A few questions on potential RME ADI-2 setup

[dyross]

Hi folks,

I've been looking for an interface that will support onboard DSP (mostly for EQ) for both monitors and headphones, and have come to be interested in the RME ADI-2 line. They seem to be very well reviewed, better value than say the UAD Apollos, and high enough quality for my headphone listening needs.

I have some questions:

First, I don't expect to need ADC, so I don't need the Analog inputs on the Pro or 2/4. That said, I'm trying to understand the differences in headphone music listening functionality between the DAC, PRO FS, and the 2/4.

1. In terms of headphone DAC/Amp performance, seems like DAC and PRO are the same, and 2/4 is slightly upgraded. Right? Are the older models still "state-of-the-art"?
2. Otherwise, the difference seems to be that PRO has balanced mode (and ability to listen to two separate headphones), and 2/4 adds Pentacon to that.

Am I missing anything?

Second, the one feature this line is missing is the ability two inputs to one output (e.g. mixing USB in with a digital in). I don't need something comprehensive like TotalMix, but I do need to be able to play audio from two laptops at the same time. I can obviously add another RME product like Babyface or UCX, but I think I can get any consumer interface that has digital in and out. I have an Audient id14 now, looks like I'd need to upgrade to the id24 for this.

So my question here is - to what extent does interface quality matter when you're just doing digital in to a mix and out? Does avoiding any AD/DA remove the benefit of a higher end product, or would I be really bummed to have a lower quality interface feeding audio into the ADI-2?

Thanks,
David

 

[unpluggged]

In terms of headphone DAC/Amp performance, seems like DAC and PRO are the same, and 2/4 is slightly upgraded. Right?

ADI-2 Pro has two identical headphone amplifiers with +7 dBu output in low-power mode and +22 dBu in high-power mode. The output impedance is 0.1 Ohm. It is possible to bridge them ("balanced mode") and get +13 dBu in low-power mode and +28 dBu in high-power mode. In SE mode each of the amplifiers can provide up to 1.5 W of power, in bridged mode they provide up to 2.9 W of power (current-limited).

ADI-2 DAC has only one headphone amplifier identical to the ADI-2 Pro's with +7 dBu output in low-power mode and +22 dBu in high-power mode. It also has a separate "IEM" headphone output with −3 dBu level.

ADI-2/4 Pro SE has two headphone amplifiers with three reference output levels in single-ended mode: +1 dBu, +7 dBu, and +19 dBu. In balanced mode the reference levels are, correspondingly, +7 dBu, +13 dBu, and +25 dBu. While the gain in high-power mode is lower than on the ADI-2 Pro/DAC, it has higher current capacity, so it can provide up to 2.1 W in SE mode and up to 4 W in balanced mode (also current-limited).

Are the older models still "state-of-the-art"?

Yes, they can drive almost any headphone with enough headroom at 0.001% THD

Otherwise, the difference seems to be that PRO has balanced mode (and ability to listen to two separate headphones), and 2/4 adds Pentacon to that.

You understand it correctly, but I'd like to add that the lower reference levels might be useful with extra-sensitive IEMs (I can notice the amplifier's self-noise on the ADI-2 Pro with my most sensitive IEMs, the Fiio FA7, but I don't use them anymore. With my daily driver IEMs I don't hear any background at idle).

In addition to that and to analog inputs (with digital RIAA correction/preamp in the case of ADI-2/4 Pro SE), the Pro variants offer fully-featured digital outputs and sample rate conversion ability. Here is a post over at the RME user forum by the user ramses that covers the differences between the models thoroughly:

ADI-2 Pro/DAC, 2/4 Pro SE - Models, Differences and Release Dates (Page 1) — ADI-2 & 2/4 Pro series, ADI-2 DAC series — RME User Forum

Second, the one feature this line is missing is the ability two inputs to one output (e.g. mixing USB in with a digital in)

This is correct, there is no mixer. The ADI-2 lineup are not recording interfaces; they are marketed as converters/processors.

I don't need something comprehensive like TotalMix, but I do need to be able to play audio from two laptops at the same time.

Yes, you will need some form of a mixer or recording interface to be able to do that.

So my question here is - to what extent does interface quality matter when you're just doing digital in to a mix and out? Does avoiding any AD/DA remove the benefit of a higher end product, or would I be really bummed to have a lower quality interface feeding audio into the ADI-2?

