What determines "believability of the reproduction illusion"

[jkeny]

@Barry2013 - are you from Oz - all your pics are upside-down

What Frank & I are maintaining is that ordinary, intelligible-sounding rooms are rendered "acoustically invisible" by our internal auditory processing whereas issues in the electronics can be much less benign & can effect "believability" to a greater extent. Remember in hearing, just as in seeing, there is the whole concept of foreground & background i.e. we isolate & process auditory objects out of their sonic background. How do we categorise some grouping of signals as foreground & some grouping as background? These are the questions that ASA tries to answer but IMO, one of the criteria would be that a sonic background is the grouping of signals that remain fairly constant or non-fluctuating & once it doesn't deviate from this it remains a background & doesn't detract our attention away from the auditory foreground objects being created by our moment-to-moment processing of the signal stream. To me this is why room acoustics, within reason, are relatively benign. A sound that is randomly out of place tends to attract our attention whereas a sound that has a regular, predictable pattern, doesn't

It's a bit like how random noise (up to a point) is noticeable (if we focus on it) but we can easily hear through it to the point that it becomes non-intrusive whereas non-random noise is acoustically intrusive at much lower levels - it's how our auditory processing is designed to function.

Edit: It's not an either or thing - it's about trying to understand the importance of the role of each element in the audio reproduction chain. To my mind speakers & room treatments can have a definite effect but these effects are of a different nature to the ones that I (& I believe Frank) achieve through attention to the electronics. My focus in the electronics area is in the realm of the PS & I find that there are substantial gains in believability to be had in this area - sonic gains that are not achievable through any other means.

 

[jkeny]

The fundamental issue underlying all of this is that we don't "hear", we "process" signals in the audio spectrum which we interpret as "hearing"
In the same way as we don't "see", we process signals in the visual spectrum which we then interpret as "seeing". We "see" a horse from any angle & recognise what it is - not because we have stored all possible angles for horse images but because we have distilled the salient features of a horse.

According to the understanding of visual scene analysis, these salient features that are important for object perception:
Changes in illumination over time
Contours
Figure-ground relationships
Subjective (illusory) contours
Figural grouping

For more explanation on these features see here but we can see that these are somewhat abstract factors that we process & yet the "fingerprint" or "profile" of these factors determine that we "see" a horse.

One of the more interesting factors is the Subjective (illusory) contours. "Illusory contours are not physically present on the retina, but are nevertheless part of our perception of a figure/ground relationship. Our brain "fills in" the missing contours, presumably because we expect to see familiar patterns that we have learned through their frequent occurrence in the environment."

Similar & different factors will likely be teased out for auditory object perception. Yet auditory perception is fundamentally different, in that it incorporates time i.e. it is processing a signal over time - we can "see" a stationary object but we can't "hear" a stationary audio signal - all audio signals involve change over time.


The "believability of the reproduction illusion" is the obvious goal of this hobby but is really only now becoming the main focus of attention with audio reproduction due to the fact that most of the gross frequency/amplitude issues have been solved in modern audio equipment. Changing our emphasis away from the notion of "hearing" & focussing more on auditory processing is where the believability aspect resides, IMO i.e in the evaluation of the abstract "factors" being processed against the "library" of stored auditory "factors". The processing & comparisons being made here are being slowly revealed through ASA - it may mean comparing the profile or fingerprint or statistics of the signal over time with the stored internal model ? The closer this match the more believable or realistic the signals are considered.

 

[Barry2013]

Thanks Jk
My IT limitations and not an attempt to do a Magritte!

 

[jkeny]

Thanks Jk
My IT limitations and not an attempt to do a Magritte!

Well your pics certainly had me "suspending my believability"

 

[Al M.]

Hi Al
Mine came from AllPosters.co.uk and I just checked their site and they have about 200 available in a range of designs.
I am sure there will be similar US outfits and I seem to remember from a TV programme that the Amish community has a very high reputation for making very highly regarded tapestries. There was a particular craft fair each year which attracted a lot of buyers but I can't remember where exactly, but there is bound to be something on the net.
Kind regards,
Barry

Thank you very much, Barry, for the info and the photos!
Al

 

[Al M.]

