Green Mountain Audio Europas

[Matt34]

Give me a break, you obviously haven't been reading the posts, especially mine!

All I asked about TLS guy is what speakers he manufactured, as he seemed to be putting himself off as a manufacturer, so I was curious about what speaker company....nothing more.. tell me, what did I say about him other than that, huh? Othere than your "buddies" assumptions?

You need to follow the thread closer if your going to start "deleting off topic posts" because the majority of them are not coming from me!

Such as the post above "Digicidal"...which again, if you have been following the thread, this guy is manufacturing crap that was never said...he is instigating and if your going act your part, I suggest you start with his post.

Like you said, this thread needs to stay on topic, and last I looked, the topic was Europa speakers, not me!


Rick

He never once said he was a commercial speaker manufacture, that was you assuming.

I don't need you to tell me how to do my job but I can help you to the door.

 

[digicidal]

Matt is totally free to delete all of my posts for that matter - it's a moderators perrogative.

And in all fairness, I do appologize to you Rich for mistakenly attributing some of Shakeydeal's comments (unfairly I might add) to you. If you refer back you can see that I didn't bother to comment until about the 30th page of this thread - and only then after reading through nearly 300 posts. I'm sorry that I got you and Shakey confused - but in all fairness you have to admit there's a significant amount of similarity to many of your posts in this thread.

As far as the comments made in referrence to GMA itself and the speakers in question - I stand by my observations/opinions, but I am more than prepared to change those opinions as more logically and scientifically supported evidence is presented to the contrary. As I clearly stated in my posts - I'm no genius when it comes to the mathematics of waveform propagation - however, I do know what the 'quack of a duck' sounds like.

 

[Shakeydeal]

but I am more than prepared to change those opinions as more logically and scientifically supported evidence is presented to the contrary

I guess expecting you to change your mind after you actually hear the speakers isout of the question........


Shakey

 

[digicidal]

I guess expecting you to change your mind after you actually hear the speakers isout of the question........

Not at all, if you would like to send me a pair of them - I will be most happy to give them a full audition and (if I am as blown away as you are) have a pair of them on order the minute I've sent yours back.

However, if I can't tell what Paul, John, George and Ringo had for breakfast before recording Abbey Road... I'll still be calling "foul" on that advertising copy posted on the site.

 

[RoyJ]

Time and phase

My apologies for this delay in response.

'Time' is often confused with 'phase'-- in speaker design, in recording and mixing, and in hearing versus measuring.

To me this becomes clear when first principles are compared:

A sound goes into the mic.
We look at 'it' go by on our Windows Player and see a complex wave. We can use wonderful programs to take 'it' apart, so it can show us its constituent frequencies, each coming and going with a particular loudness at every instant.

A sound goes into the ear.
We hear 'it' and know where it is, what it is, and if we've heard it before, know how it compares. All in a blink. Anything urgent in 'it'? Blink again... "...ou want fries with that?"

===================

Two sounds go into one mic.
We see a far-more complicated waveform, which we can still take apart and analyze. Yet, if any computer could pull out and display the two waveforms, then FedEx's computer would also recognize what I said.

Two sounds go into one ear.
We hear two 'things', which can remain in memory as two separate sounds, as well as what they sounded like together.

===================

Phase
On the `scope, we can observe the tones inside any wave, seeing when they come and go and their loudness'. If we must use the word 'phase' to help describe a particular feature, we must first choose a starting point to then be 'out/in phase' with, by X-amount of Degrees.

360 degrees around the phase-o-meter represents one full cycle of 'that', perhaps the second cycle of the lowest tone arriving 360 degrees after its very first cycle happened along.

Phase, by definition, is relative. Relative to whatever you choose.

===================

Time
From that super-complex waveform, we hear two separate sounds (especially if we've heard at least one before) and they change as time passes.

While no one is certain how, we do know part of what keeps them separated is we somehow latch onto the sound of the initial transients of each new word and note. That 'sound' lets us follow the rest of 'it' along, albeit with constant reminders of 'it' at the start of each new sound from 'it', reinforced by any expectations from previous experience (= trained listener). That 'sound' is inside the 'shape' of the waveform.

