Timn8ter said:Well, that's one down. How about having one speaker above and one below the picture? I think I tried that once but it's been a while. I think the WAF factor was about zero which is why I abandoned it rather quicky.
Hello Timn8ter,
Not having the Wife Factor you speak about, (mine always wants more, bigger, higher fidelity), I built horizontal center channel speakers for above and below the monitor over 10 years ago. They are driven by an old Lexicon CP-3. Monitor is 36" wide, center channel speakers fill that space above and below. Bottom center channel is at your ear level, top center speaker is aimed downward to your ear level. Use a piece of string. Self built cabinet for monitor/speakers was designed around this idea.
According to all the experts, this is heresy. Granted I'm not an electronics engineer or an acoustics engineer. The single vertical center channel I started with just did not sound right to my ears.
The sound stage for the center channel is about 12 feet wide in my little room and stays locked on the screen no matter where you sit.
Volume control on the Leach amp that drives them allows me to tinker with the final output.
I'm a happy camper.
Prosit
When I was experimenting with bessels I played with the 5 and 7 unit arrays, but mostly the 7 because the middle space was 0 power and perfect for a tweeter. I dropped it because an array pair had zero imaging, just a wall of sound from between the speakers. I don't recall any big difference in SQ related to distance, but I didn't really do any nearfield critical listening.
The wiring posted earlier was just from memory. I was about 6 months ago and the link I had doesn't work any more. I'm certain there was 1 ea of the -2 and -1, but I'm not certain if the -1 was on the end or the driver next to the end.
The bessel "effect" is related to dispersion outside of the plane of the array and it does work even in the very near field.
The old link I had was to a copy of a page from Don & Carolyn Davis's book "Sound System Engineering" which included wiring configurations for a number of different bessel arrays, so if anyone has this book, please post a copy of that page.
The wiring posted earlier was just from memory. I was about 6 months ago and the link I had doesn't work any more. I'm certain there was 1 ea of the -2 and -1, but I'm not certain if the -1 was on the end or the driver next to the end.
The bessel "effect" is related to dispersion outside of the plane of the array and it does work even in the very near field.
The old link I had was to a copy of a page from Don & Carolyn Davis's book "Sound System Engineering" which included wiring configurations for a number of different bessel arrays, so if anyone has this book, please post a copy of that page.
Thats interesting... I have read in several places from fairly well respected people that the Bessell array only sounds like a point source from a great distance away. The only quote I could find offhand is from the LDSG:
However I have seen Jim Griffin and others mention this as well. I hope you're right, as it would be ideal for my application.
morbo said:
My testing was pretty crude. I was using vertical arrays and even at distances less than 1 meter the dispersion was totally different than with a normal array. With a normal array, the line of the plane is very clear and once above it the SPL reduction is very very significant. With the bessel, this clear line doesn't exist. I think this may be another case where the theory conflicts with the real world in small rooms and short arrays, because I find that issues of lobing, near field/far field transition, etc aren't very significant for in-home arrays.
Another alternative would be a normally wire array but on a convex baffle to give you good horizontal dispersion. That way you would also get the full sensitivity increase of multiple drivers. You may want to look at JBL's papers for J and Spiral arrays.
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