I found a pair of these multicell 805s in 1976 and immediately realized why they were so affordable. They were nasty sounding. I eventually located a pair of JBL horns and lenses, 2397 if I recall, to replace them. It was a different world of sound, even working well indoors for a high level rehearsal system. The full size JBL lens had superb pattern control.
Very interesting, I wonder if trimming back the dividers in the mouth of the horn just a little bit would help merge the exciting signal so that there was less combing effect.
I always wondered how these measured, thanks 😀 The distortion figures are quite good at the typical SPL levels we normally use in home audio. I wonder how much it was at the typical SPL levels of a concert? Id imagine adiabatic effects start to dominate at some point due to how narrow the throat is compared to the end of the horn. My brother used to use some Altec horns (maybe those from the A7's or something similar) with 2x15" PA drivers back in the day. I don't remember it being a very nice listening experience, just exceptionally loud. Be interesting to actually hear them in a properly configured setup.
Thank you! Always wondered about the interference behavior of multicell horns, and there it is :) Not too bad for such a classic design, and a surprisingly wide disperion angle @ 10k. Now I wonder again, what could be possible in 3D print age, with much smaller, rounded clusters and a more homogenius coupling to the throat.
It would still be very difficult to improve. Every element of this design has been carefully considered for the application. My attempts resulted in slightly worse comb filtering but less horn coloration.
I found a pair of these multicell 805s in 1976 and immediately realized why they were so affordable. They were nasty sounding. I eventually located a pair of JBL horns and lenses, 2397 if I recall, to replace them. It was a different world of sound, even working well indoors for a high level rehearsal system. The full size JBL lens had superb pattern control.
Thanks for sharing. 🙂
This is interesting, thanks!
Glad you liked it!
Very interesting, I wonder if trimming back the dividers in the mouth of the horn just a little bit would help merge the exciting signal so that there was less combing effect.
Perhaps. The loss of treble on-axis to the cell is likely due to edge diffraction off the cell mouth.
@@JosephCrowesDIYSpeakerBuilding Maybe you could 3D print a replica hand grind with a dremel some changes . Just for fun
I always wondered how these measured, thanks 😀 The distortion figures are quite good at the typical SPL levels we normally use in home audio. I wonder how much it was at the typical SPL levels of a concert? Id imagine adiabatic effects start to dominate at some point due to how narrow the throat is compared to the end of the horn. My brother used to use some Altec horns (maybe those from the A7's or something similar) with 2x15" PA drivers back in the day. I don't remember it being a very nice listening experience, just exceptionally loud. Be interesting to actually hear them in a properly configured setup.
Set up properly they can be quite impressive in terms of scale and dynamics. This horn is what I benchmark for those attributes.
Thank you! Always wondered about the interference behavior of multicell horns, and there it is :)
Not too bad for such a classic design, and a surprisingly wide disperion angle @ 10k.
Now I wonder again, what could be possible in 3D print age, with much smaller, rounded clusters and a more homogenius coupling to the throat.
It would still be very difficult to improve. Every element of this design has been carefully considered for the application. My attempts resulted in slightly worse comb filtering but less horn coloration.
Love the content.
Thank you
Glad you enjoy it!
Very informative.thanks.
Glad it was helpful!
Slightly OT question, Joseph.. Is there a Field-Coil compression driver that quite impressed you (despite of cost?)
The Lamar M2 Field Coil was very beautiful sounding.
BMS 5530ND please test this driver would really be happy to hear your opinion
That looks like an excellent driver on paper. If someone wants to send to me for test I would be happy to do so.
How does your multicell horn design compare in the offaxis polar/directivity map? I don't like that combing effect...
Which multicell are you referring to?
@@JosephCrowesDIYSpeakerBuilding your 15 cell horn.