gnarly

Hi uams, The two horn loaded subs i have are DIY Labhorns (the Tom Danley design on Prosoundweb), and JTR Orbitshifters. Both are FLH, with about a 9-10ft horn path. The Orbitshifters use a single long stroke 18" firing into the throat chamber and will definitely walk around when cranked up enough. The Labhorns use dual opposed 12"s firing into the throat chamber and do not vibrate much, if any, no matter how loud. I hope that's the principle you meant.....? The combo definitely improves with active tuning. You've probably seen B&C's recommended filters for use with their passive xover in the 215-DCX suggested build. When i say "traditional PA", i mean in comparison to high quality boxes like Meyer UPA-1P's and such (which i own and compare to). It's a good sound, just lacking a little definition and openness vs what i've been hearing with the Synergy builds. I've been working on Synergy iterations for 2+ years, slowly finding improvements that continue to distance their clarity from anything else I've heard. If it weren't for some builds going backwards, i might think it's just a case of continued confirmation bias Lol. I have every intention of returning to the B&C combo, and giving it the time it deserves. Maybe even trying the 215 design. I'd like to compare it to the DIY PM90/60's that i think are outstanding high-output boxes.. But happily right now, i've hit on a Synergy build i like so much, I'm in the process if building a couple more of it, for a LCR setup.

Hi Dave, i took the dcx464 / me464 combo active like shown earlier in this thread https://community.klipsch.com/index.php?/topic/200572-bc-me464-horn-opinions/&tab=comments#comment-2628703 I don't have the passive xover, so can't compare to "non-active". From raw measurements of the two CD sections, I'd be surprised if sounded very decent without some active help. Even with the processing i put in place, it hasn't been a combo i've felt was worth pursuing further, as i'm really enjoying DIY conical MEHs. I agree with your assessment of it sounding more like traditional PA. So happy to exchange thoughts via PM if you still desire, but i can't say i've had what i'd call really good results.

Hi uams, thx. The subs are dual 18 push-push slot loaded (clamshell style PPSL). I basically took a very successful single 18 bass reflex build, and built the dual 18 PPSL scaling up the single's volume and port specs. The cabinet vibration reduction vs single 18's has been awesome. I can get rowdy and walking subs have been a problem. Are you currently using the MicroWreckers i see in your equipment list or the reflex boxes i see in your pict? I bet both work great. I agree that diffraction slots have gotten an unfair negative reputation.... No doubt there's some bad implementations, and bad CD/horn combos, using diffraction slots; but here's some dang good ones too !

Yikes ! That's quite the imagination ! No problem at all, your request will be honored.

I'm sorry to hear i was part of the reason you quit posting at diyaudio. I don't understand why you would have a problem over approaches and methods that are different from yours. Nobody's approach is the end all, be all. Tis healthy to discuss various approaches and methods as long as respect and courtesy is provided to all parties presenting theirs. I hope you can realize how condescending that sounds..."(if there are, in fact, any)".... You're correct about my "questions that aren't questions". I didn't ask any questions in this thread, other than what you mean by zeroth order? (which I'd still like to understand) I didn't disagree or present any alternatives to your first order tuning methods. I presented observations of measurements that don't reconcile with timings you discussed, and my viewpoint (theory) as to why TOF's measure as they do. Thank you for appreciating my civility, and for when you provide civility in return. I need to ask : Why is it important we see to eye-to-eye ? I don't care if you advocate a particular tuning strategy....why do you care if i advocate a particular different strategy? What is there to agree or disagree about? Both strategies work just fine. (If i ever hear proof why my strategy doesn't work, i'll happily and very thankfully accept the instruction, knowing better audible results are forthcoming !! ) I'm sorry it appears you don't like it when folks do not adopt your viewpoints, approaches, and methods. I don't know if i'll keep posting here or not, as you seem to be disinviting, directing me back to diyAudio. Seems like a pity to me...I know you have a lot to offer, that there is a lot i could learn from you. And believe it or not, i have a lot to offer you too. Anyway, later.. for now. Sincerely, Mark Peace...

No, i don't think that's it. Phase lag induced for every order of the crossover filters applies to IIR crossovers. I'm using complementary linear phase xovers which have the same phase lag (none), no matter what order used. Spectrograms, step, group delay are all just derivatives of mag and phase response....they all key off the same TOF measurements that place the woofer further away that the CD. (REW: TOF = Delay relative to loopback) 26 minutes ago, Chris A said: (This seems to have been edited away or something...???) My reply got hung up Saving...so this is a put back together attempt) I think you're having trouble using these extremely high order filters having sharp cutoffs in MEHs, that absolutely don't need those kind of filters--because the reason for using them is simply not there as it is in multiple-aperture driver/horn loudspeakers. The multiple aperture MEH's help mitigate the need for steeper xovers for sure. But MEH's can improve further still with their use. I have tuned them both ways and the steep acoustic rolloff of a large woofer crossing to a CD has been easier to get right using steep, for example. I use outdoor polars to determine whether to use steep or shallow. Working on such a project right now...

