Does Time alignment and Phase coherency make for a better loudspeaker?

I was looking at a step function response the other day, and there was as much energetic below the axis as above it.

I was thinking a silencer maker would be blessed with that as the wind they needed to suppress… but real life doesn’t work quite like that.

prior usernames - same ol loser/poser/instigator... 

atdavid

dannad

audio2design

roberttdid

headaudio

just to name a few...  :(

@cindyment , my program runs sine sweeps from 10 Hz to 20 kHz and reads same. My speakers, Sound Labs 645-8's are "on axis" over a 45 degree arc. Any frequency response variation would be a manifestation of the room. I prefer to be interested in the listening position only. The rest of the room is background music as far as I am concerned. All my comments about frequency response are in regards to the listening position only. I could actually program presets for corrections aimed at various locations in the room but it is a lot of work for locations where the music is purely background. The system was tuned to be flat at the listening position then adjusted to the target curve I like which I mentioned above paying special attention from 100 Hz to 10 kHz keeping both channels within a dB of each other across that band. This was done by making small adjustments and repeated measuring. I would like to get it closer but right now the resolution of the system I am currently using is not good enough. But, I do have my eye on a new one. Like you I am totally into digital signal processing as I do not believe there is any other way to get the job done. There is no other way to do it to be honest but, if you say that here you will get cable elevators launched at your head. I suggest you get yourself a nice set of audiophile fuses to throw back. 

Oh … Oh…🤣 How painfully needy , bordering on tragic.

Take the last pair of posts by “cindy” , and merely replace the authors monicker with a certain Narcistic and Egotistical individual then read again!

Too egregiously egotistical to even disguise the recidivism in prose , style and content , at least there has taken place a weak yet blatantl attempt at concealment by condensing the usual three paragraphs into one… Tragic 

Awwwww Bless oldhvyILIKETOSHOUTmec…. Thing is Cobba you are still not sure are you , even now !!! , why else has it taken so long to charge to the rescue?

@cindyment People here are pretty cool if you let them know who you are, otherwise, they assume that you MUST be the person they were arguing with earlier who has ten monikers so one can "gang" up on the other. Its all good. Enjoy yourself and walk away from the bitter old retired white guys, certain that you are going to try to convince them get vaccinated or the inverse....who knows these days. LOL. Be well and get the supply chain worked out...someone on here is certain there is a nefarious conspiracy!

@ghasley , I did not take offence. It would be hard to confuse me with amplifier dude. Honestly, I am just about ready to murder myself with a fork what I am doing is so boring w.r.t. work. Terribly important, but brutally boring. I am helping to source components so we can ship product. I have been writing emails and talking to brokers at all hours negotiating prices and trying to find out if their stock is real (multiple will list the same stock). I actually ended up here due to amplifierdude on another forum, and when I searched his name, came here and got caught up in the conversations. I type fast, so it take no time to bang out a bunch of posts, but the hostility here is ... honestly, just wow.  See the post just before mine ...

No matter what i write as an introduction will get torn apart. That seems be to be de riguer (sp?). I will be either too technical for some or not enough for others. I am obviously technical and I will let my works speak for themselves. I am also totally into audio being a subjective experience, i.e. we all like different things, and heck that changes with the day of the week. I just know the difference between what I subjectively like, and have no delusions about it being accurate. Love digital playback, love turntables and have several, spent far too much money on my main system, but also have several vintage systems that change about twice a year. Love the used market for that. Big money on my main system is in the room. Totally into DSP for the incredible flexibility it gives me. My system can be SS one day, and tube the next with the push of a few buttons (on the screen). Don't get too hung up on equipment except speakers, but could talk for hours and hours and hours about setup.

@cindyment while there was certainly no "offence" intended, the fact that you materialize one day and set a posting record the next likely makes some here curious who you are. Your early posturing is likely to make most indifferent at best. Many who join the site introduce themselves. Something like "Hi, I’m Nigel, I live in my parent’s basement. I have a Parasound Hint or a Whatchamacallit Dac and I’m going to challenge your preconceived notions. I am a manufacturer OR I am a hobbyist" would also be a nice start.

