What Volume do you listen at?

My guess is that when you have High End gear, you naturally want to play the music at a higher volume.

I've found this to be untrue, especially with fully acoustic music. If the system has good resolution, dynamics and a low noise level, the urge to crank it up actually decreases in my experience.

However, if you are into head-banging rock at live concert levels, maybe you have a point. I don't enjoy the jet-engine sound level of many live rock concerts so I certainly have no urge to recreate that in my home.

However, if you are currently listening at 75 or 80 dB it sounds like you're in my league. I doubt that you'll be turning things up with a new system. Hopefully you'll just be enjoying it more.

The basement is the way to go, assuming you can AC/Heat it and that that equipment can be isolated so as not to provide a nasty 'noise' floor. That being said, what you are looking for is 'live' music levels of volume. Everything else becomes just background music, and Bose can take care of that without spending $30K. When I built my last house I created in the basement a custom designed listening/media room. High WAF, live music/movie listening levels that could not be heard outside the room, no comprise with speaker placement. You can tweak forever. Looking at your picture I see the 'wife' every where, it will never work, especially with all the glass. Believe me, living rooms are like 'dressy' dresses, and you know who rules there. A small tip if you are going to the basement, put a two inch exterior, heavily striped door at the main floor entrance door to the basement. Also use these type of door every where a door is needed in the basement space. Look into Armstrong Wave ceilings and put heavy carpet on the floors and achieve a 'dead' room, then all you hear are the speakers without any room colorations. So, spend $10K on the room, and $20K on the equipment. You will never regret it.

Grand Piano = 110 db SPL, Drum Set = 115 db SPL...if you like live music or have ever played any instruments then you will know that music is loud because instruments are intended to be heard by others.

Furthermore your ear can handle from 120 db SPL to 0 db SPL (of course 120 db should be transients and never continuous) . Therefore if you want to benefit from the dynamic range inherent in real live music on your playback then you need a system capable of playing around 105 db spl continuous (with 10 db headroom) at your listening position. If this is 3 meters back then you need about 115 db SPL continuous (125 if you include peaks) from the speaker itself.

This will allow you to play any music at realistic levels. Of course you will rarely (if ever) listen to much above 95 db SPL continuous, however, transients can easily go much higher and it is the dynamic contrast which is partially what makes music lively and exciting. Rock concerts are at 105 db SPL and with a good stage system and can actually sound extremely good.

Depending on where you live the noise floor will usually be somewhere around 30 db SPL.

If you play music at 80 db SPL then 80 less 30 is 50 db spl and you have limited the dynamic range of what you hear to 50 db SPL. This is probably ok for rock or pop or small ensemble music but will almost certainly limit you in classical music with full orchestra where you get huge dynamic range in the music.

Greater dynamic range will allow you to hear more detail in the music. Natural uncompressed music rarely sounds loud or fatiguing. Stereos mainly sound loud because of distortion. The perception of "loud" is linked to distortion. Music at 80 db SPL with distortion will sound louder than music at 95 db SPL with no distortion.

At $30 K you may be able to find something that can play with close to the full range dynamics of real live music without much distortion. Likely you will want to keep turning it up if there is no distortion.

I listen at all levels, depending on music / mood / situation. That's one of the things I like most about having a nice system - it serves so many purposes while sounding great.

The "proper" volume level can be determined by focusing on one sound source in the music that is familiar to you. I use a violin, or sometimes a human voice. I know how loud a volin can play, and how loud a person can sing. It is easy to crank up the volume of the total music program to the point where the violin, for example, is impossibly loud. When you do this it's like puting a a beautiful object under a microscope: all the defects become evident.

Sometimes the mastering of the recording is a problem. For example, in a violin concerto the soloist is sometimes recorded so loudly that the orchestra cannot be brought up to an exciting volume without making the soloist too loud. However, in a multichannel system, where the soloist is in the center channel he can be toned down by reducing gain in that channel relative to the other channels. I often need to do that.