Just picked up a pair of Fuselier 3.3B speakers. They are supposed to be time and phase aligned.
How about a list of speakers that are time and phase coherent? Thiels and what else?
How about a list of speakers that are time and phase coherent?
56 responses Add your response
a minimum phase filter by definition does not muck up phase the big steep brickwall “ measure “ filters, which look better on paper DO for what i consider a phd in minimum phase error recording, visit the Ayre website and download the piano recordings done with simple microphone setup, Ayre minimum phase A to D converers. OF course it helps to have a likeminded DAC on the other end.... RIP Charley !!!!! |
Shadome, thanks for your replies. Let me clarify some speaker-design information you may have been given in error. About the sound of MQA- I have spent little time with it. The idea of linear phase in speakers is tricky to understand without going through the math, but the following definitions clarify the principle: ’Phase’ is always a relative term. Example- If two cars leave the same location 12 seconds apart and arrive at the same destination still 12 seconds apart, we can say their relative phase did not change. Now, if those two cars leave side by side and arrive side by side, we can call that time-coherent behavior for want of a better descriptor. And both were still traveling ’in-phase’, ’phase-correct’ or ’phase-coherent’. Time-coherence automatically implies phase-coherence but not vice versa. When measuring a speaker, we assign 0 degrees at the moment its first sound arrives at the mic. Most always, this is will be at a high frequency coming from its tweeter, before that tweeter goes into a breakup mode, at 10kHz or higher in a modern design. Now, as we go down the scale looking for when each lower tone arrives, most every speaker lets those lower tones drift backwards in time more and more the lower down we go. If it does this smoothly, that is linear phase. If it does not drift backwards at all, that is time-coherent behavior. Let the starting phase be set to 0 degrees up at 10kHz.Down at 7kHz, our software measures the phase as ’60 degrees Positive’.This tells us three things:
Such a speaker is linear-phase, because its designer has also taken into account the mechanical phase shifts of its drivers. Its rate of Phase Change is SMOOTH, not ’jerky’ (= ’non-linear’), which leads to a ’smooth transition between drivers’ as Stereophile’s John Atkinson writes. Time coherence is a much tougher performance standard for speakers. It is possible, by the way, to correct or offset most all of the mechanical delay in the drivers. When a speaker distorts in the time domain, this blurs imaging and details, and more important if one’s ears are open to it, ’how’ the music is being played and its emotional content. I hope this is of some help! Let me know if I can make anything more clear. Best regards, Roy Johnson Green Mountain Audio |
ATC use phase correction in their active speakers. The overall result approaches linear phase with smooth phase behaviour across the crossover. No speaker will be perfectly linear phase as mechanical drivers aren’t linear phase. That said, minimum phase filters and MQA are best avoided as they introduce significant phase distortion by delaying the arrival of high frequencies vs low frequencies. The characteristic effect of MQA is most noticeable on the plucking of guitar strings which sound disconcertingly unnatural - the transient of the string being plucked seems to start at a lower pitch than is natural. Minimum phase filters and MQA muck up natural timbre - hardly surprising given the way they shift phase around. |
Intuitive Design Summit Loudspeakers are time and phase coherent and do things that very few speakers I have heard are able to do. Still one of my all time favorite speakers. I wish more manufacturers paid attention to this. Here's a nice article by Richard Hardesty. I didn't see it previously listed. Apologize if it was. From my listening experience, I'm a big believer in time and phase coherence in speaker design. https://www.vandersteen.com/media/files/APJ%20Files/APJ13_Proof.pdf |
From that speaker design article by JA, on time/phase coherence: "Many loudspeakers are claimed by their manufacturers' marketing departments to be time-coherent. There are also a number of speakers that have sloped front baffles, implying that they are time-coherent. However, its step response immediately gives you an indication of whether or not a loudspeaker is time-coherent (on the chosen measurement axis). We're lookin' at you, Wilson Audio. ;-) Read more at https://www.stereophile.com/content/measuring-loudspeakers-part-two-page-3#v9HvcSQGM5O3Ciq3.99 |
Excellent discussion about this by JA, interesting... https://www.stereophile.com/features/100/index.html |