You seem knowledgable and are likely to enjoy it here, you are however, a bit confrontational. Additionally, most of us who have been on Audiogon for a while have no idea who or what a kenjit is either. Warm regards and welcome to Audiogon although its not my place to welcome you or not.

@ghasley , I have no idea who or what a kenjit is, but I take great offence to being compared to amplifierdude or mivmike or mikemiv, or whatever he goes by today, knowing him from another site, and in the my limited time on here. What he thinks he knows about electronics and audio far exceeds what he does, and it is pretty painfully obvious.

@tushiman1 - please grow up, this is your 4th troll post and unlike you, I am mature enough not to be baited. I am sorry you are so offended by what I say. May I suggest a book to catch up?

I was thinking it sounded more like amplifierdude or a longshot, kenjit

@mijostyn,

If you like your system, I would not necessarily recommend anything you are doing other than what you have right now. However, since you have the equipment and I get the impression like to tinker, I would look at doing a gated frequency response (over the frequencies you can) to see what your on axis frequency response is and how flat it is and see how that compares with the room response which is what I think you are saying is flat. Not as a rule, but as a guide, a flat on-axis with a declining room response after about 3KHz seems to match best average preference across a range of music. Your speakers will have less room interaction which is a good, but it also means one less variable to play with. For most rooms, as you noted, that is probably better. You may have some latitude though, since you have full equalization capability, that you can adjust your toe in to adjust direct/reflected balance, while using the equalizer to flatten the on-axis while achieving a different off axis from what you have now.  Will you like it better? Your two headed coin is as good as mine. I am certainly interested in what happens if you do. I expect a whole lot of worse, but possibly you will find a new sweet spot you like even better. This is not a 15 minute exercise.

@cindyment , Hi! Thanx for joining this post. I do not believe we have met before.

I am only advocating a flat frequency response as a reference to start because it is the only reference that makes sense.  What else would you use? My own system is boosted below 100 Hz at 2 dB per octave going down and rolled off above 10 kHz at 6 dB per octave. This is the actual measured in room frequency response at the listening position from either channel.  

What most people think of as "flat" is "uncorrected."  Having a flat, in room frequency response with an uncorrected system would be like winning the lottery. In room frequency response can vary wildly. If you tell me a system is rolled of at 6 db/oct above 10 kHz I still have no idea what the system sounds like because I have no idea what the response was to start with. It gets even worse. The individual channels have different frequency response curves and can easily be 10 dB off of each other at certain frequencies even though they are exactly the same speakers. Imagine what this does to imaging! 

Very few audiophiles have a measurement system which in this day and age is a travesty. For $300 you can get an excellent USB measurement microphone and computer program with which you can measure group delays and frequency response. You can mess around with speaker positioning and room treatment or if you really want to dial it in get a digital signal processor.  All I can do when people tell me they can do this by ear is smile.

I saw this ad for a speaker company. It looked like it came out of Better Homes and Gardens. Two black tower speakers on either side of a black fireplace with white walls, a 12 foot ceiling and black granite floors. One side wall was solid window. Imagine what that sounded like. 

Speakers that have sharp dispersion limits such as horns, planar speakers and linear arrays have large advantages acoustically in residential rooms. A properly deadened small room say 16 X 30 sounds better than a really big room with high ceilings because these rooms usually have acoustic signatures that are harder to get rid of, they echo.

There is more sense and more useful information in the paragraph above than in every thread and post on cable and fuses combined, and you could probably throw in 90% of the threads and posts on DACs and amplifiers too.

I am not saying that these types of speakers are without their own unique flaws as well, but far too much energy is spent painting the pig, not dealing with the little "gifts" the pig has left all over your listening space. Seems pointless to get hung up on things that "may" make a 0.01db, or a few microseconds of difference, and ignore the things that make 1, 2, even 10db of difference, and even 10's of milliseconds of difference.

Lots to unpack in this thread.

Would it not be best to start with how we perceive sound? Our hearing is sensitive to timing over a narrow frequency range, about 200-1500Hz. It would make sense to have time alignment over that frequency range. Many speakers with mid-woofers in the 5-7" range by virtue of where their crossover frequencies are already are time aligned in this frequency range (single driver).

