Hey guys...we need a little rallying here... - Page 5

I don't do 15s basically. I built with the 12" 2262HPL. Scroll back from here for more data:

http://techtalk.parts-express.com/sh...93#post1667893

All new JBL, the admission fee scales up quickly....

Penngray asked me if I could supply E-OSWG, 15". My proposal is 18" version for 1.4" BMS coax because after having experience with OSWG and JMLC I pay more attention to cover midrange from 200Hz and up with compression driver rather than directivity control. Best could be OSWG+JMLC hybrid 25-30".

Simulation is for round type. Dip can be removed with roundover >12cm or JMLC mouth. Here roundover is only 2".

Universe speaker (middle) uses midrange compression driver and offers better voices (not only). No matter if you use OS or other WG it's still classic PA monitor. Woofers better if cover sounds up to 200Hz. Dr Geddes use 119g Mms woofer while I use only 32g on GDN-30-400-8-SE.

5" roundover simu enclosed.

I'm from Poland (Szczecin) and Autotech is located 700km apart in Lublin.

12" OSWG-JMLC hybrid.

"Some" not all are trying to work around it Its just a fact of the design as I said before we can use roundovers and even in room placement to minimize that null.

First, I do not do passive XOs, I find no reason when DSPs are so cheap, cheaper then buying/building passive XOs and DSPs are resusable, tweeking is unlimited, voicing is much easier. I just picked up two AS100.2 amps for even more DSP power.


Now, I will give you all your points because you do awesome work I do not disagree with anything you post I just think there is more too it then what you focus on because here is small list of HIGHLY successfull speaker designs in term of SQ that are sold commercially that according to your posts have design flaws....who would buy a flawed design??

Geddes Summa


Duke's Planetarium


CS2 from Emerald Physics.


Zingaly Horn


Jack's 12" OSWG



Could it be that your focus isnt what others are as concerned about and they know how to minimize it?? You are not wrong at all and you should know your work has been incredible for DIYers, I refer to your thread all the time. Im just pointing out there is more then one way to design a waveguide speaker.

Who wouldnt want this front wall in their HT??




I will just focus on the same issues Paul W, Duke, Geddes and many others focus on because I want something that looks like many of those designs.

1.4" compression drivers "suposedly" cant play past 10khz remember?

hehe, yeah I finally got the real anwser on that. Its not that they do not play past 10KHz, its all about the directivity being lost after 10Khz which some people are concerned with.

Im no expert in audio but I have put thousands of hours into reading about waveguide builds. One thing I have learned is that everyone has their particular needs, there are compromises in ever choice and we as individuals have to pick what we are concerned about the most.

Im not convince directivity above 10KHz is important.

This post above


shows what happens above 10KHz with JMLC. Those BIG horns in Europe are insanely popular so it can not be as bad as others say it is and remember domes have no directivity much earlier and the majority listen to and love those so we know the real answer.

jzagaja, also posted this..



He is saying midrange coverage is more important then directivity control above 10KHz.

Again, as long as we know all compromises (That is the best part of discussions) we can then choose what will matter to us. I need to build them all to know the truth

Penn, I don't think Zilch is saying the Geddes, Duke etc designs using round horns and large CTC are terrible designs. He simply doesn't want to make the compromise those designs inevitably make with a null the vertical nulls. To the best of my knowledge, there is no way around the physics short of steering the null which is of limited utility. Those designers are comfortable with that compromise.

I'm pretty certain that each of those designers would have preferred an elliptical shape which would eliminate the CTC compromise. As we know creating an elliptical is more difficult and expensive.

Similarly, Geddes et al would not want to use the small biradial horn that Parham uses because of the design compromise they believe is an inferior horn due to HOMs etc. Parham is comfortable with that compromise and he is able to achieve a better CTC spacing.

If we can produce an elliptical OSWG for DIY use then we should be able to eliminate both camps' compromises.

There is still an issue with the null created by the symmetries. By my estimation, the nullis worst with a round horn, slightly better with an elliptical and progressively better as the shape approaches a rectangle.

Check Lampos Ferekidis work. Do you see any nulls?

http://www.tannoy.com/products/304/V...eet2010816.pdf

I know he isn't saying they are bad but he has stressed that the CTC vertical null is an issue so great that he would never build a speaker with that shape...that inherently calls out experts who build using that shape, that is my point. My point is simply that even though zilch may be concerned with the CTC vertical null issues others see that as a lessor concern. Im not saying it isnt there, I 100% agree its there Im just using actually designs that prove its not all that important to them and some of the speaker designs that cost $10K to buy.


Yes, this is the point of choosing different compromises.

Everything I have read, tested, measured and/or heard so far points to larger horn/waveguides being the superior design sound wise....we all know perfect measurements are not an indication of superior sound Even I can say that


I again agree. I have never said the null issue isnt there I just would debate its importance because we can manipulate the speaker to move that null out of the listening area.

I think its very important for people reading and learn to understand that the CTC vertical null issue does not always have to highest priorities and some of the best speaker designers think its less of a compromise then other issues.

The same goes for > 10KHz directivity, some care, some don't.


I have always agreed that a E-OSWG is a great choice, its the best of both worlds. Im just saying if a regular 12 or 15" OS choice existed too though I wouldnt turn it done.

Interesting design, I'd not seen that one before. Looks like it uses the B&C or BMS coaxial CD.

Crossed low that's how I prefer, CTC isn't an issue anymore.

BAH! Cop out. You never heard the $50 EconoWave HF used as intended, yet you continue to claim it sucks. It does not suck. Duke is using the same with an arguably "better" driver in his Prisms, still under $100 MSRP for that combo, despite the extremes Geddes went to attempting to squelch it from the outset.*

Admit it, Penn -- you didn't know HF comp from a hole in the ground at the time you made that assessment, and you haven't gone back to re-evaluate it since.


