User's Manual

14
User’s Guide ADI-2 DAC v2.2 © RME
8.4 Bass / Treble
The simpler form of EQ has been the Bass and Treble controls as they are found on any
‘standard’ HiFi stereo amplifier. They easily and quickly allow to modify the sound to your
personal liking (more or less Bass, more or less Treble, obviously). An even more useful
application is to quickly change the amount of Bass / Treble in smaller quantities so that music
compilations don’t have one song making the cones fall out while another one makes you think
that really happened. Producers and mastering engineers not only have their own taste, they
also sometimes fail in providing a mix that is on an average sound level compared to others. In
that moment a quick turn on the two ADI-2 DAC’s small encoders will make the music sound
perfect.
These Bass and Treble controls are limited to ± 6 dB. Everything exceeding such values should
be handled by the EQ, and/or calls for better speakers/phones. The corner frequency and
quality factor of Bass and Treble is user-adjustable in the display’s menu, making this feature
even more useful. Adapt it to meet your speakers/phones or your personal taste – it will greatly
improve your pleasure in listening to music again.
8.5 Loudness
Another legacy of HiFi amplifiers: there has not been a single one missing a feature called
Loudness. It tries to address the changes in frequency-dependent hearing sensitivity over
different volume levels. If one listens to music loud, then drops the level by at least 20 dB,
sound loses punch and glitter. HiFi amps tried to fight this effect by adding more bass and treble
the lower the volume was set. Unfortunately that never worked as intended, and just became an
additional bass/treble booster. Reason: the manufacturer of the HiFi amp could not know what
volume any position of the volume knob equals at the customer’s home. Room size, room
dampening and efficiency of the used speakers are all unknown.
But the effect of loss in perceived sound exists (read about the Fletcher-Munson curves), and
can be easily reproduced with any serious gear by comparing normal volume and DIM state
(usually -20 dB). The ADI-2 DAC offers Loudness for the analog stereo outputs, and probably is
the first time that Loudness works as intended. The user can decide how much maximum gain
in Bass and Treble should occur at lower volume settings. The user also sets the Low Vol
Reference, where maximum gain is achieved. After extensive tests a 20 dB range has been
defined as range for maximum gain to no gain while increasing volume. That seemed to be the
perfect definition of the range that needs to be addressed by Loudness.
Here is an example on how it works: the user’s typical lowest level listening volume is at -35 dB
at the unit. This value is now set by the user as Low Vol Ref in the Loudness menu. Then Bass
and Treble Gain can be set between 0 and +10 dB. Default is +7 dB for both. Increasing the
volume by turning the Volume knob causes the gain in Bass and Treble to be lowered smoothly
over a range of 20 dB. So when Volume is set to -15 dB, the music is not only quite loud, but
Loudness’ Bass and Treble are then at 0 dB gain. See chapter 31.8 for graphs.
No matter how sensitive the connected phones or speakers are, no matter how much increase
in Bass and Treble are desired – with the ADI-2 DAC one can finally adjust it to meet the
personal hearing and taste. Loudness finally works as it should have worked from the start -
another unique feature in the ADI-2 DAC.
Note
: Loudness works best in Auto Ref Level mode due to the seamless dBr scale of the vol-
ume control. Without Auto Ref Level active, manually changing the Ref Level will change the
volume without changing the VOLume value (dB). As Loudness is referenced to a 'Low Vol Ref'
setting it then might no longer work as intended, and needs the Low Vol Ref value to be ad-
justed.