In terms of sound stage, all the other information we use for position, is frequency and volume based, not timing based. With that being the case, is there a good argument for time alignment over the whole frequency range?

@mijostyn , you appear to be advocating that a flat in-room frequency response is the ideal scenario. That is not supported by most people's listening impressions or research into preference, all which suggest a sloping reduced output at higher frequencies.

There is a misconception that in-room frequency should be perfectly flat in order to perfectly recreate the original performance. It sounds great on the surface but it is a flawed premise as you are not trying to recreate the performance, you are trying to recreate what was heard by the recording/mixing engineer, and they have already adjusted the frequency response based on what they were hearing at their workstation which is usually two somewhat near field speakers, but the total response ends up closer to downward sloping at higher frequencies, especially true when they do final mix and test it on larger audio systems and/or headphones which appear to sound best when targeted at a downward slope past about 3KHz.

Some of this may even harken back to the attenuation you would experience seeing a live orchestra or concert hall at typical seating distances and distance to instruments (the front row is rarely where the best sound is).

You can turn it on and off the Dutch and Dutch 8c as well. They say for certain studio work it might be advantageous to turn it off but in a basic home environment you're probably not going to notice a difference, they recommend leaving it on. I've never noticed a difference.

((((JA asks why the speaker wasn’t time aligned since they could basically do it for free and the reply was that specific xover design sounded better without it.)))

I think the true answer is its not free!

 Actually very laborious in order to do it correctly using pis-tonic drivers networked in an-echoic neutral chamber custom tuned to 1/10th of a DB only then behave as a true coherent phase and time aligned speaker. Then in field tilt back properly done to your chair and ear height with distance from speaker allows the magic to happen. In the real world  most all designers and simple folks will run from this task.

  JohnnyR Vandersteen dealer

The last paragraph in the stereophile review of the meridian dsp 8000 JA asks why the speaker wasn’t time aligned since they could basically do it for free and the reply was that specific xover design sounded better without it. The new dsp 8k’s are time aligned with the ability to switch it off and on with the remote and tbh I don’t think I can hear any difference.

I guess if we discount the waveform, then not having speakers time aligned makes sense if we just trust our ears?

They do look like some expensive speakers.

And it makes it a bit difficult to try other cables being a fully built active speaker.

The last paragraph in the stereophile review of the meridian dsp 8000 JA asks why the speaker wasn’t time aligned since they could basically do it for free and the reply was that specific xover design sounded better without it. The new dsp 8k’s are time aligned with the ability to switch it off and on with the remote and tbh I don’t think I can hear any difference.

If this is the case ,tilling back your speakers, hummmm...I remember going to a rock concert once ,this was like 40 years ago. I noticed the speakers in the front were filled up...So when I went home I filled back my Advents and yeah I liked the sound ,they sounded different. 

To be precise the phase alignment in question is not in the recording, amplification, but in a multi element speaker where the speaker element placing and crossover design affect the time alignment of the output.

Mr. Dunlavy was an RF engineer, reportedly, and in the RF world everything is objective and measured. I heard his speakers in the early 90s in a hifi show in Miami FL. They sounded better than most offerings there. Too big and too expensive for me back then.

You can use squarewaves to measure the timealignment of speakers. Time alignment is one of many factors in sound quality, and a pretty obvious one.

Following this logic single element speakers would be better but they have their own issues.

@holmz , no argument from me. I would just like to state for the record that slow phase shifts are likely to be less noticeable than abrupt ones. It is really what happens at the cut off frequency that counts. I avoid your scenario almost entirely by using one way main speakers. All I have to worry about is the subwoofer crossover and one phase shift. IMHO the best crossover is no crossover. This is not an endorsement of dynamic "full range" drivers. The crossover is the lesser of two evils and those drivers are really not full range. Most of them have a 6 dB/oct mechanical crossover to a whizzer cone. The only real full range driver I am aware of is an ESL and even they have to have some wizardry performed with their transformers to make it work.   

