Erich, no matter what exactly it is that has gone down in the recent past, Wayne has every reason to continue explaining why he believes his products are the best option for their intended purpose, just like anyone with a business. Given that, how is this cycle supposed to be able to end? Is there a reasonable point of satisfaction to found for you? This semantic nitpicking is surely not helping.
I'm asking legitimate questions, nothing more. I'm hoping this isn't just a one sided advertisement thread used to discredit others.
From what has been claimed, this thread was started here and many other DIY sites on the same day....not to spam or advertise....but to somehow explain why constant directivity is no longer what people should look for, which is completely the opposite of past claims. And of course doing all of that while trying to discredit only one other new waveguide with bogus charts.
I'm just curious why the OP has always claimed constant directivity was the Holy Grail, and that it actually provides the most uniform directivity possible. And now that another waveguide has been shown to have all these great features, things change.
You can look, but I have never....ever said one bad thing about any other speaker product. The reverse is not true. Even in this thread, I said I think all of these horns and waveguides have their place because they are designed to do different things. JMLC, OS, EOS, SEOS, whatever. Heck, I help DIY guys here get all kinds of different horns from Poland. I have no reason to bash someone's product.
I don't think you're asking legitimate questions. I think you're picking at semantics because you want to try to make a 2-sided discussion out of this but you don't have anything to say about the engineering tradeoffs in the topic (except what we're calling them and saying about the words we're calling them).
Look, I don't know Wayne, I don't know his motivation, I don't know his business. All I know is that it seems perfectly reasonable for him to explain his idea of an ideal waveguide for a particular purpose. It would also be perfectly reasonable for others to give counter arguments (technical ones). It seems like anyone capable of doing that either feels like it is unnecessary doesn't think there is anything to argue with. So, maybe you've got a one-sided thread, but the emotional cries of "bashing" and "crusades" and etc. and going on and on about some crappy measurement (without any actual talk about WHAT we're seeing in any of the graphs)? That is not adding balance.
Maybe you feel like SEOS is being unfairly picked on? That, in itself, I think is a fair point, but there's no need to say any more than that if that's the point, and maybe just try not to take it so personally in general? It seems like you've put a lot of effort and money into the diy community. People will appreciate that without such extreme defense of everything you've worked on/with.
Look, I don't know Wayne, I don't know his motivation, I don't know his business. All I know is that it seems perfectly reasonable for him to explain his idea of an ideal waveguide for a particular purpose. It would also be perfectly reasonable for others to give counter arguments (technical ones). It seems like anyone capable of doing that either feels like it is unnecessary doesn't think there is anything to argue with. So, maybe you've got a one-sided thread, but the emotional cries of "bashing" and "crusades" and etc. and going on and on about some crappy measurement (without any actual talk about WHAT we're seeing in any of the graphs)? That is not adding balance.
Maybe you feel like SEOS is being unfairly picked on? That, in itself, I think is a fair point, but there's no need to say any more than that if that's the point, and maybe just try not to take it so personally in general? It seems like you've put a lot of effort and money into the diy community. People will appreciate that without such extreme defense of everything you've worked on/with.
Yes. Both devices provide constant directivity in their passbands. So do a lot of other horns designed for constant directivity with basically the same patterns.
This thread is really about two things, one a subset of the other.
First, and perhaps most importantly, the directivity of loudspeaker systems. As many have realized, almost no loudspeakers provide truly constant directivity. And I think it is a benefit where it can be realized. But where it cannot, I think the DI-matched two-way paradigm to be a useful compromise. I think they sound good.
Second, the horns used to provide constant directivity. There are many design approaches, each with unique trade-offs. The first CD horns traded response ripple and astigmatism for uniform coverage. They provided nearly constant beamwidth but to do so, they used diffraction which gave them response ripple. And it also gave them astigmatism - an apparent difference in the position of the acoustic center when off-axis in the horizontal compared to the vertical. So arraying these was a problem. But subsequent designs addressed these problems, and others, such as pattern flip from asymmetrical mouth shapes.
Waveguides are another evolution, and like the varied differences between CD horns, there are a variety of waveguide approaches too. In a way, one can see waveguides as smoother form of CD horn.
One difference between a CD horn and a waveguide is the absense of diffraction in the throat. That makes them unable to spread the beam in the top octave, so they cannot maintain beamwidth above about 13kHz (for a 1"throat). Of course, the benefit one gains in the trade is there is no discontinuity in the throat. This tends to make a smoother sounding horn.
Is that trade-off worth it for hifi? I think so, yes. As much as I like JBL drivers, I never really cared for ths sound of their CD horns. My first constant directivity cornerhorns used JBL 2205 woofers, 2115 mids and 2370 horns. I love those components, still, to this day, some of the best sounding drivers I've ever heard. Except for the horns, which sounded artificial to me. So I switched to radial horns almost immediately, because they provided nearly constant directivity in the horizontal, yet still provided good clear sound like an exponential. I think this was due in part to the lack of discontinuities and part to the improved acoustic load.
