To all DIY speaker freaks. Spacially align any 3 way speakers so the voice coils are all equidistant.Draw an equilateral triangle,each point will the centre of a driver.Using a compass,draw 2 circles at each point 1 outer dia and 1 inner.The size of the triangle will be determined by driver dia.The woofer frame will touch the midrange frame (usually larger) whilst the tweeter will be slightly seperated.See the final diagram as a 3 spoked wheel and position it on the baffle allowing your intuition to determine witch way you would like to rotate the 3 drivers before cutting the holes. Time align the coils if you have the patience.This is a wonderful method that came through divine inspiration to recreate What Lowther and Tannoy are doing. The system also allows you to use First Order networks. The final sound is so close to perfection becaust the science behind it is by it`s very nature,quite perfect. Cheers Leo.
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It always works when you lack measuring equipment... I prefer calling it intuition.
No, because the tweeter does not work like that. It depends on the frequency and distance to the other driver for phase, etc., so it usually is closer too and not in a distance dictated by the basket diameter of the woofer.I think that also using three -or more- speakers of the same type- in whatever manner they might heavenly cooperate - would be simpler in achieving the right results..
Right
So instead of three speakers in a vertical line, they are in a triangle pattern?
This will result in comb filtering over crossover regions in both horizontal and vertical planes rather than only in horizontal plane with standard vertical alignment. Especially with 1st order XO and it's 4 octave crossover region, not to mention phase error.
I would guess the sweet spot would be vanishingly small.
But try it, you never know how it'll sound til you try.
This will result in comb filtering over crossover regions in both horizontal and vertical planes rather than only in horizontal plane with standard vertical alignment. Especially with 1st order XO and it's 4 octave crossover region, not to mention phase error.
I would guess the sweet spot would be vanishingly small.
But try it, you never know how it'll sound til you try.
Answer
Draw an equaliteral triangle 6" all3 sides. On 1 point scribe A3" radius circle. This is a 6" woofer. Next point scribe a 2" r circle. this is the mid. On the third point scribe a 1.75" r cercle. this is the tweeter. The size of the triangle will depend on the drivers diameter.Coils will all be equidistant. Cheers Leo
Unforetunatlly, the center of the voice coil is not the acoustic center of the driver. The only way I have found to reliably find the acoustic center offset is with a gizmo like my old AA pulser. It sends out a single half pulse at the center of the crossover. Looking at the output on a scope, you can measure the offset, or slide the drivers back and forth until you find the actual offset. You must use the target crossover, as you need to compensate for phase at the crossover frequency as well.
You say that the size of the triangle, presumably the equilateral triangle with side equal to 6", will depend on the "drivers diameter". You can't mean the diameter of all of the drivers, as each driver in your example has a different diameter. Do you mean the diameter of the woofer?
In building the speaker system, the equilateral triangle is drawn on the face of the baffle board is that correct?
At best this scheme can maybe maximize the extent to which the three acoustic outputs are in phase at any frequency and at any point in space.
Some constructive criticism: Sloppy typing doesn't make a good impression. Certainly you are not the only one posting at diyaudio not showing minimal care in communicating ideas here.
Regards,
Pete
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