EqPhase FAQ Sheet
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1.  What is EqPhase? 

A system for correctly phasing and evaluating all parts of your audio system.  The Source Cd is played in your Cd player, producing tones which the EqPhase device "hears" and detects the phase of your system.  A Floppy Disk is provided to install a tone generator on your PC.  The EqPhase has a 3.5 mm input jack for reading signals from various parts of the audio system.  The kit contains an adaptor for the RCA Cable which fits in most popular audio systems.

2.  What is EqSound?

An audible tone generator for testing microphones.  It is equipped with a 3.5 mm output jack which duplicates the primary tone of the Cd to inject into inputs not reachable by Cd/PC outputs.  EqSound is a portable source of marked waveform input for use with EqPhase.  It can be used as a input source for microphones to test the phasing of the microphone and it’s cabling.  The electrical output may be injected into any part of a sound system to check cables and equipment when it is not practical to use the source CD.  

3.  What is phasing?

A speaker has a flexible cone shaped member which vibrates in and out in response to the recorded music.  If the music says move out and the speaker is connected backwards it will move in.  With a stereo system one or both speakers can be connected incorrectly, producing subtle changes in the music which can affect listening pleasure.

4.  How do I check my system?

Simply, place the EqPhase CD into your player and play track 1.  Turn one speaker down.  Hold EqPhase about 1 foot from the active speaker, turn it’s power on and adjust the dial so that only one LED is on.  If it is the Green LED the phase is ok.  Repeat for the other speaker.

5.  Suppose the RED LED is on, what do I do?

The short answer is to swap the two leads into the speaker.

The long answer is to track down the place in your system where the error occurs.

Remove the RCA cable which connects your CD Player to your amplifier, at the amp end.  Using the RCA adapter, plug that cable into the RCA end of the adapter and the 3.5mm end into EqPhase.  Test using track 1.  If the LED is GREEN the problem is further down stream.

Replace the connection to the amplifier.  Using the Banana adapter and the clip leads, connect to the output of the amplifier, observing the color code or taking + as RED and – as Black.  Perform the test.  If the LED is GREEN proceed to the speakers.  If it is RED the problem is internal to the amplifier and you will have to have it looked at by a service person.  You may be able to compensate by reversing one or both speaker connections [swap black and red].

At the speaker end use the clip leads to test.  If the leads are improperly connected check the connections at both ends.  Some wire has a rib on one side, some a stripe of some color or one wire is somehow different from the other. Re-test the speaker using the built in microphone in EqPhase.  If the speaker still reads ‘out of phase’,  the problem is internal to the speaker enclosure.  If there is only one speaker in the enclosure, deliberately reverse the leads at the speaker.  If you have to open the enclosure, reverse the leads of the largest [bass] speaker first.

6.  How does EqPhase work?

The simplest sound is a single frequency tone, such as the one radio stations broadcast when testing the ’emergency broadcast system’.  Our tone is 150 cycles per second.  We have a wave which moves the speaker forward and back relatively slowly.  We also put a burst of 2000 cycle at the top of the wave as a marker, when the speaker cone reaches it’s outward-most excursion.  EqPhase is able to tell if the marker is on the out part of the sound or the in part, which will occur if the phasing is backwards.

7.  You promised to tell me how good my speakers are.

The ‘goodness’ of a speaker is measured by how low a tone it will faithfully reproduce.  As the frequency of sounds gets lower it becomes more difficult for a speaker to produce them, requiring large speaker cones.  Two things happen.  The volume of the sound decreases and the phase of the produced sound varies from the electrical input.  EqPhase, being a phase detector, can measure this.

Play track 5.  This is a tone which starts at 50 cycles/second and slowly increases up to 200 cycles/second.  The marker is attached to the positive part of the wave.  Since the speaker has no trouble reproducing the marker it experiences no phase shift.  If EqPhase ‘listens’ to this rising tone, at first the red LED will be on by itself, then the green lights too, and finally the green is lit alone.  Notice the time when these events takes place by watching the counter on the CD player.  There is a chart in the manual which relates time to frequency.  The sooner [lower frequency] the green LED is lit alone, the better the speaker.  If the green LED is always on by itself the speaker has an excellent low frequency response down to 40 HZ or lower.

The green and red together point is about –4db and the green alone point is about –2db.

8.  My computer is connected to my sound system, what can I do?

If you merely play the CD on the computer’s drive, you are not really using the sound card and the processor.  There is a jumper cable from the CD drive to the final stage of the sound card.

We provide a 3 ½ floppy with a windows compatible program which can be used to test your sound system from your computer.  Install the program and activate it.  The blue screen allows you to ‘play’ the test tone from the computer.  Pressing the ‘SWEEP’ button brings up a green screen, which plays the speaker measuring tone.  The counter in the center is calibrated in frequency.  Place the mouse pointer over the stop button and watch the LEDs.  When an LED changes click stop to read out the frequency directly.

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