Phase Coherence or Time Alignment: Which More Imp?

This thread is really a follow on from a prior one that I let lapse. Thanks to everyone who contributed and helped me to better understand the importance of crossover design in building a loudspeaker. What I gathered from the last thread that there are opposing camps with different philosophies in crossover design. Leaving aside for a moment those that champion steep slope designs, my question is for those who have experience with speakers that are time aligned and/or phase coherent (using 1st order 6db per octave crossovers). Which is more important, phase coherence or time alignment? In other words, which more strongly influences the sound and performance of a loudspeaker? The reason I ask is because of the four speaker lines currently on my shortlist of floorstanders, three are either phase coherent or time aligned or both. The Wilson Benesch Curve's/ACT's and the Fried Studio 7 use 1st order crossovers but do not time align the drivers through the use of a slanted baffle. The Vandersteen 5's and the Quatro's both time align the drivers and use 1st order crossovers. I guess what I am asking is do you need to do both or is the real benefit in the crossover design? I'd appreciate your views.
BTW the other speaker is the Proac D25 and D38
"Phase coherence" and "time alignment" are related concepts.

I think what you're thinking of as time alignment is aligning the acoustic centers of the drivers with either a stepped or slanted baffle. This "phase aligns" them, so to speak. (Differences in phase are differences in time. Don't forget that a typical plot of a sine wave has two axis - amplitude and _time_.)

It's possible to have alignment without a slanted or stepped baffle. You have to look at what the listening axis is, and see if the extra distance between your ear and other drivers spaced farther away will make up the alignment.

Let's take a 2-way (TM, not MT) as an example. The woofer's acoustic center is 5 feet away from your ear. The tweeter's acoustic center will be farther forward. Step the baffle to put the tweeter farther back and you get alignment. Or tilt the front baffle back and you also get alignment of the acoustic centers.

Now lets assume that the woofer is at your ear level. So it's 5 feet away. The tweeter is 10" above the woofer on the front baffle. You now have a triangle with 3 sides, 60, 10, and 60.8. Just by the increased distance to your ear, you've done the equivalent of moving the tweeter back.

I'm sure that the designers of the Studio 7 took this and other factors into account, and that they're a minimum-phase design.
Partially true. In a hurry today so I'll be brief and general.

Time alignment generally refers to the alignment of the theoretical point sources of all drivers in a cabinet, such that the signals emanating from them at one moment in time all reach your ear at the same time. The sloped or stepped baffle tries to accomplish this - but of course, if you're not at EXACTLY the right seating height for that particular geometry, and EXACTLY the same distance from both speakers, and have no near field room reflections, much of the benefit is lost.

Phase Coherence problems are mostly created by crossovers as they split the frequency bands. So a time aligned speaker is no more likely to be phase coherent than any 2 or 3 way speaker, unless much care, measurement and testing and re-testing and re-testing goes into the crossover design. Without that - even though what's leaving the tweeter and the woofer may arrive at your ear at the same time, the signals from each have probably lost their phase "alignment" while travelling through the crossover and drivers.

There is some dispute over whether you could actually hear this if a crossover had a true infinite slope. But since the reality is that there is large overlap in the midrange where the woofer and tweeter are producing the SAME frequencies, if they're out of phase with each other it's bad news. In a worst case scenario, in an anechoic environment, they could perfectly cancel each other.

Not a thorough explanation but I have to run. I'll bet Roy frm GMA has expounded on this somewhere already.
Thanks to you both. Let me see if I understand this correctly. Phase irregularities caused by steep slope crossovers can be compounded by an alignment of the drivers which further distorts the arrival of sound waves at your ear. What I am wondering is which tends to have a greater impact on phase coherence--a steep slope crossover which delays the sound eminating from certain drivers or a poorly conceived alignment of the drivers? Let's take the new Fried Studio 7 for example (photos are on the website). It has a flat baffle with the tweeter flanked on top and bottom by a 6" midrange (top) and an 8" woofer (below). Is this a time aligned (or as Richard Hardesty would say "temporally aligned") arrangement? If so, great. If not, how much of an impact does this have on phase coherence? In other words, if the drivers are not temporally aligned then are the supposed benefits of 1st order crossovers lost due to improper driver alignment? Or is the phase coherent crossover 90% of the battle and the lack of temporal alignment only a small piece of the sonic picture?
Also, can we really hear these phase irregularities or what? Some say we can and others say impossible. All I know is that the phase coherent designs I've heard sound more like live music than designs using steep slope crossovers. I was at the NY Hi End Show last weekend and it was very interesting for me, after reading through the dispute between the "steep slopers" and the "first order crowd" in the previous thread, to walk back and forth between the Joseph Audio room (a steep sloper) and the Vandersteen Room (a first orderer). They were right next door to each other so I could drift back and forth. The rooms were identical. Both used (different) but high quality upstream components. Here is what I observed. The Joseph Audio room sounded like hifi and the Vandersteen room sounded like music. I could point out other specific differences that I heard but this pretty much captures the essence of my experience. I'm not prepared to say the this essential difference was due purely to the crossover designs of the two speakers but it may have SOMETHING to do with what I heard.
Steep slope crossover.
There are far too many variables from one system to another for you to conclude that the crossover method is the root cause of the difference. Our speakers are used by many discerning professionals who know what live music sounds like, since they are exposed to it every day.
Jeff, I totally accept your position. Having initiated the thread on crossover design (on which you were a gracious participant) I just thought it interesting to go back and forth between the rooms and listen to the two top models of reputable brands' that approach the crossover differently. I realize that other factors contributed to the differences I heard. I'm just wondering to what degree those differences are attributable to the diametrically opposed crossover designs. One thing I did notice was that the Joseph Audio Pearls seemed to image with greater precision than the Vandersteen 5A's. Localization of individual instruments was much easier. The images on the Vandy's seemed to float around. They weren't anchored in position as they would be live. On the other hand, the soundstage depth and width of the Vandy's was, to my ear, far superior to the Pearls. I wonder if others have had similar experience listening to either of these models and whether, again, the crossover design is in part to blame.
The speakers in our room were not the Pearls but a new model called the RM55LE. I am glad to hear that you noticed the excellent image focus of our design - something that low order fans often cite as a benefit of that approach!

