My girlfriend owns a full packaged mega drive II and I have not really put attention to it. She loves it but for me the games are a little bit limited (as not simple gameplay on one side and bad gfx/audio on the other).

Nevertheless a friend visited me today having a megadrive II with CD extension in his bag. He bought it at ebay but it seems not to work. After a minute problem was found and repaired. But I wondered that the audio output is sooo low. I also tested the console from my girlfriend and the same issue:

All consoles (except the 7800) are on volume 1 of my TV (out of 30). I can't hear anything here. If I increase the volume to about 25 i'm able to hear the sound (not very loud). I use the AV/composite cable. Both console same behavior. Having no other cable but it is 1:1 from console out to TV. Scary for me as I found no information about similar issue or complain of owners (ok my girlfriend doesn't care at all until now).

Is it true the mega drive is sooo worse in audio loudness?