Which brings me back to waveguides. The main thing that sets them apart from CD horns is the lack of discontinuitues. They cannot provide as constant beamwidth because they do not have a diffraction slot. But the only place where that is a disadvantage is in the top octave, and I think it is definitely a worthwhile trade for their improved sound quality. They are like a cross between the smoothness of a tractrix horn and the beamwidth uniformity of a CD horn. But there are a lot of differences between waveguides too, from beamwidth to aspect ratio and various other things too. So my question is, do you prefer a waveguide that leans towards the design goals of a constant directivity horn, optimizing pattern control? Or do you think it's worthwhile to use a device that provides smoother response?
I'm interested in knowing what the point of this topic is, and I mean it? It obviously is important if its being bumped every few days by the OP. so what is the point? Wayne, could you show us some measurements of what you think the ideal speaker looks like? Even if they're theoritical measurements? I've read your posts but honestly not sure what it is the current design ideologies don't capture that you're advocating for?
I am asking legitimate questions, and I'm using the same exact words that have been used for 'decades'. I'm just curious why the OP has recently changed thoughts on how the 2 ideas coexisted and worked together to now being completely different.
And it should be a 2 sided discussion when there's 2 things being compared.
Especially when there's bogus charts being used to discredit one thing over the other. That's not very good 'science'. That's advertising.His point (and he's stated it probably 35 times or so) is that his waveguide has flatter response and he thinks it sounds better because of that.
You've mentioned the bogus charts probably a dozen times now. Is there an official response graph for the SEOS 12? Could you post it please? In lieu of that could you please state which graphs you have a problem with and which are ok?
Wayne posted a bunch of different measurements of the same waveguide including a couple B Waslo did (which are fairly different from each other but still very similar), a couple from Brad (which clearly no one likes, the scaling makes it look terrible even though it's very similar to all the others) and one from you (which you claim is not correct - are you saying he manipulated the graph or incorrectly claimed you as the author of said graph?). Then tuxedocivic posted another graph which had a badly drooping top end, and because of that it was probably the worst measurement posted to date.
Ironically, the graph in post #1 (measured by Wayne?) that started all of this is arguably one of the best looking measurements posted so far with the exception of the first graph in post 61 (attributed to B Waslo). That one by Bill looks really good, and while it is a bit flatter than the rest it is also stretched out horizontally and squished vertically more than most of the others.
I was going to suggest this last week before I went on vacation but I thought it would be sorted out by now. Since it hasn't I'll suggest it now. Perhaps a reputable third party (Zaph or someone else respectable) could be persuaded to measure both the waveguides in question with full polars, both raw and on the baffles they are sold with, with the agreement that both parties would have to consider the resulting measurements to be official. The results would still be subject to subjective opinion, preference, and interpretation but at least there would be an official result shown with the same scaling. It's almost impossible to have a technical discussion if measurements from some of the most reputable people in the industry (a list that includes the omnimic inventor and a guy that's been playing with waveguides since I was in diapers) are in question.
To be clear, I don't see any problem with any of the measurements shown here. The graphs all overlay fairly well (within reason considering the different measuring equipment, conditions, etc.).
Last edited:
Hey just a guy. To comment on the measurement thing. The official measurement I believe is the Bill W measurement showing the detailed polar data. The others are in cabs, one of which was an econowave style cab with a 1.5" lip overhanging the top of the WG causing a diffraction issue.
As for the Brad measurement. I'm actually the guy who set the scale. I'm the guy who worked with Brad on his speakers. I don't have a problem with the scale. I told Wayne in PM that even though its broadly similar to other SEOS measurements it shouldn't be used cause Brad was inexperienced, there were CD issues, the woofer doesn't measure right either, and because as someone who worked with Brad on his project I don't feel it's a reliable measurement.
As for my measurement. That is a significant drop. My mic is a calibrated mic and I've compared my measurements to other zaph, manufacturers, and other diy'ers measurements a number of times without issue. It's possible something has changed. I ruled out my amp FYI, so I'm left a little unsure. Sorry about that. I'm working on it My next best guess is a setting change somewhere I have to track down, or my CD.
So ya, hopefully Bill's measurement is official enough, Erich can say. I find the scale a little to stretched for my tastes. But it seems to be a reliable measurement.
BTW, is that really the point of this thread? Flat is better than controlled directivity? I'd say its equally or more important in a finished system, but not in the raw driver response. If so I'd used different drivers. Maybe Wayne will speak more to that.
As for the Brad measurement. I'm actually the guy who set the scale. I'm the guy who worked with Brad on his speakers. I don't have a problem with the scale. I told Wayne in PM that even though its broadly similar to other SEOS measurements it shouldn't be used cause Brad was inexperienced, there were CD issues, the woofer doesn't measure right either, and because as someone who worked with Brad on his project I don't feel it's a reliable measurement.