The sense of musicality is hard to define - it is by and large a subjective topic. I think for some it means a softer tonality or euphonic balance.

What it means to me is to experience the full expression that is part of the musician's interpretation. Dynamics and subtle details that rivet your attention not on the mechanical aspects of reproduced sound, but on the human heart beating within the performer(s). Another poster mentioned that when he listened to an LP on our system that the system itself seemed to "go away" - and that is the highest compliment one can hope for.

A euphonic system will sound more pleasant on poor recordings, but it can never sound real enough to bring the performance back to life.
I don't believe you can demonstrate that having a time and phase coherent speaker is more important than having a just a phase coherent speaker. The problem in being definitive is not merely that it's largely a matter of preference - which it is, just like I prefer Patti Smith to Norah Jones - there are unresolved matters of psychoacoustics in testing something like this, as well as a particular design method's suitability to a particular use. For example, a time aligned speaker might not be appropriate for extreme near field listening; it objectively wouldn't be the best for that situation. But it might be the best in another situation.

Of course, Jeff J. thinks each kind is less appropriate for virtually every situation.
I just wouldn't focus so much on design. I would focus on what I thought would satisfy me over the long haul or you will be one of those with speakers for sell every few months. This debate about time and phase coherent speakers vs steep slope will go on forever with nothing being accomplished. Everyone is in a camp and will probably stay there until they gain enough experience listening (and becoming a critical listener)to understand what they are hearing and why.
I am in the time and phase camp and got there after many different speakers and years of analysis and listening.
Technically, ALL speakers are a trade off of one sort or another. However, phase and time aligned speakers come closer to reproducing the input signal than other designs. Steep slope speakers may swoon the listener but they have scrambled the output signal compared to the signal coming in. Would you buy an amp that screws up phase and time domain (actually high global feedback amps do this)?
Time and phase speakers are not perfect and there is lots to understand but for me, they simply sound more musical. Are they right for you? Only you can answer that.
Now, with all that said, one has to decide on what it is that they are after, wether it be dynamics, transparency or whatever. It is not arrived at easily. As your experience grows (and I actually think age plays a factor here)things will change and you may appreciate other designs.
So just don't get so caught up in all the design BS. It confuses the issue and will ultimately lead you to disappointment. Find something you like and go with it.
Also, no disrespect to Joseph Audio, but do you think he would recommend something he doesn't build? It would be like a Ford dealer telling you to buy a Toyota! If someone really cares about your musical enjoyment, they would tell you to satisfy yourself. It is you that has to be happy not them!

I went into the speaker business because I believe we have something special to offer. I think if you look at our track record, "best sound at show" year after, "speaker of the year"
excellent reviews, and a loyal group of Joseph Audio speaker owners who wouldn't give them up for anything else.

I care deeply about musical enjoyment, enough to want to share it with others - enough to bet the farm on others being able to hear it for themselves.
I have no doubt you build a quality product but so do a lot of others who believe in them as much as you. It's good that consumers have choices. If everyone liked the samething then we wouldn't need but one manufacturer! I'm all for driving the economy. But, who is to say what is right and what is wrong when it comes to listening on a personal basis? Nobody can sure decide which slope to use. Seems the best is whoever is doing the talking.
All I can do is relate my experiences in these threads for better or worse. I have been at this over 35 years. Based on that experience, it is wise that people go out and listen for themselves just as I have done(and the fellow who started this thread.) Does this mean I'm an "Authority?" No, it doesn't, but I do know what sounds good to ME and the point of these threads, I thought, was to share our personal experiences, not those who scream loudest get heard.
Most of the population has no clue to what crossover design is all about. I'm not so sure they need to know. Most don't know how a car is designed. They base their choice on looks and performance just as most do with speakers. I think here in the US, we boarder on false advertising way too much. It then makes everyone suspicious of every claim.
All I'm saying is you must satisfy oneself. It's your money and your satisfaction at stake.
Go out at listen for yourself and make a decision based on ones personal wants and needs (ie; does it look pretty or whatever.)
This "Best of the show" stuff is a little free advertising in these threads don't you think? Is that why these threads are here? Or is it for you to justify a point?
Your participation is always welcomed as any manufacturer would be but don't use it as a free format for advertisement. It just proves my point---your design based on your opinion is the one to go with. Hell, it may be but buying based on a show, review or especially advertisement is risky business at best. Tell people to compare your speakers side by side in the same room with the same electronics. Be confident enough to say comparison is welcome and recommended. That's all I'm saying.
How is it possible to build a phase-coherent speaker using 1st order filters?
I learned in electronics that a 1st order filter (ie 6dB slope) shifts the phase between woofer and tweeter by 90deg;a second order (12dB slope) by 180deg; third order (18dB) by 270 and a 4th order (24dB) one by 360deg.
This should mean that it is impossible to create phase-coherent first order systems, in a system using second order filters you'd have only to invert one driver to achieve coherence, a third order system again is impossible whilst a fourth order system is always in phase as it has been shifted by a full 360degrees.

Now, when it comes to to transient response and xover "ringing" ( electric resonance) a first order filter is unbeatable as the transient response is helped by having fewer passive components and the filters total inability to resonate. But for phase-coherency they are, together with 3rd order, the worst possible solution. You can fix 180 and 360 degree shifts, but theres nothing fixes 90 deg shifts, other than active electronics like in better bass-management systems for HT.
Dear Golix,

You are right in several ways. First-order filters shift the phase of each driver by 45 degrees, one driver's output is "leading", the other's is "lagging". Thus, the Phase Difference between them is 90 degrees, as I think you implied. But your concerns about the impossibility of achieving "phase coherency" for "odd-order" crossovers are not warranted:

For a second order filter, the phase shift is 90 degrees per driver at the crossover point. This is where your 180 degrees comes from- as the Phase Difference between them, at the crossover point. That Phase-Difference analysis extends, with your numbers, for the third-, and fourth-, and higher-order filters, at their crossover point.

