grindstone

An aside of advocacy of the original horned one - Edgar worked on khorn/belle/LS here: Suggest application of HPF, EQ to the existing (and throat-ported variants as you choose). A lot of links are broken from the board change, but there's still some geometry and sim stuff there. (Surely there's other threads, that's just what came-up first/best for me). Alternatively (or in-concert), maybe try protecting & pumping-up your khorns to see what you think (with your own ears in your own digs)? Just ideas.

That one is really pushing-it. Implem/realization would have to be (?) compression driver phase plug geom with novak-ey inlet (low diyer-friendliness). It has become a different thing, not amenable to treatment such as David's first pass (itself skimpily representative owing to HR segment limitations).

Great! Really glad to hear it, thanks. Ouch on the '09 (guess time flies). And for different reasons, thanks to both of you for all you do--you guys are both gems (though I do miss the crotchety bugger, too)

Just catching-up (lost today running-around). Looks/sounds squatty to hide 4 ft3 behind at first read (probably get pretty deep). Will look tomorrow if someone hasn't already done it by then.

Haven't always stayed-up on things on the board. Occasionally wondered if Maron's PWK letter stash ever made its way to a proper home (JRH) for archival. Just re-read an old PWK article atbout X-3's and K5's and wondered again. Anybody know? Thanks.

Unknown re bifurc--could only guess (mid)bass/turns. I've picked at it three times now, but make zero claims as to owing all the boundaries of the type. (And I did go expo right-off, btw). All I know is that it pushes boundaries in every way to achieve a 2-way ~20-20k. Guessing it also fits through a door (if in pieces?). Are you seeing anything different to make it sane-sized and still worth doing (above what's extant)?

Thanks for the correction--just saw 6XX Sd and you know... Among the more frustrating aspects of this modeling approach (TH + vanishing L12,L23) is that offsets aren't possible so the column resonance is always an undampable gut-punch (in woefully undersized designs). After working on pipes for ages, the confinement is very much constraining and unwelcome. IMO, the only way to get that tamed (again, when sorely undersized) is an offset. Highest-altitude, the thing is an end-driven open air column so it does what those do and we've long known how to fix that. David's model, being another "pinch" enroute, adds its reflection, and that one is too low to damp (and have any LF left), too. I can't argue with his approach but chafe against one waveguide segment for that whole region. You try to smooth those out and you end up with a normal fronthorn. Reviewing your atmospheric-vented Belle model, it's flirting with 110 @ 50 in < 400L. In a corner, functionally & size-wise, it's very Dean-like (if 1/8-spaced), but with a K33 instead of needing a C15, so that's something. The only reason that makes sense to me is if you're really excusion(=distortion)-driven. Otherwise, yunno, stick a 12pe32 in an Aristocrat in 1/4 the size, save the delay and go on with your life. This really is a continuum of stuff with a lot of waypoints that meet different goals. One one end, there's Wayne's driver+port pointed backwards into the trihedral. On the other end, there's these new-rev Jubes. Thinking my answer to when the diy-er applies such a config is only when it's necessary to hit your low-corner target and still mostly retain horn-ish displacement limits & save some delay. You can get the radiation-resistance bennies with horns at the cost of the delays & LF. To get low-low and still play high-enough for 2-way, not seeing any ways around Big but open to education from anywhere.

If I'm tracking, it looks like you kept the "resized" driver params after that operation? Don't do that HR will resize Everything. See step 4 above -- copy data for the driver you want to use before the resize. Need to paste the right driver in after resize & before calcs or it's junk. If not, apologies and you are now officially dangerous and loose. Saw our benefactor Dave's model at diyA, too--his way makes sense to me. Might look at that when there's a minute to sit down and look again. Tried 12" "horn" driver yesterday and yeah, that was my exp, too. I hate working in the blind w/o a transfer function/model. Go caveman with me a sec: Add an inertance in series with the normal series and parallel resonance "reflex" system, itself a compliance resonating with an inertance and against a driver (motor+suspension system). Is that what this is or am I missing it at the root level? Because the outputs are summed in the throat and we're talking macro (LF) effects in our cave, isn't that legal? (No, not reading patents, either--gotta run).

