First order/Time Phase-Coherent speakers discussions
"The game is done! I’ve won! I’ve won!"
Go listen to where I first ran into the music played behind the 'ride'....;) https://www.youtube.com/watch?v=xQ_IQS3VKjA Beautiful music, a lovely vocal, and stupendous scenery....*S* Pity all 3 are dead now. RIP, y'all. But the Ridge remains... |
@andy2 ....well.....you've likely been to concerts....outdoors...they use electronic crossovers with utter abandon.... It's the only real means to make all that stuff behave, make the beer swigger behind you bellow like a beast because of the 'axe solo' he/she/'it' just have trample their neurons into some version of 'audio nirvana' that 'us puristas' abhor the response to....(as we sip our merlots, transported by our multi-$ private systems...) *LOL* Yes, I'm being vaguely 'snotty' about that, but it is the same sort of insanity; basically, Good, and Good for You....and Them. It's only the 'pink noise' of the audience response...the yelling, applause, whistling, and general racket that's driven me to take 'roadie' and other 'specialized' earplugs to concerts, keeping my hands near my shoulders to save my hearing for why I'm there in the first place. *chagrined G* Timing becomes All.... ;) If you go crazy. well... I guess you can stay home. Not go to clubs either. Or any public events, short of chamber music....nice, Quiet stuff... Yes, being facetious...*sad S* "Poor Andy...can't take him Anywhere...*long sigh*.... Here... https://www.youtube.com/watch?v=10HjqHXpZtU&feature=youtu.be This is old...there's been 'improvements', and more pending. Read the comments. Primitive, yes. Less so now... ;) |
I won't argue, but I will say that I've never seen absolute phase alignment between drivers without electronic crossovers.In my past experiences, most competent engineers will figure our how to "fix" it. But the difference between a merely good engineer to one who can actually make money is that he understands the consequence of his "fixing". Ever heard of stories of a mad genius? They all know exactly how to "fix" things, but nobody hires him because he'll end up breaking more things than fixing. Hence I fear ... I fear ... I fear ... the electronic crossovers ... will they turn all my musics into mp3? Will they cause mad hysteria and drive me to insanity? |
@cousinbillyl You are correct about a lot of your phase conversations.... I spoke with Jim years gone by..... you might remember or go find up the thread where I said something like you can get a 1st order down to around a 15 degree phase shift??? that's what Jim did, he did remarkable work taking a 90 degree shift down to 15 degrees. I won't argue, but I will say that I've never seen absolute phase alignment between drivers without electronic crossovers. |
Any thoughts?The Walsh and HHR and full range exotic driver stuffs you mention are a bit out of my depth. And I am not familiar with some of the references in your post. I am more into conventional cone drivers and speakers - like the typical Seas of ScanSpeak stuffs. May be if you have a link that can show some pictures of your prototypes then hopefully I can chime in or maybe learn a few things. I am more of a visual thinker. |
I owned a pair of Infinity's with the ICC driver....pointed out that it was upside down on or in the cabinets. The rationale for that was that they were too 'price driven' to mount them properly.... The only way you could hear them was to lay on the floor... ....which, back then, we did...occasionally.... SF in the early '70's....get the picture? *smirk* ;) |
@andy2 ...*L* Oh, goody....R/T 'engagement! Or close enuff'... I've been DIY'ing Walsh speakers for awhile now; not the current Ohm variety, but closer to the original F's and A's and the HHR in intent, But... Size of the 'main' driver is larger than HHRs' smaller 'stand alone' driver and the German Physiks, covering the 'upper mids through upper bass'. Hand off the lower bass to a sub...they're more efficient at it (and, MHO, most of the reason folks blew up the originals, due to cone collapse...) and bass being omni by nature anyhow... High end: a smaller Walsh, lighter cone, based kinda like the Infinity 'ice cream cone' driver of awhile back. I've chatted with one who 'was there' in the creation of it, literally done on a kitchen table. We've traded stories, both on and off topic... ;) Tweet above main, vertical alignment. I have working prototypes....working on Better. "Be Afraid..." *L* Not many have heard IRL....those who have, Like. Any thoughts? |
physical alignment of the voice coilsa good start, but my requirement still not met minimize or eliminate the use of a Xovernot really likely, consider xover is a necessary evil driver voice coils are vertically aligned physically I don't care, but sounds fantastic got my curiosity? Will 90~180~360 be a minor/majorToo many variables, need more information to fully understand Will I disappear and stop being an annoyance?It's your money, your time who am I to say (Not f’n likely, but amuse yourselves with that....) If f'n involved, be my guess be f'n around |
