gedlee said:
I know this discussion is on waveguides, but lets say (hypothetically) that there some ingenious non-waveguide solution.
My guess is that it would have to be a mechanical solution or a layout solution rather than an EQ solution. Electrical signals tend to not know left from right before they get to the speaker.
I suppose this is what phase plugs, little doo-dads hanging in front of tweeter diaphragms, felt disks, and horn-loaded faceplates are all about.
Maybe you could do it with multiple drivers facing in a half-dome-shaped array but that would lead to other problems. Like the way a disco ball lights a room. spotty.
Or you could develop a swelling (ballooning) driver that expands in all directions rather than moving forward... theoretical equal radiation over your 120 degree wide cone.
Hmm. OK back to the normal discussion.
Matt
I'm getting into wave guides one of these days. It's just very interesting to see the possibilities.
y8s said:
And "maybe" we could somehow change the laws of physics so that things would work differently than they do.
"Maybe"s are fun to think about but usually don't get the job done. You have to do what physics lets you do and the hard part is that you have to know what that is. I been doing this stuff for a few years now and I have not found a solution to the problems beyond what I am currently doing. "Maybe" there are some, "maybe" not, my intuition tells me that there aren't any.
My main point is that the use of pistons in loudspeakers systems is fundamentally flawed. "Maybe" there are solutions - actually there is, its called a waveguide. It has a power response and pressure response that track each other meaning that equalizing one simultaneousy corrects the other. This is a requirement not a nicety. And I know of no other solution to this particular problem.
I need to go back and make something clear.
My post describing the use of off-axis measurements was intended to be a voice of (limited) experience in support of Earl's technique of using polar response data for crossover design and optimization (including equalization). I learned this from Earl - some of it literally by looking over his shoulder. When he and I first met I had already grasped the importance of radiation pattern uniformity (indeed, that was why I contacted him), but the "how to" parts that I have learned have all come from him. The only credit I can take is that my little voice piped up and said, "this guy knows what the heck he's doing - watch and learn", which in my math-challenged, attention-deficit, average joe way I've tried to do.
So credit for everything of value in my post should have been attributed to Earl Geddes, because he is my source. Someone once accused me of being a disciple of Earl, and yup I suppose that's true.
Duke
My post describing the use of off-axis measurements was intended to be a voice of (limited) experience in support of Earl's technique of using polar response data for crossover design and optimization (including equalization). I learned this from Earl - some of it literally by looking over his shoulder. When he and I first met I had already grasped the importance of radiation pattern uniformity (indeed, that was why I contacted him), but the "how to" parts that I have learned have all come from him. The only credit I can take is that my little voice piped up and said, "this guy knows what the heck he's doing - watch and learn", which in my math-challenged, attention-deficit, average joe way I've tried to do.
So credit for everything of value in my post should have been attributed to Earl Geddes, because he is my source. Someone once accused me of being a disciple of Earl, and yup I suppose that's true.
Duke
Duke
Thanks - its nice to know when people listen to what you have and say and learn from it.
I have learned so much in the last three years actually applying my knowledge to dozens of loudspeaker projects. I want to write another book, but I am actually still in the middle of several concepts - but thats a never ending cycle.
I was just about to write a book on "Audio Systems for Small Rooms" but then I found out that Floyd Toole has a book on the same subject coming out. Floyd and I don't agree on everything and he tends not to give away loudspeaker design secrets (guess why that is!?) so I still think that a book from my perspective might be good. I wanted to get an idea of what Floyds book would cover, but he wasn't willing to disclose much about it. I am still undecided about how to proceed.
In the mean time I have given a lot of info out here and its nice to be credited for what one does.
Thanks again.
Thanks - its nice to know when people listen to what you have and say and learn from it.
I have learned so much in the last three years actually applying my knowledge to dozens of loudspeaker projects. I want to write another book, but I am actually still in the middle of several concepts - but thats a never ending cycle.
I was just about to write a book on "Audio Systems for Small Rooms" but then I found out that Floyd Toole has a book on the same subject coming out. Floyd and I don't agree on everything and he tends not to give away loudspeaker design secrets (guess why that is!?) so I still think that a book from my perspective might be good. I wanted to get an idea of what Floyds book would cover, but he wasn't willing to disclose much about it. I am still undecided about how to proceed.
In the mean time I have given a lot of info out here and its nice to be credited for what one does.
Thanks again.
Interesting....
I have not heard Dr. Geddes work, but I've heard Duke's and it's very, very good. Many other folks think so too - Audiokinesis is generally a hit at any audio show.
You guys must be doing something right!
I have not heard Dr. Geddes work, but I've heard Duke's and it's very, very good. Many other folks think so too - Audiokinesis is generally a hit at any audio show.
