And what about runtime differences due to two different D/A converters?

You'd be better off getting a reasonably professional sub that allows you to connect satellites and also takes care of the crossover issue.

My personal opinion on this topic: it's best to avoid all this complexity of subs and get matching speakers where everything is coordinated. Or: why complicate things when there's an easier way?

But your mileage may vary

AFAIK, only the ADI-2/4 Pro SE supports an additional / separate play out path on top of the usual XLR outputs.
It was a demand from mastering engineers to have a separate play out path for a mastering chain.
There you now have TRS instead of TS outputs, which also support balanced operation.

https://forum.rme-audio.de/viewtopic.ph … 38#p183638

The current routing options are on the table - literally, in the manual pages 37 to 43.

There’s no option to drive the digital outputs from channel 3/4.
Don‘t expect this to change.

ADI-2 was never meant to be a full-fletched speaker crossover.
There are too many specialized parameters missing for this purpose, like cut filter shapes and channel delays.

You CAN use a crossover software and access all ADI-2 outputs individually in Class Compliant Multi-channel mode through USB (manual page 40).

Or you go with one of my configuration options for sub integration from here:
https://forum.rme-audio.de/viewtopic.ph … 12#p155312

(case 1): One output - main/sub on the same ADI-2 DAC / PRO output is an alternative to a classical crossover setting, avoiding steep phase shifting filters in favor of a more punchy sound.

@MC:
I have to admit, that I by myself found the routing possibilities of the digital outs somewhat limited.

I don’t think this is for hardware reasons.

I’d vote to replace the “Digital Out Source”- “Main Out”- parameter with entries for:
1/2 pre DSP, 1/2 post DSP, 3/4 pre DSP, 3/4 post DSP.

That would cover most available options.

I.e., I have a digital level meter that I can not drive the way that is typical studio usage: post source selector, pre DSP.

Digital interconnection becomes more and more important these days.
E.g. studio monitor speakers are very often equipped with those.

Another use case where routing the second DSP processor to a digital output would be very useful, and where the slight timing differences of the separate output paths would be irrelevant...

Two sets of speakers, each set for a different listening position, and each needs its own unique EQ configuration:

• RME DSP 1/2 > TRS 1/2 [out] ---> KH 120 A (desktop / near field)

• RME DSP 3/4 > S/PDIF [out] ---> LS50W II (listening chair / far field)

Thanks for the detailed information on using setup to switch configurations. That is one approach, given the way the ADI-2 is implemented. This is not a complaint about that... but rather, about the exciting potential to use DSP 3/4 on the S/PDIF channel.

For me, there are several use cases where the "Setup" remote option is less than ideal:

Case 1: Audio is being controlled by external mixer / router — for example, TotalMix Remote or ARC USB. In this case, simply mute the audio going to USB Playback channels 1/2 or 7/8. There would be no need to then go and also find the RME ADI-2 Remote to toggle the configuration on DSP 1/2.

Case 2: Both speakers active — for example, audio from work PC remains active on TRS 1/2 to the desktop speakers (for meeting alerts, incoming Teams calls, etc.) but the audio from the LP album on the turntable is routed to S/PDIF for the listening chair speakers. In this case, the desktop speakers are only turned up loud enough that I will hear any alerts, but the music stream (turntable, CD, network stream) on the S/PDIF speakers might be cranked up fairly high. I do not want the "ringing" sounds for an incoming Teams call blaring into that audio channel :-)

Case 3: Speakers are in different rooms. In this case, both speakers would be active with DSP 1/2 being used on audio for TRS 1/2, and DSP 3/4 being used for audio on the S/PDIF out.

For me, the combination of #1 and #2 is my interest. Controlling where the album audio is being routed (USB Playback 1/2 vs. 7/8) is easily done using the remote mixing/routing mechanism. But since USB Playback 7/8 could be a different audio stream (since Work PC wouldn't route there in any case), I currently need to perform any DSP EQ for the S/PDIF speakers external to the ADI-2 Pro... even through the Pro has that amazingly high quality DSP 3/4 sitting there unused.

P.s., in my case, I am not using the ADI-2 Pro for headphones. And even if I was, my preferred use case would be DSP 1/2 routes to TRS 1/2, DSP 3/4 routes to S/PDIF, and no DSP is used for Phones 3/4.

Set the unit into Multichannel mode, activate Digital Out Source - Line Out, plug a cable AES XLR out to AES XLR In and record this  digital input signal via USB. This will include Line Out volume setting, but it's the only way to record SPDIF In with PEQ (all FX).

I/O / Line Out 1/2 (or Phones Out 1/2, or Phones Out 3/4) / Settings / Loopback: “post FX to 1/2 -6dB” does the trick.

Install the remote app on the computer you have ADI-2’s USB connected to.

You could use your Macbook as an USB interface and streaming host.
Connect both ADI-2 and your USB DAC to it and route the signal.

This combination would exactly do what you request, including the streaming options.

The Loopback option replaces the USB record signal (which you currently don’t use) with the ADI-2 - processed signal that you select there.

You could use Loopback to send the PEQ’d signal back to your computer, via USB.

On the other hand, you’ve already got what you want using the Bluesound Node as interface / bridge to your other DAC, so…

You can.

This exactly is what “Loopback” does.
Every signal that goes either to 1/2 or 3/4 out can be sent to USB record, with or without DSP (like EQ etc.).