As for my measurement. That is a significant drop. My mic is a calibrated mic and I've compared my measurements to other zaph, manufacturers, and other diy'ers measurements a number of times without issue. It's possible something has changed. I ruled out my amp FYI, so I'm left a little unsure. Sorry about that. I'm working on it
My next best guess is a setting change somewhere I have to track down, or my CD. So ya, hopefully Bill's measurement is official enough, Erich can say. I find the scale a little to stretched for my tastes. But it seems to be a reliable measurement.
BTW, is that really the point of this thread? Flat is better than controlled directivity? I'd say its equally or more important in a finished system, but not in the raw driver response. If so I'd used different drivers. Maybe Wayne will speak more to that.
Again, we should go back to results obtained by Toole and others in blind listening tests. No particular directivity was preferred. Smoothness and flatness of the on-axis and near on-axis response was a much more important parameter than any particular directivity. See this post by David Smith in THE directivity thread:
http://www.diyaudio.com/forums/mult...y-pattern-stereo-speakers-58.html#post2702385
I think if you put these two waveguides with properly designed crossovers in a blind test, they will rate highly, and there will probably be no clear winner.
http://www.diyaudio.com/forums/mult...y-pattern-stereo-speakers-58.html#post2702385
I think if you put these two waveguides with properly designed crossovers in a blind test, they will rate highly, and there will probably be no clear winner.
No, the controlled directivity is essential. But both waveguides in question have that, so there's no problem on that front. He's arguing that his waveguide has controlled directivity AND flatter response. His guide isn't as controlled at the bottom of the passband as the SEOS but that's the tradeoff he made for smoother response.
As I mentioned last week, they both look like very good waveguides to me and I'm not sure I would be able to pick a clear winner even if I owned both. (I own neither.) I'm fairly certain (still) that the slight differences in raw response would be swamped by implementation (cabs, crossovers, LF driver) in a full system.
Thanks for commenting on the validity of the measurements that have been presented. I think they are all reasonable (except the one by Brad with the really big dip) but it's good to know which are considered valid by the people involved here.
Hello Audiolapdance
That's my point if the walls and only the walls are controling the directivity of the design at the lower frequencies then using that logic I can place any speaker in a corner and make the claim it is CD. This is obviously not the case.
We all know at low frequencies the radiation pattern for a system is for all intent and purposes onmidirectional, here is a 12" driver plotted in free space as an example from 80-500hz.
I don't see any advantage over a conventional box system as far as control of room modes. There is no directivity control below the Schroeder frequency like in any other system. You are still going to have to address room modes from corner placement like any other system.
Rob
Attachments
The advantage of Wayne's 3Pi and 4Pi cornerhorns over any 2-way matched-directivity speaker is their use of a 24" mid-horn which extends true CD down to 300 Hz (another 2 octaves or so). Below 300 Hz you would need a bass horn to get full-range CD, but with the trade-off of less bass extension and more upper bass distortion in the case of a folded bass horn. The last 5-6 pages of the whitepaper below explains Wayne's design choices for his cornerhorns.I don't see any advantage over a conventional box system as far as control of room modes. There is no directivity control below the Schroeder frequency like in any other system. You are still going to have to address room modes from corner placement like any other system.
Rob
http://www.pispeakers.com/Pi_Speakers_Info.pdf
There was a 24" SEOS made for that.
There are builds starting with the SEOS-24 and the BMS-4594 coaxial compression driver.Here it is next to the SEOS-12.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Here it is over a speaker using a 15" woofer:
An externally hosted image should be here but it was not working when we last tested it.
There was a guy on the AVS forum that was trying to measure his speakers for some crossover work for the first time. He had never used the gear before and his first measurements were wrong, and everyone knew it. He said he messed up.
Well of course, those were the graphs that Wayne chose to use in his recent comparisons of the SEOS, even though he knew they were completely wrong.
My guess is that if I took one of Waynes horns and aimed it at the corner in my living room and used those measurements to say his horn was bad......people might get aggravated. But I don't do that kind of stuff.
Again, I have never once said anything bad about anyone's products. Ever. I've never tried comparing any of them, never called names, never been banned from sites because of name calling, had posts deleted due to name calling, nothing.
The only thing I have done is help get a waveguide produced that was designed by a bunch of smart guys on a DIY audio forum. Then ask others to design speakers around them. That's it. I help package up those kits in my spare time. Obviously that rubbed one person the wrong way.
The Pi mid-horn is loaded with a 10" Eminence driver which means it can probably provide CD coverage to considerably lower frequencies.There was a 24" SEOS made for that.
And the SEOS 24 can provide CD coverage to considerably higher frequencies.
The Pi cornerhorns are 3-ways with a DE250/H290c on top, so they probably go higher as well.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.