Digital output attenuation volume

I found some posts about that, but need a specific answer from Roon to my issue here:
When i really need a digital attenuation,
means that the output of the connected audio device HAVE TO receive a attuanted signal as that device have no volume control ?
One way could be to process the 16bits to 24 or more-what ever the Roon sw will do,
and then make a digital stream with the maximium bit-depthness what is usually 24 bits.
So when the user maybe only want to play with a 1/10 of volume( Not SPL) then only “few” bits are remaining (after volume processing) and the resolution is decreased.
So thats maybe is working when a 16bit source is used and the “upbits” processing(16 to 24) is done.
But how CAN that works with 24 bits, when the receiving audio chain does not have a"deeper" resolution as 24 bits.
So in theory you are loosing resolution,
how can Roon handle that ?
I know that a hybrid solution (analog/digital gain) is the best, but when there is NON,
how that can be handled ?
The same also should be appear on every digital mixing desk for example,
how is that handled there without disadvantages ?


This thread I started is about auto volume levelling but I think the Guru’s (@brian) replies might help to answer your questions.

Digital mixing desks work with VCA’s or DCA’s wich stand for Voltage Controlled Amplifer and Digital Controlled Amplifier. I am a sound engineer and know for one that a good gain chain is key to get the best out of digital mixers.

Thanks Sjef,

for your friendly and fast answer.
Iam know what are say here,
BUT thats (what i understand) describe a analogue amplifier that get controlled with a digital signal,
what the best way-WHEN its possible.
Also it CAN be done with a „full“ digital stream that includes some control bits for the digital controlled analogue amps.
But then you need a special receiver that know what to do with that extra bits.
Or its much simpler, when the manufacturer control that without to have insert control bits in the stream.
But then the LS manufacturer and source/transmitter manufacturer have to be the same what is not in my case.

What my really background question is:
When you listen to a very attuented signal with „reduced“ bits,
does you recognize a difference when you listen extrem critical to that ?

My personal reason to ask that is,
that i want to use the Roon streaming with Trinnov now to my digital LS from Meridian.
The volome control in the M-LS works as you recommandet, means the DSP(digital speaker) from Meridian get the full signal and the volume „wish“ from the user go over the meridian controller(like a preamp/source switcher).
So the internal volume regulation is done in the speaker (where the d/A conversation is done),
via control bits for the (digital controlled) analoge amps.
In that way the D/A converter have allways the full bits as you know.

NOW i want to use the Roon volume control for my (SPDIF/XLR/AES) input of my Meridian LS.
The reason is that i want to avoid the internal audio processing(for music) and and feed the three D/A converter of each LS with three Trinnov Altitude data streams for high,mid and bass.
I guess, i get a better sound when the Trinnov have the FULL control over the three frequency ranges.
Also then the LS can receive a higher sampling freuqency as 96 kHZ.
The internal D/A converter in the M_DSP are 192kHz types.
I guess, the processing on the Meridian processing board(in the speaker) is the bottleneck.

So the whole idea/project is depending if i can use a „volume decreased“ digital stream without disavantages or not.

What you experiences here, what your thought about the whole idea ?


“What my really background question is:
When you listen to a very attuented signal with „reduced“ bits,
does you recognize a difference when you listen extrem critical to that ?”

Yes, it depends on the amount of attenuation. I’m using the Roon volume control sometimes instead of the analog volume control in my DAC (DEQX Crossover). With a bit of attenuation up until about 10dB everything is just fine with some loss of micro dynamics. More then 10dB attenuation results in altering the sound balance and loss in macro dynamics as well. This is with feeding just redbook 16 bit / 44.1kHz. It could be just the DAC receiver or the way digital volume control is handled and translated to redbook format. The DEQX also has the option to switch between it’s own internal analog volume control or digital volume control. The difference between these two is much smaller. The digital volume control of the DEQX is 32bit floating point. But anyway, good question. I think it will work better with higher sample rates, haven’t tried that because I don’t use upsampling. I might check it out this weekend to see ig it makes a difference when using the Roon volume control. Without volume control upsampling doesn’t make a difference in my case. Maybe because the DEQX only goes to 96kHz, maybe because it doesn’t matter anyway.