Time, by definition, is relative. Relative to whatever you choose.

"This is Your Brain on Music", written by a famous recording engineer, cites much research done on exactly the above.

===================

Where does this leave us?

We know a computer cannot separate two or more complex sounds into their original parts, not because 'they are not in the summed-signal anymore, from some weird phase combination'. It can't because we have no real idea how to program it and may never, as that means understanding completely how we hear. Which is even more complicated than vision. And why FedEx's computer hung up on me.

That two-or-more complex waves remain 'inside' that one super-complex waveform is proven mathematically and experimentally (search wave+superposition) and by ear, as we can hear them. In this photo, one wave travels down a string, then two waves from opposite directions 'pass through' each other, and finally two waves of opposite direction and of opposite polarity 'pass'. Each emerges unscathed.

Just because the strings came in while the woodwinds played does not make the woodwinds sound different, but they radically change the woodwinds' waveform on a `scope.

When complex waves are added, what we see can be described as 'changes in Phase' relative to some point, and by 'changes in the constituent tones as Time flows' relative to some starting time. Each has its uses. Specifically, for speaker design--


We don't know what's inside any complex waveform, so we'd best preserve its shape. Thus, I must make certain the lows, mids, and highs from my separate drivers arrive at your ears in the same sequence as recorded. That is the goal of time-coherent speaker design. Which automatically means phase coherent-- no need to say "time-and phase-coherent".

But any speaker can be phase coherent among any two of its drivers, without being time-coherent. This only means the peaks and valleys of the SAME SINE WAVE at the crossover frequency ONLY, coming from each driver, line up on the `scope.

It does not say each began at the same time. At best, it means one driver is 360 degrees ahead of the other, one full cycle, and thus 'back in phase'. Perhaps it is 180 degrees ahead, and thus appears upside down, so we flip the tweeter's polarity mistakenly thinking "well, that's 180 degrees I just added, so they are back in phase." No, we only flipped the polarity-- its output is still arriving too soon relative to the mid driver at that ONE crossover frequency.

In higher-order crossovers, that exact 360 or 180 timing drifts apart by a different amount at each frequency above and below the crossover, leading to even more artifacts about 'how the speaker sounds' versus how it measures.

In a proper first-order crossover speaker, the timings do not drift apart. So there is a consistency about the sound on any music and gear, at least with our speakers, which is what lays behind the comments of our Owners.


Rooms screw up time-coherent speakers, so why bother?

Of course, the room will color what is heard, and better listening rooms do not let reflections arrive too soon nor too loud, obscuring what is to be heard from the direct sound. Which will be the complex waveform arriving directly from the speakers, or none of us could point to someone apparently between our speakers. Research by Haas and by Dr. Daniel Queen are good starting points.


Recordings have all sorts of phase issues.
The `scope shows all sorts of cancellations and reinforcements going on as two or more mics are mixed, visually. But this is not happening audibly.


I hope the above helps, but just in case:

The situation is like this. If you have a group with several mics spread around a group of musicians making a recording, the mic nearest the instrument in question will have the loudest signal from what instrument is in front of it. Unless the musicians are in an isolation chamber every mic will hear every instrument, but with varying intensity depending on location. There will be varying time delays to all the other mics depending on the distance from various instruments. Those are time delays which can be calculated for every instrument for every mic which is a function of the distance from various sources and the speed of sound.

Agreed.

Now the phase of a note from any particular instrument source will be random depending on the position of the cycle it hits the diaphragms of the various mics, that is the phase shift.

OK.

You can only make a time and phase coherent recoding with a single pair of figure of 8 or cardioid mic one right above the other at right angles.

Actually, a spatially-coherent recording is being made, as this single-mic location/technique preserves the TIME and LOUDNESS of every instrument's constituent TONES relative (there's that word again) to every other instrument. Now, the mic, the mic-preamp and the recorder must handle the complex signal 'time-coherently', by not delaying any particular parts of the spectrum. They must not have 'phase shift' in layman's terms, to preserve clarity and transient response.

