Speaker Testing: why mono is better

[don'ttrustauthority]

I used the buzzwords (detached, crystal clear treble,...) only to emphasize what I mean - it's hard to use the "right" adjectives.

Trust me my brother, 'detach' is not a buzzword.

You describe exactly what you are hearing in a way that is clear and precise.

All of us could take a lesson from you.

 

[Kal Rubinson]

(If I didn't put him to sleep, @Kal Rubinson is probably shouting at his computer screen that a good multichannel system already does all of this. And he is right! But let's see how much we can do with just stereo.)

Of course but some people insist on doing it the hard way.

 

[tuga]

Of course but some people insist on doing it the hard way.

Not everyone has a large enough room or can afford a multi-channel system...

 

[Kal Rubinson]

Not everyone has a large enough room or can afford a multi-channel system...

As a general statement, I accept your point. Still, there are many (including many in these forums) who have rooms and budgets which would accommodate multichannel and, yet, still resist it. Ah, yes, there's the limited repertoire but that's another story.

Klippel (yes, that Klippel) found that the “feeling of space” makes a 50% contribution to "naturalness” (realism and accuracy), and a 70%(!) contribution to "pleasantness" (general satisfaction or preference). [blasphemy]If we take this at face value, the implication is that the "feeling of space" (soundstage, ambience, imaging, immersion, envelopment) matters as much or more than all those other factors which are MUCH easier to measure.[/blasphemy]

 

[Purité Audio]

I would like to try multi channel ( music) what do I need?
I have used my Illusonic , but it would be nice to offer an inexpensive option.
Keith

 

[DonH56]

Given the small size and reasonable wall mounts for surround speakers I suspect there are very few rooms that would not have room for multichannel music. There is certainly a large market for multichannel theater systems judging by the AVR and HTIB marketing. The biggest impediment IMO is the relative lack of source material and/or availability. If more people started asking for multichannel music it would help drive the market, but I for one have no idea who I would ask.

 

[amirm]

No one is questioning the effectiveness of single-speaker testing as a means to assess spectral defects.

Pretty sure there would have been a long line of such protesters before I did the video! Indeed I got tired of reading the arguments and having to respond with the research. Good to know that is finally behind us. Another reason video format works well for such explanations!

What I and apparently others are suggesting is that stereo listening should be used as a complement to single-speaker listening for assessing spatial quality performance because it is fitter for that purpose.

You are wishing for world peace. Sure would be nice to have but it is possible. We have enough difficulty characterizing a single speaker in listening tests. Now you want to add a second one, with infinite possibilities between them as far as positioning, then the room impact and content? You really think you can produce any kind of reliable data you can back? All you accomplish in subjective stereo listening is another unreliable anecdote which we read time and time again in subjective reviews. And reports like yourself. None of that has value or anything I can put in my reviews.

There is a reason why Harman's research frequently talks about investigating these other aspects of speaker listening, yet across many decades they have not published any work. It is such a hairy problem that they can't get their arms around it to produce anything of substance as far as controlled testing. This, despite their capabilities. And you suggest that I start to solve a problem that no one in research or industry has done?

At the end of the day, this translates into kabuki theater for some of you. You worry that your favorite speaker won't measure well, or sound well in mono so make up theories about how some other measurement or listening test method would vindicate you. Well, no such thing exists. We have the science of what is good measurements and what is good listening protocols. Combined, they produce defensible, highly reliable conclusions. This, is our charter. Not wishful thinking to make everyone happy with their choice of speakers.

 

[richard12511]

I can't provide a proof either, only a method how everyone can decide for himself if there can theoretically be a change in the ranking between stereophonic and monophonic - at least in terms of timbre.

Take a loudspeaker (preferably one that doesn't already sound perfect), place it in the middle of the room and listen to music in mono (down-sampled from stereo) and with a volume that exposes problematic frequency ranges.
Then change the sound of the speaker with the help of an equalizer so that it sounds perfect - crystal clear treble reproduction, voices and instruments detach from the speaker,...
Well, at least as good as it can be.

Then set up the speaker pair for stereo listening. Do not change anything in the equalizer settings and listen to the same music tracks in stereo (if possible with the same sound pressure level, e.g. check via smartphone app).
Try to ignore things like envelopment, sound image, ... and concentrate on whether the timbre has changed.

