he natural crossfeed filter
I pri ciple, digital sou dprocessors ca simulate all the mecha isms for directio al liste i g but the
results are, thus far, ot very satisfactory. I particular, pi ae-reflectio s are very complex a d
liste er-specific a d impossible to simulate accurately.
Fortu ately, the mai directio al i formatio is provided by the time delay a d level of atte uatio of
the sou ds that reaches the opposite ear. The CORDA EARTUBE-1 ca electro ically simulate this
process a d, with appropriate atte uatio a d delay, add some of the right audiosig al to the left
cha el a d vice -versa. This co siderably reduces the adverse symptoms of headpho e liste i g.
A u ique feature of the crossfeed circuitry of the EARTUBE-1 is that it “recog izes” the virtual
positio s of the i strume ts a d si gers i a recordi g. The sou d of a i strume t i the middle of
the sou dstage will be equally prese t i both audio-cha els a d is ’t give a y crossfeed. A
crossfeed sig al is o ly ge erated for i strume ts that are ot placed at the ce ter. The more off-
ce ter the i strume t is placed, the stro ger the crossfeed a d the lo ger its delay. This feature is
called “ atural crossfeed”.
Activation of crossfeed
The crossfeed filter ca be activated by the seco d left switch at the fro t of the amp.
Lower position STEREO.
I this positio there is o crossfeed o the headpho e outputs. We recomme d this positio for
recordi gs with a arrow sou dstage.
Upper position LOW level crossfeed
This setti g is especially recomme ded for recordi gs with a relatively high level of reverberatio
(orchestra, choir) or extreme spatial positio i g. Although the differe ce to the stereo positio may ot
be discer able to you at first, after lo ger periods of liste i g you will fi d the crossfeed positio much
more relaxi g.
While activati g the crossfeed the liste er may otice a appare t lack of bass. I stereo mode, lower
freque cies seem to be much more prese t. This is a psycho-acoustical effect a d does ot represe t
a limitatio of the crossfeed filter. Lower freque cies heard by o e ear o ly are much more u atural
to our brai tha higher freque cies a d therefore i stereo mode are more oticeable. Crossfeed
i tegrates the lower freque cies i a more atural way i to the sou dstage which makes them less
oticeable.
