How many 90 degree bends has the back wave had to go through to get to that point (rhetorical question)? You would have to determine how much attenuation has occurred to the higher frequencies to say whether or not that outside chamfer in the last two bends will be detrimental in terms of higher frequency output from the "horn".
Besides acting as a brace, that chamfer is there to provide a smoother expansion.
Besides acting as a brace, that chamfer is there to provide a smoother expansion.
Again, one needs to look at the size of a frequency in relation to the horn's shape/area at any given point along its path, so as the WL 'grows' it becomes increasingly important to preserve the expansion rate in the horn's intended gain BW to ensure that there's not enough acoustic impedance mismatch to cause reflections back to the throat strong enough to audibly modulate the driver and of course preferably none as the room's acoustics will [usually] 'chop up' its response enough as it is.
No clue though whether this particular BLH is well designed or not, just know that the few on the WWW I reverse engineered a couple of decades ago were pretty bad by my [vintage] standards, but folks overseas were enjoying them and later here in the USA, so just a FWIW.
GM
No clue though whether this particular BLH is well designed or not, just know that the few on the WWW I reverse engineered a couple of decades ago were pretty bad by my [vintage] standards, but folks overseas were enjoying them and later here in the USA, so just a FWIW.
GM
Different designers typically results in different design choices
Thus it would appear that despite the exceptional work done by Martin J. King and others, there remains an element of "voodoo" in such designs. Which is good because ultimately our ears must be the final arbiters.
Thanks for this. It definitely helps with my very naive understanding of the principles involved.
As for the rounding of interior panel ends, it actual achieves an elegant solution to a woodworking issue, IF one intends to dado the inner panels into the outer panels. The router will leave a semi-circular cut at the end of its path which can be (a) left open - inelegant and ugly (b) filled - ughh (c) squared with a chisel to accept a square cut panel end - extra work or (d) glue half-round to the end of the panel to fill the semi-circular cut - nicest.
I profess no knowledge or understanding of the relative effects of the sharp edge vs. rounded edge on the sound that ultimately emanates from the mouth of the horn, either measured or audible.
No VooDoo, RCA's Harry Olson left nothing of interest to be learned about BLH theory, design in the 1930's, just most folks have never bothered to learn from the pioneers, instead preferring to 're-invent the wheel' to suit their own [marketing] needs, proving nothing more than TL, horn alignments are the most flexible available.
GM
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