Let’s start with your comment about capacitors. Assuming the capacitor is bipolar, which pretty much all capacitors in speakers are as well as many audiophiles, it works the same in both directions of the AC signal. Voltage lag is not 90 degrees, but may be 90 degrees at some given frequency. On the second point, to a speaker, all amplifiers are essentially balanced. There is no ground reference in a speaker, so the speaker has no concept of what single ended or balanced is. It is getting some sort of AC signal. On the concept of "perfect phase", it sounds like a nice concept, except the lower and upper drivers have different excursions for a given power level, the lower driver could be playing the high frequency superimposed on a low frequency that moves the speaker in and out of phase at the high frequency, etc. When you move to the digital domain, there are techniques to correct for more of the issues. cousinbillyl172 posts10-31-2019 5:29p |
@geoffkait , and time incoherence is when the clock passes through one’s head? Just as I thought....*stare into the middle distance, drum fingers on desk....* Ok....just to muck stuff up and soil the water... I’ll assume the discussion is predicated on ’typical’ drivers on a vertical plane. ’Time alignment’ addressed by physical alignment of the voice coils; ’phase align(or mis-align)ment’ introduced or effected by the choice of crossover or selection of drivers characteristics to minimize or eliminate the use of a Xover...if such is possible... Now, What If.... The driver voice coils are vertically aligned physically, ’stacked’ one above the other, drivers facing Down. Time coherence, check. (geoff recognizes where I'm going with this...or he ignores me better than I assume...*s*....) What happens to phase in this scenario? Will 90~180~360 be a minor/major issue? Will a Tice clock thrown at this disappear? Will I disappear and stop being an annoyance? (Not f’n likely, but amuse yourselves with that....) |
This thread is getting good. Looks like most of the trolls have jumped ship. Timmy boy. I would like to disagree with you, respectfully. Perfect phase IS possible. I studied Jim Thiels CS5 crossover. The man was a genius. He used an extra 10+ capacitors to phase match the signal. Let me explain; when an alternating current (sinusoidal waveform for music) goes through a capacitor, voltage lags current by 90 degrees. If a single capacitor is used on a tweeter, it's only the +ve portion of the waveform which is affected. What do we do about the -ve portion of the waveform?. Mr. Thiel was able to 'see' the phase of the music, and manipulate the -ve portion to match the positive. At this point, speaker designers will say "wait, the speaker drive is part of the circuit, and it is irrelevant where the capacitor goes". Opps, the speaker driver is not 'in circuit', but in fact is a 'load' on the circuit. Mr. Thiel understood this, and I am a fan of his speakers. Gauder Akustic? have designed a symmetrical parallel crossover. When driven by a balanced (symmetrical) amplifier, their speaker is close to phase perfect. A Linkwitz Riley 2nd order series crossover, with drivers acoustical centers aligned, is phase perfect. The problem? very few people have heard these speakers. Timmy boy. Judging by some of your posts, you know wayyyyyy more than you are letting on. Your post on degree shifts is bang on. Too many speaker designer ignore this. Mr. Joseph of Joseph Audio also understands phase. I love his speakers. |
A single driver does a lot of things right, but has other issues that are hard to overcome such as doppler induced IM distortion. I.e. a 100Hz tone will modulate a 1KHz tone. One reason that a single driver does so many things right is that there are no phase issues.That’s not entirely true. A driver may have different phase shift at different frequencies. For example, a driver may have a relative phase of 10deg at 700Hz, but at 7KHz, it may have phase shift of 80 degrees. Not to mention different parts of the driver may not moving "at the same time". |
I don’t want to put words in your mouth, but I think you mean that a mid-woofer playing a 50Hz tone and a 1KHz tone will only be at the same position in space (phase-aligned) as the midrange playing a 1Khz tone, for part of the 50Hz cycle? ... or for any two speakers whose sound is integrated. A microphone element is thin and does not move much, so alignment of the center of movement for all frequencies is most important in playback to recreate what is recorded. timlub1,704 posts10-31-2019 2:02pmBy the way, to be clear: |