kenjit, It’s not like you are bringing up a problem that designers of time/phase coherent speakers have never considered. Obviously, any good speaker designer going for time/phase coherence is going to design with those problems in mind. This is why Thiel, for instance, designed and manufactured their own drivers specifically suited for their goals. Their last midrange driver was a marvel of engineering, and purportedly extended up to around 20kHz with good linearity. (I forget the specs for the tweeter but I remember they were amazing too). Not to mention all the specific engineering put in to specific voice coil designs, motor systems for low distortion, etc. I’ve owned many speaker designs, and auditioned many, and the Thiel 2.7 and 3.7s are simply the most coherent I’ve ever heard especially in the mids to treble (and exceptional from mids down in to bass). As well as being super smooth. They were very highly lauded in review after review for incredible clarity, smoothness, neutrality, dynamics etc. Whether the time/phase coherence gives an advantage is one thing (I can only say the Thiels image with a specificity and density that I’ve rarely heard before). But the idea that other design parameters must necessarily be sacrificed to achieve it, in terms of the overall performance or sound, doesn’t seem to be true. (As John Atkinson also said after being very impressed when measuring the Thiel 3.7s). |
I was referring to severe peaks and dips.It is still not true. If time coherence was that important every manufacturer would be doing it.Another untrue statement. It is difficult to do correctly for the manufacturer, and many people have not heard it done correctly. There are also plenty of people that just don't care or find that it doesn't matter to them. That doesn't make them wrong or right, just as wanting time and phase coherence in a speaker doesn't make those that enjoy it wrong or right. To say that is not a valid approach to building speakers is just not true. |
Not everyone can hear peaks and dips in frequency response.I was referring to severe peaks and dips. there are many that find the virtues of time coherence indispensable to their listening. If time coherence was that important every manufacturer would be doing it. And every audiophile would insist on it. That's not the case |
If you give me your green mountains, I'll make them sound ten times better just by upgrading the crossover.Maybe you should design, build and market your own speakers. Then you won't have to spend any more time looking for the perfect sound as you asked for in another thread. You know what sound you want and you feel as if you are a genius in respect to speaker design. DIY would seem to be your perfect answer to your perfect sound. Most people agree that frequency response is an important factor. Everybody can hear a peak or dip at any frequency. The same cannot be said of time coherence.Not everyone can hear peaks and dips in frequency response. There are any number of speakers with incredibly ragged response that people love that prove that beyond a doubt. In the same vein, there are many that find the virtues of time coherence indispensable to their listening. The statements of absolutes are ridiculous. |
I have Green Mountain Audio Continuum 3 with the HX crossover..They educated my listening on what phase and time coherence sounds like You're not hearing time coherence. What you're hearing is the result of all the important factors that have been sacrificed to achieve time coherence. The use of first order crossover causes an unnecessarily wide overlap to supposedly achieve phase coherence. This creates lobing and unnecessary stress on the drivers. The reality is that no woofer can do high frequencies. Thats what tweeters are for. No tweeters can do bass. That's what woofers are for. If you give me your green mountains, I'll make them sound ten times better just by upgrading the crossover. Most people agree that frequency response is an important factor. Everybody can hear a peak or dip at any frequency. The same cannot be said of time coherence. Time coherence is at worst a myth. |
LS3/5A's are not time and phase coherent either. The LS3/5a V2's step response indicates that the tweeter is connected in inverted acoustic polarity, the woofer in positive. Read more at https://www.stereophile.com/content/bbc-ls35a-loudspeaker-stirling-measurements#k1h3jRIXhiljHVoC.99 Maybe we need to revisit what is meant as being time and phase coherent. |
@prof The new Meadowlark speakers are coherent. They are fully active with onboard DAC and they have amps for each driver. The older Meadowlark offerings were a more traditional coherent speaker. Like the newer Meadowlark, the Gaylen Sanders are fully active coherent speakers.I believe the Kii speakers are also. Others are Dunlavy, Ascendo, Green Mountain Audio, Intuitive Design, Essence, and Mosaic Acoustics. |
