Quality basics: please improve digital volume control

[planetti]

Dear WiiM-Team,

can you improve the quality of the digital volume control implementation? (Do you use e.g 64bit/dithering algorithms?)

The current algorithm seems to be detrimental to sound quality, apart from the numerical bit-reduction. This general improvement would be a gain for all WiiM devices and in the future.

Some users will not recognise, but many (current) users ask for 1:1 bit-perfect, which means that they are not satisfied with the current implementation. This user group may appreciate the WiiM technical quality level.

Perhaps it is possible to add a ISO226 adapted volume level correction at the same time.

Thank you for your efforts!

 

[Brantome]

How does this “detrimental” control manifest itself?

 

[planetti]

I have the subjective impression that the soundstage presentation is "reduced", the sound is "flatter", the instruments are more "diffuse" and a bit "constricted" - when the digital volume in the WiiM app is reduced while volume level is compensated, spdif coaxial out, on headphone and speakers.

 

[hash70]

Dear WiiM-Team,

can you improve the quality of the digital volume control implementation? (Do you use e.g 64bit/dithering algorithms?)

The current algorithm seems to be detrimental to sound quality, apart from the numerical bit-reduction. This general improvement would be a gain for all WiiM devices and in the future.

Some users will not recognise, but many (current) users ask for 1:1 bit-perfect, which means that they are not satisfied with the current implementation. This user group may appreciate the WiiM technical quality level.

Perhaps it is possible to add a ISO226 adapted volume level correction at the same time.

Thank you for your efforts!

Is it not bit perfect?

 

[planetti]

If you do not tick "fixed volume" on 100% and if you use any EQ, the signal is processed and cannot be bit perfect any more.

 

[Brantome]

Is it not bit perfect?

I personally don’t get too hung up on this - to me, bit perfect means that the unit doesn’t make any unwanted changes to the stream, which the WiiM devices don’t. If you want to make changes such as applying PEQ and a volume limit to guard against digital clipping that might occur as a result of applying that PEQ, then you’re making changes to enhance your listening experience.

 

[planetti]

I personally don’t get too hung up on this - to me, bit perfect means that the unit doesn’t make any unwanted changes to the stream, which the WiiM devices don’t. If you want to make changes such as applying PEQ and a volume limit to guard against digital clipping that might occur as a result of applying that PEQ, then you’re making changes to enhance your listening experience.

Every digital processing has an influence on the digital signal, since the information is not the same as the original. Of course, there are algorithms (e.g. sophisticated tricks, filterings, interpolations etc.) which keep the distortion to a minimum or shift to inaudible regions. Depending on the quality of the algorithms and your auditive sensitivity, such processing is detrimental to the original sound.

At low level the digital volume unfortunately looses more than the theoretical dynamics with my actual Wiim devices. With some other gears the effect is not so apparent.

Brantome, perhaps your setup luckily operates with a proper gain design. But in case a setup is running at low digital levels, this effect gets more relevant.

 

[WiiM Support]

Dear WiiM-Team,

can you improve the quality of the digital volume control implementation? (Do you use e.g 64bit/dithering algorithms?)

The current algorithm seems to be detrimental to sound quality, apart from the numerical bit-reduction. This general improvement would be a gain for all WiiM devices and in the future.

Some users will not recognise, but many (current) users ask for 1:1 bit-perfect, which means that they are not satisfied with the current implementation. This user group may appreciate the WiiM technical quality level.

Perhaps it is possible to add a ISO226 adapted volume level correction at the same time.

Thank you for your efforts!

Hi planetti,

Thank you for your suggestion regarding digital volume control. Our volume table is 8-bit, and considering the maximum bit-depth is 24-bit, we employ 32-bit processing for volume control to avoid any loss in precision.

Additionally, we offer a preset EQ mode called 'loudness,' designed to enhance the lows and highs following the ISO226 standards, which might be beneficial at low volumes.

If I've misunderstood your comments, please let me know.