08-21-14: Bob_reynolds
Bruce, thanks for the additional insight. Is there a reason that most speakers on the market are not time coherent? I think so -- it's way down on the list for impacting sonics. Meadowlark claimed to be in the time coherent school and published a nice looking triangle graph. They didn't sound time coherent to me, i.e., I couldn't tell that they were or weren't. Things that have a large impact on frequency response like room correction will definitely be audible. So, time coherence may be DEQX's selling point, but that won't be reason enough for me to be interested. Bob, you couldn't be more wrong about time-coherence & it's importance to music playback. Most speaker designers simply do not understand the math & physics to make a speaker time-coherent so they skip this part totally. For the Meadowlarks you might have known how to set-up the speaker &/or what to listen for to ensure that you were seated in the right location to hear the time-coherence. Plus, guidance could have been poor from the manuf. I would strongly urge you, as Al already has, to read that "Sloped Baffle" thread he provided the link to & search for DEQX & read other things about time-coherence. I believe it will be educational to you. BTW, there is atleast one member in that thread, lewinskih01, who is using DEQX & has found it to be transformational in his system - it made his speakers trend more towards the time-coherence paradigm than before & he is pleased with the results (so he wrote). whatever makes your speakers more time-coherent will make your listening even better. And, if your system pix are the latest, I see that you are doing atleast 1 aspect of the time-coherence thing: time-alignment of drivers. You have your tweeters pointed out on both channels. This makes the path length from the tweeter a bit longer compared to the woofer which has the effect of time-aligning the acoustical centers of those 2 drivers. That helps to intergrate the sound of the drivers at the listening position. So, if this is any clue to me, you are going to like a time-coherent speaker even more. That "sloped baffle" thread is a good one to read. I 3rd Almarg & Bifwynne on your reading that thread..... |
08-24-14: Lewinskih01
Just to clarify: I participated in the "sloped baffle" thread and mentioned the DEQX, but I don't own it nor have heard it. sorry Lewinskih01, I thought you were the fella who had DEQX. In that case I must have mistaken it with the OP - Psag - of the "sloped baffle" thread who has DEQX. yeah, Bruce has a few of us waiting with bated breath on 2 of his trials - over a month ago he was going to get some Home Depot thick gauge wire to try out as speaker cables & see if they bested his current audiophile speaker cables & the 2nd is his DEQX experiment (which seems to be delayed to after Labor Day). Bruce, are you going to do that speaker cables A/B anytime soon? Or, is that just idle talk? Thanks. |
time-coherence is the way to go........I'm tellin' ya!
Bifwynne, Lewinskih01: you guys have your work cut out for you should you choose the DEQX route... ;-)
(or buy a properly designed time-coherent speaker ;-))
but it looks like the rewards are worth it. |
hi Bruce,
did you finally get a DEQX demo at your house? if yes, was it all that it was cracked up to be? thanks. |
09-23-14: Bifwynne
The DEQX home demo was completed last night. I am buying the DEQX.
Not being inclined to the use of vivid hyperbole, I do not think the DEQX is transformational. But I do think the improvements are considerable and significant enough for me to spring to buy the DEQX.