Multiple mics also preserve their own relative Times and Loudness', even after being mixed together-- to our ears, not to a `scope... even when they 'hear' the same sounds (as TLS wrote) from different distances with different loudness'. And I would add, with different 'Timbres' (Tam-burrs), or 'Textures'.

Because of these three differences between multiple mics hearing a different version of the same thing, we still follow and enjoy the sound of the violins as picked up by their main microphone. Yet, if the engineer lets another mic hear too much of them too soon, then we hear a new timbre added to them which can be irritating, but they are still heard as separate violins.

Any other arrangement will have time and phase shifts.

OK as a definition, but I would have said "... will create time delays and therefore phase shifts."

Which means a less spatially-coherent recording. Which means less clear.

Which does NOT mean the sounds from each mic are being altered by mixing them together, but are only being overlaid by each other. Which means less clear.

If a speaker is NOT time-coherent, then we hear a distorted version of that now very-complex, not-as-clear wave, still audibly containing the one hundred members of the orchestra. Side note:
A) Most speakers have become more time-incoherent over the last 40 years.
B) The reliance on 'simple' recordings, such as Holly Cole, has greatly increased over this period.
Hmmm.

Then there is dummy head recording where mics are placed in the ear canals of a dummy head. Then time and phase are as they would be for a human head. This obviously only works for headphone listening. I hope this helps.

The dummy head receives a signal that, when reproduced over headphones, is spatially coherent. And for the best 'simulation', the headphones must be time-coherent, which most are, even $50 Sonys.

Best regards,
Roy

 

[KEW]

Thanks for the response Roy.

I must admit that I am very much stretching here, but as I read your post it seems in agreement with TLS Guys statements. You elaborate, but do not seem to dispute.

I have one specific question.

When you say

... that now very-complex, not-as-clear wave, still audibly containing the one hundred members of the orchestra.

isn't a portion of the "very complex, not-as-clear" aspect of the waveform due to losses in time and phase coherency due to the recording process?

 

[RoyJ]

Thanks, KEW

TLSGuy and I do not agree, and I probably should have been even more specific as in what way.

Time-coherence of each mic's signal is NOT destroyed during mixing with the signals of other mics that hear the same part of the orchestra.

This is because they hear nowhere near identical copies of the same part of the orchestra, from the different arrival times to each mic, the differing loudness' of each, and the timbres being substantially different, along with the transients' shapes and the amount of decay (reverb) being different in each.

The different mics only overlay their different sounds, which reduces clarity because that competes for hearing the clearest signal from each mic. Which is why engineers work hard to keep mics from hearing the same parts of the orchestra. There are no losses in the recording process due to time-and-phase differences during mixing.

Yet, on a `scope, that overlay does look like cancellations and reinforcements are going on... but mathematically, the separate mic-signals are still in there and we hear those.

A time-coherent speaker best preserves the shape of that complex waveform (which contains the separate waves from the mics), so we can hear everything more clearly, and here it is up to you what the word 'everything' means. Dynamic changes, textures, images, subtleties, emotions, rhythms, pacings, twists and turns.... it's music so it is a very long list.

Best,
Roy

 

[highfigh]

A time-coherent speaker best preserves the shape of that complex waveform (which contains the separate waves from the mics), so we can hear everything more clearly, and here it is up to you what the word 'everything' means. Dynamic changes, textures, images, subtleties, emotions, rhythms, pacings, twists and turns.... it's music so it is a very long list.

Best,
Roy

How does a speaker affect the rhythm?

 

[Shakeydeal]

How does a speaker affect the rhythm?

You've never heard some speakers that just downright boogie?

And other speakers (or associated equipment) that just won't "let go" of the notes? Some speakers and amps are more communicative of the music than others.

Shakey

 

[digicidal]

I think this is exactly why (to my ears) my wideband single-driver speakers sound so much more 'right' to me than much, much more expensive 2 and 3-way speakers do (although part of it is their incredibly light cones and the lack of any crossover - or any other electronic components with the exception of the BSC).

