Phase Coherence or Time Alignment: Which More Imp?
I happened to hear the Kimber crossover, in what I thought, was 'his' speaker(?), and it sounds like "no crossover at all", the ultimate compliment. Clean clear and without that 'too many crossover parts' haze, created by overzealous engineers who try too hard IMHO to 'shape' the sound. Wow, it was great, Kudos to Ray once again! |
Suits Me, one of YOUR most obvious and glaring errors, not only proven by my many conversations with him, but archival works available to anyone who wants to, or takes the time to, or has the ability to, understand them. You wrote, as cut from the thread, and I will file it for future information about you and your business endeavors. >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.< Guess we all make mistakes, yet most of us are more gracious about pointing them out to others than you. I have really tried to remain civil with a person who has no interest in doing so. God I hate threads that break down into feces throwing like this, but really, how many times can one person apologize? Sorry G you were right this was headed for disaster with a guy like this.... |
Larry look at the patent disclosure on the government site..Patent #6381334 owned by a Mr.Alexander from there in Utah..Crossover appears to me to be a Series type.First patent uses only inductors and resistors, no caps. Second patent by the same designer adds capacitors to add back energy... not to reduce or roll out energy. Series designers use the inductance of the drivers as well as other measurements to be an intregal part of their designs.The drivers themselves are a part of the crossover.Tom |
The unit I heard, as I recall, did not have any caps, so it must have been an early version. I do remember the guy, Our tech, waxing over the crossover, talking about its absence of coloration, and again, IF I RECALL, caps. It was, nevertheless, glorious in it's clear simplicity, as if nothing was between you and the music. I remember hearing the Jura Rega, commenting on how it sounded, flaws notwithstanding, as if there was no crossover. Thanks Tom. |
One name that should not go unmentioned in this thread is John Dunlavy. He was/is a big proponent of time alignment and his speakers use a first-order crossover. If I recall correctly, John was undecided on how important phase coherence was, but time alignment was crucial. Based on how much I like his speakers, I'm inclined to agree! Also (and again assuming that I recall correctly), John felt that after his speakers (of course), Thiel came the closest to getting it right. Apologies to John Dunlavy if I'm misstating any of his positions. |
I own a pair of C/3-Ls, and have seen crossover schematics for other models, and they use a simple 1st-order series network. Period. There's no way to get a higher-order electrical network out of what's there. The published articles I've seen from Bud all talk about 1st-order series crossovers as being superior. Perhaps he was talking to you about the acoustic response? Or perhaps the "archived" info you're referring to dates back to before modern drivers allowed symmetric 1st-order crossovers? |
As Larry alluded to, Bud Fried did produce time aligned speakers. He sure was a proponent. Skrivis' C/3L speakers are time aligned, along with the simple first order crossover he stated. They also use true transmission line midbass loading - which is actually MORE important that loading the woofer that way. I'm sure he'll agree that the notes just flat out fly out of the speakers, with no smearing whatsoever. I really like my pair... Larry, I am certain your speaker venture will be a successful one. Best of luck! Please let me know if I can be of any assistance at all, Joe |
Joe about a year ago or so ..well I guess I got into a verbal pissing match with a speaker designer here on the Gon who told me that series crossovers didnt work..Well maybe he couldnt make them work but Fried made them work and the fellows with Starsound made them work..Some designers all to often, only follow what their text book or their professor told them was possible... I have heard Larry's speakers on several occasions always at his home. Always impressive, very musical yet detailed, a great look and way under priced..Tom |
Nice post, Tom! I think one can argue from a lot of different perspectives, it makes for interesting conversation and enhances everyone's experience here. However, when one tries to say that something that has been to be viable (and over an extended period) "cannot work", one sure puts themselves in a difficult position. As I reread through this thread, I am more than embarrassed to have noticed that I was flat out backwards in my Zeta description. Zeta of 0.7 is more forward, and 1.2 is more laid back. Can't believe I actually made that mistake in the morning! Surprised no one crucified me on this. Mea culpa, mea culpa... |
Trelja > As Larry alluded to, Bud Fried did produce time aligned speakers. I would like more information on this, since I cannot remember a the Fried speaker whose drivers had aligned acoustic centers via a stepped baffle arrangement, an obvious prerequisite for a time aligned, dynamic speaker. (Single driver, dynamic speakers cannot just be assumed to be time aligned, as we've discussed many times in these threads.) Is there a vintage site with a picture of the C/3L? Now, regarding Lrsky, some Fried models apparently did not have first order crossovers on all drivers. This was pointed out to me and I acknowledged the error. When I pointed out some of your errors, you simply denied what you said and what I said. It's all in the thread, not that anyone else is going to bother keeping track. However, your many errors, combined with your evasive responses when directed to your errors, frankly reminds me of Jason Bloom hitting the sauce a wee bit too much. I find that kind of denial objectionable. |
