Hi,
a little premise: I beg ur pardon in advance in case I'm talking of something obvious or already covered in the past.
Also, keep in mind that, funnily enough, I discovered this strange problem of low audio quality only recently, cos I almost never used MorphOS to play music and sounds (I do all my music/sound works on my Win based DAW which is a different story).

Well, to me it looks like AHI has some issues, because to my trained enough ear, sound quality is not 16 bit. By listening attentely to sounds (no matter which player u use, I tried many, including Ambient sound, Sox, DAPlayer...) I can clearly hear a very annoying background digital noise, which becomes more obvious when a sound is low volume or is decaying. Such a noise almost reminds me of... a resolution of 8 bits only, or, ok, perhaps 10, but not 16.
I can say that this problem affects to the same extent both the audio of my PegII and that of my "new" Mac, so it's not a matter of hardware.
Of course I must use headphones to notice it clearly, obviously.
And I checked in AHI prefs, the audio modes are always the defaults (Stereo HIFI ++)
To check the matter better, I generated a simple fading sine waveform (16 bit 44100 WAV) to be used for the tests.
But the audio format does not matter. That noise is always noticeable, no matter the source file is WAV or AIFF or any other uncompressed format. Of course I'm always talking of 44100 Hz * 16 bit samples, not less.

To be 100% sure, I even tried to listen to the same sample on an old PC (onboard audio, no audio card), and by using the simple Windows voice recorder tool (to be sure no software effects or filters or other strange things were applied), and even by using it as a system sound (to be even more sure). Well, on the PC the same sample always sounds perfect without any digital background noise noticeable, not even minimal !

So my question: is this a known problem with AHI ? Or, rather, on the PC there're some hardware filters activated ?

How many channels you have for the AHI unit you're using? Audio quality will reduce the more you have them. Using music unit or just one channel gives you the best quality, but no simultaneous sounds.

Here's a little note about it too: http://library.morph.zone/Tips_and_Tricks#Keeping_AHI_Audio_Quality_Better

WOW Thanks JPV, I reduced the nr of channels to just 2 and the noise is gone now :) :)
Frankly the #of channels is something I always overlooked, and I always thought that could at most imply more calculations and only in the event all the channels set were actually used !
LOL one should always read everything before asking stupid questions but that's materially impossible :D

Thx