Higher-order circuits, from 2nd on up, cannot be made time-coherent, because that Phase Difference each one exhibits at the crossover point does not remain a Constant Phase Difference when the tones move away from the crossover point. In other words, the drivers' Relative Phase Difference is always changing- which can be heard in many ways:

- As an image always shifting (depending on the note).
- Complex timbres which are not realistic.
- Dynamic attacks that are slurred.
- Truncation of the depth of the image in that crossover region.
- An audible "disconnect" in the depth of the image heard from the tweeter, compared to depth of the image revealed by the woofer. When an instrument demands some output from each of those two drivers, the same instrument apparently exists in two different rooms.
- There is "height" in many recordings.
- The speakers "don't measure like they sound."

Listen to a tambourine on a high-order speaker (an instrument that requires output from woofer AND tweeter), then listen to it on a decent pair of headphones, which are most always time coherent across that tambourine's tone range. You'll hear most all of the effects listed above from the speakers. Then compare using applause, acoustic guitar, piano, voice, using any wideband signal with transient complexity.

The audible effects of a constantly-changing phase relationship depend entirely on your choice of music- on what frequency range your music occupies, and also on the "frequency content" of each transient.

Different listeners use different music, some that easily reveal phase shift around the crossover point. Most crossovers to tweeters occur around 2 to 3kHz. A constantly-changing phase relationship between the two drivers above and below that crossover frequency has specific audible consequences we have all heard. In my experience, it is the leading cause for someone to say a speaker is "too analytical" or "too revealing", "too forward", or even "too exciting". One often remarks that a recording is "too harsh, too hard to listen to." It is why the preferred audiophile recordings are rather bland.

If the speaker designer physically steps that out-of-synch tweeter back from the woofer, and/or "pulls" the crossover point apart between the two drivers, you often hear "laid back", often with "a little less energy around the crossover point."

So, why use a first-order filter?
That Phase Difference remains Constant for a first-order filter: The output from the two halves of a first-order filter are always 90 degrees apart, on every frequency, not just at their crossover frequency. So their Relative Change in Phase Difference, at every frequency, is zero.

With a first-order circuit, the image does not wander on different notes, transients are preserved right down to knowing when the tip of the tongue left the roof of the mouth, and existing distortions in the recording or in your gear are not re-distorted, by being smeared out in time.

So, after passing through a first-order circuit, when the high- and low-passed signals are recombined, then the original, transient perfect, signal is recreated. Of course for a speaker, those high- and low-passed signals can emerge from drivers that have their own severe, mechanically-caused phase shifts. Perhaps the high and low sounds start off at unequal distances from your ears, or arrive at different times from "duplicate" drivers (like multiple tweeters). They could be time-warped from improperly-designed Zobel networks in the crossover circuit. Then there is a good chance that the high-passed signals will be "hazed-over" by cabinet reflections.

Fortunately, all of these difficulties can be minimized.

I hope this clarifies things. Thank you for your participation in an interesting thread.

Best regards,
Roy Johnson
Founder and Designer
Green Mountain Audio
Thanks Roy,
indeed these difficulties can be minimized with careful design!
Thats why I use Tannoy LittleReds. It uses a combination of
first and second order filters. The phase response curve shows it to shift the entire audio spectrum uniformly by 30deg compared to amp output with a slight dip and a bump around the crossover frequency (+8deg,-10deg). So it acts as a time delay
(unavoidable) with a maximum phase shift of 18deg but this is limited to about 200hz either side of the x-over frequency ie the shift starts at 1k,
goes through zero (that is the 30deg total shift) at 1.2k rises again and is back at zero (30deg) at 1.4k.
Also, being point sources, they stay in phase no matter where you are in the room, unlike common multi-driver systems.

Personally, I have NEVER heard a speaker to be 'too analytical' or 'too revealing' although I heard speakers being 'too forward' or 'fatiguing' these usually featured metal-dome tweeters. I would have thought that 'analytical' and 'revealing' are essential attributes of any accurate speaker.
Without being 'analytical','revealing' and accurate any critical listening is
obviously impossible. People having problems with these attributes should probably by a Bose waveradio and just be happy with all the money they saved. They are the reason that high quality audio is in the dire state its in.
(Sorry, didn't mean to be ranting but statements like 'too analytical' just get me going. I am also aware that it wasn't you who said it, so don't take it personal.)
In my own experience, based on spending time in recording studios and listening to every speaker I can since I was 15 I have to say that Tannoys are closest to the real thing followed by decent studio monitors. Than come a variety of planars ( fantastic at low volume but lacking in macro dynamics),
full-range drivers ( great dynamics and imaging, bad at low volume, dodgy treble and (if in a horn) lumpy bass response.
After that the majority of dynamic speakers who do everything somewhere between average and badly.

This, of course, is a grotesque over-generalization as there are really bad studio monitors and really good HiFi speakers. I have not come across any
green mountain gear here in Europe so I cannot say anything to your product.
Overall you still have to look at the whole speaker-system and not just the xover, my Tannoys have loworder filters and sound fantastic, most studio monitors use fourth order and sound very good and back in the 80' I came across some 5way, first order filtered Dynaudios which also were excellent!

Cheers Golix
(haven't founded anything but...
can explain gravity without
bending space)
Roy, I played sax for over 30 years and I became sold on time and phase speakers when listening to this instrument as well as other woodwinds (and other various instruments.) Other speakers with high slopes just destroyed a lot of what should have been there. For some years (in the past), I blamed it on electronics and/or the recordings. With time, I discovered what you already knew. I have found very few speakers that get the attack, decay and harmonics correct for me. It was extremely interesting to read your explanation and examples. It definitely follows what I personally hear.
I have noticed the positive recommendations you are receiving here and other places on your speakers. With the apparent unfortunate situation with Meadowlark, it looks like you, Richard V. and Thiel must carry the load.
It is good to see Green Mountain Audio being successful. I'm certainly going to have to give your product a whirl at some point.
Curently, I am investigating no negative feedback equipment. With time and phase coherent speakers, it has proven to be extremely interesting. There is something to it for sure. It seems to open up the presentation even more and further enhance that "You are there sensation." It is also interesting that time and phase coherent speakers, for all the critcisms they get for being laid back and not transparent, sure show this difference.
Though my own sensibilities lie with Roy, and the very cogent points he put forth, I want to make it clear that as Jeff Joseph basically said, there's more than one way to skin a cat. Jeff's speakers have established themselves as fine a loudspeaker as one can find in this hobby. I admire and respect both he and his products.
Jeff Joseph seems like a very good guy, he gave a nice presentation in New York last week. Yes, with his speakers' performance he finds himself in good company, but only through a time coherent speaker can one accomplish the acoustic output as a duplicate of its electrical input. The infinite slope cannot maintain the acoustic waveform.

