What makes a speaker too big for a given room?

My speakers have side firing woofers. How does this factor into room placement? Does this have any impact on the rules of speaker placement?

Your wife can tell this immediately because she knows when she doesn't have enough room to breath. She only needs to "listen" to herself to know it not speakers.

So, Rrog, "whether the room will allow the bass to develop properly". I was trying to think along those lines. Should this mean you want your bass produced by smaller drivers? say, 7" drivers? Because typically in larger speakers you're going to get larger drivers for the low end--maybe 10, 12, even 15" drivers (woofers, cones, whatever). In fact, a lot of subwoofers have those larger drivers--10" at least so it seems antithetical to insert a subwoofer into any small room based on that. On the other hand, a small room may not give you enough bass simply for lack of room volume and if you can get enough air movement via the larger driver (subwoofer or no) then it seems that the argument fails. I've got a 11.5' wide by 15.5' long space, open on one side and I'm debating whether I should bring in B&W 803 Diamonds (larger) or the 804 Diamonds (smaller, but still floor standers).

Full range speakers with no adjustment for bass loudness in a small room will not work no matter if the bass drivers are 3-7" or 1-15". The reason subs with monitors are suggested for small rooms is you can independly adjust bass output for the room.

There are some full range speakers that do allow adjustment of the bass level but these are basically just built in subs. My speakers have this feature and it makes them much more flexible.

The farther the individual speakers are apart on the baffle the farther away you need to sit from the speaker for the sound to integrate. You need to sit at least 9 to 12 ft away from most 3 or 4 way speakers for the sound to integrate well. Then you also need space behind the speaker or bass will be boomy among other problems.

Regarding B&W 803 vs 804 the 803's don't really put out that much more bass than the 804's. I used to have 805's with a sub many years ago. I have only heard the 803's at the dealer in a large room. That said I think you could get away with the 803's in your room. Just don't try and stuff 802's or bigger in there. The 803's would benefit from a good sub as well IMO. As far as I know they only go down to mid 30 hz. Unless their specs have gotten better over the years.

The fact that the drivers on the B&W speakers are close together on the baffle should help them integrate better in your room.

Sean

Since it seems that many people are a bit confused about this topic, I hope you guys do not mind if I sum up the good responses posted so far and also add some of my own believes and experience on the discussed topics.

Large speakers in small room problems:

1) Amount of bass. Large speakers (with large drivers) can easily overpower a small rooms by producing too much bass. Since most speakers do not allow one to adjust the amount of bass, tuning the bass output of a speaker for a given room can be extremely difficult (often impossible).

2) Speaker placement. Speaker placement in a room is crucial not only for stereo image and sound stage but also spectra balance. Placing a large speaker into a small room will limit considerably the ability to move the speaker around in order to minimize the speaker-room interaction, e.g. reflection, resonances.

3) Integration of the drivers. Large speakers with many drivers require one to sit farther away from them for perfect integration. Depending on the situation this may be impossible to achieve with large speakers in a small room.

Floor-standers vs. monitors + subwoofer

1) Volume level. Except for very expensive models, most floor-standers need to be cracked up quite a bit in order to get decent bass out of them. Often this is needed also in order to get the midrange to open up. Thus, IMO many floor-standers do not performed well at low volume levels. On the other hand, monitors excel here.

2) Speaker-room interaction. Monitors interact less with a room as they have a) smaller and more rigid cabinet walls, b) it is easier to place them in a room in such a way to minimize reflections, c) do not produce that much bass. Further, having the ability to move the bass source (the subwoofer) around the room is another huge advantage as almost always the speaker position that yields the best midrange integration and spectra balance differs from the position that yields the best bass integration in a room. Furthermore, most modern subwoofers provide additional adjustments, e.g. parametric equalizer, phase, crossover point, etc, that further aids the integration of the speaker system in the room.

3) Quality of low bass. Most decent subwoofer will have much more accurate and healthy bass than most good and very good floor-standers.

4) Mid-bass. Many argue here that most decent floor-standers get this region right while even expensive monitor - subwoofer combinations fail to do so.

Best wishes,
Paul