How to use 2 DACs on 1 Windows 10 PC, with separate PEQ profiles?

[phoenixdogfan]

I believe that question has already been discussed. Yes, in theory the devices are not in sync with one another, but AFAIK that's not a problem. Here's why.

This topic was originally created following a private chat between sweetchaos and me. That conversation was about me wanting to have dual headphone listening sessions with my girlfriend. In that case, the fact that the DACs are not in sync doesn't really matter (at least in my case with my two E30 DACs).

With separate listeners and separate headphones, the fact that may be a small delay (probably unnoticeable anyway) between both headphones just won't affect the listening experience for any of the listeners. Even if there was a small increasing time shift between both DACs, that shift can be estimated at about a couple of samples per second (or so I've been told). For a 4-min song, that's about 480 samples. So about 0,01 second. None of the listeners would be able to tell who finished first.

Of course after 40 mins of uninterrupted music, that time shift could start to maybe become noticeable (not even sure), at about 0,1 second. But here's the trick : every time you pause/stop/restart music, the time shift is reset. So unless you wanted to listen to a very long playlist with somebody else and without ever stopping the music a single time, that wouldn't really be a problem.

Besides, I'm not an expert, but Voicemeeter has a big audio buffer that may also be helping with this. I don't know all the technical details, I can just say that it works. I'm talking from experience. In our dual headphone listening sessions it all has been working perfectly for a year or so:

• sweetchaos' method for all the building blocks,
• Mega Switcher for setting two different EQ presets simultaneously, one for each headphone, with real-time fine-tuning.

Maybe other people will encounter issues, but we don't. We are very happy with this.

Ok, so using each DAC to provide a complete listening experience to two different listeners is a different thing from using two dacs to drive a multi channel surround sound experience for one user which is what I was getting at.

 

[Jose Hidalgo]

Ok, so using each DAC to provide a complete listening experience to two different listeners is a different thing from using two dacs to drive a multi channel surround sound experience for one user which is what I was getting at.

Which is why I explained you why this topic was created in the first place.

For only one user you need either a world clock or a multichannel DAC. AFAIK there's no way around that.
Except if you wanted to listen to only one song at a time in a surround setup. In that case it would work.
For Home Theater purposes, I guess it wouldn't.

Well, maybe it would, if you're lucky and not too picky about it. If your time shift happens to be as small as described (that depends on your two particular DACs because of manufacturing tolerances, so it could be bigger), you could end up a 120min movie with a time shift of about 0.3 seconds. Not bad, but not ideal either. And it's the best case scenario IMHO, assuming your player buffer and/or your Voicemeeter buffer would be big enough. That's the part I don't know.

 

[nirnav]

Thanks! Exactly what I needed. Maybe add a step for volume control macro since it was a bit confusing as a new voicemeeter user.

 

[Svperstar]

Cool! I was going to try this but I used another method.

There is an old plugin for Winamp called multiout that lets you have multiple simultaneous outputs. If you want 3 devices all using DirectSound you make multiple copies of the DirectSound DLL in Winamps output plugins. Then open up Winamp and set each instance to the DAC you want to use.

Multiple Output Plugin - Winamp & Shoutcast Forums

What is Winamp? Why is Winamp? How is Winamp? All these burning questions and issues discussed within.

forums.winamp.com

The original authors website doesn't exist but I found it in the wayback machine.

ioannis blog : Multiple Output Plugin

I just wanted to do some DAC testing but I think your method is system wide not just in a music player

 

[henologist]

Thanks for the guide! I managed to use a spare two-output audio interface for subwoofer output with this technique. It's not the ideal solution to that problem, but it works fine enough until I can get a separate DSP device in the chain. I had to set a short delay to my mains in Equalizer APO, no problems after that. My testing has just been through MusicBee and a few games to see if the delay was noticeable, will report back if I notice any clock drift after extended use.

 

[Nator]

Hi, my plan is to realize a 2.2 System with EAPO. Ideally I would take a more channel DAC, but those are a little rare and expensive (maybe except MOTU M4, but it probably has this "Windows-startup-pop" when your amp is on. Probably every "pro-audio-interface" has).
The second plan would be to take two Topping D10 and stream to those in parallel.
I think this approach is very good! But can someone tell me why EAPO alone cant do it? Cant it copy the input to another device?
And the other question is about the clock drift. Does someone have longtime experience with such a config?

 

[rcstevensonaz]

Question: can (or should) the VB-Audio Matrix software be used instead of Banana or Potato since the EQ function is being done in EAPO? (I don't think Matrix had been released when this tutorial was initially created)