Roon Nucleus Outputs Louder Audio

So a Thai entrepreneur claimed on his impressions of the Nucleus that he ‘detected’ higher SPL and assumes that the device has ‘more powerful’ output compared to his Mac mini (with Roon installed) during playback. I told him that’s not supposed to be the case, yet he affirmed his claims, saying that the phenomenon wasn’t just loudness normalization provided by Roon software, because it also affects Tidal playback.

How is this possible? I personally think Roon engineers do not want to screw up bit perfect playback, and that his claim is false, or made not using viable approaches. I mean, how on earth can the very same audio file has varying perceived loudness during ‘bit-perfect’ playbacks on the same DAC!

But if it is so (unfortunately), is there some kind of DSPs involving to get the music louder for psychoacoustic purpose?

What output? USB? HDMI? Network?

You are correct in that this is not supposed to happen. Signal Path will show you if the sound is being modified in any way.

He used USB. So he was wrong.


He however stood his ground, saying that the perceived loudness from his audio system with the Nucleus playing Tidal appears to be significantly louder than the same system with Mac mini. He also provided further information regarding the album on Tidal with which the issue is apparent: Keb Mo - Suitcase (he later said it was removed and reuploaded). Maybe some of you here with Nucleus at hand can justify his finding? Let’s hope it’s just bug, or bias.

Often when lowering the “noise” floor by upgrading to better equipment there can be a perception that the music is louder because more true sound is coming through, and is less fatiguing. I’ve noticed it myself with cable upgrades etc. I won’t say it’s louder, but going from Roon Core on a 2013 Mac Pro to ROCK on a dedicated 7i5 NUC with a linear power supply it does sound better’ lusher and bigger. I can turn up the system more now due to less fatigue at higher volumes as the sound is clearer and the background quieter.

In his case he said the volume was so much louder that he had to turn the volume knob 1-2 step down. Anyway I do not think Mac mini and Roon Nucleus (or any competent digital sources) are that different in term of noise floor.

Maybe you could look at it another way - perhaps the Mac was throttling the volume somehow and the Nucleus is right. Two subjects that are not similar do not make a study though. The best would be to compare it to an off the shelf NUC.

Macs hijack the audio, if not configured right.
Or so I understand…

The way CoreAudio works (mixing/resampling) have no effects on perceived loudness.

He later replied that the album in question was removed from Tidal, and that the issue is no longer existent, that is, both Mac mini and Roon Nucleus are now functioning properly.

Some possibilities:

  1. Different versions of the same album on Tidal (Master or different editions)
  2. Lowered noise floor as described by @Charles_Peterson - we’ve heard this effect when doing comparison of audiophile transports sending bit-perfect USB output to the same DAC
  3. Comparison against Tidal app which does volume levelling
  4. (Mis)configuration of Roon DSP, volume related features
  5. (Mis)configuration related to OS Mixer

I believed it could be different masters, as I myself have witnessed this happened before.

Anyway, can you please elaborate more on how the Nucleus is capable of outputting much audibly less noise through USB than other digital sources, say, a Mac mini (Roon-enabled)? Any measurements?

An improved source can result in a perceived louder volume. The reverse is not necessarily true - a louder volume does not logically imply the source is better, and can be caused by many things, for which I provided several possibilities.

Well this guy has made the claim and the burden of proof is on him, so where are his measurements? Anyone can make an unsubstantiated claim on the internet. Before you know it, these things have a life of their own.

What is my claim? That it could be different masters?

I haven’t made any claims, hence no burden on me. FYI Tidal (Thai) once reuploaded Black Sabbath’s early albums with louder ones. What I wanted to know whether the Nucleus is really better on noise performance, since everyone here is saying Nucleus produces less noise. I believe it is their claims that the Nucleus is better when it comes to noise.

And the Thai entrepreneur later said that the loudness issues are no longer there. He also mentioned that Tidal removed his original album from his favorite list and reuploaded it.

Before you jump down my throat, read my post. I said,

Oh sorry. I thought you were questioning my questions. Anyway, you impressed me. I rarely hear ‘burden of proof’ in typical audiophile discussions. Lack of proofs ruin credibility of claims.

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I agree with Charles Peterson re:noise floor as likely part of what is the perceived sound level increase. I just put a Nucleus into my system replacing my MacMini. Even on my lowest quality internet radio station I notice that I need to lower my preamp output. And the first hours I began listening to the Nucleus with Redbook and high res sources, it became exceedingly obvious that the noise floor had dropped among many other pluses. For engineers in the audience, I suppose the only way to “prove” actual SPL output changes would be to measure various Core running hardware in the same system against the Nucleus.

Let me conclude.
Now the entrepreneur said his Nucleus now outputs audio with ‘correct’ loudness.
And now that there’s no proof for Nucleus’s ‘superior’ noise performance, I’d say that it was different Tidal masters that caused the Roon Nucleus to output louder audio.