I hope that I have expressed this in a way for everyone of any level to understandAs an anecdotal personal experience, for awhile I was learning how to cook, so either I have to take some cooking classes, or being cheap as me, I would look up at a bunch of YouTube vids and learn how they do it. Natural I would look at vids from the famous chefs like the guy in Kitchen Nightmares and the likes. But my results were terrible and I hated the tasting. I then looked at the vids from regular folks figuring out they would be at the same level as I was. But I eventually found out that most of them basically would watch some other YouTube vids and emulate them and put up their own vids without knowing if their recipes would taste any good. I think they would just pick some random recipe, went grocery shopping, and made the vid almost like copying and pasting. I think most of them just want their face on YouTube and not really caring if their recipes would taste any good. So I gave up on that too. So I ended up deciding that I would just follow my own instincts, you know like Luke SkyWalker. I've nailed down to a few my go-to recipes that I've developed over the years so at least I don't hate my cooking anymore. Now I have a bunch of healthy recipes that I can use. I actually enjoy my cookings more now than restaurant foods. The only problem now is I still can't make my own beers or wines. Well you can't have everything I guess. Damn, I thought that I would just cook like the guy in Kitchen Nightmares by just watching his vids lols. So what's that has to do with time phase coherent? I am not telling until I am properly wined and dined as one of my dates once told me. :-) All drivers moving in perfect unison.... when one driver starts moving outward, all drivers move outward at the same time, when it comes back, all drivers move back at the same time.Physically is it possible? For example, the woofer flapping at 70Hz, the tweeter flapping at 7KHz. For every woofer moving forward and back, the tweeter is moving 700 time back and forth, so it's not possible right? One reason that a single driver does so many things right is that there are no phase issues.That's not entirely true. A driver may have different phase shift at different frequencies. For example, a driver may have a relative phase of 10deg at 700Hz, but at 7KHz, it may have phase shift of 80 degrees. Not to mention different parts of the driver may not moving "at the same time". Anyway, I spent too much time watching cooking vids to have time for time-phase coherent stuffs ... hahahahaha |
Andy2 I appreciate this topic. I know very little about it. Nice to know a little more about what effects the challenges of our speakers. Just to mention I am pretty sure Timlub has spent many years I think designing, and building speakers. He has a lot of reasonable knowledge and he is very helpful. He can help us a lot along this topic. Thanks Timlub. And I may have short changed how much Timlub knows about speaker development and execution on a high level. If I have I am sorry. |
By the way, to be clear: Absolute phasing is IMPOSSIBLE. You can get phasing done at the crossover point which is the goal. a woofer playing bass at 50 cycles will move at a different rate than a tweeter playing at 15000 cycles. When we align phase at the crossover points, that is as close as you can hope for. I hope this helps, Tim |
"
I am still waiting for someone to tell me who can understand time-phase coherent, including all the experts in the world )-: :-(" That I can help with.... First understand "Time Alignment" The speed of sound moves at the same speed at all frequencies, so the first battle would be to make the sound of the tweeter, mid, woofer or any other driver to hit your ears at the same time. The most common way is to align the voice coils, where the sound of the speaker originates from. When coils are in alignment, the sound from all drivers hit the ear at the same time. Could be done by staggering or a slanted front etc. Next ... Phasing: One reason that a single driver does so many things right is that there are no phase issues. A single driver does not have to move in unison with any other drivers. So what is phasing? All drivers moving in perfect unison.... when one driver starts moving outward, all drivers move outward at the same time, when it comes back, all drivers move back at the same time. This helps tremendously to prevent smearing or to improve pinpoint imaging. So what did I mean when I said that cross overs change phasing... A single cap or 1st order crossover, normally will cause a phase shift of 90 degrees, so to keep the next driver moving in unison, it must also be moving 90 degrees out of phase to stay in unison with the other driver. Again, 24db per octave brings you back around 360 degrees to put drivers back in phase, but the crossover parts count, the sound of the crossover parts being used and the practice vs theory that you don't truly end of with absolute phase cause most to not use 24db per octave slopes. Time/Phase Coherence is just what it sounds: Time and phase working in conjunction to form a Unified Whole. I hope that I have expressed this in a way for everyone of any level to understand, Tim |
@cousinbillyl, While I can neither confirm nor deny your deduction regarding OCD and audio time sensitivity, I do believe that your onto something. I have come to the conclusion that though for the most part that we may all basically hear similarly, we listen differently. For what ever reasons we prioritize some things we listen to differently, whether consciously or not. This amongst many other things can include the degree of perception of time in audio. |
