Where the collection of CDs is placed in the room affects the sound, too. Moving the CD collection from one location to another location several feet away can sometimes make all the difference. And paper CD cases sound better than standard plastic jewel cases, which act as resonators. For the entire bunch of CDs that’s a big honking resonator beaming up at you. But it’s much more difficult to explain why the sound is much better when all CDs are stored vertically vice horizontally. But I can certainly understand if you never really thought about it or don’t think it matters.