awesome! I'm happy to read that you now recognize the importance of time coherence to music playback. :-) it IS very significant. The time-coherent speaker manuf weren't barking up the wrong tree - no sir, they were not... So, anyway you can make your speaker time-coherent will work to significantly improve your listening pleasure: apply a Band-Aid like DEQX or buy a time-coherent speaker from the get go. Bruce, maybe you'll be transformed in time to come. I'll poll you in about 6 months & request you to pull out the DEQX from your system & give me your opinion. I'm wagering that you won't be able to listen to your system ever again without DEQX.... ;-) That's what happened to me - once you get use to a time-coherent speaker system there is NO going back even for a few seconds.... As others have already written, I too await your report after you've collected your thoughts. Thanks. |
09-26-14: Bifwynne
Drewan ...can I use the transport in my CD-8 to play SACD discs? I don't know what the bit/FR is with SACD or other high resolution discs. This is new territory for me. I think redbook CD is 16 bit/44.1 KHz. What is SACD? SACD, as you know, stands for Super Audio CD. It uses 1-bit DSD (direct stream digital) that is sampled at 2.8224MHz which is 64*44.1KHz. I.E. SACD is 64X oversampled compared to redbook CD. SACD technology utilizes noise-shaping quantization techniques to recover the 20Hz-20KHz audio while at the same time pushing the unwanted noise to a higher/inaudible ultrasonic (to a human ear) frequencies. SACD, thus, almost always used delta-sigma demodulators to convert the 1-bit DSD stream to a 16-bit/20-bit/24-bit/32-bit recovered audio. The delta-sigma demodulator is digital circuit hence there is digital signal processing (DSP) done on the 1-bit DSD stream to recover the audio. The claim of SACD is that is supposedly provides a 120dB dynamic range (while 16-bit redbook CD has an upper limit of 96dB & signal processing done with 20-bit redbook also has a dynamic range of 120dB-same as SACD). As you already know, to play a SACD disk, you need a player that is SACD capable - a redbook CD player cannot play SACDs. |
And while some might quibble over whether their system is "flawed," I think a better way to see the picture is that design compromises have been made and time coherence is just one of the compromises. This is especially so when one considers that the "cost" of time coherence may involve ugly sloped speakers, some of which look like insects, and drivers that are being asked to make sound over a wider pass band. Plus, speaker placement can be finicky and I don't like listening to music with my head in a vice. A few corrections, Bruce: (1) time coherence/in-coherence in a speaker is NOT a design compromise - it's a design paradigm. Pretty much like Ralph of Atma-sphere deciding to manuf a voltage paradigm or power paradigm amplifier. Once the designer chooses the design paradigm then you can make design compromises (quality of components & other mechanical materials, etc). (2) Drivers that are being asked to operate over a wider bandwidth in a 1st order x-over time-coherent speaker have been very carefully chosen such that these drivers have zero problems operating over that wider bandwidth. That is why most drivers on the market don't qualify. So, if the 1st order x-over time-coherent is correctly designed then the x-over frequencies will be such that these wider bandwidth capable drivers will have almost zero distortion. (3) Speaker placement of 1st order x-over time-coherent speakers is NOT finicky & you do NOT need to put your head in a vice to listen to music. Speaker placement & listening placement have some special guidelines such as ensuring that your distance from the speakers is such that you give the sound from the various drivers to integrate & that you place you ear at the correct height off the floor. This is not unreasonable - you would do this for almost any other speaker. Yes, the sliding back/forth of the tweeter to get it correctly time-aligned to the listener's particular distance is a little bit of a trial & error thing but once again it's not unreasonable. The factory cannot set this tweeter position as different listeners listen at different distances & the distances can vary anywhere from 9'-15' depending on the speaker & room size. Once this setup is good/verified by the owner, you can shake you head like Stevie Wonder/Ray Charles or like Cerrot you can dance in your seat - sound from the 1st order x-over time-coherent will not vary.... You seem to be misguided on these few points &/or forgot that these points were discussed at length in the "Sloped Baffle" thread. Anyway, here they are again for your reading pleasure. :-) Hope that this clarifies & helps. Thanks. |
09-29-14: Bifwynne
Sorry Bombaywalla, I still think some time coherent speakers look like insects or Dr. Who Dileks.