Richard Vandersteen though that I'm more sensitive to time domain shifts than most people. Not that I have golden ears, but it's just where my sensitivies lie. For other listeners, higher order cross-overs may be perfect for them - so yes, there is more than one way to skin a cat.
I have no doubt Jeff Joseph is a good designer based on his beliefs and having never met the man, I'll take your word that he is a good fellow(which I'm sure he is.) However, I'm of the camp that there is only one way to skin a cat. These two designs are too far apart for even a sorta right pick between them. Sorry, this falls into a more right or wrong area. Otherwise, it forms a who cares theory (which is probably a good one since most will pick what sounds best to them no matter what the design.)
My opinion certainly doesn't invalidate anyone else's choice. I'm sure these speakers have a loyal following just as most other brands. They just weren't for me.
I've tried to like the sound of Joseph speakers, but I don't think I ever will. It seems a lot of other listeners think they're great, so yes, it's possible to design a time in-coherent speaker and still have an audience. Personally I stand behind time coherent design. A lot of the (expensive) speakers that I heard at the show in New York last week struck me as designs that were made by music lovers who never actually go out and listen to live music. I've always found time coherent designs to be all about music, and not hi-fi.
I have to agree with Zkzpb8. Overall I thought the sound at the show was pretty bad. I can only think of one or two rooms where I was really enjoying what was going on and the Vandy room by Audio Connection was, IMHO, clearly the best. Most of what I heard elsewhere was crappy audiophile stuff--you know, "great" recordings of bad music and sound effects. Far too many "demonstrations" and far too few folks who actually seemed to like music. In the Audio Connection suite they played all kind of stuff and, to my ear, it all sounded great. It's funny, I've been looking and listening to speakers for about a year now and have boiled my search down to 4 models--three of which are phase coherent designs. I may be one of those who is also sensitive to phase and time relationships. I donno.
"I have noticed the positive recommendations you are receiving here and other places on your speakers. With the apparent unfortunate situation with Meadowlark, it looks like you, Richard V. and Thiel must carry the load. "

There are others. Karl Schuemann is working on phase-correct designs, and then there are a couple of people or groups of people carrying on Bud Fried's work.

In addition, I wouldn't count Pat McGinty out just yet. :-)
The "X number of listeners thing it sounds swell" argument doesn't impress me because it also applies to Bose speakers...

"Professional" listeners? Like recording studio engineers or musicians?

I'm not sure I'd rate most studio engineers as a good recommendation for speakers. They often are listening for different things than the end user of the recording is.

I might respect a musician's opinion more, but I have no way of knowing whether they have actually compared "more correct" speakers to "steep slope" speakers, or whether they just find that Brand X "steep slope" speaker is better than a bunch of other incorrect speakers.

My opinion is that a speaker with steep slope crossovers doesn't stand much of a chance of being able to reassemble the original waveform at my listening position.

Whether that's important, and whether "time and phase coherent" speakers can reassemble the wave form correctly or not is where there's a lot of argument.

At that point I have to fall back on my own listening experience, and say that I feel that phase-coherent designs work better for me. They provide a better window into the recording.
That should have been "X number of listeners _think_ it sounds swell."
Skrivis, I was refering to major manufactures of well established companies. It is good to hear that Bud Fried's work is being carried on. I always had a ton of respect for him and was sorry to see his passing. Audio lost another great man. If I may quote something he said, "Someday, all speakers will be time and phase coherent." He truly believed in this concept.
I didn't want to say much about Pat McGinty because I really have no first hand knowledge other than he closed shop. I wouldn't think a man of his potential would stay down for whatever reason. I agree with you and would expect his return in the future. Lets hope so.
So far, in the time and phase camp, I have tried Meadowlark, Vandersteen and Thiel. I have really got to try Roy Johnson's designs out at some point. I also go back to listen to steep slope speakers from time to time to help keep my perspective. Now that my kids are out of college and out of the house, I have plenty of free time. It's nice to get back into enjoying the hobby again.
After this and other long, fact filled threads on the topic, we still don't know that Fried did not and doesn't make time aligned speakers.

He believed in first order series crossovers.

On that topic if Roy Johnson happens to read this: What about the higher order series crossovers like the Kaminsky? They claim phase coherence. Have you studied these? Thanks.
It has been a while. I recall seeing phase coherence but not time coherence. I did not pursue Kaminsky's work because it could only be implemented in an active crossover. Again, it has been many years, and I could be thinking of something or someone else. What I remember for certain about Kaminsky's work is that it was excellent, and it is worth examining again. Thank you for the reminder.

Series crossovers have advantages, and disadvantages. We use parallel circuits, which seem to have fewer disadvantages. I do not agree with statements like "better dynamic coupling of the drivers, using a series circuit", as I have never seen any definition of what that actually means.

Bud Fried made so many important contributions- he will be missed. The first speakers I heard that opened my ears in many, many ways were his original IMF transmission line speakers, in 1972.

