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Time Domain measurements?

UliBru

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Ok, if there is no ideal speaker then the remaining question is how much deviation from perfectness is acceptable and why do we appreciate some error but not the other one. It may also be necessary to think about how speakers, ears or other recording equipment are influencing the music content.
 

haraldo

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Ok, if there is no ideal speaker then the remaining question is how much deviation from perfectness is acceptable and why do we appreciate some error but not the other one. It may also be necessary to think about how speakers, ears or other recording equipment are influencing the music content.
I am not sure I think that way, we need to measure speakers up and down and in all ways, but a perfect measuring speaker does not guarantee anything, does it?
- A well measuring speaker does not need to be good
- A poor measuring speaker is crap
- If it sounds good, it's good
- if it sounds bad, it's crap
It's the only way I can look at it.....
 

tuga

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There is no such thing as an ideal speaker, I don't think there is any speaker that can do that .... go to a concert hall and listen to Leif Ove Andsnes playing a Steinway Model D, it cannot be reproduced by a hi-fi system .... at least I never heard it, and I auditioned the very very very best that Oslo Hifi Center has to offer, many times ... (including Geir Tømmervik's own rig with custom Kef Muon) very good but not there ...
Real (2-mic / 2-channel) stereo is imperfect (more with speakers, less so with headphones).
You can't expect the reproduction of a recording to sound like the original event, even when reproduced with the most accurate system.
 

haraldo

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Real (2-mic / 2-channel) stereo is imperfect (more with speakers, less so with headphones).
You can't expect the reproduction of a recording to sound like the original event, even when reproduced with the most accurate system.
There for sure will be differences, but would be nice to get close to the same experience, but we are not there .....

John Atkinson once talked about the difference between a real grand-piano and a reproduced grand piano as a difference between radiating surfaces, so if you need to make a grand-piano reproduction sound well you just need a lot of cone area on your speakers, because the grand-piano has a very large radiating surface. With small speakers there is not enough cone area to reproduce the "grandness", according to Atkinson.

Anyways, I think there is something with simply having more "available" cone area
 
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Absolute

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Personally I think the problem we have regarding lack of realism in a playback-system comes mainly from these things;

- Recording
- Acoustics
- Dispersion
- Capacity

To my ears I find that good speakers with controlled on/off-axis behavior sounds remarkably similar in near-field where the room and dispersion characteristics matters less. That's expected due to the fact that we then emphasize the frequency response and minimize the time-related issues that comes from the room/speaker interaction. If we continue to explore the realism aspect, I'd put money on the notion that a real-life trumpet in a anechoic chamber would sound the same as a loudspeaker with equal frequency response and enough capacity in that anechoic chamber, if the recording allowed for it.

In a room where the dispersion characteristics will affect how everything sounds there's no way to make a speaker sound like a real trumpet/piano/guitar. If you reduce the room's impact on sound, you (should) get closer to the real thing.
Of course, the easiest way to perform this experiment is to take both the instrument and the speaker outside and try.

I seem to remember Dutch & Dutch taking the speakers and some musicians to an anechoic chamber to compare in a blind test, but don't know how that turned out. @Martijn Mensink ?
 

tuga

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Personally I think the problem we have regarding lack of realism in a playback-system comes mainly from these things;

- Recording
- Acoustics
- Dispersion
- Capacity

To my ears I find that good speakers with controlled on/off-axis behavior sounds remarkably similar in near-field where the room and dispersion characteristics matters less. That's expected due to the fact that we then emphasize the frequency response and minimize the time-related issues that comes from the room/speaker interaction. If we continue to explore the realism aspect, I'd put money on the notion that a real-life trumpet in a anechoic chamber would sound the same as a loudspeaker with equal frequency response and enough capacity in that anechoic chamber, if the recording allowed for it.