Guess you have probably spot this topic allready

It seems it depends on how many bits your dac receiver can handle.

Hi @brian

I’ve not try digital attenuation via Roon, would be possible for DSD without converted to PCM then back to DSD? If yes, would it be safe (does it remember the last settings and any fail safe feature) to connect the DAC directly to a power amp and use Roon’s digital volume control? Do you recommend it? Thanks

Thanks Sjef, thanks here. Sorry for misunderstanding, i mean not upsampling in frequency terms, i mean “upbits” from 16bits to 24 bits. So my question is:
When you listen to a attenuated signal using 24bits and x2 upsampling(means 88.2kHz OUT of Roon (when that is possible with your DAC),
how does that sound with ROON volume control on-
compared to get NO volume control from Roon(also with 24 bit and 88.2kHz) means your DAC make the same attenuation (in dB)
So you can compare the 2xfs upsampling 44.1 and 16bit up to 24 bit from ROON WITH volume control pure to your DAC volume attenuation(No upsampling here as you allready get 24/88.2).
Would be interesting that you “get not biased” -when that is possible … i know…

Part of your answer is in the link. Roons volume by “upbit” in your terms and then shifts the bits to unused bits so the dac “sees” it as a lower volume but with the same resolution as the original signal. Works perfect up until there are no more “empty bits” to fill.

Can’t comment on possible sound changes in your situatuon because it differs from mine so cannot back it up by testing. Any comment would be pure speculation from my side and therefore meaningless

Thanks again Sjef. Hopefully you dont the impression that i want to force you for something- that is not the case.
As the D/A conversion in the meridian also a “hybrid” solution as

  • i suspect-
    your “analoge”(digital controlled or not ?) attenuation?-
    the comparement of ROON or not Roon volume control listening test should be similar.
    Of coarse, only When your analoge attenuation is digital controlled.
    Sorry i have no idea how your analoge attenuation works.
    Anyway thanks for your help here.

My analog attenuation is a pga2310 I thoughr from remembrance. It’s a voltage controlled ladder attenuator actually. It’s at the outputs of the dac. My dac is actually a crossover and preamp in one. VCA’s are handy here because it controls the six output channels synchronous. But you are right, this volume control in my DAC has no influence on the Roon volume control and vice versa. They are two different independent controls.

Anyways. I’ll do some test this weekend.

Sounds interesting-to bad that are you far away—

You are right, if you have a 24 bit signal and the DAC accepts only 24 bits and you reduce volume digitally in Roon, you will shift the bits down and fill the top with zeroes and therefore lose the bottom bits.

But that doesnt mean this is relevant. Just because the original signal was 24 bits doesn’t mean it is significant. The bottom bits are noise, the recording chain does not have 24 bits resolution.

And neither does your sound system. I remember reading a reviewer gush over a fabulous power amp, the quietest amp he had ever measured, the noise was about 130 dB below max power of 300 W, which means 21.6 bits! And since you normally play at less than 300 W, the dynamic range is even less.

Thanks Anders,

yes in my brain in know that 24 bits are a good marketing thing, but as iam not an expert of psyschoaccustic,
i dont know what is really important or not.So the “selfbiasing” is a bad thing…
But as the brain make “crazy” things refer to hearing, what are not “logic”,
i learned my lesson that finally a (hopefully unbiased) listening is the best.
So iam starting here to get some thoughts or experience how big that issue can be. Finally, only the ear/brain can decide, but i want to be sure, before i start the whole project.
That doesnt mean my sound is not excellent right now, but…;-)) “you never know”

We have some architectural issues with doing a DSD software volume control–our memory buffers for streaming are too long to put a volume control in the core (since a 5+ second delay for volume changes would not be acceptable user experience), and most endpoint hardware is not powerful enough to do it on that side.

