Tony L
Administrator
Larger multi-way loudspeaker systems need space for best driver integration. Sit too close and the contribution of individual drivers becomes obvious and coherence can suffer. Not something you can fix with EQ or room treatment. Even concentric drivers don't get away from this effect completely.
I've been thinking about this a bit of late and I'm far from sure I agree. If you think about it most 3-ways have the treble and mid driver no further apart than in a typical 2 way, e.g. compare something like a NS1000, Ditton 44 or AR3a to say a LS3/5A, small ProAc, Sonus Faber or whatever and there is little difference between the centres of the mid and tweeter of the 3-way and the bass-mid and tweeter of the 2-way. The distance between the bass and mid of the 3 way is a lot less critical as the wavelength is obviously a lot longer down there, and it just has to be better than anything you'd ever achieve crossing a small 2-way to a external sub. Another area the 3-way wins outright is the crossover between the mid and tweeter can be higher and therefore further from the most critical human voice zone than the 2 way as the dedicated mid driver does not need to flap about handling bass.
FWIW I actually think the NS1000 / Ditton 44 / AR3a style sealed 12" bass three-way is the least compromised format of moving-coil loudspeaker developed so far. It is certainly the area I'd be working on were I a speaker designer. I also think it's one of the nicest looking too as that form-factor just looks 'right'. Whilst I've heard / owned speakers that are far larger and far smaller I suspect this is the hot-spot both logically and practically.