Warmest regards, Bud. Thank you for everything.
Roy Johnson
Founder and Designer
Green Mountain Audio
First order crossovers, 6 db per octave, are the only one's which 'supposedly' offer the least phase shift, that is energy storage, and shift from one driver to the next.
The issue at hand is the enormous amount of work that each driver, since it rolls in and rolls out at 6 db per octave, has to operate over too wide of a frequency bandwidth,causing notable limitations in dynamics , or distortions which are unacceptably high.
When I worked for THIEL Jim Thiel would attempt to compensate (in part) by using special pole piece which allowed for linear treatment of the magnetic field over the coil in the driver throughout its proposed excursion, since that excursion was by necessity very long throw. This is like saying the sky is blue, because the ocean is too. It is a self defeating, and repeating argument, and certainly a condrum for designers who chose to use this cross over design.
Some designers, feel that first order crossovers place too many negatives in the picture for a natural and relaxed sound; not to mention that the lobing effects of the drivers at various distances (you do the math) causes frequency anomolies, such as suck outs and the inverse, causing room reflexions which look nothing like the output at the speaker. That may sound benign, but imagine, every echo and room reflexion sounding different than the signal at 8 feet, or at your listening position, this causes for a confused signal to the listener. So, some question, "what if a combination of slopes could create a sound"... that, at the listener and throughout the room, are close to identical as the actual measured output of the speaker; i.e. no lobing issues, and no tweeter having to operate like this, in this scenario. Using a 3K crossover point as many do, (too high in my opinion) but in that instance, the driver is down 6db at 1500Hz, then 12db @750Hz, 18db @375. (It's after midnight don't check the math with a calculator PLEASE) So significant midrange information is coming from a (generally 1" dome). That, IMHO is too much to ask of a driver of that size and excursion potential. Plus, again the issue of the lobing, caused by sharing of common frequencies, with the mid range, which in turn is also, asked to put out vast quantities of bass, making enormous excursions. A recipe for disaster for the wrong driver.
This first order design is one of those engineering arguments which looks great on paper, but in practice faces significant challenges, and the creation of drivers which operate in a manner not generally available to them by dent of their very design, and the known limits of drivers, given the laws of physics.
Other solutions, other than phase coherence gained through first order networks, IMHO is the answer. But time and space don't allow for all to be said here.
Thank you. Those crossovers interest me, but it seems the patent holder (?) has a kind of underdeveloped speaker site and seems to charge a lot for the speakers, which, of course, I've never heard.
I don't understand your post. There is no 'patent holder' per se on cross overs; what 'site' are you refering to--and who charges a lot for their speakers?
Sorry, not being sarcastic maybe I'm just thick today, but I really don't understand your comment/question.
Please clarify.
It's odd that Bud Fried, (who I had the pleasure of knowing) is part of this conversation, and as Lincoln might have said, "it is altogether fitting and proper..."
Bud Fried's TL series made be become an audiophile back in the early 1980's. I fell in love then, with the, almost polar opposite, THIEL, and met, eventually worked for Jim Thiel. The one undeniable comment about Fried, or IMF as they were after the first split, (women, you know)--were the most 'musical' speaker around. They had the magic, and people didn't talk about 1st order, or this and that, they were too busy playing music to talk about it.
Plus, with no 'time alignment' they imaged wonderfully.
But, and this is not sentimental fluff, the music came out of the boxes just like it's supposed to.
I guess, Fried more than any other product was my inspiration for my speakers, (to be released, God help us soon). I just tried my best to make them sound like music. Forget the popular jargon, and make them sound like something that makes you want to sit 'all the way through an album', and not get up and change the record or disc, because it sounds to 'bright' or amusical.
An acquaintence came by during my final voicing, and said, (this is from the heart, not a commercial) 'your speakers make me want to listen to music again." Honest to God, a comment like that will put tears in your eyes.
I think about Bud, (and Jim) and their influence as opposite as they were, and thank them both, because without either, the industry would be poorer.
Sorry for the melodrama, but I mean every word.
I have to agree with Lrsky, although I usually prefer not agreeing with anyone. The theories of speaker designs are interesting, but the actual experience is what matters ultimately. All speakers are compromises - and overall it's pretty amazing that you can etch a pattern into plastic with a cutting head, play it back with a tiny diamond, amplify that signal a gazillion times, and then have it come back at you sounding ALMOST exactly like it did going in.

I've heard many of these new "wonder-speakers" with all sorts of expensive drivers and internal wires that are just unlistenable (to me), and I've heard 20 year old designs with some updates (like my Dahlquist DQ-20i's) that keep beautiful music sounding that way. And despite whatever a designer does with Phase and Time, room interactions play a huge, huge part in what you'll actually hear.

I have heard both Joseph Audio Pearls and Green Mountain C-3's a fair bit and they're both great speakers with different attributes for people with different "ears".
I had a trade pass at the last HES San Francisco and went back and forth without having to wait on lines between Joseph Audio and Avantgarde Trios and came to the conclusion that if I had to live with one or the other at home, I'd pick the Pearls as less fatiguing - not what you would predict for a steeper slope crossover.
I also have spent a few hours audiotioning GMA C-3's and found them to be spectacularly dynamic, very detailed, and also a bit bright/forward in the mids (for my taste) - also not what you'd predict from a 1st order design.

So go figure...

Great post.

In my opinion, the only manufacturer who really implements low order crossovers properly is Jim Thiel. His crossovers are complex, but he is much more advanced in his thinking than any other designer in that camp. If you took his speakers and ran them at moderate listening levels in a well damped listening environment and sat at just the right height you'd hear the best results that particular method has to offer.
Actually, I WOULD expect the 'forward' or brightness from a first order design. It's almost a sure bet that everyone who's heard THIEL would agree that they sound forward in the high frequencies. My speakers measure flat, (inasmuch as any can or will) yet the tweeter is invisible to the ear; this has the effect of making fatigue a virtual non factor. Plus older recordings, some of the sixties abortions which sound so awful, (this was the moment when engineers found the eq switch, I like to say), and they sound different than contemporary, but listenable, instead of ear splitting.
The principal design behind any speaker, should be fidelity, that is the output should equal the input, and here we're walking a fine line. A quarter of a db across a broad enough bandwidth, makes all the difference in the world tonally.
I theorize that the forwardness comes from the rather 'odd' sounds created by the multiple bandwidths covered by the drivers-- and how tonally mismatched they are in reproducing what should be similar sounds. That 'blend' of sounds creates a secondary sound, amusical to me, which I find offensive, and 'bright' as described by
Opalchip, even though he surmised that first order 'would not' sound bright.
This is based on listening to the contribution of the drivers individually, as they 'try' to play frequencies, which reside normally, well out of their range.
Theory, not scientific fact, but my ears hear the composite of each individual driver, and the sound is abberational.
Dear Josephaud- with my unbridled respect for you, I hubly accept this complement.
Thanks, and I look forward to seeing you again soon, (perhaps in Vegas.)
> There is no 'patent holder' per se on cross overs

Please forward your remarks to Richard Modafferi _and_ Roy Kimber, and let me know what you find. OTOH, I don't know if Kaminsky is still alive, or if that site is a licensee of his, or what. (Here's a small hint: "Our Infinite Slope (US Patent #4771466) reduces wave interference down....") God, I mean it's so obvious.