LOL, Bruce. In my post I NEVER referred to the looks of the speakers - I was trying to stay technical & to the point - but for some reason you like to bring up this topic every time you can - it seems to give you pleasure, no? ;-) I did audition another unnamed "Brand X" 1st order speaker about 2 years ago and my reaction was surprise and disappointment. It was just plain ugly. sorry to read this - not every speaker designer knows how to design a good 1st order time-coherent speaker. From your text, tho', it looks like you were pre-dispositioned to dislike them; their looks seemed to have over-taken your better judgement...... Hey man, at least I'm coming over to your side of the street. I bought a DEQX and effected time coherence improvements. yup! And, I'm happy to see that esp. since you've realized what time coherence is all about & how it positively affects the music playback. It didn't take too long for you to convert once we had all that discussion in the Sloped Baffle thread! :-) You're a quick learner, I say. And, my speakers don't look like insects. ....but they look like coffins where you can bury your previous time-INcoherent music playback.... ;-) |
10-01-14: Drewan77
Answering about the Chord DAC, this was input to the DEQX via the phono analogue input so maybe this has some bearing on the slightly dull sound. what??? Are you serious?? you input your DAC into the phono analog input of the DEQX & let DEQX RIAA equalize your DAC input?? (The assumption here is that the input is called 'phono' because of the equalization being done to the signal; otherwise, DEQX would have called simply called it an analog input). You know that phono is RIAA equalized because the bass freq are compressed to make them fit in a reasonable amount of space on a LP?? The effect of this would have been to accentuate your bass & make all your music bass-heavy. And, you actually made a critical listening decision based on this connection?? wow, Drewan77, I'm amazed..... |
thanks for clarifying, Almarg. RCA/single-ended input might have been a less confusing word to use... |
Woo-hoo, Almarg!! :-)
I was happy to read your post indeed & am looking forward to your personal experience with time-coherency thru DEQX.
From my personal experience & from Bruce's experience I believe that you will be nothing short of amazed what time-coherency can do for music play-back. It's the only way to go & I'm sure that, like myself & Bruce, once you get used to time-coherent speakers you won't ever go back. :-)
Like many others I'll be watching this space for your feedback.
Thanks for joining the time-coherent "gang" - you will not be disappointed.... |
Bruce,
good to read that you continue to like your purchase of DEQX & that you've come over to the side of time-aligned speakers. :-) Glad you recognize & hear what time-alignment can do for music playback - I feel that all my posts weren't all in vain...... at least one person listened & benefited. :-)
I'll be sure to read Kal's review of the DEQX in the Dec issue of S'phile. Thanks for this heads-up. |
11-12-14: Kr4
Got mine in the mail today! some insider benefits, Kal! ;-) some of will have to wait until the near end of Nov before we see the Dec issue.... |
Hi Almarg,
yes, you are correct - misstatement on my part. Sorry guys!
indeed the linear power supply operates at its designed output voltage (which is over-designed to ensure it will accommodate the max program material voltage) & the extra power dissipated will be (power supply voltage to amp output stage - voltage of program material) * current. And, correct again, the power amp output stage mostly operates at the average voltage of the program material. |
Lewinskih01, i thought that we had a lengthy debate on Acourate in the "Sloped Baffle" thread with Roy Johnson & others & we (mainly Roy J) concluded that Acourate did not have the Math right to correctly check the impulse response of the speaker & correct its response? I'm pretty sure that you were part of that discussion. Despite this did you still decide to use Acourate? thanks. |
question out loud how folks who spend a small fortune on top of the line speakers can even know how good their speakers sound if they have a screwed up room. So, even if one owned time aligned speakers like Vandies or GMAs, all the time alignment in the world will not fix a screwed up room.
Bifwynne Amen!! (& I have written & said such a thing before too many times to count now). Good to see Bruce echoing the same now..... here's a cut & paste from a (cheeky) post (cheeky parts scrubbed) from back in 2012 when one Audiogon member started a thread called "Room Treatment made me cry.....a little" - he had discovered the huge benefits of room treatment.... 03-26-12: Bombaywalla
Amazing and not expected, at least not this level of improvement and emotional connection.
I'm very happy for you now that you are so emotionally connected to your music during playback. Good job!
