Which HQP Filter are you using? [2023]

[jussi_laako (Jussi Laako (Signalyst))]

@MistaLovaLova

Does controlling volume via HQPlayer affect dynamic range in any way? I usually keep it as low as -20dBFS because of my class A amplifier being run in bypass mode (bypasses internal volume control chip - big difference).

No, the digital noise floor is far far below analog noise floor. Analog noise floor is in any case limited by physics (thermal noise). Modern issue is gain mismatch, where you end up having back and forth attenuation / gain with additional analog stages, which causes increased distortion and dynamic range degradation. Cutting some of that out helps improving output fidelity.

Output levels between -10 dB and -20 dB usually give best performance figures from DACs. So if you can get gain matching around -20 dB that is a very good result.

@MistaLovaLova

My strategy has been to leave my amp in medium gain (at low gain it attenuates the incoming signal more, thus decreasing its dynamic range, as I believe it to be the case) and then volume-control via HQPlayer and my DAC - with the emphasis on the former, however I need a hardware safety net to protect my ears if something goes wrong, hence I would not consider using software alone. If anything, I’d maybe look at a better amp.

Yes, it is good idea to have safety margin. In best case the maximum would be limited by actual DAC output plus amplifier gain. But there are other ways.

But preferably the “DAC volume” is not digital volume inside the DAC…

@MistaLovaLova

I’m wondering how much volume attenuation can be applied in HQPlayer before we even start approaching the area where a 16-bit song’s dynamic range might suffer. I’d think that it’s likely much higher than the -20dB I’ve been using.

Good starting point figure is that it would need over 96 dB of attenuation, so the amount of dynamic range 16-bit has to begin with.