Enjoyed the story and the pics very much, garyrc. Thanks for posting. Seems like all of us like what "exciting" sound has currency when we're young. -------------- Fred: Take your base model (David's type, here): 1. Copy the driver data (to memory) 2. Add New record 3. Resize wizard -> scale. Use the cube root of the scaling you want 4. Paste the driver data back in 5. Check the throat (S1-3) sizes vs. driver, edit your VRC & LRC, Ap, Lp etc. 6. Hop in LS Wiz, change the manuals on S2,S3 etc to auto (lock 'em together) 7. Slider yourself bleery, take many screens & upload to World I think that gets you cut loose on looking at smaller stuff. Apology if I've misread/misunderstood. Been waiting for you to cover the web with K-sims since the PH geom was added. You'll need to ask the paraflex guys to show you which PH models to use (guess there's activity on FB, but not a FB person). Draw them a system model of the K or even a crude schem and ask them to implement you a baseline/framework. The problem with that thing is always the aperture specifics. Needs (IMO) really to go akabak or 3-D/FE/BE methods. Doing a scalable akabak script for K's like X did is a pain in the shorts--we're all too old to be that gung-ho anymore; takes a kid like X. Unless it's about naps (I can be gung-ho about naps). It's just drawing pictures & thinking out parametric waveguide and radiator sections. Use the HR akabak export as a start (BP6S? or even this thing). Have to change pi/2 to 2pi first, then it'll export--you have to add corner reflectors in the script for that. If you wanna hack one together, we can look at it offline. Start with the picture, though--the picture is Everything before you edit all that script stuff (and you'll need x,y, & z coord for radiators, too). Keeping subscripts and directions straight will only go easy with a good picture. Even then, sometimes one needs spreadsheets. Did I mention to draw a good picture? Anway, thanks again for stimulating technical/design discussion.

Allow me to say thanks for visiting & stirring-up something technical again (seems different around here, that way). Sounds like you saw behavior similar to what I saw. There's a happier spot if you go big and are aiming for low. No clue what driver is employed, and uncomfortable reverse-engineering our host's design on their own board, so I'm staying off the K33 and Jube size on general principle. May well be pointless to try to apply the configuration to other (ie less LF) applications. Could never greenlight the S-8 Classic build as 400L is up there for my spaces and current driver-subs are iffy. Moray started a thread here somewhere for alternative drivers and I recall a couple rising to the top. The C15W stands alone for that cab and it's the lynchpin of it playing smooth, high, and almost low-enough (but not low-enough for sheets and sheets and 400L to get a nice 50Hz, IMO). This would seem a better use of 400L+ than that. World is full of 50Hz boxes (that's the problem). 760L is a Whole Other Thing (tm). Don't know xmech of k33's, but that seems way past banging even with 15Hz HPF (?). Box losses will take some of the (bottom of the) LF off, but the room might put some back on so boosting remains opaque, here. Good ballpark, though, and apparently faithful in principle. Stipulated that something higher-travel would fly. Re the atmospheric-vented reflex, throat-ported, and normal fronthorns, seems not a fair fight to go size-for-size w/o changing drivers to be what's best for each design type, but I get the comparison and appreciate the work. That should certainly get a look and be a bunch of work to do right. They're just all so different (and I'm arguing probably have different goals. This is the crux, as always. Unsure anything else plays as low, as high, as loud (& surely Klipsch would add as clean) as this thing. Thinking that's the point (?) underpinning size justification. At LF, people routinely argue a lot of throat geometry differences away, but... Thinking it'd take a 3-D look (not our 1-D) to really get after what's happening in R-J/Novak-ey throats. Suppose a person could do a full lemon throat to more broad-band the port (?) but we can't quickly/easily see that stuff in lumped-element-land and it might be exactly wrong, anyway; just a thought I associate with "R-J" albeit only one shape of theirs. The parallel (port-throat) walls are close-enough where it might matter though, if a person tried to throttle these style ports for more damping. In the home, sure--probably not pushing it that hard. Also thinking 2 turns isn't enough to kill that parallel port-throat resonance unless that cone can't break-up to excite them. If there's truly port tubes in there, then keeping that trash out of band enters, too. Thanks for the work! Dunno. We can get 105+/W in a corner with a lot of easier/smaller stuff, it's going after the 115 that separates the chaff. These things look to be able to do it and down-low, but they're not petite. Haven't seen Dana around here in a long time, and it's too nice here to read patents right now. My sense is still that these are only worth doing if you're going for low+loud. It does seem to play higher than it has any business playing, though, with things I tried. That's probably the point--low+loud+high--to meet that schmancy top driver. Glad people still make statement products. Hope they are a screaming success for the mothership, but I've definitely slept in smaller volumes than 760L Sims here say that going real small is pointless for LF and the thing can be just a beast down low when you don't. We know the diff between 20's and 40's is non-trivial, and this config seems to get it done and save a magnet over the previous rev. A very hard problem of a 2-way with crushing bass would appear to be solved. BFM's MR applications might be the next sweet spot up higher for these geometries. Unknown. I think we might've arrived at the same spot, but the utility differs. I'm still at hrmph for most people, but it seems a solid approach for those with large spaces. My spaces are headed the other way these years. Gotta be a pretty visceral and immersive experience, though.