In a room where the dispersion characteristics will affect how everything sounds there's no way to make a speaker sound like a real trumpet/piano/guitar. If you reduce the room's impact on sound, you (should) get closer to the real thing.
Of course, the easiest way to perform this experiment is to take both the instrument and the speaker outside and try.

I seem to remember Dutch & Dutch taking the speakers and some musicians to an anechoic chamber to compare in a blind test, but don't know how that turned out. @Martijn Mensink ?
The unsurmountable barrier, when using a pair of speakers, is that both direct (instrument or vocal) and reflected (room cues, audience noise and handclapping) sound are created/reproduced and reach the listener coming from the same sources located in front of the listening spot.
Stereo creates the illusion of left to right and azimuth/depth location of the phantom sources but venue cues that should be coming from the sides and even from behind the listening spot are also generated in front of us. (I am referring to live unamplified acoustic music performed in a space with natural acoustic characteristics)



On top of that the listening room is creating its own reflections and the overlaying of original cues and our room's acoustic footprint makes the recreation of the original venue ambience confusing.
A livelier room will produce more envelopment or immersiveness (and help the speakers disapear as source) but it will also have a negative impact on the audibility of the recorded cues and thus lower fidelity.
But, as with other aspects of sound reproduction, whether one chooses a deader listening environment and/or narrow dispersion speakers or a livelier room and/or wide directivity transducers is a matter of preference.
 
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Hipper

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Is this where psychoacoustics come in as we each create a phantom image from our source of two speakers, and that is the great variable amongst us listeners. We seem to hear through some of the 'guff' our listening room produces, perhaps more so as we get used to it, but not all.

It's always seemed logical to me that the effects of our listening room must be removed as much as possible to hear the original recording. It is in the hope that the recording contains cues that can be picked out and correctly interpreted.

I've found that with careful positioning and adding lots room treatment (too much for some no doubt - lots of bass traps and some thinner panels to reduce reflections) plus a bit of EQ has a significant impact on the decay times (making them both lower and more even across the frequency response [FR]) and phase (making that considerably smoother too), as well as a smoother FR. The sonic result is crisper sounds and a feeling that the music is 'right'.

Going back to the OP then:

I am wondering if time domain affects perceived stereo imaging and depth.
I would say 'yes', but if it comes from room treatment it may well reduce the width and depth of the stereo image, which in many people's view would be a negative.

Of course this is very recording dependent and I mostly listen to studio bound recordings. I usually get a strong phantom image and a fair spread of the sound but only at and between the speakers. I do not get much depth or wider stereo imaging beyond the speakers.

Whilst I hesitate to say this, I would guess that a reasonably good speaker in a correctly treated room would be far superior to an excellent speaker with no treatment at all.
 

Martijn Mensink

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Personally I think the problem we have regarding lack of realism in a playback-system comes mainly from these things;

- Recording
- Acoustics
- Dispersion
- Capacity

To my ears I find that good speakers with controlled on/off-axis behavior sounds remarkably similar in near-field where the room and dispersion characteristics matters less. That's expected due to the fact that we then emphasize the frequency response and minimize the time-related issues that comes from the room/speaker interaction. If we continue to explore the realism aspect, I'd put money on the notion that a real-life trumpet in a anechoic chamber would sound the same as a loudspeaker with equal frequency response and enough capacity in that anechoic chamber, if the recording allowed for it.

In a room where the dispersion characteristics will affect how everything sounds there's no way to make a speaker sound like a real trumpet/piano/guitar. If you reduce the room's impact on sound, you (should) get closer to the real thing.
Of course, the easiest way to perform this experiment is to take both the instrument and the speaker outside and try.

I seem to remember Dutch & Dutch taking the speakers and some musicians to an anechoic chamber to compare in a blind test, but don't know how that turned out. @Martijn Mensink ?
At a show we did a blind live vs. recorded demo. We recorded several instruments in the anechoic chamber and played them back over a single 8c. The same musicians were present in the room and played the same piece or motif live in the room. Very interesting demo and a lot of people were fooled.