You guys must be doing something right!
It is indeed unfortunate that I have been unable to exhibit my work for people to actually hear - its not that I haven't tried. But I think that it is safe to say, and I think that Duke would agree, that from what I have heard of Dukes speakers and what he has heard of mine, mine would probably be judged as the better sound by the majority. I know that I do things that Duke wishes he could do, but can't for various reasons.
Duke and I tried to make a business together, but he ran into some problems and ended up having to move to Idaho and that pretty much sank the ship. Then I tried to get a business off the ground in Thailand, but that seems like it may not make the "cash-flow" hurdle, despite making the best speakers that I have ever heard. Who knows where that will end up.
I recently went to NYC to upgrade a clients speakers using some newer proprietary changes that I had found in Thailand and once again I found that those speakers, even in an average room and a poor setup, sounded absolutely fantastic.
I have never had someone who owned my speakers not like them, although there aren't really very many of those people arround.
I displayed my work at RMAF once and found that totally lacking. People would walk in, listen to something that they weren't familar with and walk out grunting about it not sounding good. There is simply no point in trying to show off anything in that kind of environment so I have not gone back.
I still contend that every sound system setup that I have done personally is head and shoulders better than anything else that I have heard.
But that "fact" and a dollar won't buy a cup of coffee these days.
The market for high quality audio is remarkably small - and shrinking. The money these days is in automotive (billions) and Home Theater, but 95% of Home Theater is fairly low end small speakers. The volumes of low end products are amazing while the volumes of hi-end stuff is insignificant.
Duke and I tried to make a business together, but he ran into some problems and ended up having to move to Idaho and that pretty much sank the ship. Then I tried to get a business off the ground in Thailand, but that seems like it may not make the "cash-flow" hurdle, despite making the best speakers that I have ever heard. Who knows where that will end up.
I recently went to NYC to upgrade a clients speakers using some newer proprietary changes that I had found in Thailand and once again I found that those speakers, even in an average room and a poor setup, sounded absolutely fantastic.
I have never had someone who owned my speakers not like them, although there aren't really very many of those people arround.
I displayed my work at RMAF once and found that totally lacking. People would walk in, listen to something that they weren't familar with and walk out grunting about it not sounding good. There is simply no point in trying to show off anything in that kind of environment so I have not gone back.
I still contend that every sound system setup that I have done personally is head and shoulders better than anything else that I have heard.
But that "fact" and a dollar won't buy a cup of coffee these days.
The market for high quality audio is remarkably small - and shrinking. The money these days is in automotive (billions) and Home Theater, but 95% of Home Theater is fairly low end small speakers. The volumes of low end products are amazing while the volumes of hi-end stuff is insignificant.
Thanks, panomaniac!
"Always two there are... a master and an apprentice." - Yoda, speaking about the Sith.
Okay I'm joking here - I'm a believer and a student, but not an apprentice in the sense that one day I'll be able to do what Earl does.
Earl's designs are acoustically superior to mine in several ways - I say this based on what I know; there is even more that I don't know. I would indeed expect the majority to prefer his systems in a blind audition (I've made a few "tweaks" to mine since Earl heard them, inspired by his observations - and of course I haven't heard his latest refinements either but what I heard a year and a half ago was magnificent).
Thus far my speakers probably win WAF (which is like one general saying to another "Oh yeah? Well.. my army has prettier uniforms than yours!"). I go in a bit different direction in some areas, like the bass extension/efficiency tradeoff, and have a bipolar in my lineup (a different stroke, for different folk). So there may still be a niche for my designs even when the day comes that Earl's speakers are on the market here again.
Notice also that I have not discarded my dealer hat; I hope to represent Earl's product line when the day comes.
Duke
"Always two there are... a master and an apprentice." - Yoda, speaking about the Sith.
Okay I'm joking here - I'm a believer and a student, but not an apprentice in the sense that one day I'll be able to do what Earl does.
Earl's designs are acoustically superior to mine in several ways - I say this based on what I know; there is even more that I don't know. I would indeed expect the majority to prefer his systems in a blind audition (I've made a few "tweaks" to mine since Earl heard them, inspired by his observations - and of course I haven't heard his latest refinements either but what I heard a year and a half ago was magnificent).
Thus far my speakers probably win WAF (which is like one general saying to another "Oh yeah? Well.. my army has prettier uniforms than yours!"). I go in a bit different direction in some areas, like the bass extension/efficiency tradeoff, and have a bipolar in my lineup (a different stroke, for different folk). So there may still be a niche for my designs even when the day comes that Earl's speakers are on the market here again.
Notice also that I have not discarded my dealer hat; I hope to represent Earl's product line when the day comes.
