What KaiS said.

The RME implementation of "Loudness" needs no correction.  It is a MOST Useful functionality, and I wouldn't be without it.

In general, I am glad that this function is there, I have not seen anything like it in other sound interfaces. Along with the automatic output level, there are all the conditions for connecting to a direct power amplifier. But I want a more accurate implementation. , In my opinion, it is now implemented primitively.
Note: machine translation is used

You can adjust the amount of loudness correction in bass and treble separately.

Interesting, thanks! I expected to see something similar in this ADI2Pro.

Not at all. We added an improved version of the 'HiFi - simple analog electronics' standard, which works subjectively very nice when changing the volume level. We never said that we added one or the other exact standard.

I wasn't aware that Acourate can do that - impressive! But the decription is unclear, so you may be able to tell me how it works exactly:

- change the (EQ) curve respective to the currently chosen playback gain (fixed mode similar to the ADI's way of working)

- change the (EQ) curve respective to playback signal (the actual sample level in the respective frequency area). This would be the absolute real deal, as it takes the volumes of everything within the playback signal into account and processes it according to what its acoustic output level would require. Obviously this then equals a full FX processor that might make the music dynamically sound different than anything heard before, and therefore disliked (opens up the usual can of worms - yes, it is fully compensating the ear's loudness effect, but does not represent what the sound engineers heard when they mixed and mastered the playback...).

That said we think about a longer time to add such an FX ourself - make the Loudness not only work according to the VOL setting, but also the actual signal level. But then again the resources in the ADI are limited, and it would still use the existing, simple Bass/Treble scheme to do its work. We'll see.

An example of the implementation of this function in LM1036.
As done in ADI-2 Pro (measurements in the first message), it is not at all similar.
https://yadi.sk/i/0hVOSar92zdyrw

I can not see something on that page, and I won't discuss this further, sorry.

Hi

it works off a referencelevel. This referencelevel can be set manually at a certain volume level (volume knob)
The refence level means no correction is made. If the volume is lower than the reference level then the correction is made according to IS226 2003. If the volume knob is higher, than the corrections will made also according the difference to ISO226 2003.

Now how to get the reference level.

1) I use JRiver EBU R128 to level all files psychoacoustically to the same  level.
Then I play a cal-File (white noise) and calibrate the referenclevel of acourateconvolver to 85dB SPL.
So Volume knob 0dB= 85dB SPL (in acourateconvolver).

This assumes tha the mastering was made with 85dB SPL. This may be the case (for movies , SMTP standard says this), For music it may not be correct. Mastering engineers often ignore any standard!

No problem.
Acourateconvolver has an adjustment to adjust the reference level while playing +-10dB. Means the reference level can be adjusted if we go with above example from 75dB SPL to 95 dB SPL (reference level 85dB).

Okay acourateconvolver is a convolution engine capable of standard 65'000 taps (FIR filter) or more, depending on the power of the computer, sampling rate , number of channels.

Anyway.

The trick is to set a reference level on the volume knob. The user has to level all music with EBU R128 to the same level.
Calculate the EQ curve relative to this reference level observing ISO226 2003. This may be also possible with IIR filters.

So the EQ is just set to the differenc of refence levle and actual volume (voluem knob). Thsi should be pretty easy to do.

audiovero: Uli Brüggemann, the owner may have more info how it is implemented.

I just can say it works great (with my RME UFX II ).

Peter

Check if loudness setting is correct:
Changing volume settings must not change perceived tonality, only volume.
so bass and highs stay same!

Peter

ISO226 2003 is an average of many psychioacoustic tests. So its the best we can generally assume.

If you want personal measurements, this is possible but I do not know any mastering engineer who does that.
In AV receivers I have not seen any reference to standards. What are the psychoacoustic rules you mention in AV receiver? Its somehow vodoo in there looks like.

Room acoustics does not play any role in this and loudness correction is not for room correction. It just compensates the nonlinear frequency response versus SPL.

At least ISO226 2003 works fine for me.

Peter

This is not true.
Unless you overdrive them speakers measure the same at any level.

What is very nonlinear is the ear not the speakers.
Loudness is exactly to correct the perceived loudness of your ear, not the speakers.

Studio monitor level calibration to the 85 dBSPL standard is full of obstacles.

Most get lost in the selection of the test signal, reference level and measurement method.

ALL “how to” advices I found in the internet err one way or the other.

If you do it right you end up with a level that is too loud for every day music listening (or music production).

Why? The standard is simply not made for working on contemporary music, but for cinema film work, where the soundtrack has much more dynamic.