Again, for anyone who doesn't know, I am a part of the current Fried loudspeaker operation. I needed to get involved because of my feelings for Bud. Suits_me, I was also thirsting for the information you are seeking at one point. I could not read enough about the Frieds. Thankfully, a significant amount of this can be found at http://imf-electronics.com/Fried/index.html, including the C series of pyramidal, time aligned minimonitors. There are a lot of pdfs of old sales literature. Amazing how quickly and profoundly the computer has impacted this area, most everything here was typewritten and mimeographed. I have Bud's personal pair, and sure enough, they have been tweaked and tweaked, but think that the pair Skrivis owns are probably not all that different sounding. They have an uncanny ability to produce music without so much of the resonances that we never notice until we have a pair of loudspeakers that don't produce them. Also, as someone who has been around enough audio equipment as I have, to find a pair of speakers that image as these do really leaves one impressed. I also have the matching O subwoofers that they sit on, but don't look anything like that on the website, as they switched to a design that was narrow and deep ala what is currently in vogue. I think you'll agree with me when I first perused the site that the description of the man literally being a generation ahead of his time was accurate. Alas, there will NEVER be another... |
Suits me: You don't need a stepped baffle to get time-alignment. A sloped front baffle actually works better. Bud did recommend that most of his bookshelf speakers be listened to from a certain axis. This brings me to my next point, and it involves an earlier comment I saw about the new Monitor 7 and Studio 7 not being time-aligned. The acoustic center of a typical tweeter is closer to the plane of the front mounting plate than in a woofer. Since you're sitting out in front of the speakers, we can say that you're closer to the tweeter (to the tweeter's acoustic center). That's a bad thing if we're looking for time-alignment. So we need to move the tweeter farther away (or the woofer closer). Stepping the baffle can move the tweeter farther away, as can sloping the baffle. With something like the Monitor 7s, you're meant to listen on-axis with the woofers. The tweeters are off-axis, so they're farther away from your ears. In this case, time-alignment is accomplished without sloping or stepping the baffle. All we're really looking for is to align the _distance_ from each driver to your ear to be the same. So Bud had designs that had sloped front baffles, and he also had designs where you were meant to listen from a certain point where the distance from the drivers to your ear was equal. I used to listen to my Betas on stands that tilted them back. An possibly equivalent method would have been to place them on taller stands. In this case Bud recommended tilting. I can only assume that he looked at the positioning of the drivers and their respective acoustic centers and determined that placing them tilted back was correct. He recommended that the A/3s that my brother owned be placed on taller stands, with the woofer at ear level. As you can see, it's difficult to judge whether a speaker is time-aligned or not, unless you also know where your ears are meant to be in relation to the drivers. BTW, I don't feel stepped-baffles are a good idea because you can get big problems with reflections and diffraction. Fried suggests another problem: "We have developed as our first possibility three drive systems, in time proper enclosures, joined by a network that makes them phase coherent. These we must get to work in a phase aligned fashion, i.e., all providing the proper data to the listener at the proper time. The only way known to the author is to place the drivers on a sloping baffle, so that the propagating center of each driver is in vertical alignment with each of the others. If we place them on a flat board, we will be phase coherent but not phase aligned; if we place the bass units out in front, with a step back to the mid, and another step to the tweeter, we will get proper time at just one seat on axis, every other seat in the room being very out of phase; and we will have introduced severe problems in the vertical plane. The best we can do is to slope the baffle, either by designing it in; or by recommending that the speaker be used on a tilt back stand." Note that he re-thought this later and arrived at time-alignment as done in the Monitor 7s as an alternate. (I first saw that same arrangement on the Studio IVs.) |
I regret that I never got subwoofers to match my C/3-Ls. I am planning to buy a pair of Monitor 5s, which likely don't image as well, but have better bass and maybe even better midrange due to less reflections back through the cone. The Monitor 7s evidently may have bass that's a bit better than that, but they use a tweeter that is not as good. Perhaps a much deeper C style cabinet would help avoid reflections, but you're still dealing with pretty tight spacing. The larger cabinets of the floor-standers give you much more room for the line and its folds, but you get a larger front baffle along with it. Topping a rectangular cabinet with a truncated pyramid would help, but then your cabinet costs go way up. |
Suits_me> Is there a vintage site with a picture of the C/3L? There is a picture at: http://groups.yahoo.com/group/IM_Fried/?yguid=180415640 They appear to be of early-middle vintage, judging by the drivers. My C/3-Ls resembled these at one point, although I used a single piece of foam to cover the tweeters without a cutout for the dome. (The foam they sell for air-conditioner filters works quite well.) |
