How do you chose speakers based on room size?

Thanks, Halcro. There can be other reasons for the perceived tonal balance to change with level, but I think differing thermal compression characteristics among drivers is usually the main one.

Heykay, even though your 12 by 19 foot room would probably be considered "medium sized", the fact that it's open into another large room means that it's in effect a "large" room as far as the bass region goes. My opinion would be, either go with speakers "voiced" for a large room or consider using a sub with the intention of adding a little bit more energy across the bass region (rather than merely filling in below the main speakers, which is the more common usage for a sub). In many cases an opening into an adjoining room acts as a huge bass trap and can actually be beneficial, provided you can get the bass level up enough to offset the loss of bass energy.

Duke

Duke, That explains alot and makes a good case for a midrange driver that covers as much frequency range as possible.

I forgot to mention that I do have a Rel Studio III and I was using it with Sophia 1s which I just sold and was going to upgrade to the 7s or 8s but was curius about room size and Maxx 2s the height looks like it might be an issue with eight foot ceilings in room. And also on my rear right behind seating there is a long hallway that opens to bedrooms.

Duke ;

Like the others ...your explanation has cleared up a lot of things that I have noticed along the way ! Thank you .

What I was trying to get at concerning the 'guidelines' were things to look for that were specific to the size of room that the speakers are to be used in , not an all in one approach .
What design characteristics would be favorable for speakers in a small room that would not be favorable for speakers that were to be used in a large room and visa/versa ?

Thank you .

"What design characteristics would be favorable for speakers in a small room that would not be favorable for speakers that were to be used in a large room and visa/versa?"

Well this depends somewhat on where the speakers are located within the room but in my opinion in a small room you generally want the bass rolloff to start fairly high but it can be gentle. This should synergize better with the anticipated boundary reinforcement than a speaker that is "flat" down to a fairly low frequency. Conversely, in a big room you need speakers with more bass output, relatively speaking, because the room isn't going to help you out as much.

In any size room I like fairly uniform radiation patterns in the midrange and treble region. In a small room I like a fairly narrow pattern that can be aimed to minimize early sidewall reflections, but there are people who like omnis in small rooms (the reflections from an omni are likely to be spectrally correct, which is desirable). I like to have at least a 7 millisecond delay before the onset of reflections other than the floor or ceiling bounce, and that corresponds to a path length difference of about 7 feet. So something like baby Maggies located 3.5 feet in front of the wall would probably be feasible (I'd prefer 5 feet out, but we're talking about the minimums here).

In a medium or large room where we'll have a good 10 milliseconds or more before the onset of reflections from nearby walls, we can freely use speakers that have a wider pattern (dipoles, bipoles and omnis conceptually fit into this category if they can be placed far enough out into the room)). Such speakers give a greater relative level of reverberant energy in the room and in my opinon more closely approximates the sort of soundfield we experience at a live performance. Now there are competing schools of thought that object to "adding" reverberant energy via wide-pattern speakers, but that's another topic for another day.

So to recap, you usually need a lot of bass output in a big room but not nearly as much in a small room, and (in Duke's opinion anyway) wide-pattern speakers are better suited for medium or large rooms than for small rooms.