Hi, I’ve done some ambisonic recordings of ambience in very quiet environments using the SoundField SPS200 mic and a SoundDevice 788T recorder. The resulting recordings are A-format, and I use the SoundField SPS200 plugin to convert the A-format recordings to B-format. The resulting recordings have a bit of hiss that I suspect come from the recorder. The sound is very similar to recordings done using the 788T with no mic connected, and with the same recording levels as when doing the ambience recordings. I’d like to use Isotope RX4 to reduce the amount of hiss, and I’m wondering what would be best practise when dealing with 4-channel A- and B-format signals.
RX4 is not able to deal with multichannel files, so I’l have to split the 4-channel recording into two stereo tracks, do noise cancellation on them, and then merge back into four channels again. However I can envisage three different approaches to this: 1) I treat the original A-format recordings, and afterwards I convert the processed files to B-format using the SPS200 plug. 2) I treat the converted B-format recordings. 3) I decode the B-format files to A-format using the BtoA decoder from Ambisonic Toolkit, remove noise, merge, and then reencode to B-format using the ATK AtoB encoder. I’m sure the first option will be the best when considering noise reduction only, as it reduce hiss before the four channels gets mixed. At the same time I’m concerned that it might offset phase information between channels, and hence interfere with how the SPS200 plugin compensates for distance between the mic capsules. For the same reason I’m thinking that processing of the B-format signal might interfere with phase information between the four channels and hence distort the spatial information. Do anyone else have any experience with this, and have a recommendation for what workflow leads to the best results? Thanks, Trond _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