In mine and many others opinion , The room / speaker interface and speakers is the most important thing in audio.. a well and properly treated room and judicious care in speaker selection , speaker positioning and listening position setup will trump any minor change electronics make.. and will reveal whatever changes the electronics do make..
I have gone thru many levels of room treatment and DRC etc.. and the better you get it all , the more the suspension of disbelief that you are listening to hifi is lifted and in general the better the soundstage and imagery which both contribute to realism.
If you are serious about your listening , you would not dismiss either room/speaker acoustics or the equipment used to generate the signal. It is a combined approach with careful attention to both that is needed.

+1

Excellent post.

 

[Al M.]

Okay, what happens, for you, in a "bad room" with the sound from a recording you know well, in terms of how it comes across? Does it make it sound more "fake", or unpleasant - what disturbs you about the reproduction?

Look here, for example, for one of my more recent experiences when I removed the corner tube traps from my room:

http://www.whatsbestforum.com/showthread.php?20189-ASC-tube-traps-effect-of-their-absence

Now you tell me how you would rescue with electronics the issues that are clearly acoustic in nature. Answer: you cannot.

I should point out, however, that my speakers are far from the front wall (the wall behind the speakers), more than 6 feet as measured from the back of the speakers. I prefer this for soundstage depth, imaging and energizing the room. If, like in many other cases, your speakers are much closer to the front wall, some of the problems may not occur. I cannot help but notice that many of those who advocate extensive room treatment have a rather large distance between speakers and front wall in their rooms as well.

 

[DaveC]

If you sit closer to the speakers you get of course more direct sound as well. You can do this more easily with monitors than with large speakers of course, because of a minimum seating distance required for proper driver integration for large speakers.

Yeah, I've experimented a lot with single drivers that can be used nearfield and it helps but it's still not as good as a directive speaker, no matter how good you think the rest of the system is. And pretty much every speaker that can be listened to nearfield has significant limitations.

 

[DaveC]

@Barry2013 - are you from Oz - all your pics are upside-down

What Frank & I are maintaining is that ordinary, intelligible-sounding rooms are rendered "acoustically invisible" by our internal auditory processing whereas issues in the electronics can be much less benign & can effect "believability" to a greater extent. Remember in hearing, just as in seeing, there is the whole concept of foreground & background i.e. we isolate & process auditory objects out of their sonic background. How do we categorise some grouping of signals as foreground & some grouping as background? These are the questions that ASA tries to answer but IMO, one of the criteria would be that a sonic background is the grouping of signals that remain fairly constant or non-fluctuating & once it doesn't deviate from this it remains a background & doesn't detract our attention away from the auditory foreground objects being created by our moment-to-moment processing of the signal stream. To me this is why room acoustics, within reason, are relatively benign. A sound that is randomly out of place tends to attract our attention whereas a sound that has a regular, predictable pattern, doesn't

It's a bit like how random noise (up to a point) is noticeable (if we focus on it) but we can easily hear through it to the point that it becomes non-intrusive whereas non-random noise is acoustically intrusive at much lower levels - it's how our auditory processing is designed to function.

Edit: It's not an either or thing - it's about trying to understand the importance of the role of each element in the audio reproduction chain. To my mind speakers & room treatments can have a definite effect but these effects are of a different nature to the ones that I (& I believe Frank) achieve through attention to the electronics. My focus in the electronics area is in the realm of the PS & I find that there are substantial gains in believability to be had in this area - sonic gains that are not achievable through any other means.

I totally agree and have always agreed with the importance of electronics, or else I wouldn't have bothered to build my own.... but the one thing that isn't correct is that rooms can be "acoustically invisible", let alone ordinary rooms. I think the issue is there are room effects that make a big difference and others that do not, you seem to group them all into one category which is not correct.

TBH, it doesn't sound like you or Frank have investigated and experimented with room effects nearly enough.

And as far as speakers go, some may have much higher expectations... I certainly don't think many speakers in the lower price levels are capable of reasonable performance and I rarely hear a speaker under $5kish that is any good at all. Many have glaring problems as a result of cost savings, and those who don't still commit sins of omission.

