O1A Decoder - 22.2

O1A Decoder - 22.2

Host Support

Host TypeSupport


Output24Hamasaki 22.2



This plugin takes a first order ambisonics (O1A) mix and decodes it as a 24 channel Hamasaki 22.2 surround mix.


The channel ordering used is:

1Front Left
2Front Right
3Front Centre
4LFE Left
5Back Left
6Back Right
7Front Left/Centre
8Front Right/Centre
9Back Centre
10LFE Right
11Side Left
12Side Right
13Top Front Left
14Top Front Right
15Top Front Centre
16Top Centre
17Top Back Left
18Top Back Right
19Top Side Left
20Top Side Right
21Top Back Centre
22Bottom Front Centre
23Bottom Front Left
24Bottom Front Right

The plugin is available in the O1A Decoding plugin library.


Control: Method

Three methods are supported, "Basic", "Reconstruction" and "Tinted Reconstruction". Generally, "Basic" is recommended except where the speaker rig to be used for playback is known and has been set up accurately.

BasicThis method produces a resilient decoding which should play well on a range of speaker systems including large venues.
ReconstructionThis method controls the soundfield at the centre of the listening space to produce a clearer spatial image. It relies on the speaker layout being set up accurately.
Tinted ReconstructionThis variant of the Reconstruction method performs HRTF-based tinting on the audio stream to strengthen the spatial image. Again, it relies on the speaker layout being set up accurately.

Control: LFE Crossover

This determines if any audio is sent to the LFE channel. It may be set to "Off" and this is recommended. If enabled, audio is extracted from the main mix into the LFE channel using the indicated crossover frequency (between 1 and 200Hz).

Control: LFE Gain

If the LFE gain is active, this gain is applied to it. Some export formats may need this set to -10dB to take into account a +10dB gain applied during playback.

Please note that a further -6dB is applied in addition to this setting to compensate for the presence of two LFEs in the 22.2 configuration.