Andy, you have opinions that you don't understand. I'm happy to stick to your original premise, but slamming others for giving accurate information does not work. You never know, a couple of these guys could be speaker designers and worked with most of the quality parts that you have mentioned. If you want my help say so, I'll chime in. If you'd like to continue telling everyone how it is. I'm done, Tim |
| Post removed |
I built a speaker. Accuton Diamond tweeter, Accuton 2" ceramic midrange, Acoustic Elegance TD6m midwoofer, Acoustic Elegance TD15H+ woofer. I fine tuned a Linkwitz Riley 2nd order 4-way series crossover. After the crossover was set, I tested and fine tuned driver depth (time alignment). This took more time than fine tuning the actual crossover. At normal listening levels, the speakers are fabulous. At concert hall levels, there was something that was ever so slightly off. After double checking everything, I conducted an experiment; tilt the tweeter/midrange/midwoofer section sideways (yes it looks funny). After a few test listens, viola!. I had set my tweeters 1mm too deep. Or, the foam on the back of the 2" ceramic midrange was thicker than the tweeter, so it didn't sink as deep. It's now perfect. Time alignment achieved. My wife can't hear the difference. She thinks I'm an idiot. I have OCD. After I took the online test, a brief explanation was given; people with OCD reorganize complex patterns in their head. I can 'sense' the improvement, my wife can't. My conclusion: some people can sense phase issues, some people can't. Or, I'm just another idiot. |
@geoffkait , @tomic601 , big *S*...one of my faves too. But we surely need more coherent heroes of late, and that's about as much as I'll go into That... Re 'electric supercars': Lotus Evija...and let's watch what Formula E does for the breed. And most of today's cars owe a lot to superbikes and the racing of.... ;) For once I'm enjoying this forum, since I'm on the verge of wading into these weeds with my DIY endeavour. Since IMHO I'm a long-standing skeptic of the 'perceived' vs. 'measured', analog vs.digital, this X vs. Z 'enhancement' to the audio experience, a 'lively discussion' of the subject at keyboard is appreciated by y'all. *S* Please, carry on...and play nice, 'K? ;) Or I'll sic the Watchmen on y'all...*L* (Oh, FYI...have a Behringer DCX2496 to play with. Yup, digital domain domination...) |
Time Phase-Coherent speakersAre great when done right, so long as you don’t drive them with something like this. 75 degrees at 8khz, and still 40 degrees at 1.5khz. Then you may as well flip a coin with regard of mid to tweeter phasing or how you distant mount them from each other. https://ibb.co/WzTLkkL Cheers George |
You are right that alignment between speakers in a cabinet matters, but localization via timing is based on the arrival time difference between your two ears of the same sound, whatever that sound is, even one that is not coming from a time aligned speaker.
|
nice Little Feat reference Geoff, didn’t know ya had it in ya ” but only time will tell IF he’s a legend from heaven, or sent here from hell” Speaking of time, since 1977 with more than a quarter million time and phase ( and other cool stuff, because you know its a SYSTEM ) loudspeakers sold :-) my vote is legend... |
I think you need to work on your bias as it is unjustified. More and more of the high end speaker market will go digital/active cross-over as the limits of analog cross-overs are a hard brick wall that cannot be scaled. I suggest doing some reading into it, it will likely change your bias if you keep an open mind about it. If your turntable is only $5K, almost entry by audiophile standards today, then a good DAC, not even one that expensive streaming 24/96 or 24/192 either Qoboz or Tidal is certainly going to touch it if you compare recording to recording. So much has changed in just the last 5 years. I will emphasize again there is distortion in dynamic speakers that cannot be corrected with an analog cross-over. It just cannot be done. In the digital domain, there is even the ability to address resonances that again, you just cannot do in analog. I am actually working on a "DIY" 3-way right now, with Accuton mid-bass and midrange. I have not picked my tweeter yet. The level of driver integration and flatness of response after correction is just not possible with an analog cross-over. andy2 OP689 posts10-30-2019 10:54p Why would I want to use the same design methods we have been using for 100 years when superior ones exist? Lead, follow or get out of the way :-)
|
For what it is worth: The genetic difference between chimpanzees and man is 1%. Any two random humans differ by less then 0.1% genetically. Message: Small differences matter. In my experience, time/phase coherent speakers reproduce for example the applause of the audience in a life-like manner. Depending on the recording technique, they reproduce a space better. Inches matter. The distance between your ears or time difference of the arrival of a sound is what allows to localize the origin of a sound. Say that’s 6 inches or ~ 16 cm. Some may have bigger heads. 1 cm doesn’t matter? Think again. |
Posted without comment:
Let's also not forget the P100D is the fastest accelerating production cars till at least 60mph, and the P90 not far off, so essentially supercars. There are a lot of them out there.