If you were OK with PCM only, you could do it. I don’t recommend it or not recommend it–but I view software volume control as more of a utility than an enhancement.

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I have been playing with it extensively today. I tried Volume control of the DEQX vs Volume contol of Roon.

First thing to note is that the volume control of the DEQX is way more convenient. It works with a button on the device itself, and it has a remote control that works instantly. The Roon volume control scale is not very refined and the slider is a bit akward in use but that could be a matter of getting used to. The most unconvenient is the fact that Roon remote has to be open and ready to grab for it. When I use my Ipad as remote it goes to sleep after a while and it takes up to 5 seconds for Roon to be up and rady again. Pretty long when you only want to change the volume. If this all doesn’t matter for you then fine. My view is the same as Brian’s, it’s more a utility, a nice to have then a practical alternative to your volume control.

But what about sound quality. Well, that’s a though one. As said I tried both ways. Set the volume control of the DEQX to max (scary) and use Roon, or set Roon to max and use DEQX volume control.

Well the results where about the same as I have concluded before. Up to about -10 db there is no difference whatsoever. From there I thought subtle changes are creeping in, not instantly but just very gradually. In the extreme case of setting DEQX to max and using Roon for volume I was constantly in the range of -30 to -45 dB . In this range there is a clear loss in overall quality. Again, could very wel be DAC dependent. It just sounds like your amplifier has lost some of its power, in other words you lose quite a bit dynamics, sound stage flattens out, and micro dynamics and detail are degraded. Conclusion. Well, for convenience sake I would say no. Sound quality wise it depends I guess. My DEQX certainly loves to be fed with stronger signal then -40dB that’s for sure.

Also tried the difference between Analog volume and digital volume control in the DEQX itself again. The difference here is pretty small, but then again, it’s a 32bit floating point volume control. It doesn’t have to truncate the signal to 24 bit like Roon has to to be compatible with the dac’s input receiver so it’s not a question if Roon can handle it. It’s just not the right place in the chain for a full digital volume control I guess. Use it for convenience, set your main control elswhere in the chain.

Wow- a big thanks for doing all that-very interesting.
Have to spend you a drink…
Will thin over and come back

No thanks, it was an easy experiment that didn’t even involve a soldering iron

Sorry, my english is to bad to understand that humor??

I have some questions about the sound quality (SQ) of the volume levelling function.

My starting point is fixed volume in Roon, with volume controlled by my DAVE DAC/pre-amp. Always playing redbook FLAC files. Sound quality is excellent. But if I employ Roon’s volume levelling, then SQ takes a noticeable dive, with a duller, flatter, less dynamic sound, Which is a shame, as I really like the idea of this function when flitting between different albums etc.

So my questions are:

  1. Does the Roon team agree that there is a SQ degradation when using volume levelling?
  2. If yes, are there any other settings I can try to counter this? I’ve originally tried an overall volume gain adjustment (can’t find it now or what it was called), but this didn’t seem to help SQ, although it did bring overall volume back closer to the fixed volume situation.
  3. If there are no improvements to be had, any chance of a minor UI enhancement to show up-front the album and track volume db values? As is already done for album dynamic range. This would mean I could at least predict the required volume for the next album/track to be played and make a pre-emptive manual volume adjustment on my DAC/pre-amp. If the Roon team considers that to be too cluttered, then a next best alternative is to have a shortcut key to more quickly bring up the file info display, or an option to have file info always on top?

In contrast, I’m very pleased with the SQ of Roon’s Parametric EQ. Whatever SQ degradation it may or may not have, in practice it’s insignificant compared to the gains of getting a more balanced sound through headphones etc. (Edit: I’d also like to have an option to have the DSP window always on top. Please?)

FWIW, the typical reductions I get with album volume levelling are between -10db and -16db. And my EQ settings have a much smaller variation typically under 3db.