 

[jkeny]

I totally agree and have always agreed with the importance of electronics, or else I wouldn't have bothered to build my own.... but the one thing that isn't correct is that rooms can be "acoustically invisible", let alone ordinary rooms. I think the issue is there are room effects that make a big difference and others that do not, you seem to group them all into one category which is not correct.

TBH, it doesn't sound like you or Frank have investigated and experimented with room effects nearly enough.

You are probably correct Dave & I freely admit that this is just my limited experience & resultant thoughts on the matter. Frank seems to have more exposure to room treatments than me.

 

[Barry2013]

Thank you very much, Barry, for the info and the photos!
Al

Thanks Al.
Sorry the photos were upside down but hopefully you can adjust them
I had another look at the AllPosters site and a number of the tapestries are available in different and larger sizes which may be helpful although I am sure there must be other sources over there.
Barry

 

[microstrip]

(...)

Edit: It's not an either or thing - it's about trying to understand the importance of the role of each element in the audio reproduction chain. To my mind speakers & room treatments can have a definite effect but these effects are of a different nature to the ones that I (& I believe Frank) achieve through attention to the electronics. My focus in the electronics area is in the realm of the PS & I find that there are substantial gains in believability to be had in this area - sonic gains that are not achievable through any other means.

I am not Frank, but I have been saying it for long.

Another more controversy aspect is that in my limited experience you should start from the electronics/source/cables and only then perfect the acoustics/room. These aspects are complementary and it is very easy for amateurs to kill the believability of the system playing with a few panels and bass traps. You can easily improve bass but IMHO most of the time the systems I have listened to using such treatments had no "soul" - an old forbidden word for believability.

Believability is the main reason I always return to the large Soundlabs. Considering my musical preferences, it is much easier to get it using either the Soundlabs or even the Quad ESL63 and modern derivatives. I could get it with box speakers, but the system would be much more critical and need much fine tuning, unfortunately involving a lot of expense.

 

[Rodney Gold]

I have never relied on the LIAR test , as my room is optimised for the sweet spot .. its a fully sealed room .. so not a lot of opportunity to do the sound wafting thru the house thing..

Suffice it to say that when I asked the guest house next to us if my music disturbed them .. they said "no" "in fact some of our guests ask if there is a band nearby"..so I suppose my system passes the LIAR test....

But yes , room treatment would aid a LIAR test..if you had a massive bass boom and used DRC or traps to cure it , the sound in the other room would probably benefit too as also not having that bass boom , and boomy bass is generally not at all conducive to believability.

Al , my speakers are 38% the length of my room (8m) into the room , definitely gives a lot of depth the soundstage, on an aural and visual basis .They are in free space so to speak

 

[microstrip]

(...) I had another look at the AllPosters site and a number of the tapestries are available in different and larger sizes which may be helpful although I am sure there must be other sources over there.
Barry

Most tapestries are not proper sound absorbers and their acoustic properties are very variable and unpredictable - see the F. Toole book on this aspect. His recommendation is to use clipped pile woven carpet with porous backing over a thick felt underlay. See http://www.whatsbestforum.com/showthread.php?8226-Psychoacoustics-of-Room-Reflections/page4

 

[DaveC]

Another more controversy aspect is that in my limited experience you should start from the electronics/source/cables and only then perfect the acoustics/room. These aspects are complementary and it is very easy for amateurs to kill the believability of the system playing with a few panels and bass traps. You can easily improve bass but IMHO most of the time the systems I have listened to using such treatments had no "soul" - an old forbidden word for believability.

It depends on the speaker... it won't work well to put a speaker designed in a dead room in a live room and try to tackle room acoustics last. For example Focal, many find them unbearable in a live room but if you put them in a dead room they can sound amazing. In the same room Wilsons will sound like they have no "soul"...

People also tend to put cables last and I'm not sure that's a good idea... if you carefully audition components and find the perfect match using warm, smooth cables (typical) and then switch to more neutral cables it might throw everything off, but the truth is warm, smooth cables will smooth out all the detail and kill believably. Interconnect cables in particular can do a LOT of damage! Most copper IC cables are a bottleneck...