In a similar vein, your opinion that you would expect a first order crossover speaker to sound forward is without foundation. It's fine if you like Thiels, or if you like that attribute, but there are other first order designs which are anything but bright, including Vandersteens and presumably out of your awareness Symdex.

When Thiel was first getting dealers, including Herb Hamburger in PA, he maintained that other speakers rolled off the high end improperly. It was a design decision, which in my opinion he has somewhat moderated since the early days.

And most speakers do not measure flat to 20khz, although in recent years more and more might than was the case in the past.
I said there are no patent holders on First Order Crossovers, not 'any crossovers', and I didn't mention the Infinite Slope or Ray's special, relatively new crossover, as I recall--the issue at hand though, isn't that no one can patent them, its just that one infinitessimal change makes enforcing the intent of the patent impossible. Jim Thiel who had not patented anything up through 1999 when I worked for him, said, and I am recanting his words to me, as to the efficacy of patenting what I thought were some great ideas. It simply isn't realistic to patent certain items which are replicated with such frequency and similarity, in which changes of small measure destroy your case in court.(Not to mention the cost of enforcing, and protecting your patent.) I do notice from his web site that he has a patent pending re his SmartSub.(So all things change in time.)
The comments I made about first orders sounding 'bright' were, in this context, probably more regarding THIEL. Vandersteen is not only, not bright, many people find it lacking in what they call fine detail. I say they sound rather neutral and pleasant. One designer I was roaming the CES show with when it was still in Chicago, so an Ice Age ago, said upon hearing the latest Vandersteen, "Typical Richard design, not bad, won't offend anyone, but it lacks enough detail to make it interesting."
I have a wide berth of listening experiences, having visited about 100 stores across the United States while working as Director of Sales for THIEL, owning a retail store for 12 years, and attending every CES for many years; and my experience was that MANY 1st orders sound odd, and as Joseph of Joseph Audio was pointing out after my post, Jim is the most talented or advanced of the known designers employing first orders, and that the issues surrounding that design are, at least to him the same as to me. "Sit in the right place, eliminate room reflections, and play them at a moderate level." (I paraphrased to save time.)
What I hear, (and I don't expect you to hear the same thing by the way) is that the sounds emanating from the drivers well out of the dominant sound (frequency) range, sound odd, and amusical, creating a sound which is foreign, (to me) from the orignal and or intended sound.
Jim Thiel, insofar as I know, still thinks that all speakers should go 'flat' to 20Khz, it's just that most designs don't achieve that goal.But the perceived 'brightness' that people carp about with THIEL's aren't near the 20Khz region anyway, more like the 4 to 8Khz regions.
I hope this clarifies what I meant in my previous comments.
I'm unsure if we have trolls in this thread. Lrsky used to work for Thiel, goes through an attack on first order crossovers, then says he likes Fried speakers, which are first order. It doesn't make a whole lot of sense, along with his rank ignorance on the patent issues. Josephaud then offers highly damning praise to Thiel speakers, thus offending them and Roy Johnson (decidedly not "the only manufacturer who really implements low order crossovers properly",) whose participation here is far beyond that of others in terms of technical information.
>I said there are no patent holders on First Order Crossovers

This is not what you said. What you said is right in the thread, and I quoted it. Go read it again. At any rate, your incorrect claim doesn't apply anyway, since the Kaminsky crossover I referenced is not first order. So sorry for your multiple confusions.

I didn't read the rest of your post.
Two things really, Suits me. Fried yelled at me constantly about THIEL speakers and their damnable first order crossovers. He did not use a straight 6db per octave crossover as proven on his archived information which I would be glad to send to you.
Second, I am sure, and I apologize that I misspoke about the Patent--what I should have said is, if there are any active patents on first orders, (the subject here) they are not being inforced, due to the issues you chose not to read.
Let's be friends, in the spirit of Bud, one of the industry giants. His spirit is alive in all of his products, that's for sure. And boy did he hate a true first order. My wife would laugh at me, as I would hold the phone away from my ear, as he would yell about the 'evil' of that kind of crossover. "They don't work, Goddamnit", as I recall. He was a hoot, who I will surely miss.
Friends, I hope...
BTW he used a first order on the bass, and a third on the mid treble, as I recall.
In response to the above, in Richard Hardesty's "Audio Perfectionist Journal Watchdog list," a letter was posted by Bud Fried that was aimed at JA in Stereophile for stating that time and phase were unimportant. He went own with an explanation and then concluded by saying "I think someday ALL speakers will be time and phase coherent." I don't remember wether it was actually published or not but it does seem to be in direct contrast to the statemnt(s) made above. Now, did he have a change of heart in his old age, was he BS'ing JA or what's the deal here?
At any rate, it's nice to know that Richard Vandersteen is a second rate designer of time and phase coherent speakers. I feel somewhat disappointed that I and hundreds of thousands of others have put up with a rolled off speaker lacking in resolution and of questionable design. I guess I could call him tomorrow and ask for my money back. Of course he then would ask why and I would have to tell him that based on Jeff Joseph and some other fellow who has speakers coming out are the only ones who know how to make a speaker correctly. He would then ask where I saw this and I would say on 'Audiogon." When he got through laughing, he would probably tell me to kiss his ass!
My exact comments regarding my opinion of Vandersteen was, that, " I say they sound rather neutral and pleasant."
As far as coherence, the initial thought of the discussion, has been lost. It had to do with Suits Me stating that "then says he likes Fried speakers, which are first order."
If one goes to Frieds stated work and crossovers on certain products, which I just referenced tonight, he used 3 db per octave slopes on the woofer, then 18 db per octave, which is third order cross over on mids and tweets.
This has turned into a hornets nest of confusion, for which I can take some credit probably. But Fried, most definitely was NOT a proponent of true first order networks as described as 6 db per octave, the proof of which is listed with his archival work, and my personal conversations with him, in which he found that to be unacceptable, in the design of loudspeakers.
I have nothing but profound respect for Rich Vandersteen, and what was said in my quote was by someone I was with. Truthfully I probably shouldn't have repeated it, other than to point out that his speakers are NOT forward sounding as are the THIEL's.
The 'some guy' who has speakers coming to market is me, Larry Staples, who studied under Jim Thiel, and Albert Von Schweikert, and has 25 years invested in the industry.
It takes thick skin to take a stand on these, supposedly hobbiest friendly sites. If I offend anyone by recanting past experiences I am profoundly apologetic. I found Bud Fried to be passionate, and brilliant. He was a grad of Princeton as I recall, and a fantastic representative of the field of audio, as is Mr. Vandersteen.
We all have disperate ideas on what works in design. Nobody has all the answers. I am struggling to make my product come to market and only hope to have a fraction of the success that Bud and Rich Vandersteen, and Jim Thiel, as well as the others who have contributed so much.
My speakers are a tribute to design by listening, not intellectualizing what 'should work'. I voiced my product, making it sound as I personally think real music sounds like. Some will like it others won't. Be aware that I am only ATTEMPTING to add to the science and art of building speakers.
Please, no one, take offense at any misspoken words.