In the end though, I think there's no way to fool a trained ear with a demo like this. In line with what you're saying, every instrument has its own radiation pattern. Where do you place the microphone to accurately capture its timbre? Every loudspeaker has its own directivity pattern, which differs from the instrument. If there are any reflections in either the recording space or the playback space you'll have incongruent cues.

I haven't read the rest of this thread and the current subject seems a bit off-topic, but I'd be happy to share my view on realism. If you wish to create a really convincing illusion that you're listening to the real thing, you'll have to look at technologies such as binaural recording and playback, higher-order ambisonics and BACCH. Remarkably realistic illusions are possible. Just not with traditional stereo in a normal living room.

With respect to the importance of time-domain behavior my position may surprise some people. In our Dutch & Dutch 8c - a DSP empowered active loudspeaker - I linearized the phase response by means of an FIR filter. The filter fixes the phase-distortion caused by the two 4rd order Linkwitz-Riley filters at 100 and 1250 Hz. From a theoretical point of view flat phase response is better than a rotating phase response. We could linearize it without paying any real price, so I did it.

If you look at the science, it's not so clear-cut that normal phase-rotation caused by a 4rd order crossover is audible, or if it's audible if it's a serious problem. There are indications that it might be audible, but probably only under controlled conditions with very specific signals. Like I said, we did it because we could. Not because it's a huge improvement in sound quality. The impulse response looks very nice though!

On the other hand, many of our customers have reported to me that the 8c sounds better in linear phase mode. Those reports come primarily from our mixing and mastering customers, who listen in relatively dead studio environments. These have all been sighted tests, but these people are trained listeners who usually have very good sounding systems in good rooms. Therefore I think there's probably some truth in these reports. Having said that, I personally find it quite difficult to hear a difference. I've been able to tell a difference in a single blind listening test on some test signals we made a couple of years ago, but only under more or less ideal conditions. Nothing statistically significant with music.

At the time I was a pretty well-trained listener, but I was primarily trained in timbre and artefacts. Those were things I was trying to perfect with the 8c back then. I never really trained myself to hear phase distortion. Today I'm sure I'd fair worse than back then, because I haven't really trained my ears much lately. Listening is a skill you lose if you don't keep practicing. When our next speaker goes into the development phase I'll get back to training again.
 

Absolute

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This is an excellent reply, muchas gracias Mr. Mensink!

I have the same impression after experimenting with Kii Three and the phase correction. Blind testing in my very reflective living room was largely inconclusive so I left the question well alone for my own peace, but in some cases/songs I felt I could sense somewhat of a consistent difference leaving me with the impression that it might very well be audible in less reflective environments.

I think it's one of those things that's nice to have, but not one feature worth sacrificing other things for.
 

Martijn Mensink

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Do you have plans for "next speaker"?
So many plans, but so little time. We've made a couple of proof-of-principles and early prototypes that we consider to be very promising, but nothing is planned for release any time soon. Our development is focused on improving the IT architecture and adding features to the 8c.
 
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So many plans, but so little time. We've made a couple of proof-of-principles and early prototypes that we consider to be very promising, but nothing is planned for release any time soon. Our development is focused on improving the IT architecture and adding features to the 8c.
Thank you for your honest response.
 
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Actually, Anselm Goertz has evaluated this topic long ago with the K+H O500C: Sorry, only in German

Conclusion 1:
Group delay or separated amplitude and phase response graphs are more descriptive than a step response graph.
Amplitude response is most important and variations are very obvious and easily heard.
Whereas, the strong visual differences in step response graphs are not experienced as dramatic changes in sound.

Conclusion 2:
With or without phase compensation the speaker sounds very good.
Nevertheless, the phase linear setting improves sound quality a bit.
Most improvement happens in the bass region.

So, yes, linear phase response is good. But a step response like the mentioned Genelec will not make this speaker a bad one.
It's the other way round: A linear phase response would make the already very good Genelec even better!
 
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