........ it's been written & said (if you attend audio shows, informal gatherings at friends' places, dealer's showrooms, etc) that the room is perhaps the most important interface to a music playback system. You could get 1 item each from every Stereophile A list OR TAS's best of the best OR from your favourite audio mag and you could connect those components together in your listening room & you will find that your sonics are not A-list at all; in fact, not even close until you treat your room. You could have trolled the A'gon archives for tomes written on this subject to find that the room is the inital/final frontier w.r.t. playback. Anyway, I/we are happy that you learnt this ......... Enjoy your music...........
Bombaywalla |
02-28-15: Bifwynne
Roscoe ... how are you making out with your DEQX? maybe i should pull my mind out of the gutter. LOL! ;-) "faring"? seriously, yes, this is the big question i would also like the answer to. do we have another convert into the time-coherent speaker camp?? ;-) thanks. |
I agree, in general, that when a manufacturer or its representative is asked a direct question re. a change (such as use of a SMPS in the latest rev) & the subsequent answer avoids answering that question, that is not inspiring & leads the mind to think that something's being hidden. Maybe Almarg can press the issue at a later date when he's ready to purchase the HDP-5?
OTOH, SMPS power supplies for use in power amps have made good strides in the overcoming their output noise issues (that would increase distortion in the music signal path & wreck performance). We see this evidence in many amps today - Anthem's Statement M-1 mono, Benchmark's AHB-2, Belcanto amps, Jeff Rowland amps & the quite popular Ncore 1200 series amps - just to name a few. So, the technology of low-noise SMPS for audio applications is out there; whether DEQX has accessed it for their HDP-5 is the question that needs confirmation. It seems to be a reasonable assumption that they have but we know quite well where assumptions can lead us sometimes!! ;-) I also think that DEQX wouldn't do something regressive to ruin their highly touted HDP-4 & Premate by putting a noisy SMPS in the latest HDP-5 but who knows sometimes manuf do things that they think are progressive only to be told by the user community it's regressive....
I agree with Almarg that it's a safe bet to think that the HDP-5 has a quiet SMPS but reading/hearing it from the manuf rep would have a reassuring effect... |
03-24-15: Ptss
Bombay(hope it's ok for short-otherwise I could use Walla?). I try to address everyone by their chosen moniker without abbreviating as a mark of respect to that person. doesn't cost me anything - i use ctrl-C & ctrl-V to accomplish that rather than typing the moniker. Saves time & makes the other person happy that i addressed them as they want to be. but if you are averse to typing, sure.
Appreciate your comments. I think we can never overlook that in todays world there's an unavoidable intense pressure on manufacturers to create "newer", faster and "cheaper".
true. but in audio, it's all about the sound quality even when manuf use cheap components because even those cheap component audio manuf know that the human ear is very sensitive to distortion & if their gear doesn't meet the min requirements of the human ear not hearing distortion, their gear is not going to sell. So, it's not like an automobile that uses cheap components that break in 1-2-3 years vs. 10 years because in such a case (autos) you can still sell the product & not have the consumer come back for a long while. OTOH, in audio, if you have unacceptable distortion, one listen & the consumer will be out of the door looking for something else & the audio manuf will have a zero sale. so, yeah, audio manuf are pressured to make things newer, smaller, cheaper but distortion has to be kept below the average-Joe's hearing level. Also, just to point out - the "newer" fad is very much an American/USA thing. In other parts of the world, "newer" is not always better & once people are satisfied with the performance of whatever piece of equipment they have, they don't necessarily get an itch to switch it out with something newer. In the USA they seem to have this itch pretty badly. Different culture.....
Which power supply is less expensive?