Larry R. Staples
LSA Group
I'm really having a great time watching the discourse in this thread!

Larry, I am happy to hear you were a friend of Bud's. I really do feel an emptyness in his absence. I am honored by all of which is being written about him here.

What I personally feel is Bud's greatest gift to us is his lifetime of continually improving the craft that so many of us (Jim Thiel, Jeff Joseph, Larry Staples, Richard Moddafieri, Ray Kimber) have immersed ourselves in with all of our hearts.

It is true that Bud was outspoken, opinionated, and could be downright ornery. However, for those capable of seeing the truth, he dedicated his life into laying the foundation which we all could build upon. He knew that life was finite, but also knew that the art/science would never cease. His hope was for us to learn from his life experience - all of the work, successes, mistakes, etc. to build upon his lessons learned so that we did not have to reivent the wheel. Seeing people ripped off by shamanism or BS would enrage him. If that ruffled feathers along the way, I can think of no higher compliment to pay the man. For those who he came to become fond of, there was boundless fun, humor, respect, generosity, and love.

While I believe and am invested in first order series crossovers, low Q drivers, transmission line loading of the bass and midrange drivers, and time alignment, who am I to say that another approach is not without merit? Again, there are so many fine sounding speakers, in many different flavors, that we can respect those who have faithfully dedicated themselves to the craft.
Trelja long time no write.
Yes, Bud was a legend, and old time, old fashioned, 'tell it like it is, kind of guy.
Last night when I started writing about how much I loved his speakers, (and owned the ALS30's, I think they were called though my heart was with the TL 50's at the outlandish cost of, I think $2500. in 1978) it was frankly before my techno awareness. So when I was properly upbraided for liking him, thinking his work and Jim's were (no pun) polar opposites, my memory kept telling me that he was not a first order guy.
Then when someone wrote that note about me liking him, I had to go, both to my memories of our many conversations, then to the archives, and research his work.
There, in what appears to be old Royal typewriter print,
gotta love the days before computers, was the description of his design. I mispoke, (it was after midnite and I was tired, 6db in the bass, though above I mistakenly said 3db,
anyway, then 18 db per octave in the mid/tweet crossover.
Heck, I should have remembered, as I mentioned above, he was a hoot. When the G2A(?) came out to good press, he would call me weekly and raise holy hell with me for selling THIEL's CS3. And his language, Hell I thought I knew all the words, he must have visited the Profanity 101 Classes at Princeton. HA!!! He was the most loveable curmudgen.
I remember a few years later seeing him in Chicago, the home of the Consumer Electronics Show for years; I saw him, and as I recall he had had heart bypass surgery--that must have been in 1986? I remember, when we shook hands, I was alarmed at how thin, and cold his hands were; but it did not alter his enthusiasm or excitement for life and audio.
I miss him already. God, what and influence. I, without being corney bow at the altar of he and Jim THIEL, Joseph Audio, (hence my shock and pleasure when he agreed with my thoughts on crossovers). My only shock was when someone took umbridge at his comment about THIEL. It was a complement to Jim's genius, and as is often the case on these hallowed threads, someone thought Joseph was being negative about him. Shame, because he was expressing true admiration, just noting his shared view of a design, certainly not Jim, another, later day legend.
And (long winded here), Jim Thiel, is just as wonderful a person to work for as one might imagine. Always gentle, and kind, and hard working, the true American dream--from a dirt floor garage start, to an international company.
Thanks for the memo, and kind words. The audio business is better for Bud, Jim, Rich Vandersteen, Joseph, Gayle Sanders, Roger West, and(another mentor) Albert Von Schweikert. Thanks for them and many I have forgotten.
(Oh God, how could I forget Peter Snell, one of Jim's good friends, who died at, I think 37--a genius snatched from audio all too soon.
God Bless Bud!!!
There's been a lot of pointless carping and sniping about 1st order vs non 1st order designs of late.

I suggest we all listen with our ears and choose what sounds best to us in our system. It's quite clear that there is a wide variation in what different people consider to be the "best" in audio, so I have little doubt that no single approach will appeal to all tastes.

