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.
What is EqSound?
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
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.
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.
How do I check my system?
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.
Suppose the RED LED is on, what do I do?
short answer is to swap the two leads into the speaker.
long answer is to track down the place in your system
where the error occurs.
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
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].
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.
How does EqPhase work?
simplest sound is a single frequency tone, such as the one
radio stations broadcast when testing the ’emergency
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
You promised to tell me how good my speakers are.
‘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.
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
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.
green and red together point is about –4db and the green
alone point is about –2db.
My computer is connected to my sound system, what
can I do?
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.
provide a 3 ˝ floppy with a windows compatible program
which can be used to test your sound system from your
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