ASIO and exclusive modes can be used if EQ APO is attached as a Voicemeeter plugin. This is a newish feature. It doesn't actually work as an APO, it uses Voicemeeter's Audio API instead. I use this configuration.
That is interesting. By this I assume you mean if you attach EAPO to Voicemeeter virtual input device in the Configurator, you can still do ASIO to that device and EAPO will work. Or is there a different way to attach the EAPO as a plugin to use Voicemeeter API?
In any case, this won't help him because of the need to split to two devices and separate EQ for each. The selector won't be available for the outputs A1 and A2 inside EAPO if attached to the Voicemeeter input. So the following is not possible:
I haven't tried two DACs at the same time, though. In principle, EQ APO should distinguish outputs A1 and A2, and you can assign different filters to them.
You can attach EAPO to Voicemeeter output devices as post in the Configurator (which seems to be in permanent beta) but I have had problems using it this way from crashes to distortion. So, I wouldn't recommend it.
Hence my suggestion to attach EAPO to the two USB devices instead downstream from VoiceMeeter (at the expense of not being able to do direct mode/ASIO) to those devices.
- I don't know what the EAPO "device selector control" is, and Google doesn't help. Do you have a link ?
- Would I need one config file mentioning both physical outputs, or two separate config files ? I guess I need to find a nice EAPO tutorial.
When you install EAPO, you get two different confusingly named apps in the Start menu under Equalizer APO group. One is called the Configurator. This is used in Admin mode to attach EAPO to audio devices and unrelated to any filters or other things you do to process the sound. The latter is done via the other app called Configuration Editor which is a GUI front-end to create and edit the config.txt file it uses to process the audio.
In the configuration editor you can specify filters, pre-amp levels, crossovers, etc. The order of processing goes from top to bottom. You use the + sign to add a "control" (filter, volume, selection, etc).
The selection controls you add affect the controls you add under it. You can add a selection for a particular channel or for a particular device to which EAPO is attached. When you include this control, the controls below it applies to only that selected channel or device until it meets the end or another selection is made later on. All these are converted to corresponding lines in config.txt.
So you can put a device selection control and choose one device and then add the processing elements below t. Then you add another device selection control to choose another device and then put the processing elements for that device under it. That is how you separate processing for different devices.
While everything can be in one file (config.txt), I find it cleaner to separate them out in a tree. There is an "include control" you can choose in the Configuration Editor where you can specify a file to include. It will be as if those controls in the included file are inserted at that point but you can edit that included file separately in a different tab.
So it may be like (not the exact syntax)
Select Device 1
Include Device1.txt
Select Device 2
Include Device 2.txt
in the main configuration file and the EQ filters for each in the two included files.
You can further nest includes in each of those files if needed.
It's good to know that Voicemeeter inputs support ASIO regardless of the outputs. But I don't know if it would be best for me to use ASIO or not between foobar and Voicemeeter. As said by
@DDF in his topic, it looks like ASIO isn't needed anymore when EAPO is configured properly and with a -4 dB preamp gain (regardless of the individual gains for each EQ preset I suppose). I'm a bit lost here.
You should do this steps, one at a time so you aren't juggling multiple things at the same time because when you get no audio the first time, you have no idea where the problem is.
1. Install VoiceMeeter first and set it up without any EQ (no EAPO) as I suggested earlier. Use the simplest and most stable driver mode everywhere (e.g., MME)
Test it out so that you are getting the audio as you need to the two headphones from foobar simultaneously. Debug this until you do without getting confused with EAPO. Note any problems in distortion (may need buffering change in Voicemeeter) or latency (though this shouldn't matter for two channel audio unless you are mixing it with something else).
2. Now install EAPO and attach to the USB devices. The default will do nothing. But play again and make sure that you are still getting the audio through both.
3. Now open the Configuration Editor of EAPO and put in the device selector for each with a pre-amp volume setting only (so not to complicate with EQ settings etc) to make sure the two can be individually controlled with volume without affecting the other so you know the device selector is working.
4. Now put in the EQ settings for each and test it out.
Once you have the above working, you can try changing the access to the devices above to WDM or ASIO if you like to see which works and which don't. Keep the one that works.
You don't need the -4dB attenuation in the pre-amp volume unless you notice some problem after all of the above is done (highly unlikely) but leave the preamp volume at -0.2dB. This is a totally different issue so don't try to juggle this also with the rest of the stuff above.
Just remember, you include and set only one thing at a time and you will likely succeed. Otherwise, as a beginner, you will be tearing your hair out trying to figure out which of the different things in the chain is the problem when you are unable to get it to work.
