I believe it's mainly because they want the box a certain shape (narrow). If the speaker box can be made whatever size the deisgner wants (wide but not aesthetically pleasing) then a lot of trade-offs can be eliminated.
Very low speaker impedance
Hi folks, I would like to know what is the reason that some speaker designs have such a low impedance. For example the lowest impedance of Kinoshita studio monitor speakers is less than 1 ohm (near short)! Why does the manufacturer choose for this kind of ridiculously low impedances? Do speakers with low impedances sound better than speakers with normal (between 4-8 ohm) impedance? Some of those speakers do sound excellent: Apogee Scintilla, Kinoshita studio monitors, the old Thiel CS5i. If the answer to this question is: yes, then most today's speaker manufacturers are compromising the sound of their designs for a more benign impedance behaviour, so the consumers won't be having trouble with their amplifiers. With other words, the choice would be a commercial rather than audiophile one. Are there speaker designers out there who want to give their response?
Chris
Chris