Duke
"like the bass extension/efficiency tradeoff, and have a bipolar in my lineup"
Duke - sorry but I don't follow this. I am not sure what a bipolar bass extension is or I don't understand something.
Last I remember you and I were doing the bass exactly the same way - multiple subs placed around the room - which I would still contend is the best way to skin that cat. We simply analyzed the situation and concluded that IF one is going to use multiple subs, THEN it made no sense to push the LF extension in the main speakers. Now this does, admittedly, leave us in the situation that one really has to buy subs for our speakers if full LF extension is desired (which it often isn't), but that is a situation that we choose to accept.
Duke - sorry but I don't follow this. I am not sure what a bipolar bass extension is or I don't understand something.
Last I remember you and I were doing the bass exactly the same way - multiple subs placed around the room - which I would still contend is the best way to skin that cat. We simply analyzed the situation and concluded that IF one is going to use multiple subs, THEN it made no sense to push the LF extension in the main speakers. Now this does, admittedly, leave us in the situation that one really has to buy subs for our speakers if full LF extension is desired (which it often isn't), but that is a situation that we choose to accept.
audiokinesis said:
The ESP12 - 1/4 the size of an ESP15 and very nearly the same sound quality - would be my bet in a WAF contest. I am hoping that I can get my hands on some of those. The ESP10's are so small as to be called "cute".
Earl,
Well my wording was unclear - I was talking about two different things.
I've opted to extend the bass down into the mid to lower 30's (depending on positioning and room acoustics and amplifier output impedance), so my current models can be used without subs in most cases - but my efficiency is lower than yours. My little four-piece subwoofer system is mainly aimed at owners of planar speakers with insufficient bass extension (since the subject of subwoofers came up, let me mention that I'm using Earl's asymmetrical multi-sub approach with his permission). I agree that multiple subs spread around the room is the best way, but it's a tough sell in most cases. Dipole owners on the other hand are usually frustrated enough with conventional subwoofers that they're more open, and dipole owners have already accepted the idea that their speaker system is going to dominate the room.
The bipolar speaker isn't a new type of bass loading - it's just two sets of drivers, one on the front and one on the rear of the box, with (in my case) some vertical offset to the rear woofer to stagger the distances from each of the woofers to the room boundaries The main purpose of the controlled-pattern offset bipole is to increase the relative amount of late-arriving in-room reverberant energy without increasing the early (pre-10-millisecond) reflections, so they should be positioned to allow sufficient time delay before the reflected energy from the rear-facing drivers arrives. I am a strong believer in a relatively late-arriving, well-energized reverberant field. I use the same 45-degree toe-in that I learned from you. This is the speaker I showed at RMAF last October, which I think panomanic heard.
Duke
Well my wording was unclear - I was talking about two different things.
I've opted to extend the bass down into the mid to lower 30's (depending on positioning and room acoustics and amplifier output impedance), so my current models can be used without subs in most cases - but my efficiency is lower than yours. My little four-piece subwoofer system is mainly aimed at owners of planar speakers with insufficient bass extension (since the subject of subwoofers came up, let me mention that I'm using Earl's asymmetrical multi-sub approach with his permission). I agree that multiple subs spread around the room is the best way, but it's a tough sell in most cases. Dipole owners on the other hand are usually frustrated enough with conventional subwoofers that they're more open, and dipole owners have already accepted the idea that their speaker system is going to dominate the room.
The bipolar speaker isn't a new type of bass loading - it's just two sets of drivers, one on the front and one on the rear of the box, with (in my case) some vertical offset to the rear woofer to stagger the distances from each of the woofers to the room boundaries The main purpose of the controlled-pattern offset bipole is to increase the relative amount of late-arriving in-room reverberant energy without increasing the early (pre-10-millisecond) reflections, so they should be positioned to allow sufficient time delay before the reflected energy from the rear-facing drivers arrives. I am a strong believer in a relatively late-arriving, well-energized reverberant field. I use the same 45-degree toe-in that I learned from you. This is the speaker I showed at RMAF last October, which I think panomanic heard.
Duke
Let me make a comment relative to Earl's post #477 in this thread on the preceding page.
It would be a mistake to surmise that Earl has an unreasonably high opinion of his own speakers and therefore dismiss the knowledge that he has to offer because his wording isn't all politically correct. Consider the possibility that somebody out there is building the best speakers, and maybe just maybe it's the guy with the best science - whether or not he passed political correctness class.
Duke
It would be a mistake to surmise that Earl has an unreasonably high opinion of his own speakers and therefore dismiss the knowledge that he has to offer because his wording isn't all politically correct. Consider the possibility that somebody out there is building the best speakers, and maybe just maybe it's the guy with the best science - whether or not he passed political correctness class.
