I am building a center channel channel for our living room Home Theater. I had several drivers already I decided to use, 10 3” FR drivers and a Morel 1” dome. I decided to add the 1” dome above 10k as it has pretty smooth off axis response and the FRs get a little ragged that high.
I plan on wiring each set of 5 in a Bessel alignment to keep horizontal beaming to a minimum.
My question is horizontal spacing. I have no limit up to 60”, but I was wondering if anyone had an ideal of optimum spacing with them being in a Bessel, I really don’t know where the acoustic centers will be and how they will sum. I really do not feel building test baffles and measuring and was hoping someone on here would have a tip.
Thank you!
I plan on wiring each set of 5 in a Bessel alignment to keep horizontal beaming to a minimum.
My question is horizontal spacing. I have no limit up to 60”, but I was wondering if anyone had an ideal of optimum spacing with them being in a Bessel, I really don’t know where the acoustic centers will be and how they will sum. I really do not feel building test baffles and measuring and was hoping someone on here would have a tip.
Thank you!
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That was kind of the plan and I think was going to be the best option! Tweeter is only taking over above 10k where the FRs start to get a lot of ripple off axis.
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Deleted member 375592
It is purely an esthetic issue. It needs to be flat and no more than 3 1/2” high. I had thought about that as well. If depth wasn’t an issue and I could hide the shape then that would be a great option I think.
Linear for a Bessel…..the fwd lobes of opposing phase need to be quadratic in order to sum properly.
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Deleted member 375592
I tried to run my old beamforming scripts. If I have not screwed up anything...
... which may not be what you want...
... which may not be what you want...
Where do you guys find this stuff? “Forward lobes of opposing phase need to be quadratic” …
I think a concave shape might be better with the lobes, but op is concerned with delay?
I think a concave shape might be better with the lobes, but op is concerned with delay?
No, not what I want, and I really appreciate your model! That is why I was trying to go with 2 separate 5 driver Bessel arrays. I was hoping this would prevent that type of focused output but I wasn’t sure how the 2 arrays would combine, that was the intent of this post. My hopes were that since both 5 driver arrays would not behave like symmetric line array I could have much better horizontal dispersion.
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Deleted member 375592
Shading is done several ways usually by using resistors or connecting speakers in series and parallel. This way the speakers in the center of the array are louder than the outside speakers. For example with a five speaker array you have one speaker connected at 8ohms, the other four are connected in series and parallel at 8 ohms for a system at 4 ohms. The first speaker gets 1/2 the power and the other four get the other 1/2. There may be better ways to shade your array, this is just an example. The outside 8 drivers will have the same frequency response as the center two but they will be less loud, this focuses the perception towards the center two speakers and allows much higher power handling.
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Deleted member 375592
Even if he weights the array as per the Hamming window (1:0.8:0.5:0.2:0.1), the main beam width will be only 2 times wider.
I'd get 10 small boxes from a dollar store and experiment with them "live". It is way too easy to make a mistake :-(
I'd get 10 small boxes from a dollar store and experiment with them "live". It is way too easy to make a mistake :-(
Arrays are only practical when run with DSP imho. Wouldn’t it be easier to add a passive lowpass to the outside drivers and only use the two (or one) fullrange(s) adjacent to the tweeter up to the crossover to the tweeter? So that you essentially build a 2,5 system?
And @markbakk
Ahhh, not sure you guys caught my original post, these are being wired in a Bessel arrangement.
Where the one speaker is out of phase? That would explain the five drivers. 🧐 That would be a Bessel array, I guess. I think people though you were putting in a Bessel crossover.
OK, now that we know what you are up to, I agree with @mayhem13 keep everything close together. There is no reason why you can’t build a larger box to fit the width of the mantle. Just for esthetic purposes, but still keep the drivers close in the middle.
OK, now that we know what you are up to, I agree with @mayhem13 keep everything close together. There is no reason why you can’t build a larger box to fit the width of the mantle. Just for esthetic purposes, but still keep the drivers close in the middle.
That is what I was thinking. And keeping the large width will increase cabinet volume and allow a little more extension on the bottom end as well I think.
Also, I think I will add a defeatable high pass filter @150Hz for the 2 out of phase drivers, beaming shouldn't be as bad that low and it should just act like a Nestorovic alignment, I don't want to lose a ton of output in the 100-200Hz range as there is a pretty hefty handover to the subwoofer. It will be easy and on a toggle switch, so if it doesn't work, I can leave it bypassed...