[LAU] correct jconvolver matrix gain for convolution reverb?

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
To: Fons Adriaensen <fons@...>
Cc: A list for linux audio users <linux-audio-user@...>
Date: Thursday, January 31, 2013 - 1:02 am

hi fons, hi everyone!

playing with aliki and jconvolver again. i've recorded some sweeps from
a single neumann kh120 loudspeaker into a tetramic. the IRs have been
deconvolved and normalized, and after that their direct part and floor
reflection have been trimmed off.

now when i put those files in jconvolver with a gain of 1 (which is
inserted into a post-fader aux fx bus), the reverb level is way too
high. i see that you always use a gain coefficient of .5 in your
b-format examples - why?

i would like to start with the "correct" reverb level and go from there.
the initial (peak) normalisation was done in ardour. maybe i should have
normalized the initial impulse area to unit energy rather than the
highest peak to unit amplitude, but i'm not quite sure how to accomplish
that. the normalization feature in aliki doesn't seem to do anything, or
i'm misunderstanding something.

below is the config file. ignore the five inputs for now, the level
problem is evident when using just a single input.

any hints would be much appreciated, and yes, as soon as i've listened
through these IRs properly and fixed the config, i'll be happy to share
them with everyone.

best,

jörn

/cd .
#
#
# in out partition maxsize density
# --------------------------------------------------------
/convolver/new 5 4 256 400000 1.0
#
#
# num port name connect to
# -----------------------------------------------
/input/name 1 Input.LL
/input/name 2 Input.L
/input/name 3 Input.M
/input/name 4 Input.R
/input/name 5 Input.RR

#
/output/name 1 Output.W
/output/name 2 Output.X
/output/name 3 Output.Y
/output/name 4 Output.Z
#
#
# in out gain delay offset length chan file
#
-----------------------------------------------------------------------------------
/impulse/read 1 1 1 0 0 0 1 LL.wav
/impulse/read 1 2 1 0 0 0 2 LL.wav
/impulse/read 1 3 1 0 0 0 3 LL.wav
/impulse/read 1 4 1 0 0 0 4 LL.wav

/impulse/read 2 1 1 0 0 0 1 L.wav
/impulse/read 2 2 1 0 0 0 2 L.wav
/impulse/read 2 3 1 0 0 0 3 L.wav
/impulse/read 2 4 1 0 0 0 4 L.wav

/impulse/read 3 1 1 0 0 0 1 M.wav
/impulse/read 3 2 1 0 0 0 2 M.wav
/impulse/read 3 3 1 0 0 0 3 M.wav
/impulse/read 3 4 1 0 0 0 4 M.wav

/impulse/read 4 1 1 0 0 0 1 R.wav
/impulse/read 4 2 1 0 0 0 2 R.wav
/impulse/read 4 3 1 0 0 0 3 R.wav
/impulse/read 4 4 1 0 0 0 4 R.wav

/impulse/read 5 1 1 0 0 0 1 RR.wav
/impulse/read 5 2 1 0 0 0 2 RR.wav
/impulse/read 5 3 1 0 0 0 3 RR.wav
/impulse/read 5 4 1 0 0 0 4 RR.wav

--
Jörn Nettingsmeier
Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487

Meister für Veranstaltungstechnik (Bühne/Studio)
Tonmeister VDT

http://stackingdwarves.net

_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]

Messages in current thread:
[LAU] correct jconvolver matrix gain for convolution reverb?, Jörn Nettingsmeier, (Thu Jan 31, 1:02 am)