I can easily grasp the concept of time-coherency being very important... but I could grasp that to begin with. I think the main issue raised by TLS has still not been addressed here by Roy - which would easily be confirmed by a FR graph conducted by a 3rd party (i.e. like the NRC's facility) is how accurate they are.

I am fully aware that you are committed to a belief that the superiority of your speakers cannot be adequately measured with a simple FR chart, or even waterfalls - but that shouldn't mean that their basic capabilities can't be. Do you have some charts for these (or any GMA designs) that you could link to or post for us Roy?

My reasoning is this - although I still do and always will take issue with some of the marketing copy you employ - and allowing for there being 'magic' associated with time-coherence that will not show on a chart... a FR chart would still at least indicate the tonal accuracy of the design. I'll even go so far as to say that a speaker that wasn't as coherent but had slightly better response would still potentially sound much worse than a coherent design. This makes perfect sense.

However, at the same time - if the FR is really all over the place - showing sweeps of many db at any given frequency... then I would be very dubious as to it's ability to produce a completely believeable image. It might still be more believeable as a speaker with a perfectly flat FR and absolutely horrible time-alignment. However, tone is readily identifiable - particularly in the midrange - and if it wasn't extremely important then timbre-matching the L/C/R speakers would have to significant value and barely detectable as better or worse - which is clearly not the experience of almost everyone that's heard setups done both ways.

Perhaps you could shed some light on the measurable performance of your speakers - even though it would not show "the rest of the story" so to speak.

 

[highfigh]

You've never heard some speakers that just downright boogie?

And other speakers (or associated equipment) that just won't "let go" of the notes? Some speakers and amps are more communicative of the music than others.

Shakey

"Won't let go", as in 'undamped and highly resonant'? Yeah, I have heard them. How would that be a good thing, rather than respond to the signal and not impart their own additional resonances?

Are these the ones that sound 'chocolatey'?

 

[Shakeydeal]

Overdamped is more like it. Constipated, if you will. NOT a good thing. And no, I do NOT want a speaker imparting it's own additonal resonance.

Shakey

 

[JerryLove]

I can easily grasp the concept of time-coherency being very important... but I could grasp that to begin with.

We all can (phase coherency), and for a while (the 70s) the builder community thought it was (notice that most "time aligned" speakers are from that era). Then someone (Toole IIRC) actually did a lot of blind listening tests and discovered that it wasn't.

 

[TLS Guy]

Thanks, KEW

TLSGuy and I do not agree, and I probably should have been even more specific as in what way.

Time-coherence of each mic's signal is NOT destroyed during mixing with the signals of other mics that hear the same part of the orchestra.

This is because they hear nowhere near identical copies of the same part of the orchestra, from the different arrival times to each mic, the differing loudness' of each, and the timbres being substantially different, along with the transients' shapes and the amount of decay (reverb) being different in each.

The different mics only overlay their different sounds, which reduces clarity because that competes for hearing the clearest signal from each mic. Which is why engineers work hard to keep mics from hearing the same parts of the orchestra. There are no losses in the recording process due to time-and-phase differences during mixing.

Yet, on a `scope, that overlay does look like cancellations and reinforcements are going on... but mathematically, the separate mic-signals are still in there and we hear those.

A time-coherent speaker best preserves the shape of that complex waveform (which contains the separate waves from the mics), so we can hear everything more clearly, and here it is up to you what the word 'everything' means. Dynamic changes, textures, images, subtleties, emotions, rhythms, pacings, twists and turns.... it's music so it is a very long list.

Best,
Roy

Roy this last post of yours makes no sense at all. Of course each mic being at one location can not be out of time or phase with itself. Unless you use an isolation booth all the mics will hear and respond to everything, but the intensities of various instruments will be different for each mic because of proximity effect.

However the whole ensemble is only time and phase coherent at each location.

Now when you mix the feeds for multiple spaced mics you are mixing sounds from multiple locations and so you are mixing signals with different time paths to different instrument and different phase relationships. To maintain any thing different flies in the face of logic. That is why you see it on your phase scope and it does not lie. You can't explain that away.