When you feed the monitoring frontend — the ADI-2 Pro/DAC in this instance — digitally, you don't need to be concerned so much about the signal quality. Additionaly, the SteadyClock FS of the ADI-2 converters can use even not very clean incoming clock and regenerate it with its femtosecond clock. In the end, when choosing the interface to feed the RME, you need to pay attention to its features (e.g. how many analog and digital inputs it has, how flexible its mixer is, will it allow mixing sources and route them to the digital output(s), does it support SRC, and so on), usability, driver stability, and support.

After a couple of years of using the ADI-2 Pro standalone, I added a UCX II to my setup, and it works very well. Previously I had an interface that had no digital outputs, so I could not as easily use the ADI-2 Pro for direct monitoring, for instance.

 

[dyross]

Thank you very much for the comprehensive answer!

You understand it correctly, but I'd like to add that the lower reference levels might be useful with extra-sensitive IEMs (I can notice the amplifier's self-noise on the ADI-2 Pro with my most sensitive IEMs, the Fiio FA7, but I don't use them anymore. With my daily driver IEMs I don't hear any background at idle).

I don't (currently) use IEMs, but just to make sure I'm understanding this properly:

In terms of using extra-sensitive IEMs, both the DAC (-3 dBu) and the 2/4 (+1 dBu) will be quieter than the Pro (+7 dBu). Right?

In addition to that and to analog inputs (with digital RIAA correction/preamp in the case of ADI-2/4 Pro SE), the Pro variants offer fully-featured digital outputs and sample rate conversion ability. Here is a post over at the RME user forum by the user ramses that covers the differences between the models thoroughly:

ADI-2 Pro/DAC, 2/4 Pro SE - Models, Differences and Release Dates (Page 1) — ADI-2 & 2/4 Pro series, ADI-2 DAC series — RME User Forum

Great resource! Are there clear subjective differences between the different DA chips, or just better measurements?

When you feed the monitoring frontend — the ADI-2 Pro/DAC in this instance — digitally, you don't need to be concerned so much about the signal quality. Additionaly, the SteadyClock FS of the ADI-2 converters can use even not very clean incoming clock and regenerate it with its femtosecond clock.

I don't grok this, but I am understanding the gist to be that, no, I shouldn't worry too much about digital signal quality since it's not lossy and can be "improved" by SteadyClock.

Does that hold true for mixing of digital signals? My naive understanding of DSP makes me thinkg that two signals with the same SR and same clock can be trivially mixed "perfectly" with basic DSP arithmetic operations. But maybe that's where a poor clock or poor SRC actually hurts?

In the end, when choosing the interface to feed the RME, you need to pay attention to its features (e.g. how many analog and digital inputs it has, how flexible its mixer is, will it allow mixing sources and route them to the digital output(s), does it support SRC, and so on), usability, driver stability, and support.

Yeah, the SRC, AutoSync/SyncCheck, and driver stability all motivate paying up for RME, rather than buying another Audient (I run into annoying SR and clock issues on my current Audient).

After a couple of years of using the ADI-2 Pro standalone, I added a UCX II to my setup, and it works very well. Previously I had an interface that had no digital outputs, so I could not as easily use the ADI-2 Pro for direct monitoring, for instance.

This sounds like a great setup! I'm thinking that while the Babyface is a bit cheaper, the form factor of UCX goes nicely with ADI-2 (and you can just stack them on your desk, right?).

Cheers!

 

[rcstevensonaz]

Mixing? For mixing, you can also use USB in multichannel mode on the ADI-2 Pro and 2/4 and then do the mixing on a PC. For Windows, VB Audio Mixer is a great option for managing the input & output channels.

Turntable? If you want to directly connect a turntable, the Pro 2/4 has built-in RIAA capability

Subwoofers? If you expect to use subwoofers AND you want to do the DSP adjustments within the RME, then the Pro 2/4 will have you covered, since it can support both the 2.2 audio output and still also leave the headphone as well.

 

[dyross]

Mixing? For mixing, you can also use USB in multichannel mode on the ADI-2 Pro and 2/4 and then do the mixing on a PC. For Windows, VB Audio Mixer is a great option for managing the input & output channels.

I'll read about multichannel mode, thanks for the suggestion. I'm pretty comfortable with DAWs (mainly Reaper), so I can probably work that out.

Subwoofers? If you expect to use subwoofers AND you want to do the DSP adjustments within the RME, then the Pro 2/4 will have you covered, since it can support both the 2.2 audio output and still also leave the headphone as well.

No subs yet, but this is definitely something I'll need to keep in mind for future.

Thanks!

