@mijostyn --
... Image size has nothing to do with volume but, a big image at high volume is very impressive when distortion is low. Unfortunately, the distortion of all speakers increases logarithmically with volume. Getting low distortion at high volumes is not easy.
Image size and density(!) has everything to do with volume and coverage pattern, in addition of course to acoustics and overall implementation. Such a main speaker - certainly one that combines large air radiation area with high sensitivity and prodigious power handling - will maintain (for a speaker) low distortion at high volumes, in a domestic environment not least. Somewhat easier to achieve with dynamic drivers than planar speakers and electrostatic dittos, btw.
Wide dispersion can make a speaker sound bigger and louder but at the expense of detail and focus.
Controlled or constant directivity offered by horns doesn’t strike me as leading to lack of detail and focus, even with a large sweet spot. If anything I find it sounds rather natural.
The best use of subwoofers is to lower distortion in the main speakers particularly at volume when large cone excursions put the suspension in a non linear position in it’s range and a lot of doppler distortion is produced. That fact that most subwoofer users do not take advantage of this by using a high pass filter on the main speakers boggles the mind.
Agreed, and using actively configured speakers makes the choice of high-passing the mains the more natural decision. However, if you had ample, effective cone area to begin with, in addition to high sensitivity, cone movement would be the lesser issue - even less so when high-passing such main speakers.
Do they [i.e.: subs] make a system sound larger? I suppose if you equate low bass with size. I don’t as the image size stays the same whether or not my subwoofers are on and I use four of them.
There’s a lot of spatial information - and in effect: image size - that can be retrieved from low frequencies, classical music material in particular. Spaciousness to some, bass-iousness to others ;) Preferably this requires of subs (that is: more than one, and preferably two, four or six) to be placed symmetrically to the mains and hooked up in stereo. The stereo coupling, for it to have effect, would need to be done with a cross-over no lower than 70-ish Hz, from where (on up) high-passing will have the most advantage in relieving the mains anyway.
Sounding big and going loud are two separate issues.
Sure, but that’s not to say the two can’t go hand in hand.
This single most important characteristic determining image size is the speakers pattern of radiation, point vs line source. Other characteristics are relatively minor.
Optimal coverage pattern as a determining factor of image size isn’t exclusive to a line source. You’re trying to monopolize a line source as the sole game player here - hardly the big picture, if you would.
Any speaker can go loud with enough power. The problem is doing it without distortion.
That’s the beauty of high sensitivity; the wattages available - not least by-passing a passive cross-over when actively configured - being all the more effectively used. More power produces more heat, no way around it, and there’s only so much of it that can be dissipated before thermal issues will arise. So, any lower sensitivity speaker can’t simply "go loud [enough]," for named reason.
Line source dipoles have a beautifully detailed image because they limit room interaction by limiting dispersion.
Indeed, among other reasons as well.
Horns can do the same thing for people who prefer the smaller image of a point source.
My pro cinema horn hybrid speakers can fill a medium sized auditorium (a large auditorium with bigger horns on top) rather effortlessly. You think they sound small-ish?