You can ameliorate it to a degree as far as time by putting delays on the mics. This is of limited use because the time paths for all instruments to each mic are different. The delay does nothing to correct phase.

I have made hundreds of recordings in my time and know the problems well first hand and up close.

 

[TLS Guy]

You've never heard some speakers that just downright boogie?

And other speakers (or associated equipment) that just won't "let go" of the notes? Some speakers and amps are more communicative of the music than others.

Shakey

I don't want speakers to "boogie." I want Peter Walker's "Closest Approach to the Original Sound."

I think I have a good idea how to get very close, but I'm skeptical about you given the above post.

 

[GranteedEV]

We all can (phase coherency), and for a while (the 70s) the builder community thought it was (notice that most "time aligned" speakers are from that era). Then someone (Toole IIRC) actually did a lot of blind listening tests and discovered that it wasn't.

Not to get into this again but I think in an interview, Kevin Voecks of Harman (and formerly of SNell) once said that he used to be totally against high order crossovers and was always trying to get the phase aspect (respectfully, i won't claim time) perfect until he actually heard the LR4 and never went back. The Salon uses not one, but three 4th order crossovers in a 4-way design.

 

[digicidal]

Some speakers and amps are more communicative of the music than others.

I was fine with your statement until this part. And no, I'm not saying that different amps and speakers don't have different sounds - however, there can only be one right. That right is the sound that occurred at the time the recording was made (or at the very least the sound that was committed to the media recorded in the case of mixed/produced recordings).

If the producer has bad ears and/or monitors - then what you're listening to on the CD/LP/TAPE/FILE will never be the sound that actually occurred in the studio... but it's at least as good as you'll ever have unless you were one of the musicians and you then have your memory of it. Unfortunately we can't play that!

However, if you're saying that amps can impart anything other than "extra" sound (note I didn't say "better") with the exception of more power enabling better control over the transducers involved at the speaker - then I totally disagree. Speakers are definitely a series of compromises - on this fact TLS, Roy, and pretty much everyone else agrees. In an amplifier - there is no reason to not have a totally flat and completely time-coherent sound... as it is merely voltages.

Now if you mean the warm sound of tubes and some exotic SS amps (which I will even agree to being ejoyable) you are not talking about 'accuracy' any more than you are with a DSP mode/filter. There is something being added to the sound (or taken away in the case of the rolled highs of many single-ended tube designs).

I love me some tubes - don't get me wrong - just like I love me some FR single-driver speakers... but I don't ever confuse that appeal with being more accurate to the original experience... it's not! I tend to find it more relaxing and reminiscient of the "good ole days" but it's still WORSE in a truly clinical sense.

Please clarify that statement if you will, as it would help me better understand the position you are coming from. Thank you.

 

[RoyJ]

Matt is totally free to delete all of my posts for that matter - it's a moderators perogative.

And in all fairness, I do apologize to you Rich, for mistakenly attributing some of Shakeydeal's comments (unfairly I might add) to you... I'm sorry that I got you and Shakey confused - but in all fairness you have to admit there's a significant amount of similarity to many of your posts in this thread.

With all due respect, it seems this tells many here there is somehow a conspiracy afoot, moles everywhere... Yet, since these Owners are all saying similarly positive things, there might be technical reasons those might be true, which are indeed found on our site. And some of those I have endeavored to explain here.

By the way, since few here have apparently heard of us, search for "Green Mountain" on Audiogon and Audio Asylum, to see these same comments made by a whole lot of Owners over and over. As with any 'possibly good' product, this uniformity of opinion is about our only hope of finding the best gear via the internet, I think.

Best regards,
Roy

 

[RoyJ]

How does a speaker affect the rhythm?

Hi highfigh,

The rhythm can sound sluggish for several reasons:

• The most common one is when the woofers' signals were given lots of extra time-delay by a higher-order crossover acting below 300Hz. FYI, this is equivalent to many extra 'feet of distance traveled through the air'.
  The woofers are very late.
  
