Thanks Freddy!
For right now, it accidentally ended up as Mr. Bates suggested - the woofer cabs are so tall that the full range drivers fire over your head if you're relaxing on the couch, so the listening area is off axis (below the HF laser beam).
Which means I'd also have to divert the sound downward somewhat, disperse it in the vertical plane as well as horizontal, or just tip the full range cabs forward so that they aim down towards the listener.
Did I mention these things will go loud? I wanted "11" and I got it, and then some... Nice to have the headroom and have the occasional loud jam session when the kiddos aren't around.
For right now, it accidentally ended up as Mr. Bates suggested - the woofer cabs are so tall that the full range drivers fire over your head if you're relaxing on the couch, so the listening area is off axis (below the HF laser beam).
Which means I'd also have to divert the sound downward somewhat, disperse it in the vertical plane as well as horizontal, or just tip the full range cabs forward so that they aim down towards the listener.
Did I mention these things will go loud? I wanted "11" and I got it, and then some... Nice to have the headroom and have the occasional loud jam session when the kiddos aren't around.
those 12 make good noise and will play bass drops in my Karlsonator (how much upper bass peaking = ?? as did not measure it and cabinet was away from walls)
you could make a cardboard and tape mini-klam - suspend that in front of the driver - that would divert energy downwards - crazy but worth a try = Look at Alan Weiss patent - this lens was used on a one inch Eminence compression driver - there was a crazy story which I missed about his speakers at the old Karlson forum - something about the "mob" and baseball bats ;^)
http://patentimages.storage.googleapis.com/pages/US5943431-2.png
a T-P tube K-tube might deflect somewhat - the highest Fs tend to travel straight down a pipe.
here's ny half baked diffusor idea https://i.imgur.com/Jo8E4w7.jpg - you could turn it the other way or make one with a "cross" slot
ask WHG on the plate lens - i assume they have some downwards deflection (?) - wonder if 3mm Baltic birch is good for the plates?
you could make a cardboard and tape mini-klam - suspend that in front of the driver - that would divert energy downwards - crazy but worth a try = Look at Alan Weiss patent - this lens was used on a one inch Eminence compression driver - there was a crazy story which I missed about his speakers at the old Karlson forum - something about the "mob" and baseball bats ;^)
http://patentimages.storage.googleapis.com/pages/US5943431-2.png
a T-P tube K-tube might deflect somewhat - the highest Fs tend to travel straight down a pipe.
here's ny half baked diffusor idea https://i.imgur.com/Jo8E4w7.jpg - you could turn it the other way or make one with a "cross" slot
ask WHG on the plate lens - i assume they have some downwards deflection (?) - wonder if 3mm Baltic birch is good for the plates?
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here's Kock's refracting lens patent with lots of prior art Patent US2684724 - Sound wave refractor - Google Patents
dunno it the Kock and Harvey article is available outside of the society (?)
here's the Hartsfield patent Patent US2848058 - Compressional-wave lens - Google Patents
Here's a bit on Winston Kock in NASA archives - the lens shown looks much like the one presented with a fullrange speaker in G.A. Briggs book "Loudspeakers" (very "Deco" - almost like a car grill too)
NASA – 120 Years of Electronic Music
here's a cool plate lens - I guess plastic tubing could be cut for spacers, use common machine screws
and nuts to hold an assembly together. - Or with some the size to work with the Fane's whizzer, thin wood, plastic,
cardboard and hot glue.
dunno it the Kock and Harvey article is available outside of the society (?)
here's the Hartsfield patent Patent US2848058 - Compressional-wave lens - Google Patents
Here's a bit on Winston Kock in NASA archives - the lens shown looks much like the one presented with a fullrange speaker in G.A. Briggs book "Loudspeakers" (very "Deco" - almost like a car grill too)
NASA – 120 Years of Electronic Music
here's a cool plate lens - I guess plastic tubing could be cut for spacers, use common machine screws
and nuts to hold an assembly together. - Or with some the size to work with the Fane's whizzer, thin wood, plastic,
cardboard and hot glue.
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hey GM, Stromberg-Carlson used a perforated clear plastic grill with ~ 1.8" holes over their cone tweeter on the Super 400 12CX. I wonder if that had function other than protecting the tweeter cone? It was fairly open (a type of screen rather than holes drilled or punched) so any effects may not have been deliberate.
007 - Here's a Kock and Harvey paper that's interesting https://ia801602.us.archive.org/7/items/bstj30-3-564/bstj30-3-564.pdf
I've only heard one plate lens JBL, long ago and in a too small room (up too close) My X15 Karlson sounds similar IIRC with a simple slotted metal pipe.
maybe foam-core and glue would be suitable for a tweeter slant plate
007 - Here's a Kock and Harvey paper that's interesting https://ia801602.us.archive.org/7/items/bstj30-3-564/bstj30-3-564.pdf
I've only heard one plate lens JBL, long ago and in a too small room (up too close) My X15 Karlson sounds similar IIRC with a simple slotted metal pipe.
maybe foam-core and glue would be suitable for a tweeter slant plate
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Mark Hardy came up with an idea - be something to try in cardboard just a nutty thought -- what about the trick used by Altec on the 603B? - mhardy6647 - High Efficiency Speaker Asylum
Thanks for the additional info Freddy, its all good reading material for sure.
I went ahead and made a cardboard mockup of a plate type lens. Plates are 4" deep x 15" wide, with a 60 deg total angle cutout in the middle, and they are mounted at a 45 deg angle. This was just a sort of rough shot in the dark.
