• Registered: 2021-10-12
  • Posts: 8

Topic: In / Out levels discrepancy

Hi, I recently purchased an ADI-2 Pro FS BE and am enjoying it so far.

I have noticed that when the Main Output and Analog Input are set to the same reference level, and I send a test tone out and record it back in, then the levels are different.  For example, if I generate a -12 db tone in my DAW (Reaper), then the Analyzer screen shows -18 for Out 1 and -22 for AN 1.

I expected that a -12 db tone in my DAW would register as -12 db for both Out 1 and AN 1 on the Analyzer screen, but instead I have three different values.  Can someone explain the discrepancy?  Thanks.

  • KaiS
  • DAW Mastermind
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  • From: Germany
  • Registered: 2020-02-05
  • Posts: 3,157

Re: In / Out levels discrepancy

Did you set ADI-2 Pro‘s:

• Input “Trim Gain” at 0 dB?

• Output Volume to 0 dB?
NOT 0 dBr!
The “r” says you have “Auto Reference Level” on, which could explain your result.

• Cable is a correctly wired, balanced XLR-XLR?

KaiS's Website

3 Reply by intalentive (edited by intalentive 2021-11-09 02:38:04)

  • Registered: 2021-10-12
  • Posts: 8

Re: In / Out levels discrepancy

The trim and outputs were set to 0.

The issue is that I had the main out sending to mono left.  When I turned mono off, then the Out 1 level became the same as the DAW level (-12).  There is still an input level discrepancy of 4 db (at -16).

4 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
  • Registered: 2007-04-06
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Re: In / Out levels discrepancy

Then search more. Other FX active, EQ active, Loudness, Bass/Treble, set to the same Ref Levels...

Are the level meters in the ADI set to show pre, post or both? The pre setting will show the real level coming from your computer, no matter what the DAW claims.

Regards
Matthias Carstens
RME

MC's Website

5 Reply by intalentive (edited by intalentive 2021-11-09 18:18:40)

  • Registered: 2021-10-12
  • Posts: 8

Re: In / Out levels discrepancy

I think I found the source of the discrepancy. It was the test tone itself. If I use a simple sine wave, then the levels are very close (off by 0.1 db at most). The same is true if I use a natural signal.

But if the test signal is an impulse train, then the discrepancy returns. I don't think it's a problem. I assume it's a property of the impulse train.

Edit: Yes, this is certainly it. Silly of me. The impulse train is non-negative, while the recorded response has both positive and negative values, leading to a lower peak reading.