RME Audio ADI-2 Pro, User Manual

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User’s Guide ADI-2/4 Pro SE - v 1.0
But how relevant are these 'low' values anyway? At what point do you actually hear crosstalk?
LPs only manage 25 dB and subjectively already offer full stereo, FM radio is at 30 to 35 dB.
Fortunately, the ADI allows you to try this out for yourself!

Play a nice 'wide' piece of music as a multi-second loop, adjust Width from 1 to 0.99 and lower.
Typically, a change is only audible from about 0.95 on.

Set the balance in the player to the far left or right. Now try to hear when the signal shifts
minimally to the other side by adjusting Width. At 0.99 it is typical not to notice anything, but
at 0.98 a very small panorama shift should be detectable.
The table below shows the crosstalk in dB that was present during the test. The conversion is
linear, and is therefore (unlike volume) also linear for the ear. The change from 1 to 0.99 makes
a huge jump, and 0.9 corresponds to LP level.
After these tests it becomes clear why the industry has never had a problem delivering head-
phones with 3-core cables.
Width R dB L dB X dB
1.00 -114.8 0 114.8
0.99 -46 -0.1 45.9
0.98 -40 -0.14 39.9
0.97 -36,5 -0.2 36.3
0.96 -34 -0.2 33.8
0.95 -32 -0.3 31.7
0.9 -26 -0.4 25.6
0.8 -20 -0.9 19.1
0.7 -16,5 -1.4 15.1
0.6 -14 -1.9 12.1
0.5 -12 -2.5 9.5
0.4 -10,5 -3.1 7.4
0.3 -9,1 -3.7 5.6
0.2 -8 -4.4 3.6
0.1 -6,9 -5.2 1.7
0.0 -6 -6 0
This problem naturally does not occur with balanced operation, one gets the full crosstalk atten-
uation as it is available from the DAC and output stage.
Note: To prevent overload at Mono = Width 0, the level is lowered by 6 dB (Pan Law). When
testing, it is therefore important to note that when adjusting, there is also a change in volume, not
just a change in width. In the table this can be seen as value of the left channel. The effective
crosstalk attenuation is therefore the difference L - R (X dB).
Note: Crosstalk due to a resistor in the common ground line does not fully correspond to the Width
effect, since Width performs a pure mono transformation, while the common ground resistor leads
to a phase-inverted signal on the other channel. A very high crosstalk therefore also leads to a
lowering of the monaural signal components, i.e. mostly the bass. However, these effects are not
relevant for the above experiment, the audibility of rather low crosstalk.