Example 1:
ADI-2 Pro in DAC-Mode, the 1/2 main signal, Optical In, with some PEQ boost, to USB record:

- I/O / Line Out 1/2 / Settings / AD/DA Source: Optical
- I/O / Line Out 1/2 / Settings / Loopback: post 1/2 -6dB

sends the 1/2 PEQed signal to USB record 1/2, with the level lowered by 6 dB to avoid overload.

Example 2:
ADI-2 Pro in Auto/USB Mode, the 3/4 signal, Optical In, with some PEQ boost, to USB record:

- I/O / Phones Out 3/4 / Settings / Source: Optical
- I/O / Phones Out 3/4 / Settings / Loopback: post 1/2 -6dB

sends the 3/4 PEQed signal to USB record 1/2, with the level lowered by 6 dB to avoid overload.

ADI-2’s output volume is NOT included, every other DSP function is.

No go on this so far... ADI-2/4 Pro and Ayre QB-9 Twenty DAC both connected to 2015 MacBook Pro via USB... I can route directly to QB-9 Twenty, and I can see that the ADI-2/4 Pro is getting signal, but I can't figure out how to route into the ADI-2/4 then out to QB-9 Twenty.

In Midi Setup Studio it shows the ADI-2/4 Pro, but when I do a scan, it does not show the QB-9 Twenty dac.    Perhaps there is software needed in the QB-9 Twenty for that to be possible, but MIDI sees the QB-9 Twenty in devices, but I just can't figure out how to route.

Getting this to work and eliminating the Bluesound Node altogether would be great. 

I suppose another configuration is:

Macbook --> Optical Out to ADI-2/4 ---> USB out to QB-9 Twenty USB in

I saw a reference by MC stating "the USB cable needed to be removed before making the change (to Loopback?), and that it's clearly stated in the manual".  Perhaps I'm misreading the purpose of that, but I don't see that reference in the manual, and I can't see how to enable Loopback just from the front panel.  It mentions it's at the bottom of the I/O menu, but I don't see it.

This one is a challenge, for sure.  I feel like I'm one click of a button off... we'll keep at it.

This is a very useful insight to explain why it needs to be unplugged for changing the Stereo / Multi mode, any why there is no need to unplug it when simply shifting between the various USB, Preamp, DAC, AD/DA, etc. modes.

i would encouraging adding the phrase "...so that the number of recognized ports will be reset" when making future comments about needing to "unplug the USB cable before making the change." And perhaps adding into the manual if not already there.

By adding the "why", it is clear and easy to remember. Without adding the "why", people create their own reasons which may or may not be accurate.

Edited to shorten the size of my original comment.

The average Joe/Jolene (or even just Jo) are not using RME equipment :-)

Agreed. RME manuals are widely recognized as a work of art! But I don't believe those 28 pages address this specific aspect. And in fact, the manual itself is ambiguous as well, as I note in my comment below. And I'm not sure that a Google search would have provided the amazing brilliant insight that KaiS offered in their comment. (Though that comment will now hopefully start showing up in future searches)

This topic is related to a pretty specific (and somewhat esoteric) aspect: that the USB cable must be unplugged when changing between USB CC-Mode Stereo and Multichannel but not when changing between the Device Mode. This isn't something people will discover on their own by plugging / unplugging / changing settings. And yes, the entire point is to remove the need for long-lasting and fruitless internet research!

KaiS, your comment is ***exactly*** what  finally unlocked the mystery!!! Your comment was the missing piece that is NOT in the manual, and that I had never seen mentioned anywhere before!!! And your comment is what finally allowed me to intuitively understand exactly why MC keeps saying "you need to unplug USB when changing the CC-mode" while also saying that you don't need to unplug when just changing the the device mode.

Your comment and help was so brilliant, I strongly believe it should be incorporated into that RME manual so that is becomes even more amazing manual.

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Here is the current manual for ADI-2 Pro FS R (page 28 in my .pdf file)
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14.1.3 Device Mode / DSD

Basic Mode
Choices are Auto, AD/DA, USB, Preamp, Dig Thru and DAC. See chapter 17.

CC-Mode
Choices are Stereo and Multi-channel. The ADI-2 Pro supports two Class Compliant modes: 2 channel I/O, which allows to use sample rates up to 768 kHz even with iOS devices, and 6/8 channel mode to give access to all I/Os simultaneously. In multi-channel mode the sample rate is limited to 192 kHz. To be able to change the mode USB must be disconnected.

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My commentary on that section:
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The last sentence says "To be able to change the mode USB must be disconnected". While a strict reading of that sentence would argue the context is CC-Mode, it occurs within the section titled "Device Mode". So it is somewhat ambiguous which "mode" is being referred to; or whether both modes ("CC-Mode" and "Device Mode") are in context.

-------------
Proposed change to the wording in the manual that removes some of the ambiguity and incorporates the extremely useful (IMHO) insight shared by KaiS:
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14.1.3 Device Mode / DSD

Basic Mode
Choices are Auto, AD/DA, USB, Preamp, Dig Thru and DAC. See chapter 17.

CC-Mode
Choices are Stereo and Multi-channel. The ADI-2 Pro supports two USB Class Compliant (CC) modes: 2 channel I/O, which allows to use sample rates up to 768 kHz even with iOS devices; and 6/8 channel mode to give access to all I/Os simultaneously. In multi-channel mode the sample rate is limited to 192 kHz. To be able to change the USB CC-Mode between the Stereo and Multi-channel options, the USB cable must be disconnected. After making a change to the CC-Mode, the number of ports recognized by the host computer will be reset once the USB cable is reconnected.