@fleschler , sounds very nice. I like cherry very much. Echos are very disruptive.

mijostyn  Right you are!  My custom built listening room has highly damped side walls and ceiling with all 3/4" cherry plywood walls (besides the SR HFTs & internal wall bass traps of activated charcoal chambers, etc.) and is only 19' X 15' X 10'.   

My family room is also nearly all wood but drywall finished 30' X 18' X 19'.  It has very significant reverb.  Talking comprehension across the room is especially difficult although listening to music and speech from long wall TV with separate audio is quite clear (speakers close to the wooden floor).  I wouldn't want to trade rooms for music listening.  My wife and I have to speak very loudly to be heard across the room.  The live room with high ceilings seem to blanket sound at a distance.

@mijostyn lets say we have two wide band speakers.
And we time align them in the 10-20kHz region.

One has a 12dB/octave HPF slope at 2.5 kHz.
The other has a 24 dB/octave slope also at 2.5 kHz.

The phase between those two will look different in the DC to ~5kHz region.

Then lets say we have time aligned a woofer and sub at 120 Hz.
The sub is in a bandpass box, and the woofer in a sealed.
as the frequency goes towards DC the two will deviate in phase from each other.

We could address both of the phase in the first case, and the group delay in the second case with a DSP to correct the phase, or at least in the tweeter case, some XO magic can be done to better align them in phase in the ~2.5 kHz region. (I cannot do it in solder, but many can).

Usually the time alignment is done, in a “minimum phase” sense… and it is done somewhere where the phase is not swinging wildly from say, group delay.

So they are tied at the elbow, but they’re distinctly different once we talk about more than a single frequency. At any given frequency they are effectively able to give the same correction.

@holmz , phase and time are attached at the elbows. It is certain easy hear what happens to imaging if you compare the two channels 180 degrees out of phase. The smaller the phase angle the harder it is to hear. Time, when you are talking about a few milliseconds or less with subwoofers is audible if you cross where I do up at 100 Hz. Lower down it is something you feel. As time variation increases the transient response of the bass has the edge taken off and you do not feel the impact as abruptly. Go to a small jazz club.  Listen and feel the bass drum. That is what you are shooting for. Time aligning subwoofers empirically is a real PITA. With a measurement mic you can do easily and know that you have it right on. The advantage of DSP here is that you can keep the subs where they perform best and align but delaying the signal of which ever speakers are early. 

As for room acoustics I have come the realization that too much absorption is better than too little. The acoustics of the venue are either in the recording or are being created with echo. There are not many instances where we listen to music in small rooms. You really want to minimize all early reflections but in a small room they are all early until they bounce around several times. Speakers that have sharp dispersion limits such as horns, planar speakers and linear arrays have large advantages acoustically in residential rooms. A properly deadened  small room say 16 X 30 sounds better than a really big room with high ceilings because these rooms usually have acoustic signatures that are harder to get rid of, they echo.

Reflections certainly change frequency response which can be easily seen with a measurement mic. But, they also smear detail and ruin the image.

@mijostyn I would like to be a Buddhist, but that is about as far as I got. But I do know enough to know that snarkiness is not a positive attribute.

I am pretty sure that the phase is usually more critical with bass than timing.

Our ears and brains are good at getting the direct path, and depending on the speakers directivity and echoyness of the walls, then reflections usually affect the frequency response.
The more delayed echos, can add some ambiance.

I agree it gets complicated in a room.

As I said earlier in this thread, I have compared 2 speakers, one set time aligned, the other set, not.

They are Jeff Bagby's DIY kits, the "Kairos" speakers, and his "Adelphos". Same drivers (the great SB Acoustics 'Sartori' ring radiator tweeter and 6' MID), same size enclosures. The Kairos are aligned, the Adelphos were designed for those who don't want to tackle building an angled enclosure. 

As good as the Adelphos are, the Kairos created a bigger soundstage and more precise image. 

@jeffvegas , I will do it for you. One way, 8 foot ESLs are King.

@holmz , you can be snarky all you want as long as you are right. If I posed as a Buddhist everyone would die laughing.