 

[Sir Sanders Zingmore]

Subwoofers? If you expect to use subwoofers AND you want to do the DSP adjustments within the RME, then the Pro 2/4 will have you covered, since it can support both the 2.2 audio output and still also leave the headphone as well.

Can you set crossovers and delays in the Pro 2/4?

 

[rcstevensonaz]

Can you set crossovers and delays in the Pro 2/4?

Fair point. My understanding is that the crossovers can be set, but I do not believe the ADI-2 series has support for delays (room correction). The UCX II, etc. now support such room correction; but not ADI-2.

However, the DSP application running on the PC could handle the room correction, and then route Front L/R on USB channels 1 & 2 which will be sent to Analog 1/2 output. And, the crossover and time adjusted output for the subwoofer(s) can be routed on USB channels 3 & 4 which will be sent to the Phones 3/4 output (which can be routed to the TRS 1/2 jacks on the pack panel). One note: if you don't mind the subwoofer output from the front of the device, the ADI-2 Pro FS R can also do that.

Of course, all of this is a moot point if your subwoofers has built-in DSP and can peel off the lower frequency for its use and also has line outs that will send the higher frequency on to the speakers.

 

[Sir Sanders Zingmore]

However, the DSP application running on the PC could handle the room correction,

Yes, but my potential use-case would include analog inputs. I don't think the Pro 2/4 can take analog in, convert to digital, send that to a PC for crossover and delays and then loop back to the Pro 2/4. Or maybe it can?

 

[unpluggged]

I don't think the Pro 2/4 can take analog in, convert to digital, send that to a PC

Why not?

 

[unpluggged]

In terms of using extra-sensitive IEMs, both the DAC (-3 dBu) and the 2/4 (+1 dBu) will be quieter than the Pro (+7 dBu). Right?

Yes, obviously.

Great resource! Are there clear subjective differences between the different DA chips, or just better measurements?

You don't listen to the chips, so you can't attribute any differences you perceive to the chips alone. And also the measurements are not better, they are just a bit different between them. Choose your model based on the feature set, not on its BOM.

Does that hold true for mixing of digital signals? My naive understanding of DSP makes me thinkg that two signals with the same SR and same clock can be trivially mixed "perfectly" with basic DSP arithmetic operations. But maybe that's where a poor clock or poor SRC actually hurts?

Yes, mixing two synchronized digital signals of the same SR and bit depth is mathematically trivial.

This sounds like a great setup! I'm thinking that while the Babyface is a bit cheaper, the form factor of UCX goes nicely with ADI-2 (and you can just stack them on your desk, right?).

Well, theoretically you could, but the units both dissipate some heat, so I would not recommend stacking them. Definitely not without an adequate airflow around them. But you can mount them side-by-side in a rack on a tray such as the RME Unirack, for example: https://www.thomannmusic.com/rme_halterung_19.htm

 

[Sir Sanders Zingmore]

Why not?

I didn't say it couldn't. I said I didn't think it could and then asked if it could.
Can it? If so, how is it done?

 

[unpluggged]

I didn't say it couldn't. I said I didn't think it could and then asked if it could.
Can it? If so, how is it done?

What do you mean, how? It's an audio interface. You use the analog inputs as your inputs and the outputs as your outputs on your DSP software or DAW, that's how they do it since full-duplex sound cards became available in the early 90's.

 

[Sir Sanders Zingmore]

What do you mean, how? It's an audio interface. You use the analog inputs as your inputs and the outputs as your outputs on your DSP software or DAW, that's how they do it since full-duplex sound cards became available in the early 90's.

I mean how?
Can you for a second, remove the assumption that I'm familiar with using a DAW or what a full-duplex sound card is? Once you remove that assumption then perhaps you can understand that I don't know how it would be done

So if anyone actually wishes to help here (rather than pointing out my idiotic ignorance ) the question is:
How would I set up a Pro 2/4 to digitise its analog input, send that signal to a PC (well actually a Mac in my case) for processing, take that processed signal back in to the Pro 2/4 to be converted to 4 channels of analog and fed into amplifiers.

 

[KSTR]

How would I set up a Pro 2/4 to digitise its analog input, send that signal to a PC (well actually a Mac in my case) for processing, take that processed signal back in to the Pro 2/4 to be converted to 4 channels of analog and fed into amplifiers.