Loaded question. ;-) The correct answer is "depends". Linear power supplies have been around for a long time so their hardware has been in production for a long time as well. Plus a lot of the hardware for a linear power supply is also used in industrial applications thereby giving it the economies of scale from a pricing stand-point. To make a low AC ripple, high current, fast transient response linear power supply is not an easy task. It requires some careful design, careful layout esp. of the grounds & some expensive components. To take it further, some audio manuf are using a regulated linear power supply. And, this is an even tougher job esp. when the bandwidth of the regulated power supply is to be large (> 100KHz). There are some audio manuf who have a 1MHz regulated power supply but it's relatively low current (3-5A) & used with front-end components. You'll be asking why 3-5A when front end components often using 1A or less? It's the dynamic headroom required when you have large signal variations in the program material that suddenly draws a lot of current from the power supply. This momentary current draw can be very high & the power supply needs to support it otherwise the music loses its sparkle. The linear power supply can be made cheap & you see this in a lot of power amps in the market where you have high wattage but with very little current delivery to support those watts meaning that such high wattage amps cannot be used with difficult speaker loads. Cheap linear power supplies will also squash the dynamics in front-end components sucking out the life of the music. Linear power supplies can be made very expensive like the ones you see in high wattage, high current power amps that weigh a ton. You see expensive linear power supplies in 2-box or multi-box preamp units. A linear power supply is expensive from a power dissipation perspective - you have to design its max voltage for the max peak voltage of the program material but in normal operation the linear power supply operates mostly at the average voltage of the program material. The difference in the peak & average voltage is dissipated as heat. Of course, you don't know what the max voltage of the program material is so you have to over-design further leading to more heat dissipation. SMPS power supplies have been around since the 1960s but used extensively in places other than audio. All power supplies in airplanes are SMPS - efficient & light-weight (compared to a linear power supply) where weight is a big issue. Their harmonic distortion performance for audio probably sucks but who cares in that application. So, it can be made cheap - there are hundreds of planes manuf each year & each plane uses many, many SMPS power supplies. For audio applications, harmonic distortion is paramount so the SMPS output spectrum has be cleaned up so that you have vanishing low (something like -120dBc) distortion. That takes a lot of effort - good design, careful layout especially separating the analog & power/switching grounds and some expensive components that have low ESR/DCR such that the output ripple is low. So, a SMPS is a complicated circuit that had a lot of failures initially for the audio application because people just didn't understand how it worked & how to reduce its output distortion. That has changed for the better & continues to evolve. 1st you used to see class-D amps with linear power supplies. Now you are seeing class-D power amps with SMPS. These are not necessarily cheap & the best are very expensive. It takes some good amount of engineering to keep the SMPS (located in the same chassis as the amplifier stage) from spraying high freq noise into the amplifier. You will now say " the noise is high freq so it's out-of-band w.r.t. to the audio so why should i care?" The answer is that all electronic components have some non-linearity (nothing is linear from DC - infinite frequency) & this non-linearity will respond to the hi-freq spurious emitted by the SMPS & will mix it down into the audio bandwidth. Once that happens the distortion looks just like an audio/program material signal & is impossible to separate. When this happens, the life of the music is simply sucked out. To avoid this, takes some concerted effort. So, a SMPS can be made cheap & it is also expensive to make. Now you know why the answer is "depends"!! ;-) hope this helps...... |
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The reason I ask relates to the relatively large physical spacing between some of your drivers, which based on pictures I've seen I suspect is around 3 feet between the lowest of the four woofers and the tweeter. On my speakers, also, the two woofers are a significant distance (about 15 inches) above and below the two tweeters, which in turn are about at listening height.
The reason I started thinking about that is it occurs to me that the greater the physical separation between drivers, the greater the distance should be between the speakers and the measurement microphone, which in turn (assuming the speakers are not measured outdoors) will necessitate shortening the duration of the measurement window (prior to arrival of the first reflections), which in turn will raise the minimum frequency that should be corrected and/or reduce the accuracy of the corrections.
The reason I'm envisioning for that is not related to off-axis dispersion of the drivers, since the mic is placed at the level of the drivers which presumably have the narrowest dispersion (i.e., the tweeters). What I'm envisioning is that with the mic placed at tweeter level, the closer it is to the speaker the greater the difference will be between the distance from mic to tweeter and from mic to other drivers. And if the drivers are widely spaced, the amount of that path length difference will be significantly different than the difference between those path lengths as they exist at the listening position, due to the shallower angle between those drivers as viewed from the listening position.
