Volume level seems low in Microsoft Virtual Audio Driver (MSVAD) sample

Question

Hi,

I am using Microsoft Virtual Audio Driver (MSVAD) sample on a Windows10 laptop.

Ref: https://github.com/HSpear/virtual-audio-wire/tree/master/Microsoft%20Virtual%20Audio%20Device%20Driver%20Sample

I configured this driver to expose virtual mic and speaker devices having 16bit 48KHz configuration. I set this virtual speaker device as default on my laptop and play some audio-video content. As this is a virtual device and work as null renderer, so I am capturing this speaker sound using IAudioCaptureClient (in loopback) and play it on other actual audio device.
Now the issue I am observing is that the volume level of this speaker is very low. 100% volume level of this speaker is far low than 100% volume level of any other speaker on system. So,

1. is it a limitation of this device being virtual or is it due to any configuration issue of driver?
2. Is there anything we can do in driver sample to fix the issue?

Though there is an amplitude value which is to be multiplied to the raw audio data in order to increase/decrease volume level, but as I am capturing sound from this speaker, so I think this amplitude factor is not going to hele me here.

Please suggest how it can be handled.

Thanks.