Time to practically try some corner case concepts. The sphere for minimal diffraction. A cavity as a backward exponential horn to minimise "box" sound. It will not be full-range but I thought this was best placed here anyways.
I got a mould for the horn from a fellow DIYer who owns a lathe. The sphere form is an inflatable ball for training - 65cm. I have used appr. 3 layers of gypsum-pads to form the shapes. The stand is from a previous projekt and made out of concrete blocks intended for gardening etc and joined together with "concrete-glue".
Driver will be a Faital Pro 3fe22 but I also have a SS 10f/ that i might want to try if this turns out to be promising. The truncated sphere will only be an impedance transformer / baffle and not a cavity for the driver. SB 13....- COAX is on the radar also... The sphere and the horn will only be softly connected to each other - probably separate stands.
I will reuse my corner-lines for bass - hope to x-over to the Globes at 300Hz, maybe 2.
Sphere is in the back drying :-D
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I got a mould for the horn from a fellow DIYer who owns a lathe. The sphere form is an inflatable ball for training - 65cm. I have used appr. 3 layers of gypsum-pads to form the shapes. The stand is from a previous projekt and made out of concrete blocks intended for gardening etc and joined together with "concrete-glue".
Driver will be a Faital Pro 3fe22 but I also have a SS 10f/ that i might want to try if this turns out to be promising. The truncated sphere will only be an impedance transformer / baffle and not a cavity for the driver. SB 13....- COAX is on the radar also... The sphere and the horn will only be softly connected to each other - probably separate stands.
I will reuse my corner-lines for bass - hope to x-over to the Globes at 300Hz, maybe 2.
Sphere is in the back drying :-D
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Broke the molds + did a baffle. Quick test play seems promising (as they always tend to do 😉 )
Next is to mount all on the stand...
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Next is to mount all on the stand...
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Its playing and very nice so. Its just laid in a chair so a bit iffy. Again, could not wait to hear one... 🙂 Now the task to mount them on the stand. Very dynamic and detached sound - love it 🙂 It is especially nice to hear cymbals being reproduced coherently.
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Not really. I don't think it matters soundvise and the astetics is ok for me - for the time being 😉. On to the stands...
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I have to admit that they take more air than I had anticipated 🙂
WAF is probably on low side - if one don't happen to be lucky :-D
Still, I kind of like the look of them - maybe it will change when I get two in the room.
Fortunately they really make a difference.
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WAF is probably on low side - if one don't happen to be lucky :-D
Still, I kind of like the look of them - maybe it will change when I get two in the room.
Fortunately they really make a difference.
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Thankfully my partner is very forgiving with my hobby!
2-300hz is pretty high to crossover with the subs so far away?
2-300hz is pretty high to crossover with the subs so far away?
Congrats!
Ideally one would like to delay the globes, yes.
I will try just passive 1st order and some EQ to begin with.
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Ideally one would like to delay the globes, yes.
I will try just passive 1st order and some EQ to begin with.
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Playing 2 horns on stands but only one has a globe - promising. Molded a fundament to one of the horns - this seem to have made a considerable impact - marvellous detachment of the generated sound from the driver and all of a sudden much cleaner. Very nice. Gypsum seem to be a very nice material both sound-wise (non resonant but still hard) and easy to work with with a freedom of shape.
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Both channels complete, just the permanent fastening mechanism for the globe hanger remains. EQing and general adjustment going on. These play really interesting. I'm very satisfied with the outcome so far. Gypsum has been a joy to work with, both as pads and moulding/gluing duties. It also remains to widen the gap between the drivers and the globe a bit more so that som really soft stuffing can be inserted to seal the gap - I don't what any stiff contact so that vibrations can transfer in any direction...
LR 4th, 400 Hz
Contemplating Harsch XO ...
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LR 4th, 400 Hz
Contemplating Harsch XO ...
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Are there any idea/calculations behind exact globe size?
BLANDA MATT Serving bowl, bamboo, Height: 5" Diameter: 11" - IKEA
BLANDA MATT Serving bowl, bamboo, Height: 5" Diameter: 11" - IKEA
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Well, the size sets the lower frequency limit for where the "baffle" is giving support. The relation is that the radie supports down to half the reproduced wavelength. I don't know how abrupt the none-support kicks in - probably 6 dB/oct, maybe 12.
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