Although timing errors can affect imaging frequency response variance between channels causes much more damage and that is easy to demonstrate.

As long as DSP has control over individual drivers it can perfectly adjust timing in one listening location. Most multiway speakers do not allow for this. They have to be bi or tri amped. However, time alignment is most important for subwoofers as diminished transient response affects impact. Fortunately, subs are amplified separately. DSP was extremely effective 25 years ago with the advent of Radomir Bozevic's TacT Audio. He wrote the book on "room Control." With the faster processors we have today it is even better due to increased bit depth. My solution to the problem since 1979 was to use one way loudspeakers with subwoofers. There was no easy way to time align subs until the mid 90s with TacT's processors. Today the best are probably Trinnov's units. But inexpensive and effective ones are available from MiniDSP and DEQX. Used correctly they can improve almost any systems performance even the ones owned by digitally phobic people. It is all just lay instinct. 

Rooms certainly are "Time" sensitive. Reflections occur in time and their timing determines how we will hear them. Unless you like listening to bands in a closet early reflections are always bad. People say that late reflections are in part a benefit and one should not get rid of all of them or the room will sound "dead." I am not so sure about that. Timed reflections are in the recording giving you a sense of the size of the venue the recording was made in. Studio recordings frequently have fake late reflections added (reverb). The problem for home reproduction is that these sounds do not come from the right direction. I am beginning to think that in most home situations there are no late reflections only strong vs weak early reflections. If the room is big enough you get echo which is peculiar to that room and only pollutes the music with sounds that are not supposed to be there. 

I just think it's amazing I've started a discussion without saying anything is the KING. 

@rooze  I wonder if the Evolution Acoustics MM3s which have a family resemblence to Dunlavy Vs have similar time alignment.  Does anyone know?

Despite the truly great sound emanating from Dunlavy's, I cannot tolerate single point/seat listening.  Sure, it's great for me, but not for my wife and my friends who sit across a 10 foot couch.   I am looking at speakers more like Von Schweikert's which have a very broad listening/seating area for tonal equality many feet in width.  My wife hated the Monolith IIIs in 1997 prior to my getting Legacy Focuses and double pair of Hallographs.  

I suppose if someone in Washington state or Alabama had a set of Thiels then they could be tested on a Klipple.
Then would have something objectively interesting.

@audition__audio , That different time correct loudspeakers have different tonal balances suggest that your complaint might be the result of something other than time correctness.

Other than the Thiel CS 5 and 5i, I don’t think the other Thiel models cross-overs are that much more extrodinarily complex than some others.

While you are certainly entitled to your opinion and indeed many other’s share it too, the Thiel’s have also been reviewed by others as having something of the opposite impresson. They tend to measure relatively flat.

Little snarky there holmz...I was referring to the sound of multiple musicians playing the same music with space between them. I attend concerts I don’t mix, and ones I do mix I listen to unamplified sound from various areas during sound check including right in front of or on the stage. If you can’t understand my posts, why are you here?

I am not always the model of all things Buddhist, which is also why I asked the question ending in the question mark.

As there no way to adjust non sound reinforced music it also is hard not to be snarky. The only thing that really needs adjustment anyhow are the speakers. The rest is time-n-phase correct.

Appolgies for the tone, in any case.

Most of Thiel's speakers have demonstrated to me how a single aspect which I think is incorrect can sour the entire speaker and the listening experience. I could never get past the aggressive/forward quality of the treble. To me JT efforts to achieve time/phase alightment did so at tremendous expense. Check out the complexity of many of his crossover designs. 

actually the major difference is the Jim T objective to be flat at the listening position vs at 1m for Richard V. One can debate the merits of both. Until recently i owned both and while i prefer the Vandy, I can understand the allure of increased treble energy inherent in the JT approach.

