Should i use volume limiter, line out level vrms or pre-gain?

[Dangogh]

I saw a thread says that 2vrms is better for wiim pro plus, so should i adjust in the volume limiter or pre gain? Also how does the limiter and pre gain affect the quality?

 

[hgo58]

I saw a thread says that 2vrms is better for wiim pro plus, so should i adjust in the volume limiter or pre gain? Also how does the limiter and pre gain affect the quality?

This depends on what input and output you use.

The voltage settings is for the analog output only (after DAC).

The pre-gains are digital and before EQ.

Volume limitation is a upper digital volume level.

If any of those are set too high, it may cause distortion. Else they don't cause any sound quality issues.

 

[harkpabst]

I saw a thread says that 2vrms is better for wiim pro plus ...

And while some have asked if a higher output voltage was always better I can't remember anybody giving a positive answer. Even if someone said so, I disagree.

The (max.) output voltage should match the input sensitivity of the power amplifier or active speaker. If it's too high you risk distortion overdriving the input. If it's too low you cannot make use of the full power and risk additional noise.

 

[Erebus]

match the input sensitivity of the power amplifier

Interesting. I have my WiiM Pro Plus set to 2Vrms and it seems to work fine. Best I can tell from the specs of the Fosi amp is that input sensitivity is 280mV. Do I have my settings wrong?

 

[hgo58]

Interesting. I have my WiiM Pro Plus set to 2Vrms and it seems to work fine. Best I can tell from the specs of the Fosi amp is that input sensitivity is 280mV. Do I have my settings wrong?

As long as you play on low volume it doesn't matter.

It is however best to align the output voltage to the amplifier and then turn up the volume settings on the WiiM. A high volume (60-80) makes a better dynamic range.

 

[Erebus]

best to align the output voltage to the amplifier

So what would that be for 280mV?

 

[hgo58]

So what would that be for 280mV?

I would try 200 mVrms. If you think it's to low then 500 mVrms.

 

[Nanook]

As long as you play on low volume it doesn't matter.

It is however best to align the output voltage to the amplifier and then turn up the volume settings on the WiiM. A high volume (60-80) makes a better dynamic range.

"A high volume (60-80) makes a better dynamic range."
I don't think that this holds true. I have not seen components in the WiM Pro Plus analog output stage that would switch the gain of this stage (please correct me if I'm wrong). Thus this "output voltage setting" will very likely use the digital volume control in the DAC chip and will reduce the dynamic range of the DAC.
When I find the time, i will measure the S/N for different "output level" settings.

The WiiM volume control spans 50dB only. When vol=100% yields 110dB SPL, the 1% volume setting will still result in 60dB SPL - too much for background listening.

The "volume limit" setting seems to be a Pre-gain upstream in the digital domain, just like the normal volume control and it applies to all outputs.

Analog Output:
When using the analog output of the WiiM, using the "output level setting" allows to get the output level at vol=100% down. The limiter in the digital path will make sure this level is not exceeded.
-> Compare traces 5 and 7 in https://forum.wiimhome.com/threads/does-using-eq-degrade-sound-quality-in-wiim-pro.6534/post-149606

In case you have heavy boost EQs in equalizer, these will get limited to the output level you have set. I would thus not recommend this if you just want to "shift" the volume control range to lower listening levels as the limiter may step in when you approach vol=100% (trace 5).
I would rather use the "volume limit" setting (trace 7) that yields the same volume without engaging the limiter.

Digital Output:
When using the digital output, the "volume limit" setting is a very nice feature. This basically is a Pre-gain for the EQ (to make sure the limiter does not engage at volume near 100% when boost settings in the EQ are used).
I do use it to reduce the output level when listening at low SPL (see example above).
The "volume limit" acts in the digital path and covers all outputs, analog as well as digital.
For details see: https://forum.wiimhome.com/threads/does-using-eq-degrade-sound-quality-in-wiim-pro.6534/post-149817

In case you use a volume control downstream (external DAC or integrated amplifier) I would set the "volume limit" (=pre-gain) to almost the same attenuation as the largest boost in the EQ. This will make sure the limiter does not engage and will provide some headroom for ISPs in case you're close to vol=100%

 

[Nanook]

Spectrum_1kHz_0dBFS_vs_Vout-setting:
Toslink input level: 0dBFS
Output level scales as expected. 8dB down for line output level 800mV compared to 2V and 20dB down for 200mV compared to 2V
Noise floor remains unchanged.

Spectrum_1kHz_-60dBFS_APU60dB_vs_Vout-setting:
Toslink input level: -60dBFS
APU @ 60dB gain instead of Scaler @ 7dB gain.

Spectrum_1kHz_0dBFS_different-settings:
Toslink input level: 0dBFS
No matter in which way I achieve ca. 20dB lower output signal, the noise floor does not change.

--> All of these three "knobs" ("volume limit", "volume" and "line output voltage") adjust the volume in the digital domain. The impact on the remaining dynamic range is the same.
This is not a problem. Under real world listening conditions you can easily spend 40dB of the ca. 120dB dynamic range for volume control.