Never looked until this instant. What I'm seeing in 5 grueling minutes of sims: - stupid amount of efficiency down low if you make it big (400L) - drops like a stone (~6th?) - unloads less-poorly than some other stuff - ringing b*st!@^ No-offense to anyone, an apparently re-patentable hrrmph is what I got in 5 minutes. (Perhaps it takes more than 5 min work to achieve patentability? Rhetorical). Be some work to tame one. Interesting corner on the Great Efficiency-Bandwidth exchange? Be nice if some gung-ho person plotted the transfer function but that's not gonna be me today. Beats working the Saturday list, though. Have to poke at it some more. What are you seeing? (Remember the "Have you considered a career as a commercial artist?" pitches? Nice artwork).

I would only add that bracing effects can be heard even at lower levels over time. Live it it clamped-up a week+ and then unclamp it and listen. I realize you've already gone exo-skeletal, but if you're changing them at all, they aren't survivors and the easier construction route would seem to be bracing if laziness is a factor. There can be a lot of discussion about _why_ it's different, but it is. If you treat it all as a chance for hearing education, it becomes Science! There are seemingly boundless reasons to admire PWK's engineering, but it's also worth noting the man had a business. My sense is that PWK would say it's all horse-puckey ("dimes worh of difference") and that Dennis would, in a one-liner, say exactly what bracing to use and where to put it (while managing to have an edge to the post). They are both routinely still missed.

Wow so that's what the cane can look like? Just fooling. I had to have my cane grilles off when I really cared about listening, FWIW. If it was me, I might take the chance to make another set of grille boards w/ different grille material, too. Keep the originals for non-use or resale, etc. All that said, I have a serious soft-spot for cane and wish more of the old grille stuff (besides instrument amp fabics) were available. If you don't know and just want something to hold until you are, I'd staple the 4 corners--the corners and midpoints are the unwieldy bits (unless you have loose tots, almost nothing is (grand-)kid-proof but well-secured cane comes close).

Nice work, thanks for posting pics. I'd never have that kind of patience being that close.

Not that I have one, but for ref--do you care if grilles match? It's a bugger to find cane in my exp.

Thanks for posting. I applaud anyone would makes anything and hangs it out there. Here's an ijnspirational (or completely demoralizing) link to a guy's gallery of his bass bin. https://imgur.com/gallery/a0U99NP

Thanks for spelling that out. The way I read it the first time, I thought you made a 2-way with the basshorn which was what spurred those questions.

Thanks for mentioning...another driver I missed somehow. So, the 2/3-bolt PRV is used with the APT200 tweeter horn and the little horn reaches low enough so far? Any shaping or level-matching tweaking yet or just sort of lashed-up for an initial trial?

D*** kids...seen 'em come and seen 'em go. Never understood why they all think they have something important to say to me.

For posterity, just tripped over one more while this thread was up.

oh no, the subliminal morse-code bots have achieved sentience. high snr, though.

Yeah my first thought at that Nyquist was "Bart Simpson"...

Godspeed. Damn this last year...

IMO, the new norm is just a magnifier/catalyst. From higher altitude, it's also the logical result from global out-sourcing that has been happening for decades. We're lucky to have domestic driver suppliers at all anymore and I'm grateful they're still extant. Some raw materials are a bugger, though, and uneasy politics would seem to exert price pressure too. The chip-foundry thing will be interesting to watch as well. Gawd do I sound like a geezer or what? Appreciate the heads-up, Dave. Guess we get to do more with less...again...can't even feel it anymore : )

Congrats on freedom to use retirement time and money for what it's for! Please share as you see fit