I assume that the lower audio quality is caused by using a joint stereo compression and a mono audio source.

When the other codec dials into your Prima it will most likely be using a mono connection. The mono connection will use the full available bandwidth for the mono audio. Your Prima is probably setup for joint-stereo, but that does not matter in this case as the mono audio comes from the remote system and your Prima will decode this fine.

But when you use the (joint stereo) Prima to call the remote codec, the remote system will recognise the joint stereo stream from your Prima and assume that that is what you want in return as well. It will therefore return a joint stereo stream. Unfortunately the joint stereo encoder is less efficient when it has to work with mono audio and this results in a lower audio quality.

Older codecs will always return the type of audio that has been setup for their encoder – regardless the type of audio the in calling system uses. When you dial another Prima the chances are that the remote Prima is setup for mono encoding, which then results in a higher quality. To get a different setting back someone actually needs to change the settings on the remote codec.

There are two solutions to your problem (unless my assumption is wrong of course!).

1 – When you want to receive a mono stream from a modern codec like Isys Pro or AudioTX then use a mono stream to dial in. The automatic recognition system is there to allow you to select the type of audio you want to receive. By calling into such a codec with a mono stream you will receive a mono stream that uses the full bandwidth for the one audio channel.

2 – Disable the auto-recognition on the remote system and set it to “return always mono”. But if the remote system is also used with other studios then this may not be a useful option - other users may depend on the fact that they can select the audio type by the way they call into the codec!

Hope this helps!