|
A decent active crossover in knowledgeable hands will crush the performance of a top tier passive crossover.Haha so much crushing that nobody is bothering doing it except for some cheap eight dollar headphones. Real life hello? Anyway, let's put it to rest. Hi end market doesn't care for your digital amp and digital dsp stuffs stuffing into a speaker with drivers bought from China OK. Have you never bought any high end stuffs before? Can't you tell the difference between a $7K amp and some cheap digital make in China amp? I am not going to use any stinking digital with my high end drivers bought from Seas or ScanSpeak or Accuton. It's like taking Ms. Kate Upton to McDonalds OK !!! What am I going to do with my $5K vinyl table? Ain't no stinking ADC will touch it lols. How about my $7K McIntosh tube amps? Ain't none gonna fit into the back of the digital speakers. The heat alone will burn up your speakers. So why don't we put all these digital nonsense stuffs to rest. Maybe there's a "Made in China" forum where you can go to make your case there :-) |
"There is still some or even a lot of reading on digital if you want to start pushing the limits / doing custom FIR filters, etc.Digital is for low end stuffs. High end and expensive stuffs are pure analog. Consider it a lesson." That used to be true, but that particular part of the landscape may be changing. The only true weakness for digital (as long as it has all the proper inclusions of capabilities, which don't they always have) is the sound quality. That's been true of CDP's, DAC's and everything else digital...only there, sizeable advancements in sq have been made through power treatments. And digital crossovers should not be left out of that picture. Power treatments, particularly the quantum kind (which don't have all the weird side effects that component-based [caps, transformers, or other parts] power conditioning does), are beginning to change the game in favor of digital in general. It adds to the cost, but it compares extremely well to the best analog, when done sufficiently well. "With digital actives, you just dial it up and listen for yourself...a whole lot easier and faster that way.When someone claims something is "a whole lot easy", I go like "hello, what has he done?"" I'm talking about sitting in your listening chair (with at least a mockup of the speaker design in front of you) and then going through the listening/evaluation trials of whatever drivers-vs-crossover recipes you might want to investigate...maybe make some measurements with Omni-mic to confirm some things and you should have most or all of your answers right there...the process shouldn't even take you one, whole day to test, if all goes well. You may not be able to actually measure, say, the waterfall plot of the finished design (I suppose you could if had the right test gear), but you might be amazed at just how far down the road this will take you toward a solid, finished design in one take. I tend to go through this same process several times on different days so I can average out my own moods, predilections for listening for different traits, listening awareness levels and so on, in an effort to help me take my own fallibility out of the equation. But, you get an excellent feel for things like step-loss issues, phase issues, dispersion and all the rest of it, all at once. I used this process to design a pair of open-baffle stand mounts, which are not hard to build anyway, but if you're looking to build some giant-sized box, then you would have to make a good enough mockup to listen and test with. |
Andy, you have shown in your comments that you have a VERY LIMITED KNOWLEDGE. A decent active crossover in knowledgeable hands will crush the performance of a top tier passive crossover. Maybe you should explain what time phase coherence is from your point of view so that we can properly respond. So not to waste your time again. I was talking about time and acoustical phase alignment and how they are effected by the electro magnetic structure of a driver as well as the parts chosen in the crossover and the order of crossover design itself. Active designs make much of this benign and allows correct time and phase alignment with steep slopes. |
High end expensive stuff from companies with sufficient depth to design and program signal processing electronics, i.e. like Harman companies, are doing high end in digital. That’s not I see in REAL life. Most of the most expensive speakers on the market are analog. I can only speak with real life examples. Sure with imagination anything is possible. There are a few digital stuffs but they are few and far in between and hi-end market does not take them seriously. Like Ferrari or Porsche or Lamborghini, nobody wants to drive an electric supercar. |
A lesson? High end expensive stuff from companies with sufficient depth to design and program signal processing electronics, i.e. like Harman companies, are doing high end in digital. They may not be making $100,000+ speakers that way, but that is mainly because that is not their market. They are things you can do in digital signal processing that literally cannot be done in the analog domain. There are aspects of dynamic speaker correction that can be done in digital firmware that cannot be done in analog, and when you start talking about more sophisticated multi-driver speakers, that just compounds. High end analog speakers are a market, but not the epitome of what is possible. That will only come with advanced digital signal processing techniques. andy2 OP685 posts10-30-2019 10:03pm |
it has not been mentioned, but remember there is acoustic phasing as you have been discussingIt’s so obvious I didn’t to waste people time like you just did. Properly done active should always be betterYou have no idea. Talk is cheap lols. Want to pack the entire lab into your speakers? There is still some or even a lot of reading on digital if you want to start pushing the limits / doing custom FIR filters, etc.Digital is for low end stuffs. High end and expensive stuffs are pure analog. Consider it a lesson. With digital actives, you just dial it up and listen for yourself...a whole lot easier and faster that way.When someone claims something is "a whole lot easy", I go like "hello, what has he done?" |
