1 (edited by jiw 2018-07-16 12:42:41)

Topic: ADI-2 DAC. EQ cut increases meter indicated level

After utilisation of the EQ only with gain below 0 dB (settings below), the meters indicate output levels higher than the attenuation of the signal from the volume control relative to the used reference level, e.g. meters reading -7.0 with volume control at -10.0 dB or meters reading "over" with volume control at 0.0 dB.

This occurs with auto reference level on (+1 dBu ref. level auto selected) and off (at -5 dBu ref. level) and does not occur with EQ disabled or enabled but flat. Dual EQ has no particular effect.

The deviations seem to increase when decreasing the gain of the EQ filter and occur with music (up to +3.8 dB deviation) but not with pure tones (sines) (0.0 dB deviation for frequencies far from the filter frequency).

A 100 Hz square wave has ~1.5 dB higher indicated level with EQ on vs. EQ off but with pink noise the issue does not arise.


The EQ settings are (for both L and R with dual EQ on):
B 3   G -10.0   F 142   Q 2.5
All else G 0.0. 

Firmware version is 21.

2 (edited by Basken 2018-07-18 15:40:06)

Re: ADI-2 DAC. EQ cut increases meter indicated level

The short answer:
This is expected behavior - not of this particular unit, but of EQing in general.

The somewhat longer answer:
https://sound.stackexchange.com/questio … tput-level

No EQ operation comes "for free" - and the deeper the cut / steeper the slope, the more artifacts will result as a consequence of the above - so i guess this is food for thought when using aggressive eq'ing to combat acoustic issues; -10db is a fairly serious cut, and will result in significant ringing in the passband ..

Rune Borup @ FishCorp
Producer / Engineer / Composer
RayDAT > 2 x ADI-8 QS | AES+SPDIF > ADI-2 Pro