WHat about four speakers.......


When you are in a concert hall, sound hits you from all sides. Why arent there high end systems with four speakers; the listener would pretty much sit in the center, you get a box to delay the rear speakers ever so slightly to imitate those sound waves taking longer to reach your ears. What are the ups and downs of a second set of speakers behind you, even without any sort of delay? A few of you guys must have tried this, thanks......
mythtrip

Showing 1 response by sean

Mythtrip, it sounds as if you and Dr Amar G. Bose have visited the same concert halls : )

Honestly though, his published theory as to how he came up with the design for the original Bose 901's is very similar to some of what you stated above. The main problem with his design is that it uses multiple drivers and suffers from severe comb filtering. In effect, the design creates almost as many problems as it tries to address.

As Duke stated, omni's are capable of producing a very expansive soundstage but are also more susceptible to reinforcement / cancellation from room boundaries. If you can get a good pair of omni's properly set up, the soundstage is pretty amazing. I have a pair of point source ( one driver per cabinet ) omni's and they produce a soundstage that literally "wraps around you" and "engulfs" you on some discs. I have never heard any other speakers ever do this. To be honest though, the electronics in this specific system also play a key part in this as these speakers have not always produced this effect. This is true even though i have not altered their position over the course of many, many component / cable changes.

Dipole's aka "planar's", "stat's", "ribbon's", etc... are capable of doing this, but not to the same extent ( at least in my experience ). They do tend to sound far more open and less "congested" than what most "boxes" are capable of as a general rule. The problem with a dipolar design is that the rear wave is out of phase with the front wave, creating an instant problem with cancellation. In comparison, the specific omni's that i have radiate in a 360* pattern while keeping the signal in phase. So that you have a better idea of what i'm talking about, here's a picture of what they look like. The specs as published are VERY incorrect though, so take them with a grain of salt. The only thing that the manufacturer got right is that you need AT LEAST 100 wpc to drive these. I have two pairs of these with one looking like the picture and the other having a slightly different design.

All i can add to the above is that once you experience a system that has a very expansive ( wide, deep and tall ) sound stage, you will find it hard to listen to "boxes". They will, for lack of a better term, sound very "boxy". Obviously, some designs are better at "disappearing" than others, but much of that will also be up to the electronics that they are connected to. Sean
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