Duke
gedlee said:
🙁
Sounds like we won't get a chance to actually buy a pair after all?
That's a drag.
I sat there for hours that day and thought they sounded spectacular.
Truly re-adjusted my perceptions of what's possible in a loudspeaker.
But THAT is the whole problem isn't it?
Constant directivity speakers sound "dull" at first. The *real* truth is that conventional tweeters do it all wrong.
Dome tweeters do a million things wrong, but our perceptions are accustomed to these errors.
I'm always amazed when I see people drop $3000 on a new TV, then pair it with a $150 set of speakers. I think this is mostly due to WAF. Optimally a speaker like the Summa should just be hidden behind an acoustically transparent wall, where it's looks won't be an issue.
I can relate to what he mentioned in#447, but it would also be ineresting to hear what he will say in #477.😉audiokinesis said:
Basically there are two camps in speaker design. One technically orientated, and one feeling orientated. I, like Earl, am more technically orientated, but I do also respect those that are more feeling orientated. The difference between these two camps is that the Technically orientated is trying to do the best to reveal what the performer is trying to express to the audience minimizing the designers bias and interpretation. The feeling orientated is trying to take the music and give it his own interpretation. Probably very few have heard Earls speakers, but I think development and sales require totally different knowledge. Every designer should have a high opinion of his/her design, there is nothing wrong with that, and it usually means the designer spent enough effort to release somthing he/she is poud of, effort we should all respect.
One of my own challenges is how do I not get into a defensive mode during sales, and just have fun with the relationship. Once I auditioned a pair of speakers, and the designer kept asking me what I thought on the spot. I had to pull a specific CD and explain using a specific passage and a specific musical instrument to clearly explain things. Others have done the same when they auditioned my speakers, and I thank them very much. The thing about comments from people is that they don't compare apples to apples. Smaller speakers have different limitations than large speakers, and multi-driver speakers have different limitations that single driver speakers.
Earl,gedlee said:
I am taking a different approach to find out how to bring technology to different market levels. Technically, it may not be the best design, but if we want to raise the bar on audio quality, we need to first determine what is best for a specific market sector and price range. If the wife does not like the looks, then the market is small. If the wife does not like the price, then the market is limited. This is somthing quite interesting because after going through some seminars on brand creation and marketing, I get encouraged to come up with new designs. When we look at lots of brand names that women are familiar with, they started out at very high price levels, but gradually target various markets quite cleverly. Something we technology people just have to learn I guess.
I wonder if you have any speakers in Taiwan or not?
Patrick Bateman said:
Patrick - this is very perceptive and IMO 100% on. The very first time I setup a pair of Summaa and listened, I thought wow something is very very odd - they did not sound like I expected, they sounded very different. But I gave them a chance knowing that there was some real science there and maybe, just maybe, the science was right. Some three years later I can't stand to listen to anything else.
This should actually have been anticipated. We know from numerous marketing studies that first time listeners are atracted to things like bass boom, shrill highs and even high distortion. These are things that they can really "hear" and can hang there impressions on. Have them listen to a pair of completely nuetral loudspeakers and there is nothing to hear, they sound flat, dull, unexpressive - to the unknowledgable they just don't sound right.
This was the thing that struck me at RMAF (and I forgot to mention it) was that many people would conclude in only a few seconds that the Summas didn't sound good. Clearly, the situation that I was talking about was at work. And how would one combat it at a venue like RMAF where people are literally running from room to room? I just didn't see that as happening. Thats why I won't ever show at a venue like that again. It does allow for the "different" to be accepted.
But after three or more years of continual listening and development I am so certain of being correct that I have bet (and maybe lost) a great deal of time and money on it. I've not given up, but I have been seriuosly stalled.
Which is exactly what I do. See the WAF stems form the belief that speakers are furniture. If they are not furniture then the situation is quite different. But once again, we EXPECT our loudspeakers to look like furniture and no one is going to hide something like that. Basically audiophiles shoot themselves in the foot when they make really nice wooden cabinets that they want to put in the wifes living room.
soongsc said:
I think that it is important for people to understand my motivation. If I were told "You can get rich making and selling 'popular', but lousey speakers." or "You will have to stay poor selling quality ones." then I'd probably just quit and become a professor. I am not in the least motivated by making money. It's the work, the extension of knowledge, and the glorious physics that motivates me.
I am more than aware of branding, marketing, sales, etc., but I have no interest of doing that kind of thing to sell my work. My "partner" claimed that he was, but that seems not to have been the case.
I am fortunate enough to be able to take this position - my wife is a tenured adminstrator at a University. Nothing is more secure that that.
If my endeavours are not a success then I can only say how sorry I will be for all of you who will miss out on what I have been enjoying.