Hello Chaps,
I plan on building a classic style stack of speakers and wanted to have a dedicated top section which house two BMS 4594, I want to take full advantage of a narrow vertical coverage with increased SPL of stacking the two drivers to line array style waveguides as depicted here. http://copyright.lenardaudio.com/laidesign/images/a07/a07_evlens.jpg
so with two stacked vertically I was trying to find out how I can take advantage of the midrange freq of the driver with a horn flare exit after the waveguide.
Are there any horn design principles at hand that go in tandem with the path correction from the waveguide itself, I was hoping to get a good load from 4-500hz.
My guess is that with creating a larger format horn that I would need to be careful of how the horn exit affects the HF creating a narrower beam along the horizontal axis and balancing that with trying to load the line source lower. Do I also need to take into account the path length of the waveguide itself as I am presuming that has some inherent loading with the small line lengths that create the matrices of path correction OR do I treat the line exit to be a completely new source and design the horn how I like. That then poses the question does any horn curve function have any advantage at this point, tractrix etc.. or just go straight conical with a flare. As for the vertical I would just place a smaller flare within the range of the vertical dispersion. Attached is a very rough exacerbated version of what I mean.
Sorry for the "wordiness" its been difficult to find much information on horn flares from line source exits for coaxial comps.
Thanks!
I plan on building a classic style stack of speakers and wanted to have a dedicated top section which house two BMS 4594, I want to take full advantage of a narrow vertical coverage with increased SPL of stacking the two drivers to line array style waveguides as depicted here. http://copyright.lenardaudio.com/laidesign/images/a07/a07_evlens.jpg
so with two stacked vertically I was trying to find out how I can take advantage of the midrange freq of the driver with a horn flare exit after the waveguide.
Are there any horn design principles at hand that go in tandem with the path correction from the waveguide itself, I was hoping to get a good load from 4-500hz.
My guess is that with creating a larger format horn that I would need to be careful of how the horn exit affects the HF creating a narrower beam along the horizontal axis and balancing that with trying to load the line source lower. Do I also need to take into account the path length of the waveguide itself as I am presuming that has some inherent loading with the small line lengths that create the matrices of path correction OR do I treat the line exit to be a completely new source and design the horn how I like. That then poses the question does any horn curve function have any advantage at this point, tractrix etc.. or just go straight conical with a flare. As for the vertical I would just place a smaller flare within the range of the vertical dispersion. Attached is a very rough exacerbated version of what I mean.
Sorry for the "wordiness" its been difficult to find much information on horn flares from line source exits for coaxial comps.
Thanks!
Attachments
Yes, 90 degree horizontal coverage but as mentioned that could be influenced by the midrange loading.
That's the point. Is the loading necessary? Sometimes going after one precludes the other. Is this for domestic use?
I am just exploring line source options to take advantage of narrow vertical coverage with a coaxial driver.. it's necessary to bring out the best in the driver itself otherwise I would have just stuck with a normal compression driver. This will be for PA use as the driver can play well from 500 Hz Up. Is an additional larger flare even needed?
It is if the wavefronts haven't formed properly at all the frequencies you expect of it. Then they'd go wide out of the adapter and some would resonate back through it.
So you want your guide to establish the waves, and then once at the right size you gently terminate the mouth by rounding it back.
Now, if you can do that and get some loading at the same time then OK. Have you considered playing with hornresp?
So you want your guide to establish the waves, and then once at the right size you gently terminate the mouth by rounding it back.
Now, if you can do that and get some loading at the same time then OK. Have you considered playing with hornresp?
I had a similar question. My thinking on this at the moment is that idealy the line array waveguide is transforming the plane wave from the circular aperture of the compression driver to a rectangular plane wave in the shape of the waveguide. As in a phase plug there will also be an associated area expansion rule through the line array waveguide, this will set the low frequency cut-off and also influence high frequency distortion characteristics. However for the purposes of simulation I think you can just consider the waveguide as a plane wave in the shape of its mouth. In terms of the horn then you would design a conical horn with mouth flare with the included angle of the horizontal setting the horizontal dispersion. However for the vertical (in the ideal case) the wavefront is plane and not curved as such it will start to exhibit 'beaming' at quite a low frequency and so any vertical wall angle will have limited effect on the vertical dispersion. Danley have made devices that curve the wavefront correctly for the vertical expansion such that the vertical directivity is also constant rather than narrowing with increasing frequency (see Jerico line).