 

[NorthStar]

1.Quality music recordings by the best music mixing producers/record engineers using the best mikes and recording techniques with the best recording machines in the best recording studios and live venues where the best musicians and singers (including Opera and chorals) perform @ their best the music we all love. ...Be it Classical orchestral or Chamber or Jazz or Blues or World music. ...Including New Age and Instrumental.

2. A quality DSD128/256/512 DAC.

3. A quality USB cable or pair of stereo/multichannel interconnects.

4. A strong power supply.

5. A pair of top-notch loudspeakers.

6. A good room with good acoustics.

7. Adequate audio signal amplification.

8. A clean preamp.

9. Quality speaker wires.
________

• http://www.stereotimes.com/comm0699a.shtml
• https://books.google.ca/books?id=pr...music reproduction the most realistic&f=false
• http://gizmodo.com/5214792/giz-explains-the-difference-between-100--and-100000-speakers

 

[Barry2013]

Most tapestries are not proper sound absorbers and their acoustic properties are very variable and unpredictable - see the F. Toole book on this aspect. His recommendation is to use clipped pile woven carpet with porous backing over a thick felt underlay. See http://www.whatsbestforum.com/showthread.php?8226-Psychoacoustics-of-Room-Reflections/page4

Thanks for that.
I guess it depends on how well damped your room is to start with and that thick carpets could overdo things so suck it and see is probably the best option.
Mine does not sound as if it is in need of further damping but certainly worth thinking more about it.

 

[dallasjustice]

To believe or not believe . . .

 

[still-one]

1.Quality music recordings by the best music mixing producers/record engineers using the best mikes and recording techniques with the best recording machines in the best recording studios and live venues where the best musicians and singers (including Opera and chorals) perform @ their best the music we all love. ...Be it Classical orchestral or Chamber or Jazz or Blues or World music. ...Including New Age and Instrumental.

2. A quality DSD128/256/512 DAC.

3. A quality USB cable or pair of stereo/multichannel interconnects.

4. A strong power supply.

5. A pair of top-noth loudspeakers.

6. A good room with good acoustics.

7. Adequate audio signal amplification.

8. A clean preamp.

9. Quality speaker wires.
________

• http://www.stereotimes.com/comm0699a.shtml
• https://books.google.ca/books?id=pr...music reproduction the most realistic&f=false
• http://gizmodo.com/5214792/giz-explains-the-difference-between-100--and-100000-speakers

If I really needed your points 1 thru 4 for "believability" of the music I was listening to I would get out of this hobby. In general I choose music by artists or genre's I like and worry more about the performance rather than about how well it was recorded. There are very few albums I play that don't sound great.

 

[fas42]

Look here, for example, for one of my more recent experiences when I removed the corner tube traps from my room:

http://www.whatsbestforum.com/showthread.php?20189-ASC-tube-traps-effect-of-their-absence

Now you tell me how you would rescue with electronics the issues that are clearly acoustic in nature. Answer: you cannot.

Al, I just had a look at that thread and it's very interesting what your experience was - I'll comment on it from my angle.

You say that without room treatments the soundstage was flat, but then with the addition of the adjusting of the room aspects the depth factors, etc, were greatly improved - my take on this is that there were enough artifacts in the direct sound which after interaction with the room prevented the listener's mind from understanding the acoustic cues sufficiently to "see" the 3D information. Moderating the room allowed the mind to deal far more specifically on the direct sound, and spatial information in the recording now made sense; when that equilibrium was disturbed by removing the tube traps the additional "chaos" in the sound was now too much, and believability was strongly impacted.

This follows on from what I have said many times: room treatments are one way of allowing the mind to focus on the information in the recording, but IMO the better alternative is to improve the quality of actual sound at the point when it's produced by the surface of the speaker drivers; "improving" here means reducing the level of audible artifacts which are added by the playback chain.

What happens for me is that the soundstage is never flat, once the electronics are sufficiently sorted - the world of the recorded event extends from the speakers back to as far as the acoustics of the recording say it should go; in some instances this stretches for 100's of metres, figuratively speaking.