System are working together and the Polarity Checker indicates the Green Green Red pattern, then your system is said to be in absolute polarity with the software. This means that a positive pulse on the software ends up in your listening room as a positive pulse. With many non-symmetrical waveforms - particularly male vocals, trumpets, clarinets, etc. , - there can be a perceived difference in the acoustic reproduction of the sound. Systems in absolute polarity tend to be more natural sounding. [. . . ] 1 (10043-2-G) Los Angeles Philharmonic, Erich Leinsdorf conducting. Recorded at the legendary MGM Sound Stage One. You should be able to recreate the orchestra sitting in a semi-circle around you: the concert grand in the upper left corner of the stage. The Violins and cellos in front followed by the woodwinds further up towards the back of the stage and on a higher elevation and in the very back rows, the trombones, and percussion (including the massive timpani drums) Notice in the first 20 seconds how the sound "seesaws" front to back between the violins and cellos. [. . . ]