One has to determine his personal “sweet spot” normal listening level, set up a perfect sound for this level, and then use the Loudness Function based on this.

They probably do, I don't know. The only studio I know that handles movie sound, is Galaxy. And they have a sort-of loudness compensation.

But...

That's not the kind of loudness compensation we're talking about here, as it is closely calibrated to the speakers and the room. Doesn't look like it's possible to implement in an audio interface, as you don't know the output chain and the room.

In broadcast, people often have to work outside of a studio, so calibration is often simply not practical.

Oh, BTW, I was hit by the security questions of the forum software again. This time, I only had to answer four questions before my post was accepted...

Yes, that is also my observation.

Anyway seems mixing is mostly done louder than the listening level at home. So there kicks in the need for loudness compensation.
And, yes, where the reference level is must be guessed. A rather strange thing nowadays with all the digital tools. It is never written on the label nor somewhere on the digitalmedia, may be not even known to the mastering engineer as he sets his comfortable level (whatever that is).

I listen at my comfortable level and sometimes at a level which is about real level (to my guess). On acoustic intruments this is possible, a trumpet, a violin, clarinett, piano, voice this works.
For synthetic, electronic music no clue.

So the Loundess function is usefull and would be easier to work with if the reference level would be known.

This is a principal problem, not a problem of a specific implementation of the Loundess function.

I'm following along in this quite interesting discussion, and believe the Pschelbert's observations/usage closely mirror those of myself  Thus it would seem to me that without a Level Normalized input, and perhaps an actual SPL measurement at the Ref Level...we are asking RME to engineer some form of Other-Worldy Magic that can Laser-Focus upon a wildly moving target much to the Amazement,and Satisfaction of all. 

Here in the Real World,

I quite like the existing Dynamic Loudness functionality, and feel it has worked well for for me over a considerable period of time. Used wisely, it is a genuine asset to our enjoyment.    Now then of course, I would never ignore an improved method of calibration!   I'll continue to follow along. 

Thanks to all for the thought-provoking discussion!

Best to All,

Curt

*Further thought:   I enjoy Dynamic Loudness for it's real purpose. ie: Maintaining a relatively uniform Tonal Quality while Vol is reduced, and my focus lies elsewhere.  I do NOT have the Volume at Mouse Levels for close listening!   My Vol. is Up, and Dynamic Loudness is nowhere to be found.

At the Dinner Table?  Vol. IS turned down, but that's hardly Critical Listening time!  Just gimme the Potatoes dammit!      Dynamic Loudness could be Auto-Tuning Dusty Springfield's voice, and I may not notice. 

Just One User's Opinion...

There‘s a simple explanation, in line with what I told above:
At 20 Hz almost every speaker exceeds it‘s excursion limit at 10 W input power if not mounted in a totally sealed cabinet.

PA Systems use a multitude of speaker, filtered and excursion controlled to avoid the problem.

Instrument speakers, made for guitar amps, have extremely short voicecoils to achieve sensitivities of 105 dB/W and more.
So with those the overload effect is even more prominent.
For the purpose they are made this doesn‘t matter, distortion is part of their job.

I don‘t think this all matters for a lot of people here:
Loudness Function is for listening low level, where you don‘t have overload.

Plus - if a system overloads at normal (not excessive) listening level one should do something about that.
Most speakers are already quite loud (for home use) at 1 W, without overload.

@KaiS

The measurements were done with the speaker mounted in an infinite baffle, in an anechoic chamber, avoiding any form of overload. I also wasn't looking at the extremes of the frequency curve, but roughly between 400 and 8.000 Hz.

Sorry Fellas, but how did Speaker Design enter into this discussion?

RME doesn't produce speakers, so let's dispense with the un-related chatter, or move to a new thread.

Ja?

Curt

Maybe it will be useful
Curves of equal loudness relative to the level of 90dB SPL, ISO-226 2003
https://yadi.sk/i/qrS3gbZIP39DhA

You can do about 85. But little will change there, the direction is clear.

Hey All!

I think the preceding is GOOD information!   I've long Championed the Value of Dynamic Loudness, but realize that my subjective "Loud Point" will not be the same as others.

Using the 85db SPL reference is a fine way of getting every user calibrated to the same standard, and this IS the RME Methodology!   

This same 85db standard would also be applicable to the perennial question of "do I need attenuators?"

I see MUCH good here, and would surely encourage the group to follow suit.

Enjoy everyone!

Curt

@MC:  Perhaps this information might be added to the User Manual at some time?  I believe it to be very helpful.