Step One - Identify and Verify Channel Conguration
• Use Track 3 of the RTTI/3Sixty set up disc to verify position of Left, Right, and Center outputs of the 3Sixty.
• Verify operation of the fader if inputs to 3Sixty are connected to Front and Rear outputs of the source unit.
• Until the 3Sixty is set up, only left and right channels will be evident. Sub and Center outputs will only become
active after Step Six (setting up the 3Sixty) because you have to congure them.
Step Two - Measure the Maximum Output Level of the Source Unit
TIPS before starting:
• Always set Bass and Treble to “FLAT” and any loudness feature to “OFF”. Balance and fader to “CENTER”.
• De-emphasize or disable any equalization wherever possible (either factory source units or aftermarket). Often with
some “premium sound” OEM audio systems there is a menu selection for this.
• If volume is numeric, be sure to note the maximum listenable “number” of the volume position. Nearly every
aftermarket source unit has some numeric or visual indicator of the volume position.
• If there is no volume reference on a factory source unit (such as rotary encoders that just free spin once it reaches
maximum and do not show a volume count) it’s best that you can achieve full volume before visible distortion with
the scope. This is a case where it would be better to get the output in the location where volume is able to go
maximum with little or no distortion. Sometimes, in a factory audio system, this will be between the source unit and
the amp. Generally though, you will nd going to the factory amplier output is the best strategy because it also
provides a pretty robust output voltage compared to the output voltage from the source unit.
• Disconnect the outputs of the 3Sixty at this time!!!
a) Connect the O-scope probes to the source unit’s audio output. With an aftermarket source unit, you can connect right
to the preamp output with an RCA “breakout” you make yourself. With an OEM source unit, this may be at the source
unit itself or at the factory amplier (either the input or output side). Generally
with an OEM system, you want to start at the factory amplier output.
b) Place the RTTI/3Sixty set up disc into the player and select Track 7 (1kHz tone at
0dBFS). This assumes a full range output, but you can always play an alternative
low frequency 0dBFS track for subwoofer or very high frequency outputs when
checking output of a factory installed source unit or amplier (Track 6 or 8).
c) Play the track and adjust the volume on the source unit until you see distortion on
the scope. Soft clipping is okay, but you don’t want to reference a hard clip. If the
O-scope is not auto ranging, you will need to dial in the resolution once the signal
starts to play.
d) Read and record the voltage level of the scope on that output. Repeat this process
with the appropriate test tones in each of the necessary bandwidths or on other
outputs that will be connected to 3Sixty. This process will give you the “reference
level” of the source unit.
Step Three - Identify and Verify Signal Polarity
TIP - Information about Evaluating Polarity (Electrical/Mechanical)
With speakers there would appear not to be too much concern on the topic of electrical connections. Nothing could be
further from the truth. The reason this is the case is that you are dealing with speakers – plural. If you only had one
speaker in the whole audio system to consider, you couldn’t hook up the wiring wrong (or at least your ears wouldn’t
know the difference). When you add that second speaker (and every one thereafter), you have to consider the phase of
each speaker with respect to the others. Since speakers move out and in (a series of pressure and vacuum), you can
either have those speakers working together or working against each other. Speakers are said to be in “absolute phase”
when they are all working together acoustically. This yields the most focused placement of instruments, singers, and
sound effects as they were originally recorded and allows for the most accurate low frequency response. When one or
more speakers are “out-of-phase” with other speakers, the result is destructive interference (just like that air leak problem
when mounting, only the interference isn’t between the front and back of one speaker, it’s from opposing speakers
“ghting” each other).
System Set Up Tips
The sine wave test tone on the O-scope
should look similar to this example. If the
top and bottom of the wave form is attened
off, that indicates clipping. The maximum
useable output level will be where the onset
of clipping just begins.
