I'm building some rather unconventional speakers. The bass is a WOP24 9.5" and I am expecting to cross over at around 300hz (it's a DSP setup, so I don't have to decide crossover points in advance, but that's my guess).
The enclosure is unconventional as I said, and it's proving expensive and complicated. I've been slaving over a hot CAD machine for months.
What would make it really, really easy is if the woofer could point upwards instead of forwards.
Is that a clever but unusual solution, or a bit of blind idiocy?
I'd probably better expand. The bass in a 354mm tube, the mid / treble in a 204mm tube. They are a layer of generic sonotube, followed by plastic pipe for rigidity, followed by acoustic insulation, all in a stainless steel pipe.
That much is easy. What is less easy is making a stand that makes interior decorators go "wow" without spending an absolute fortune.
What would be really simple would be making the bass enclosure the stand, by simple sitting it on its backside and pointing it at the ceiling. I could also point it at 45 degrees. It would be easier NOT to do that though.
The stand is being plastic printed, so complex shapes are not an issue. The issue is the difficulty and expense of printing physically large objects. And of course while sthe stand can be made any size or shape what is has to accommodate is fixed in shape and dimension. The bass tube is 540mm long and 354mm in radius, the mid / treble tube 450mm long and 204mm in radius.
The enclosure is unconventional as I said, and it's proving expensive and complicated. I've been slaving over a hot CAD machine for months.
What would make it really, really easy is if the woofer could point upwards instead of forwards.
Is that a clever but unusual solution, or a bit of blind idiocy?
I'd probably better expand. The bass in a 354mm tube, the mid / treble in a 204mm tube. They are a layer of generic sonotube, followed by plastic pipe for rigidity, followed by acoustic insulation, all in a stainless steel pipe.
That much is easy. What is less easy is making a stand that makes interior decorators go "wow" without spending an absolute fortune.
What would be really simple would be making the bass enclosure the stand, by simple sitting it on its backside and pointing it at the ceiling. I could also point it at 45 degrees. It would be easier NOT to do that though.
The stand is being plastic printed, so complex shapes are not an issue. The issue is the difficulty and expense of printing physically large objects. And of course while sthe stand can be made any size or shape what is has to accommodate is fixed in shape and dimension. The bass tube is 540mm long and 354mm in radius, the mid / treble tube 450mm long and 204mm in radius.
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Yes, but I always assumed that was a clever design intended to use the ceiling as a radiator. I don't want to do that, I just want to save plastic 🙂
It wasn't... at low frequencies the driver acts as an omni. Depending on the frequency one calls low, just look at the horizontal and vertical plots of a driver of the size you aim to use. Depending on the driver size, if the wavelengths you ask it to play are larger than the driver size, it will radiate in every direction as if it were an omni.
The only example I had on hand. A 7 cm or 3.5" driver. See how both horizontal and vertical directivity plots show output in every direction below about 800 Hz?
So if it is playing below 800 Hz in this case, it wouldn't make a difference if it's pointed up or horizontal. It would radiate in every direction anyway.
Disclaimer: The plots above show a differing horizontal vs vertical directivity pattern. Horizontal pattern has been determined using Akabak and the used enclosure shape while the vertical shape belongs to a single driver in an array, hence the difference in patterns seen here...
The only example I had on hand. A 7 cm or 3.5" driver. See how both horizontal and vertical directivity plots show output in every direction below about 800 Hz?
So if it is playing below 800 Hz in this case, it wouldn't make a difference if it's pointed up or horizontal. It would radiate in every direction anyway.
Disclaimer: The plots above show a differing horizontal vs vertical directivity pattern. Horizontal pattern has been determined using Akabak and the used enclosure shape while the vertical shape belongs to a single driver in an array, hence the difference in patterns seen here...
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A part of you must know that this acoustic design transcends the crossover. As you work out the details the crossover limits should become apparent. You then know how far to take it.