Does It have to be loud?

I listen at 50 to 60dB measured at listening chair.

When I play Nirvana, I can listen to it at 50-60 db outside my building.

It is great advantage if you only need 70 dB. It greatly reduces the cost of a system. Unfortunately it only leaves you with 80dB peaks less 30dB noise floor = 50 dB dynamic range but it does offer an advantage in that almost any system will do a pretty good job at these modest levels including Bose speakers. No need for market leading 120dB THD+N performance as it won’t be audible anyway.

Nice reference -elizabeth.
I want it louder, more power.
Happy Listening!

Well duh! The big difference between ho hum run of the mill Bose waveguides and a great high end system is exactly what they are trying to demo - clarity and great low distortion full range sound at realistic dynamic live music levels.

Big face palm! I would not expect a sports car demo only in downtown rush hour bumper to bumper traffic.

Tastes in music listening vary as widely as tastes in food and drink, or anything else imaginable. After five decades of listening to more live music(every genre/studio/auditorium/outdoor/two or three times a week/two to four hours a pop) than home audio systems, suspension of disbelief only happens with realistic SPLs(whether loud, as in Pink Floyd/Heart, or soft, as in Classical/Flamenco guitar). Many equipment manufacturers voice(and demo) their equipment with realism in mind. That’s probably why loud/dynamic pieces, are chosen by some to demo. To convey that their gear can deliver, when called upon. Nothing wrong with requesting a softer audition, if that’s your preference, and- YES: just like some live music venues, room overload happens and lower SPLs work better, in such instances. The only thing that gets in the way of my extended enjoyment, of music played at realistic levels, is distortion. If a system can’t convince me(loud AND soft/micro and macrodynamics), without distortion(or damaging itself), I’m not impressed.

if i blow tuba it'll be loud so if i hit drum.

That’s funny! You totally misunderstood my post. I’m impressed.

For me it’s all about Dynamic Range, not loudness per se...

Well, that me be your (Geoff) preference, but there certainly is more to it than dynamic range. For example, one could choose to listen to Tchaikovsky's 1812 Overture or Ravel's Bolero, each of which have reasonably high dynamic range. If you then choose to "top out" the max decibel level of that dynamic range at say 80db, you've done an injustice (IMO) to the great work of those composers. So again, volume/loudness *does* matter.  

Geoff, you should be impressed. Looks like I know about and have listened to more music than only Grateful Dead :)

For me it’s all about Dynamic Range, not loudness per se which usually means having to turn up the volume more for recordings with high dynamic range. And loud recordings don’t necessary have good/high dynamic range, in fact that usually means they don’t.

Depends on the type and specific song of music you’re listening to. IMO, each song has a particular decibel range that makes it sound "right". For example, listening to certain Led Zeppelin songs will be more enjoyable, IMO, in the 90 - 100 db range as opposed to 70 - 90. So in answer to the thread title, no, it doesn’t have to be loud; but often times it should be.

^ and destroy voicecoils.

Yes, lower is better for extended listening! Levels over 90 db peak can become tiring!