yeah most modern desktop towers now days are low power enough to be quiet enough for most bedrooms, the smaller form factors tend to have higher speed fans that can really crank up under load (think gaming consoles) but overall they are consuming a fraction of the energy they once were and thus wasting much less energy as waste heat.. they also have better temp monitoring and fan controlling than they ever have.
the only reason to go silent anymore is for like recording studios or people whom are just very hypersensitive to the stuff.. Ive got a full rack cabinet packed full of networking, A/V equipment and several servers and the loudest gear are the datacenter quality PoE midspans.. and because high frequency noise is so poor a penetrating modern building materials none of it is audible outside the room when the solid core door is closed.. and were talking ~1000W of gear at average that has arrays of fans running constantly.. but all oversized and intelligently controlled so its almost always spinning things at low speed.. only when everything starts back up at once can anything be heard in the house.. then its usually dead silent due to an outage.
I guess my point is, its often cheaper just to put cheap off the shelf gear in an appropriate location where true silence is not a requirement.. then dont worry about it.. Silence is rarely nessicary, its often a gimmick sold like Monster Cables.. quiet is good enough.. I shoved an obnoxious PS3 and PS4 combo in my living room into a wooden cabinet (in same spot) with large temp controlled fans and now its more than quiet enough as the simple wooden cabinet doors do more than I'd expected.. they have superior airflow than before and the external fans are silent, so they rarely kick to high speed and when they do its basically inaudible.