In other words, it seems to me that if drivers are spaced relatively widely, and the mic is not moved correspondingly further away from the speakers during the speaker calibration process (with the downside of shortening the "window," and hence the accuracy and/or low frequency extension of the corrections), the speakers may be corrected for a timing error that won't exist at the listening position.
I've done some geometric calculations for the 15 inch distance between the woofers and the tweeters on my speakers. At a 4 foot measurement distance the path length differential between the distances of the mic to the tweeters and the woofers is 0.18 feet. At my 11.5 foot listening distance that differential is only 0.06 feet. The difference between those differences is 0.12 feet, corresponding to a propagation delay at the speed of sound of about 0.11 ms (milliseconds). Which would seem to mean that the DEQX will correct for a 0.11 ms timing error that won't exist at the listening position, if my speakers are measured at a distance of 4 feet, and a somewhat larger error than that in the case of your speakers.
The planes of the baffles on my speakers, btw, are such that the woofers are mounted a little forward of the tweeters and mid-ranges, presumably to help with time alignment. But that is unrelated to the point I am describing.
Also, to provide a bit of perspective on a 0.11 ms timing error, that would be readily perceivable on the step response graphs JA provides with his speaker measurements in Stereophile, those graphs having a time scale of 1 ms per major division. One of the purposes of those graphs being to provide some idea of the time coherence or lack thereof of the speaker. I understand what you are getting at, Almarg. These exact considerations are important when we are setting up a time-coherent loudspeaker in a listening room - the distance of the listening position relative to the driver plane is important such that the drivers integrate at the listening position to avoid a separate-tweeter-separate-woofer effect. I know that Green Mtn Audio had a heck of a time with the review magazines who never did understand the concept & almost always put the mic at the tweeter level & to their self-created dismay found that the drivers did not integrate & that the time-coherent speaker was not what the manuf advertised!! I understand that it took an enormous amt of effort on Green Mtn Audio's part to educate the reviewer. That's why if you look at the measurements in Stereophile of any Green Mtn Audio measurements they look terrible - they were mostly all done incorrectly! But the effect was devasting to the business, as you can imagine. So, I agree that you would need to push the mic further away based on the driver vertical separation BUT you run the risk of measuring reflected sound as well. I suppose that's why the manual recommends mattresses/cushions/blankets in between the mic & speaker. Maybe what's better is using some room reflection treatment material like the Owen Corning 703/705 sheets? A royal PITA but maybe worth the effort esp. if outdoor measurements are a no-go for you? I suppose you are shortening the measurement window to avoid catching the reflected sound? It's a trade-off (like all of engineering!! ;-)) In your calc - the error is 3:1 - 0.18' at the measuring distance & 0.06' at your listening position. that's a pretty big error looking at it in absolute terms but... Maybe that's not much of an issue? If I understand this correctly, the human ear cannot tell an echo (reflected sound) if the reflected sound is less than 1/15 of a second (& 0.11mS is much less than that) but, as Drewan77 stated, you could end up with a "hollow" sound if you measure indoors due to partial reflections. I also suppose that measuring outdoors is better because you have a perfect absorption environment - no echoes.... |
thanx for the update re. your DEQX purchase, Almarg. I was about to find this thread & ask whether or not you had purchased the DEQX box but I got my answer when I was trolling this forum.
An engineering approach to installing DEQX in your system. Cool! :-) |
He also asked to me to position the mic at the precise spot of my ears. No kidding!! yup, no kidding! this is where you found the drivers to integrate best & the DEQXpert leveraged off that info to make the measurements. Any closer & you would have had the similar timing errors that Almarg wrote about. Makes sense.... |
thanks for the clarification Almarg. I forgot that DEQX also does room correction. yes, makes sense that the mic is at the listening pos for room corr. |
Bifwynne,
Vandersteens are not only time-aligned, they are time-coherent which is the superset & what you want in the 1st place.