And for the discussion we should keep it technical, or at the very least preface all subjective comments as such.
If you read my posts above, I tried to express the theme that it is probably wise for the general "Audiophile" to not get so immersed in crossover engineering and go out and listen for themselves to the various designs. I also stated that it was THEIR money and satisfaction that was at stake.
I believe that a person's idea of "Good" sound is so highly variable that any and all designs can be considered.
I just happen to be in the first order camp and have been there for a long time. I have based my opinions on 40 years of experience of listening to various designed speakers in my own room side by side. I personally feel this is the only way to judge a speaker and unfortunately, many do not have this opportunity. I just don't think that dealers stores and shows are the place to make a decision (or honestly formulate an opinion) but that's the way it is.
As I have stated so many times, I feel that preserving the waveform is of great importance. I always step back from time to time and listen to other designs to maintain a perspective and to me personally, the compromise in higher slope speaker designs is just too great for crirical listening, even though, I will admit, some sound very good. Hell, I use steeper slope speakers in my home theater because I have never felt it was THAT important used in this context (with the exception that I do believe the drivers need to be matched.)
We will just have to agree to disagree on the ultimate merits of each design and I'm sure this debate will go on and on. It's always interesting though.
Nice post, Larry!

Only one thing, I'm sure that Bud is turning over in his grave right now regarding your feeling that he went to Princeton. As you will well remember via this prodding, it was "Fair Haaaaaaaaavud".

All I will add is that he was truly a member of The Greatest Generation. During his time there, he received every degree they offered, medicine and dentistry excepted. Though he was frail later in life, his energy, enthusiasm, and confidence, and wit would put any 23 year old to shame.

I am a better person because he befriended me. He and football great Johnny Sample have both made indelible marks on my life.
Sorry Bud, what a disgrace to accuse him of graduating from Princeton. LOL! Actually, it was so long ago, I figured I had a fifty fifty shot.
Again, what a mind, what a guy. Legends like him will last forever.
Years after I opened my store, a guy I had been trying to THIEL-ize, came in, and had found either the TL 50's or the Studio Monitors. They were magnificent. Music rolled out in the bottom like almost no other. Wow.
Transmission lines don't work according to some, who say the laws of physics, and length of the bass wave preclude it- I say, TELL THAT TO THE WONDERFUL BASS ROLLING OUT OF THEM !
Trelja am I correct in saying that a true series crossover has to to pass all the information sent to it by the amplifier, unlike most every other crossover design? Tom
>what I should have said is, if there are any active patents on first orders, (the subject here) they are not being inforced, due to the issues you chose not to read.

You're still confused. First, I was never talking about patents on first order crossovers. I asked the expert, Roy Johnson - not you - what he thought of the patented Kaminsky _higher order_ series crossover which claims to be phase coherent. This crossover is relevant to this thread; and the thread itself is a perfectly legitimate topic for discussion: Phase coherence and/or time alignment. The thread is not titled "first order crossovers" as you seem to think. This is why I wanted an expert's opinion on the Kaminsky, which makes radical claims.

You then made everything confounding not only by mis-speaking, but by denying what you posted on this point specifically. Your other posts have a high degree of error and even internal contradiction, imo, but rather than go through it again I'll just keep it in mind for my future reference when I check your posts and your products.

OTOH, I may have gotten some of my information on some Fried crossovers wrong. I always appreciate corrections regarding my own misconceptions or lack of specificity. It seems some of Bud Fried's crossovers were asymmetric...but I don't know model by model.
Hi, Tom.

Please forgive me for not fully understanding your question. From what sense do you mean, "a true series crossover has to to pass all the information sent to it by the amplifier, unlike most every other crossover design?"

To be honest, I really have no idea why the series crossover is not used more. Despite the "black magic" that surrounds crossovers, this one even being on another plane, it is no more complex or difficult to understand than a parallel network. Though, I would allow that the most simple first order parallel network (cap inline with the tweeter, plus coil inline with the mid/woofer) is probably the most easy for folks to envision.

What I think sometimes scares people is when they see the schematic of a series network. It looks all wrong on paper, as our minds have grown accustomed to seeing the cap go with the tweeter, and the coil go with the mid/woofer. With a series network, the same is true, but it took a very simple parable that talked about what was actually happening before it clicked for this dunderhead. Of course, I sound ridiculous in this post, because I cannot draw out a parallel and a series network, and I wish I could. Suffice it to say that it looks odd, with the coil in parallel to the tweeter, and the cap in parallel to the woofer.

Bud got started down the series crossover road while at one of his visits to Dynaudio. In talking to someone, he noticed two crossovers on their desk. Bud being Bud, he asked about them. The employee mentioned, "Oh, they're different. These are the series crossovers and these are the parallel." Bud asked what was different about them, to which the reply was, "Well the series crossovers are just better. Both from a sonic and measurement standpoint." Of course at that point, Bud's question was, "Well then why the hell do you even offer the parallel crossover?!?" The answer was, "Nobody wants the series crossover because they've never seen them before, and whenever we send them a diagram, they run away."

Again, Bud being Bud, he didn't run away. He built them, tested them (and saw their much superior dynamic range), listened to them (musicality plus cohesion - less sense of listening to individual drivers), and soon after never built another parallel network outside of to have something to show as a comparison for testing or at shows for dealers, customers, friends.

What was even a surprise to Bud was when I used to discuss them with him last year. He never heard of Zeta, which is the means to alter the rolloff and sonics of a series crossover. The traditional first order Butterworth (6 db/octave) values of the parallel network yield the same 6 db/octave rolloff have a Zeta value of 1.0. By altering the cap/coil values in relation to each other, one can lower the Zeta (for example - 0.7, slower rolloff - more laid back sound) or raise it (1.2 faster rolloff - more upfront sound). He never heard of this before, and nothing made him more happy than discourse he found interesting. It was something that he wanted us to experiment with together. Alas, he fell ill before we got to play...

I hear in the series crossover a sense of cohesiveness that I instantly noticed each time I listened to the Roman Audio Centurions. The Centurions use Ray Kimber's patented DiAural Crossover, which is just a simple series crossover - though I have never looked at the patent. As Ray was another one of us Bud Fried proteges, I consider it a homage to Bud. Anyway, the sound of these speakers just knocked my socks off. They were creamy, smooth, yet detailed and dynamic. Musical, and I realize that is a vastly overused term. The cohesiveness in the sound haunted me. I could not stop thinking about them. I later understood why, it was the series crossover, the drivers act in unison, as opposed to working on their own.