Hi Chris, i should first ask what do you mean by a "zeroth order crossover" ? Not familiar with that idea... Here's my two cents... So far, on every MEH i've built (maybe a dozen counting fully developed prototypes), the woofers have always measured further from the mic, than from the CD. This has occurred despite the fact the woofers are closer to the mic than the CD,....... as in the drawing you posted. And it occurs whether taking time-of-flight measurements with no filters in place, or with linear-phase low passes of any order (which don't have any group delay). I've come to the conclusion, perhaps wrongly, that the natural acoustic low pass of the woofer is the source of the delay. Well that, and also i believe that our FFT measurement programs use the Hilbert-Transform to make TOF determinations under the assumption minimum phase represents correct timing. At any rate, i know all my builds have had to add delay to the CD. For the first time recently, i tried adding small 4" mids between the Cd and woofer (even though not needed). The mids also need delay relative to the woofer. With the woofer at 0.00ms, mids delay is 0.32ms, and CD is 0.83ms & 0.90ms (hf & vhf dcx464 coax sections) You can see from the spectro, those delays put timing right on target. (other than i got a small bobble at 250Hz, xover between woofer and mid)

Thx, I saw the AES3 cards and was hoping you were using it for your digital signal processing. But like you say, anything can be done with the Cores, and maybe you had something else going on with it... I'm such a huge Q-SYS fanboy too... Here's the schematic I'm currently listening to. It's for a 4-way MEH on top a dual 18" sub. 500i fed via Q-Lan from a 110f. 16384 taps on all FIR filters! (just to keep from messing with different delays Lol) Now i just need the super amps you guys are talking about 😁

Langston, may i ask a quick question unrelated to thread topic.........what does the Q-SYS Core do? Thx, Mark

Hi Edgar, in my previous reply, all I did was push against pre-ringing being significant. And your question did ask what is important (to me)..... and as you said, i do go to great lengths to eliminate phase shift/group delay... So to try to explain further... Logically and intuitively, flat mag and phase make sense to me for reproduction. I think everybody is on board with flat mag (subject to house curves and preferences of course). But we all know how much phase audibility is debated. Personally, i want to do what i think and intuit, is technically right, whether audible or not. Seems like a can't loose, and will probably win, as well as learn something strategy. And so far, the flat mag and phase effort, along with extending it to smooth polars, has been paying big audio dividends. Subjectively I could wax on alot...but i don't really see the point...suffice it to say , tonality, clarity, transients, low end dynamics are making me a very happy camper. Of course, i can't really separate the processing gains from the speakers' acoustic design gains, but since almost all the considerably varied speaker designs i've attempted have shown similar sonic gains, i have to credit much of the sonics to a common processing technique. Anyway, if i may go back to the cost of potential pre-ringing vs the gains linear phase might bring... here's an example of the tradeoff (as i see it), that illustrates the order of magnitudes difference between the tradeoffs plus and minus. This is a measured not simulated, linear-phase LR 96 dB/oct electrical xover, where both the low-pass and high-pass sides have been summed together. For me, there isn't much pre-ring, due to complementary cancellation. What small pre-ringing there is, seems like a tiny price to pay for the outstanding Step Response. As i'm sure you well know, only first order can achieve a step response like that. And this is 16th order !! Gives so many degrees of freedom combining drivers acoustically. I feel like a kid in a DSP candy store...who walks out into a rocking live concert Lol

Gotcha. Thanks 🙂

What demonstrably audible pre-ring are you referring to? I hope not that FabFilter youtube....that thing's ridiculous imo. I mean, what is the high Q filter in it, min-phase? or lin-phase? And what is the point of it even being in place? If it's min-phase it should be fixed with min-phase....applying lin phase to it is a joke. If it's lin-phase, it's even more of a joke... Pure contrived marketing imo...... How do I choose which audible effect to worry about, and which to ignore ?.... Good question...🙂 I guess it's as simple as the audible effects i can hear in my real world builds, and my real world testing. No hear, no worry. Can't really say i feel i need to read about, what to worry about...

Yeppers, the 0.01% hit that pre-ringing might maybe bring, is indeed 10x larger than the 0.001% hit to audio bliss that audiofools typically worry about, huh? ......haha

The sound degradation in the FabFilter youtube is very easily heard, so i'm not sure what you mean by saying it needs to be lossless to be heard. I think the worst MP3 would make such a contrived comparison obvious. That's my point really, it's contrived crappola for marketing purposes.... It's not representative of any real world pre-ringing issues, imho.

Yes, I've seen and heard many of those studio type presentations regarding pre-ringing. They all have a simple common trait, imo..... they all use a very high Q electrical filter supposedly linearized (the idea of which is nonsense) ..... carefully constructed to prove their point. Fabfilter is one of the worst....pure marketing on a fish hook. Lol Bogus amogus big time! 🙂 imho.