Has anyone on this forum designed or built a bessel array? If so, how did you wire the drivers? How did you design the crossovers? I've found info on what a bessel array is, but haven't found details on how to buid one. As an experiment, I was thinking of making a 5x5 arrangement of tweeters. Any thoughts or advice? Thanks.
I've experimented with them, using the info in 'Sound System Engineering'/Don & Carolyn Davis. Since there's no efficiency gain and you must be fairly far away for them to 'jell', they are of extremely limited use IMO.
The 'expanded stereo' variant can make for a nifty horizontal stereo TV speaker array, or in mono layout, a wider 'sweet spot' HT CC with the same tonal balance than the L-R mains if 'fullrange' drivers are used.
GM
The 'expanded stereo' variant can make for a nifty horizontal stereo TV speaker array, or in mono layout, a wider 'sweet spot' HT CC with the same tonal balance than the L-R mains if 'fullrange' drivers are used.
GM
Feds27 is right on with using a bessel array for a center channel. I played with the 7 driver amplitude bessel alignment. The center driver gets a 0 factor so that's where the tweeter went. I didn't like that imaging was nil in a stereo arrangement, just a big wall of sound between the speakers. It did work as far as dispersion and eliminating the line array effect.
My link that showed the wiring config doesn't work any more. Maybe Feds27 could post it for us. I'd like to give it another shot as a center channel.
Going from memory it was +1,+2,-2,0,+2,+2,-1 for the 7 unit array and +1,-2,+2,+2,-1 for the 5 unit array. The "-" amplitudes are accomplished by wiring the driver out of phase. I wired the 2's in parallel and the 1's in series to allocate the power accordingly. I think the 5x5 is 1st row the same as the first column, so the minuses run diagonal.
1st row +1-2+2+2-1
2nd row -2+2+2-1+1
3rd row +2+2-1+1-2
4th row +2-1+1-2+2
5th row -1+1-2+2+2
My link that showed the wiring config doesn't work any more. Maybe Feds27 could post it for us. I'd like to give it another shot as a center channel.
Going from memory it was +1,+2,-2,0,+2,+2,-1 for the 7 unit array and +1,-2,+2,+2,-1 for the 5 unit array. The "-" amplitudes are accomplished by wiring the driver out of phase. I wired the 2's in parallel and the 1's in series to allocate the power accordingly. I think the 5x5 is 1st row the same as the first column, so the minuses run diagonal.
1st row +1-2+2+2-1
2nd row -2+2+2-1+1
3rd row +2+2-1+1-2
4th row +2-1+1-2+2
5th row -1+1-2+2+2
Thanks
John,
Thanks for your reply. I'm tempted to try it out with some cheap $5 McIntosh tweeters that are available at the following link. I'm curious as to how this might sound as a center channel.
Regards,
Fed
$5 McIntosh Tweets
John,
Thanks for your reply. I'm tempted to try it out with some cheap $5 McIntosh tweeters that are available at the following link. I'm curious as to how this might sound as a center channel.
Regards,
Fed
$5 McIntosh Tweets
In my post above, I made a mistake. The 5 driver bessel has no -1, otherwise it is correct, but just one of the 2 pwer factor drivers is wired out of phase.
Sorry, I haven't touched a bessel since I found the lack of imaging. ScottG mentioned one time that he has used a 5 driver bessel with tweeters with success.
Sorry, I haven't touched a bessel since I found the lack of imaging. ScottG mentioned one time that he has used a 5 driver bessel with tweeters with success.
Hello!!
Can somebody help me, please! I write the article about Bessel Arrays, so I wonder where were the weighting factors taken? So how can we get them? From Bessel function? Can somebody explain please!
And why n=1 is always taken, why, for example, not n=2, 3,....
Thank you for your answers!
Can somebody help me, please! I write the article about Bessel Arrays, so I wonder where were the weighting factors taken? So how can we get them? From Bessel function? Can somebody explain please!
And why n=1 is always taken, why, for example, not n=2, 3,....
Thank you for your answers!
From the Philips paper it appears that n=1 is the easiest to implement.
Attached the Philips paper, the patent is here:
Patent US20060018490 - Bessel array - Google Patents
Attached the Philips paper, the patent is here:
Patent US20060018490 - Bessel array - Google Patents
Hi,
You will probably find answers here:
http://www.xlrtechs.com/dbkeele.com/PDF/Keele (1990-10 AES Published) - Bessel Arrays.pdf
b
Thank your for your answers!
I've seen all this papers and patents! But they didn't answer my questions!
I found the directional characteristics of 5, 7 and 9 elements for n=1 and for n=2 and 3. And for n=3 the directional characteristics are better than for n=1. And now I wonder how were all the weighting factors taken? I'm interested in acoustics or maths way. In all these papers they just say that's better. But why so??
I've seen all this papers and patents! But they didn't answer my questions!
I found the directional characteristics of 5, 7 and 9 elements for n=1 and for n=2 and 3. And for n=3 the directional characteristics are better than for n=1. And now I wonder how were all the weighting factors taken? I'm interested in acoustics or maths way. In all these papers they just say that's better. But why so??
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