All flawed until proven otherwise, and no, I would not buy any of them without that, and certainly not for $10K, when I can build WITHOUT that flaw for $200.


Anyone not suffering the delusive effects of imaginary gonadotrophia syndrome, of course.


Fine. For some, aesthetic preferences trump the facts, obviously.


I have documented the difference with both BMS and JBL 1.5" drivers for readers to evaluate.


You've apparently missed the point of all of the power response discussions of late.


Non-sequitur. Domes without waveguides to bring their directivity under control are all but dead. I fully expect Linkwitz will discover this soon.


Yes (can't fool mother nature), but with a 60° conical crossed at 450 Hz, they are only minimally intruding into the vertical beamwidth....


*In classic form, Earl couldn't resist crapping in Duke's new product introduction thread, either....

Check VQ100:
http://www.tannoy.com/products/305/V...eet2010720.pdf

Yes, 100° conical, and bigger than -10 dB elephant dung in the verticals within that beamwidth at ~500 Hz.

Dispersion is collapsing quite severely in the top octave, both horizontal AND vertical, as well; that horn exhibits NO pattern control up there....

I think what we see with many commercial designs, whether the Tannoy's referenced or many JBLs, etc is that they are much less concerned with a narrow vertical for cinema or SR applications. A 10-15deg listening window is likely acceptable and not at the top of their list of priorities.

For multi-seat HT in a small room (sitting <15' away) a 10deg window is awfully tight. Can it work? Maybe. Is it ideal? Far from it. If you are listening at 10' I think a window of 20deg is more appropriate and that is nearly impossible with a round horn assuming the horn is still holding pattern at the crossover point.

Penn, I don't think that listing a set of designs, even ones that are quite nice, proves much. Many people would say their 85db sensitivity speakers are adequate and that pro drivers are a waste. We know that is not true, but those people simply aren't willing to compromise in other areas like us.

Compromises and priorities. Some could care less about directivity, nulls, HOMs or even sound quality. They want looks or cheap or something.

This group wants ultimate performance and we are picking nits about where we'd be willing to compromise. If we can develop a EOS WG those nits should no longer exist...I wonder what nits we will come up with then.

Anyone thought about CBT design for a nearly perfect vertical dispersion pattern? Unfortunately, they need to be 2-way, so it limits horizontal dispersion....

JSS

I haven't explored in CBT's in depth but I don't think they provide the horizontal directivity we want and the horizontal trumps the vertical IMO. I could be wrong though. What are you thinking exactly?

I am prototyping the small 1-way group-delay-steered CBTs with 2" drivers everyone is ignoring, and will be mating them with a pair of Insubnias.



Other than more informed choices, uhmm, ZIP....


Footnote: I hope everyone is getting this: the information is often there in the manufacturer's specs, and a committed critical eye ferrets it out. Used to be, they'd conceal it or simply lie, but not so much anymore....

I should prove a lot to many that have no other reference, go ask Paul W, Duke, Geddes or a few others about the CTC if you do not believe what Im posting. I listed a set of designs from expert designers showing simply showing that the CTC focus is different for them then for Zilch. That is all, they still meet the criteria I believe is the most important, High sensitivity, Clean SPL dynamics, power response, controlled directivity up to 10KHz and beyond (See I do not agree with Geddes on everything here).

This group does want ultimate performance (no one is spending $$$ like myself or Zilch though to find out) and with all due respect to Zilch and his incredible DIY skill set/resources, I would still pick what Duke or Geddes designs over his products if they are offered to DIYers for a reasonable price tag.

Until I build something similar to Duke or Geddes I will not know the truth (neither will anyone else). IMO, All discussion point to that null issue at XO being overplayed from one side of the aisle more or less its more of a "Against Geddes" thing (I do understand why but Im not concerned about human behavior patterns )

I just care about overall waveguide speaker performance and Geddes Summas or abbeys ARE THE highest quality reference we have.

Too bad we can not measure HOMs because if we could plot them properly maybe the CTC null issue becomes less of a concerned when the HOM plot for those narrow waveguide is ugly. Again, this is just choice and everyone free to choose what they want, I have 6 different CDs, 5 different waveguides and I have run them all so I already know the lowest cost econo-waveguide choice is far from what I consider a high end speaker so I know my reference point.

I think we do agree that if we are going to do something custom then we should strive for the EOS design.

Not true at all I plugged in all the values I needed in my DCX and compared to the QSC/BMS4550 the JBL (Pyle version)/ Selenium choice and they sucked. Take it for what its worth, you can think the low cost solution sounds great. I needed no more info then to know it has SQ issues. Everyone can make their own conclusions on the product, I wouldnt want to take that away.



You have issues with Geddes, everyone knows that and understands why (if they have followed the discussions for years). Geddes isnt doing himself any favors either.

Im not sure why you are posting a syndrome and about delusions from such syndrome. I have no delusions, I take all the dicussions and can read between the lines very well. I not only read but I do listen and buy products to test, Im not hearing the same conclusions you have. Sometimes we also like our speakers to look half decent too

Again, this is all choice, you can enjoy low cost solutions with simple XOs, hard core pro boxes with lips and no roundovers. I would guess you think your highest quality build is better then Geddes Summas? Only a controlled listening test would put that conclusion to the test.

I learned a long time ago there are many, many, many, many ways to design a speaker successfully. One needs to define their application first then find the speakers that meet the goals of the application. There is not one designer out there that is better then all others and all expert designers should be mindful of that when they are given everyone lessons on who does what wrong Because it does not help those trying to learn.