DPLAMB-FIR (07-2009)


This is the first Soundfield method. It's actually pretty simple and for years
this has been the most used method, because it also gives good separation.

Everything is freeware so you can download all here : DPLAMB-FIR
Let's first have a look at the layout :



The first thing to do is to run it once and make the RMS's of the fronts equal
to get a better soundfield :



I took "Year of the cat" again as example and made the RMS of the Left and Right
from the original stereo equal to each other. In this case -17 Db.
The settings for the DPLAMB instnace :



For the rears "Hilbert Transform (med) is the default but do experiment with the
other selections. I suggest to leave the Forward Dominance on 1.91.
Because this is an Ambisonics method, adding gain to one channel influences the
other channels too. RMS doesn't need to be like 0,-0.5,0,-4,-1,-1 . The only dis-
advantage of this method is the low center. We added an extra gain here to the C,
but do realize the Ambisonics field is partly destroyed ! Ambisonics should
always be the last process before the recorder. If you leave the center at 0 Db
gain, you'll get true Ambsonics. Giving the Center a positive value, will leave
the corners in an Ambisonic state while the Center is not. In 99% of the cases
this destroyemnt of the total Ambisonics Soundfield is not noticeable enough and
then we can give that Center that extra bit it sometimes misses.
The spreadsheet cannot be used in the rgular way, but you can use it to determine
the differences in loudness between stereo songs and aplly this with the master-
gain to the surround.

Happy encoding !!

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Layout and Guide by The Dynamic Duo
The Dynamic Duo : Kempfand & Eye of Horus
It's not allowed to republish this method ! !