Yet, the difference is pretty impressive... the beam out of the Fane was maybe 15 degrees wide or something, now its a full 60 deg wide. It sounds great, I haven't heard anything weird with it yet. It did mute the highs a bit, so they were eq'd up a little to compensate. Coincidentally , it also seems to deflect the sound downward somewhat - despite the jokes that it does not. (It really does point some sound down for short people... lol) In my case, this is ideal as the seated listening position is below the centerline of the Fane by approx 8 inches.
I'm almost happy enough to just leave the cardboard version! But will probably do it in aluminum at some point...
Jesse
I went ahead and made a cardboard mockup of a plate type lens. Plates are 4" deep x 15" wide, with a 60 deg total angle cutout in the middle, and they are mounted at a 45 deg angle. This was just a sort of rough shot in the dark.
Yet, the difference is pretty impressive... the beam out of the Fane was maybe 15 degrees wide or something, now its a full 60 deg wide. It sounds great, I haven't heard anything weird with it yet. It did mute the highs a bit, so they were eq'd up a little to compensate. Coincidentally , it also seems to deflect the sound downward somewhat - despite the jokes that it does not. (It really does point some sound down for short people... lol) In my case, this is ideal as the seated listening position is below the centerline of the Fane by approx 8 inches.
I'm almost happy enough to just leave the cardboard version! But will probably do it in aluminum at some point...
Jesse
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Thanks! A little rough around the edges and maybe a bit oversized in depth - though it seems to me that you need a certain depth to account for the dia of the whizzer cone and to cover that spread with your desired angle.. and what i have now seems to address that just about right. But no math was involved yet - i found some formulas for calculating some parts of it, but couldn't figure out all the variables. I'll poke around some more.
Fudged with the eq more this morning and found it sounded just fine with the equalizer off! The shouty bits around 4k are somewhat muffled by the lens, and the peaks out past 10k sound fine. I'm amazed. I wonder how it would sound to someone with more discriminating ears, but sounds great to me - have not been able to stop listening to music on it!
Fudged with the eq more this morning and found it sounded just fine with the equalizer off! The shouty bits around 4k are somewhat muffled by the lens, and the peaks out past 10k sound fine. I'm amazed. I wonder how it would sound to someone with more discriminating ears, but sounds great to me - have not been able to stop listening to music on it!
cardboard would be less apt to "talk" than say thin plywood.
here's a familiar looking lens - maybe not so useful with FR - ha - its got my dumb "cross" idea
https://patentimages.storage.googleapis.com/09/18/6e/748e9391c208b9/CN104780487A.pdf
here's a familiar looking lens - maybe not so useful with FR - ha - its got my dumb "cross" idea
https://patentimages.storage.googleapis.com/09/18/6e/748e9391c208b9/CN104780487A.pdf
How so? For some of the 4khz muffling, or some of the dispersion spread increase?
I was planning on making a more permanent lens out of aluminum or even fiberglass circuit board material - it would be disappointing if the results were not as well good with the finished product! I had considered thin plywood as well, bit it's relatively thick (as is the cardboard i used)
Freddy, my understanding was that the cross or other cover with shaped cut out, and also the k aperture, was that it was only effective on lower frequencies, not the highs?
Thanks,
Jesse
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Self damping; we're dealing with huge diffraction, so the more rigid the deflectors, the more diffraction plus some portion of the BW will be traveling over the surfaces plus the SoS will be different, which admittedly some will find more musical, while others more fatiguing, i.e. will tend to sound brighter, more detailed, but it's just akin to white noise.
Unfortunately, unless one has access to the old JBLs, DIY is the only option to audition them, but since your goal is to damp/diffuse the driver's wideband HF 'shout' it seems like experimenting either with the existing or different materials such as Styrofoam, etc., is the better path.
Personally would try different scalloping patterns and if it sounded promising, then tin foil bonded to them on one side, otherwise, go back to full size to tin foil, then add to the top and last to the edges since it's corrugated before moving on since early on an overseas DIYer sent me two pair of dirt cheap 5"? 'FR' drivers with one pair tricked out with a foil covering, which completely turned some really bad sounding drivers into some that slightly bested in clarity my super tweaked RS 40-1354s, quite a feat for the times, especially considering the RS have damped/tweaked whizzers and his just dust caps.
In retrospect, maybe a somewhat damning indictment against whizzers or at least the decades long de facto designs used.
GM
Unfortunately, unless one has access to the old JBLs, DIY is the only option to audition them, but since your goal is to damp/diffuse the driver's wideband HF 'shout' it seems like experimenting either with the existing or different materials such as Styrofoam, etc., is the better path.
Personally would try different scalloping patterns and if it sounded promising, then tin foil bonded to them on one side, otherwise, go back to full size to tin foil, then add to the top and last to the edges since it's corrugated before moving on since early on an overseas DIYer sent me two pair of dirt cheap 5"? 'FR' drivers with one pair tricked out with a foil covering, which completely turned some really bad sounding drivers into some that slightly bested in clarity my super tweaked RS 40-1354s, quite a feat for the times, especially considering the RS have damped/tweaked whizzers and his just dust caps.
In retrospect, maybe a somewhat damning indictment against whizzers or at least the decades long de facto designs used.
GM
I'm convinced that the problems with the Eminence 12lta are attributable to the whizzer, which, as you pointed out to me many moons ago are the same size as many full range drivers cone.
When I get time I'm going to reduce the whizzers diameter (and beg P10 for EnAble templates)...... it will be the last gasp in my attempts to get a tweeter to integrate without sucking the vitality / character from reproduction.
@ sbcrx
The two 'biggest' improvements I made to the 12lta where:
Doing away with the dustcap - that happened after 20 mins of free air listening.
Powering them with valves or SE ss.
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