Custom Low shelf filter

[rd01]

Hi, newly created account.
I set this filter in the left channel of my headphones

Filter: ON LSC Fc 82.12Hz Gain -16.52dB Q 0.9024

Can I increase the filter gain as the system volume increases?
I need this because as the volume increases the bass difference in the channels tends to disappears

[Juha]

You need to know the system volume level before you can control the filter parameter by it. If you find registry info for lets say volume slider position of the default playback device (Windows may keep that info somewhere) then you could try get that info to EqualizerAPO by using registry related expression commands (and if you find that info, you could calculate an expression to modify the Gain value for your LSC -filter).

[rd01]

Exactly, where i can found all registry related expression commands ?

[rd01]

i'm trying finding windows registry key

[rd01]

I found

reg query HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\MMDevices\Audio\Render\{43952444-1aac-40e4-9ebf-85a20cade6f9}\Properties /v {9855c4cd-df8c-449c-a181-8191b68bd06c},0

where {43952444-1aac-40e4-9ebf-85a20cade6f9} is my soundcard endpoint and {9855c4cd-df8c-449c-a181-8191b68bd06c},0 supposed volume proprierty, but is a REG_BINARY value, how can use this in apo ?

[Juha]

Hmm... EqualizerAPO supports only string type (readRegString) and integer type (readRegDWORD) so, ... . Also, it's possible that this value is not constantly updated but only on certain situations as like when shutting down the Windows.

An alternative would be separate utility which writes the playback level (or volume slider position value (hmm, there are software volume sliders and master volume slider)) to file you have the LSC filter defined (included in config.txt). I did instruct someone to do something like this few years ago but as I'm on Linux now I can't help in building the utility. Here's the post. Note! On same thread, there's also AutoHotkey Sript by Brad Ling you could try (dunno what all it needs to be modified to get the script work for your usage.

You need to calculate the dB parameter value for LSC filter using

On WinVolInfo.txt

Eval: defaultdB = -16.52
Eval: WinMainVol = 30 
Eval: WinMainVoldB = -18.300640 
Eval: WinMainVolf = 0.300000 

Eval: LSCGain = make your calculations here

Filter: ON LSC Fc 82.12 Hz Gain `LSCGain`dB Q 10.0

Edit: Attached the project files and binaries (exe -files) for this utility. Copy .exe to equalizerapo config folder so the include file does not need path.

In config.txt:

Include: WinVolInfo.txt