Set USB Mode to "multichannel", set it Device Mode to "auto", connect USB and be done, see manual, chapters 17.1 and 17.4.2

 

[unpluggged]

I mean how?
Can you for a second, remove the assumption that I'm familiar with using a DAW or what a full-duplex sound card is? Once you remove that assumption then perhaps you can understand that I don't know how it would be done

So if anyone actually wishes to help here (rather than pointing out my idiotic ignorance ) the question is:
How would I set up a Pro 2/4 to digitise its analog input, send that signal to a PC (well actually a Mac in my case) for processing, take that processed signal back in to the Pro 2/4 to be converted to 4 channels of analog and fed into amplifiers.

As I pointed out, you set your software to receive audio from the ADI-2(/4) Pro's inputs and to send it to ADI-2(/4) Pro's outputs. How you do this specifically depends on actual software in question, but I guess it's enough to set the desired inputs and outputs as defaults in your OS's audio settings. Again, we don't know which particular OS and DSP software you use, so this is as detailed description as I can offer.

 

[rcstevensonaz]

Yes, but my potential use-case would include analog inputs. I don't think the Pro 2/4 can take analog in, convert to digital, send that to a PC for crossover and delays and then loop back to the Pro 2/4. Or maybe it can?

Yes it can, along with sending all of the other inputs,, and being able to play back separate channels to all of the outputs. This means you also have an option of sending properly mixed analog to subwoofers and digital to speakers (e.g., Genelecs, Neuman, KEF LS50 IIW, etc.)

Also, VB Audio Matrix will also be able to take as input anything being played on the PC (e.g. from your browsers, audio apps, etc.) as well as capturing the input (i.e., routing & mixing) for anything you send to the PC from another devices (e.g., to USB or S/PDIF ports on the PC).

Similar for Mac, using audio drivers available for MacOS.

And, for any event where your PC is down (e.g., bad board, crashed disk, software having issues), you can always fall back and simply have the RME ADI-2 route audio directly from any of the input to the audio outputs so that it completely bypasses the USB send/receive until you get the PC fixed or software issue resolved.

For the USB IN (RME Inputs to PC):

• Channels 1/2 = Analog input (from Neutrik, so unbalanced or balanced)
• Channels 3/4 = AES (or S/PDIF)
• Channels 5/6 = S/PDIF (or ADAT)

For the USB OUT (PC to RME Outputs):

• Channels 1/2 = Analog 1/2
• Channels 3/4 = Analog 3/4
• Channels 3/4 = AES (or S/PDIF)
• Channels 5/6 = S/PDIF (or ADAT)

Copied from Page 43 of the ADI-2/4 Pro SE (v1.3) manual. Configuration information is essentially identical on the ADI-2 Pro FS. And keep in mind that for simplicity, this diagram does not reflect the option to change the mapping of the second set of analog outputs on the back from Analog 1/2 to Analog 3/4. Highly recommend downloading and reading through their manual for the ADI-2 or 2/4 Pros...

 

[rcstevensonaz]

I guess it's enough to set the desired inputs and outputs as defaults in your OS's audio settings.

If you are using the USB multichannel for intput / output to a Windows PC, you want to run VB Audio Matrix since that has the ability to manage the 6 input channels and the 8 output channels from the USB, including both routing and mixing functions. You cannot do multi-channel USB input / routing / output with the default Windows drivers.

Macs are a different beast and I believe may be able to handle that... I'm not currently a Mac person so others need to comment on this aspect.

Also, the RME forums are a great source of information. But keep in mind that they are directed primarily towards professional audio users, though there are still many posts that relate to home setup usage.

 

[unpluggged]

You cannot do multi-channel USB input / routing / output with the default Windows drivers.

Where did I state otherwise?

Also, the RME forums are a great source of information. But keep in mind that they are directed primarily towards professional audio users, though there are still many posts that relate to home setup usage.

You are preaching to the choir.

 

[rcstevensonaz]

Where did I state otherwise?

My mistake then. I thought your early comment to "it's enough to set the desired inputs and outputs as defaults in your OS's audio settings" meant that standard Windows OS could properly handle the USB multi-channel input / output. (Though, I do believe that standard MacOS can; but not positive either way on that)

You are preaching to the choir.

That comment was directed towards the poster who is looking to join the choir, not those who already have deep familiarity with RME's product line. Sorry if the context of my comment implied that I was directing it towards you... that was not at all the intention.

 

[unpluggged]

My mistake then. I thought your early comment to "it's enough to set the desired inputs and outputs as defaults in your OS's audio settings" meant that standard Windows OS could properly handle the USB multi-channel input / output.

No, I was just describing the possible procedure of selecting inputs and outputs. The context here is using the PC as DSP for analog inputs of the RME and outputting the processed signal through the same RME device. I think specific DSP software should have its own input and output configuration options, though.