If you decide to pull the trigger on Vandys, get the 5A or higher. They are expensive but the sonics will surpass your present-day speaker & more & make you forget about upgrading for a (long?) while. Do audition them in your home, if possible, before buying. I've heard the 5A at a dealer's & I was not disappointed. thanks. |
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Btw, you referred to "time alignment" and "time coherence." What is the difference between the two terms?
Bifwynne sorry, I got side-tracked with my other hobby - photography. Processing some pix from a recent air-show & looking into other lens. Darn! why did I have to choose photography + audio both money sinks!! Thanks for Drewan77 for taking the lead to answer. His reply is mostly correct. Almarg has addressed some clarifications already. Time alignment is when the speaker designer arranges the drivers in such a way that their acoustical centers are on the same vertical plane. You've seen this done a number of ways: sloped baffle (BTW, that was another great thread!) with the tweeter on top & woofer at the bottom because the tweeter's acoustical center is way in front of it & the woofer's in almost on the driver itself. 2nd way, is what Focal does - makes the front baffle curved. It's an arc of a very large diameter circle. If you put drivers on an arc the distance from each driver to the listener's ear is the same. The tweeter is not on the arc recessed just a wee bit to account for its forward acoustical center. 3rd way, which is what we've seen in Dynaudio's Confidence 5, where the tweeter is at the bottom & woofer on top. The linear distance from the bottom-most tweeter is longer than from the woofer & makes up for the forward acoustical center of the tweeter. Time-coherence is when a speaker introduces no delays to any frequency in the 20-20KHz range. No driver hence no speaker is linear from 20-20K so you'll see speakers that are time-coherent in the 200-8KHz or 10KHz range. A speaker will introduce a delay in the sound - it has to since it's a causal system but what I mean here is that the speaker does not introduce more/less delay at one freq vs. another. IOW, all freq are equally delayed thru the speaker. When this happens, the leading edge of the tweeter, mid, woofer all arrive at the ear at the same time, as Drewan77 already wrote. For a speaker to be time-coherent, it will be time-aligned & will also be phase-coherent. A time-aligned speaker is not necessarily time-coherent. Simple answer...
You time align speaker drivers or driver sets to each other to 'achieve' time coherence No, this statement is not fully true. Time-aligning is just one thing to ensure time-coherence. And, it's a physical attribute of the speaker meaning you can see it/touch it. The other very important thing to ensure time-coherence is to use a 1st-order x-over such that the time-delays between any 2 freq & amongst all the freq is not disturbed at all. If you don't do this, time-aligning will have no meaning. When you go thru the math, 1st order x-over ckts are the only ckts that do not disturb the phase relationship amongst all the frequencies. Many speaker manuf tout their product to be phase coherent. Yes, they are BUT only at their x-over freq & a little +/- of that. This is easy to for a speaker manuf in the biz for any length of time. The key is to make the speaker phase coherent over the entire audio spectrum. This takes special skill & the use of 1st-order x-over ckts that inherently do not disturb the phase. Otherwise you end up compensating for the x-over & by the time you finish the entire x-over is complicated & destroys the music signal totally. Hope this clarifies.... Thanks. |
Thank you for the kind works Bifwynne.
Yes, correct - for those who cannot & will not buy time-coherent speakers DEQX is one answer to the problem. And, I believe the DEQX people were smart when they realized that the room acoustics play an imp part & they incl room correction as well. I think we can safely say that 99% of the people live in homes where the room sucks! Does that mean these people cannot have good sounding playback systems? No, they surely can with room correction - either passive (tube traps) or active (PARC, DEQX, Lingdorf, etc).
Re. DEQX taking into account driver distortion - I think DEQX does that already. You put a mic in front of the speaker & measure. DEQX sees distortion. It does not itemize the distortion - X% from x-over, Y% from drivers, Z% from cabinet, A% from room. How does it know where the distortion is coming from? To it distortion is distortion. When it does a correction for the speaker is lumps all the distortion into one number & tries its best to fully correct it. Then, I believe, you go to the next step & do room correction with the mic at your listening position. And, this 2nd part takes out the other big contributor.