  
• The high series-impedance that these higher-order crossovers put between the woofer and the amp reduce greatly the damping factor of the amp, which means less control or 'tautness'.
  
  
• But that lack of electrical damping can be offset by making the woofer's suspension stiffer. Yet a stiffer suspension suffers more from 'sticking friction', failing to move on small signals. And that 'turns off' the cone motion on small signals, which means we can't hear as well small, graceful sways to the rhythm nor changes in bass dynamics. The bass just isn't "as good" when we turn it down.
  
  
• The acoustic stuffing inside the enclosure can be far too close to the woofer's cone, literally having the air-mass stuck to the cone being dragged back and forth through it. Like opening your car door on the freeway, that's a lot of resistance to the motion.
  
  Look up 'Effective Moving Mass' for any woofer's cone, and compare that to its 'Moving Mass'. The difference is the air stuck to the cone (several inches deep, on both sides) through air's own viscosity.
  So we are all listening to 'air-piston woofers' on their front sides, especially as they get smaller and stroke harder. No wonder bigger woofers hit harder.... Just imagine the actual hard cone laying several inches below the 'front' of the air-piston that is actually doing the sucking in and out which makes the sound pressure change in the room.​
  
  
• The enclosure can flex a lot below 100Hz, and we lose impact and definition. MDF has a problem when you run in the woofer screws without a threaded insert- the face of the wood flexs in and out from the inner skin of the wood. Because it is just layers fibers glued together. Get it wet for example, and find it not as strong as paper.
  
  
• The enclosure can wiggle on top of the carpet or the floor itself can move. Thus, the woofer doesn't, and impact and clarity (definition of both rhythm and pitch) suffer.
  
  
• When time-coherence is achieved in the mids and highs, the bass sounds tighter, because the leading edges (which are mids and highs) of most low-bass notes are better defined.
  
  
• And I have heard speaker wire that makes the bass boomy, no matter what speakers or amp were used. Just thought I'd throw that out there for those who have not yet heard the differences. Because we don't have very many good retailers left, and the majority of reviewers are of no help.

Best regards,
Roy

 

[RoyJ]

I think the main issue raised by TLS has still not been addressed here by Roy - which would easily be confirmed by a FR graph conducted by a 3rd party (i.e. like the NRC's facility) is how accurate they are.

I am fully aware that you are committed to a belief that the superiority of your speakers cannot be adequately measured with a simple FR chart, or even waterfalls - but that shouldn't mean that their basic capabilities can't be. Do you have some charts for these (or any GMA designs) that you could link to or post for us Roy?

Thanks, and I would remind you that they are on my site, in great detail, including how the measurements were made with what signals.

Having the NRC make measurements would not change my sales. I have no technical need for the NRC or their equivalent, nor do my customers.

I invite anyone to have a detailed look at the independent measurements performed on my 13-year old retired design, the Continuum 1, on my site. Have a look at the room it was measured in, too! Check out our Eos model's measurements recently performed by the UK's most experienced reviewer, Keith Howard. I forgot the ones that Home Theater Magazine did on our first two-way, in 1999. I think those might be on our site for the retired Continuum 0.5. Done by the founding editor, and a drummer, who went on to work for Dolby Labs for several years.

Be happy to answer questions on any of these reviewer's results as time permits, as I have already done for our old Diamante test in Stereophile.

... I'll even go so far as to say that a speaker that wasn't as coherent but had slightly better response would still potentially sound much worse than a coherent design. This makes perfect sense.

Agreed more than you can know.

... However, at the same time - if the FR is really all over the place - showing sweeps of many db at any given frequency... then I would be very dubious as to it's ability to produce a completely believeable image.

Our dB +/- is clearly stated on our site, and how we obtained that.

Perhaps you could shed some light on the measurable performance of your speakers - even though it would not show "the rest of the story" so to speak.

I thought I have been doing that, by presenting how time-coherence works and measures, along with the common problems of measuring speakers of any sort.

All I can offer concerning "the rest of the story" is already on our site. No way could I repeat that here, sorry, as there are so many aspects to speaker design.

Best,
Roy