realtime导出虽然可以解决快速导出的问题，如果仅仅是一首歌还没有问题，但若是四十集电视剧实时到处就要好几天。我经过多次试验，发现rme的freface800和9632可以解决此问题
33.5 Recording a Subgroup (Loopback)
TotalMix supports a routing of the subgroup outputs (=hardware outputs, bottom row) to the
recording software. Instead of the signal at the hardware input, the signal at the hardware output
is sent to the record software. This way, complete submixes can be recorded without an
external loopback cable. Also the playback of a software can be recorded by another software.
To activate this function, click on the white label in the third row while holding down the Ctrl-key.
The label's colour changes to red. In case the channel has already been part of a group, the
colour will change from yellow to orange, signalling that the group functionality is still active for
this channel.
In loopback mode, the signal at the hardware input of the corresponding channel is no longer
sent to the recording software, but still passed through to TotalMix. Therefore TotalMix can be
used to route this input signal to any hardware output. Using the subgroup recording, the input
can still be recorded on a different channel.
就是在它的TotalMix设置中正确的设置就可以，但要注意不要自成回路造成自激。
