Have some Radian Neo745PB CD's + Ciare PR614 Horns to use in a 2-way build.

[weltersys]

Another display of my gross ignorance: When horns are put in flat baffles is it always for the same reason that woofers (particularly for open baffle speakers) are, to at least prevent much of the waveform of the lower frequencies from being reflected off the wall behind them and cancelling? At the risk of asking-as I am hardly a math wiz-how is the size of that baffle calculated to effectively minimize that range of lower frequency cancellation?

Perry Marshall just answered your question regarding woofer dipole baffle size at the bottom of this post:

Post in thread 'Bitches Brew Build Thread - Perry Marshall's Live Edge Dipoles'

2025-03-08 12:39 pm

am I correct in thinking that the main compromise with that approach is forfeiting the phase correction and phase benefits of FIR filtering in the upper range EQ (top 2 octaves?)? But Dirac should take care of that anyway? Any other issues or complications to know about if using the SHD instead of Flex?

Yes, Dirac should take care of that anyway. I'm not aware of any other issues or complications with using the SHD. You can use the MiniDSP Device Console and load in the settings to the Flex Eight module, then hand copy the filter settings into the SHD. Not difficult.

In...

• perrymarshall

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Regarding monopole woofers and high frequency horns designed for mounting on flat baffles their dimensions often are simply related to "what fits", and the vertical height if the cabinet is designed to be a floor standing unit.

And how does application of this use of horn and/or woofer baffling differ from what NicoB is pursuing here?

A flat baffle could be considered a 180 degree horn down to around the wavelength of it's width or height.
Sound travels ~1130 feet per second, so will start to diffract around (behind) a one foot diameter baffle at 1130Hz.
Increase the baffle to two foot diameter (61 centimeters), 1130/2=565Hz.
At higher frequencies, the horn's polar pattern is unaffected by the baffle dimensions.
The "wrap around" is also known as the "baffle step" response, where the pattern transitions from "half space" to "omni".

The "X" shape horn throat is designed to turn what may be a "t" shaped polar pattern into a rectangular pattern.

Art

 

[AllenB]

When horns are put in flat baffles is it always for the same reason that woofers (particularly for open baffle speakers) are, to at least prevent much of the waveform of the lower frequencies from being reflected off the wall behind them and cancelling?

Not necessarily. Some are just meant to end flat so extending this makes sense. On the other hand you don't want to put a baffle near a tractrix like horn. They give full bass support and let sound go behind them at the same time as I was saying earlier.