For those interested , no violin in flat at both 1m and 3 m...... of course if your reference is 32 track studio stuff, keep chasing your tail....

it does seem that snippy and snarky are in fashion, unfortunately - i fall into the rut occasionally as well

as for time alignment allowing the brain to work less hard, maybe so, dunno, but while i would agree that vandy's are very relaxing to listen to, my recollection is that thiels are less so, in fact they are quite dynamic and can get edgy, so not sure time alignment is behind their characters (more likely the metallic tweeter used in thiels)... other speakers are lovely and relaxing - harbeths, spendor classics, grahams... those are not time aligned

An argument I've heard for time/phase alignment is that it relieves your brain of the burden of reconstructing the sound as it originally was.  The various frequencies that make up any sound are normally all related in time and most speakers don't preserve the relationship.  Your brain is good at fixing this before you perceive the sound so you don't exactly hear the difference but you can sense the relief of your brain not needing to do the work.  

I don't know if it's true but there are sure a lot of people that like Thiel, Vandersteen, etc.  If I perceive it, and I think I do, it's a relaxing quality that other speakers don't have in my experience.  It sounds more correct and I can just relax and listen.

Little snarky there holmz...I was referring to the sound of multiple musicians playing the same music with space between them. I attend concerts I don’t mix, and ones I do mix I listen to unamplified sound from various areas during sound check including right in front of or on the stage. If you can’t understand my posts, why are you here?

Room treatments do not add to coherency.  Room treatments subtract.  The speaker must produce a time or phase coherent sound field in order to produce that astonishing three dimensional soundstage.  The reflections- both airborne and the mechanical interaction between the speakers and the floor (as well as to the amps and other components) though small they may be smear the sound.  The room treatments remove those reflections to restore coherency and detail as well as bring more clarity to the bass.  That is my experience.  

Good for you, but the topic was time and phase... so you are out of sync.

Past attempts at DSP were abysmal failures, but perhaps significant gains have been made in the past few years. Funny I still dont consider DSP a viable option which is probably not wise. Just dont like the idea of DSP at a fundamental level. 

So you were bit biased?

I phase and time align every concert venue I mix (hundreds overe decades) , and my home rig also. I never said phase and time don't matter, I simply was pointing out that live music with no sound reinforcement is never specifically adjusted for time and phase, and it still sounds great. Musicians hopefully play in sync and in tune, but not always perfectly and it can still like magic.

 

The signal from a person playing or singing is, by definition, time/phase aligned.
If there is no speaker reinforcement, then why are you there?

the fundamental problem with any question like this is of course any one element of successful design can matter, but the specific impact of that element can only be felt only if all else is equal... design of something as complicated as a loudspeaker is highly multi-variate, so ’all else’ is never ever, ’equal’, far from it in fact ... so it ends up being an interesting theoretical discussion with little to no real world applicablity

'does the type of insulation matter in how an interconnect sounds'?

'will a different brand of capacitors in a linestage improve the sound'?

'do r2r dacs sound better than delta sigma ones?'

and so it goes, round and round...

Also, "still SOUND like magic." Jeeze....

That's "over" not "overe."

I phase and time align every concert venue I mix (hundreds overe decades) , and my home rig also. I never said phase and time don't matter, I simply was pointing out that live music with no sound reinforcement is never specifically adjusted for time and phase, and it still sounds great. Musicians hopefully play in sync and in tune, but not always perfectly and it can still like magic.

Just tilt your head back to the desired angle..voila, time aligned 😉

Time alignment is about when the sound reaches your ears from the drivers in your speakers. Getting it right adds realism to the sound. Wilson Speakers are built to be listened to time aligned. The smaller models are not adjustable in that regard and require a setup within some relatively tight parameters to sound best. Not to far from the listening posistion or too high/low. The middle and upper models have adjustable modules for each driver alowing more flexbility for the seating posistion and room size. Is it night and day? Yes if you are used to listening to your system with $50K and up speakers, well set up and driven by really good amplification and sources, so at least six figure system. Otherwise, not so much. This is a final touch for well designed systems.

Ever heard any of John Fuselier’s loudspeakers from "back in the 80’s"? Time and phase aligned, with excellent coherency and pulse response. Soundstaging and imaging were exceptional. Spectral balance varied between different iterations/models, but all had an uncanny ability to sound real. If you are familiar with them, then you should know exactly what I am talking about.