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[MilezMetal]

Hi, I was wondering if JRiver's equal-loudness feature implements the latest revision of ISO 226 that was released in 2023?

Details can be found here: https://www.iso.org/standard/83117.html

I'm very interested in using it in conjunction with the WDM driver as it may well be the solution I've been looking for.

Thanks

[Awesome Donkey]

Pretty sure it uses the R128 algorithm for the Volume Leveling feature, which can be used with Peak Level Normalization. I don't believe it's been changed or altered in probably 5+ years.

[mattkhan]

Loudness is implemented as iso226:2003

https://yabb.jriver.com/interact/index.php/topic,76608.0.html

What's the difference in the 2023 version?

[MilezMetal]

Pretty sure it uses the R128 algorithm for the Volume Leveling feature, which can be used with Peak Level Normalization. I don't believe it's been changed or altered in probably 5+ years.

As far as I am aware, the R128 algorithm is used to determine playback level whereas ISO 226 is an EQ that adjusts based on the SPL during playback to accomodate how we perceive different frequencies at different volume levels (i.e. increasing bass more than treble as the playback volume is lowered).

The original topic from when the feature was released notes that it approximates the 2003 revision of the standard and I was wondering if it had been updated to accurately reflect the 2023 revision.

The original topic can be found here:
https://yabb.jriver.com/interact/index.php?topic=76608.0

[mattkhan]

Tbf the difference seems pretty minor though I guess that might make it fairly easy to update

https://www.researchgate.net/publication/374956941_Revision_of_ISO_226_Normal_Equal-Loudness-Level_Contours_from_2003_to_2023_edition_the_background_and_results

The differences from the 2003 edition are only 0.6 dB at most, and the 2023 standard can be regarded as the same as the 2003 edition in terms of practical use.

[MilezMetal]

Loudness is implemented as iso226:2003

https://yabb.jriver.com/interact/index.php/topic,76608.0.html

What's the difference in the 2023 version?

I may have misunderstood but the original topic mentions that it approximates the 2003 revision rather than implementing it exactly.

Without access to the published document we can't see all the changes, but after some reading online it appears there are at least three:

The threshold of hearing at 20 Hz was lowered by 0.4 dB to reflect updates in ISO 389-7:2019.

The power exponent relating loudness perception to physical intensity, as formulated in a 2004 academic paper, was implemented.

Mathematical expressions were adopted to preserve the appropriate number of significant digits.

[mattkhan]

Yes it seems to be some small tweaks across the range, likely perceptible but "within ±0.3 dB for loudness levels over 10 phon" is not going to be a material change, probably perceptible on a decent well calibrated system but not sure you would know without A/B'ing it