Volume level on audio CDs too weak

RasPi 3 Model B Rev 1.2 with Volumio 3.179 with HifiBerry Digi+ Pro 2017 connected by WLAN 2,4GHz. Attached to Raspi is a LG DVD Rewriter GH22NS40 by USB 2.0 to SATA adapter. It plays Audio CDs. HiFiBerry S/PDIF output with BNC coax cable to S/PDIF electrical input (AES3id) on DAC.

Using Volumio for web radio (for example www.swissgroove.ch ) volume level attains 0 db at peaks on DAC. Also tracks from Soundcloud.

But for playing audio CDs on Volumio volume level is too weak. Missing approx. 5-8 dB Left and right as per DAC volume meters.

How to get some more dBs on audio CD volume? Is there a Alsamixer somewhere in Volumio for level adjustments alsamixer - Wikipedia ?

Howold are these CD’s? If you play CD’s that were released before the loudness wars, they will sound weak. That is the downside of playing old fashioned high dynamic range CD’s. One just has to turn up the volume.

Modern radio stations and lots of music on Soundcloud is highly compressed and therefore louder. Radio stations are even worse because they tend to compress the music even more on top of the compression that’s already in modern music.

You should try a recent pop/rock CD to check if there really is a problem with CD playback.