So, as you are playing music, the driver is still distortion (as it always did) but the DEQX correction curve has an inverse function to straighten this out. So, I believe that driver distortion is included to whatever extent the measuring mic can pick-up & whatever is the correction capacity of DEQX.
I'd be interested in others' comments too. Thanks.
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Thanks again Bifwynne. Glad I was able to contribute.
Very good responses from Almarg & Drewan77 esp. his feedback from personal usage over the past 3 yrs. I've also heard Magicos sometime back & agree with Almarg's findings.
Agree with Unsound - the Joseph Audio slopes are called "infinite slope". yes, they sure appear to be brickwall filters. He often gets a best of show award & I've heard his speakers - good sound but they never stood out.
Bifwynne, it looks like you've convinced yourself that your Paradigms are at the end of the line now. Only you can tell this & we take your word for it. If you try open baffle speakers, there are a few commercially available - Emerald Physics & DIY kits from Siegfried Linkwitz of Linkwitz-Riley fame. Maybe you want to order his kit & make it yourself?? This might be another option (other than building Drewan77's design)??
At RMAF2007 Nelson Pass was there himself in one of the rooms showing off his open-baffle speaker driven by one of his First Watt amps. It was quite experimental at that time but maybe that design is mature now & ready for ordering as a DIY kit?
Thanks. |
Thanks for the feedback Mike_in_nc. My friend used to have a TacT - wasn't the 2.2X but an earlier version - and he sold it shortly after he bought it. I think he owned it a year +/-. He said the same thing - there was a grain/hardness & said that the in-built D/A converters were not good enough.
I believe that TacT is long gone & replaced by Lyngdorf(sp?) - it's the same designer I understand but under another company name. TacT & Lyngdorf are out of Denmark, if I remember correctly...
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Thanks for the detailed update Almarg. Looks like you are making steady progress with the HDP-5. It's time consuming but that's the nature of the beast. The hardwork is all in the prep (pretty much like home-owner projects) to make good measurements as the correction (hence listening pleasure) is only as good as these measurements. |
For sure there are still going to be a lot of very satisfied users provided measurements are taken to the optimum in the environment available
Drewan77 the fact that anechoic or outdoor measurements is the only way to get the best out of the DEQX has to be considered a (big) down-side to this piece of software. The people at DEQX are obviously smart (since they've come up with this clever DEQX box). At the same time don't they realize that audio gear is almost always very heavy esp. speakers? They've got to realize that 99% of people will simply not have the opportunity to take their gear outside or to an anechoic chamber for many reasons. This, then, would create a sub-optimum DEQX setup & would eventually count against DEQX in the long run. It's also going to be a (big) deterrent for many others reading this thread & realizing that there's no way to get the best from or the most natural sound from DEQX unless they carry their gear outdoors/anechoic chamber... In my books this is a major ding against DEQX. |
Drewan77,
OK. thanks for the clarification. So, we are talking degrees of perfection here & not something that blatantly wrong when doing an indoor correction.
And, judging by your last post, it seems that if one of us listened in your room with your indoor correction, we, not knowing your system, might not even be able to tell the slight nasal quality to the mid-bass. You are aware of this since you have done an A/B comparison many times. "Slight" is a fuzzy term but I'll take your word that it's hardly perceptible & maybe only if you point it out to the listener. |
Psag, good to note that I'm not the only thinking along those lines...... |
Almarg, good to read your 12-02-2015 post where you wrote that making your speakers time-coherent has been very beneficial to you. :-) Great to read this. :-) Great to see that now there are 2 independent members who've put in much effort to go the time-coherent route only to reap its immense gains & that I was not out-of-line on insisting on this path....
Naysayers of time-coherent speakers take particular note! |
From a practical perspective, this whole thing is looking more and more like Enron or "Dark Energy Generators." "Enron" - I haven't heard that word in a long time..... ;-) |