If the timbre changes, for better or worse, you have a strong indication that the ranking of speaker may change slightly from monophonic to stereophonic.

Interesting. Overall tonality tilt from 20-20,000 is definitely different from mono to stereo. Out of curiosity I measured to see what's going on.

If I'm shooting for a 10dB curve from 20 to 20, should I be using the stereo measurement as a target, or the mono?

 

[tuga]

Given the small size and reasonable wall mounts for surround speakers I suspect there are very few rooms that would not have room for multichannel music.

You obviously don't live in the UK...

 

[DonH56]

You obviously don't live in the UK...

No, but I have a small surround system set up in my office, which is 10' x 10' (3m x 3m). Are your rooms typically smaller than that?

 

[abdo123]

Are your rooms typically smaller than that?

well no, but usually a room has a little bit more than a couch at the center. In my living room, I'm sitting all the way at the wall oposite to the TV (~3.5 meters). I don't know how forgiving these systems are but i think sitting so close (inches) to the backwall makes it difficult to have surround speakers.

 

[ctrl]

If I'm shooting for a 10dB curve from 20 to 20, should I be using the stereo measurement as a target, or the mono?

If you export the REW measurements as .txt files, with the help of VACS, I can create all kinds of evaluations for you - e.g. normalization to mono measurement or stereo measurement to better see the differences.
You don't have to adjust the sound pressure level of the measurements for this, it can all be done afterwards.

 

[DonH56]

well no, but usually a room has a little bit more than a couch at the center. In my living room, I'm sitting all the way at the wall oposite to the TV (~3.5 meters). I don't know how forgiving these systems are but i think sitting so close (inches) to the backwall makes it difficult to have surround speakers.

My desk is in the corner and surrounds on shelves at the sides. With a couch against the rear wall you could place surrounds on the side walls (surrounds go to the sides); not much you can do for rears but 5.1 is usually pretty good IME and I have not seen much if any mch music content go above that in channel count.

 

[abdo123]

My desk is in the corner and surrounds on shelves at the sides. With a couch against the rear wall you could place surrounds on the side walls (surrounds go to the sides); not much you can do for rears but 5.1 is usually pretty good IME and I have not seen much if any mch music content go above that in channel count.

the surround speakers should not be at the side wall.

 

[tuga]

Pretty sure there would have been a long line of such protesters before I did the video! Indeed I got tired of reading the arguments and having to respond with the research. Good to know that is finally behind us. Another reason video format works well for such explanations!


You are wishing for world peace. Sure would be nice to have but it is possible. We have enough difficulty characterizing a single speaker in listening tests. Now you want to add a second one, with infinite possibilities between them as far as positioning, then the room impact and content? You really think you can produce any kind of reliable data you can back? All you accomplish in subjective stereo listening is another unreliable anecdote which we read time and time again in subjective reviews. And reports like yourself. None of that has value or anything I can put in my reviews.

There is a reason why Harman's research frequently talks about investigating these other aspects of speaker listening, yet across many decades they have not published any work. It is such a hairy problem that they can't get their arms around it to produce anything of substance as far as controlled testing. This, despite their capabilities. And you suggest that I start to solve a problem that no one in research or industry has done?

There is scope for different interpretation of some of the data which questions some of Harman's critical listening methodology.
I consider you to be someone who cherishes knowledge and thus I would expect you to at least contemplate this possibility, not that you solve it.
And more importantly, this is not a personal attack on you nor on Toole.

Most of us understand that you have your limitations.
Producing a comprehensive set of measurements is already very valuable work.

 

[abdo123]

If you export the REW measurements as .txt files, with the help of VACS, I can create all kinds of evaluations for you - e.g. normalization to mono measurement or stereo measurement to better see the differences.
You don't have to adjust the sound pressure level of the measurements for this, it can all be done afterwards.

Wait a sec. Do you guys measure speakers and do speaker correction?

or is this just at the software level?

I have been looking for someone that measures Speakers like Amir (but in the EU) for an eternity.

 

[Kal Rubinson]

I would like to try multi channel ( music) what do I need?
I have used my Illusonic , but it would be nice to offer an inexpensive option.
Keith

I have not used the Illusonic in a long time but there are some easier options. However, this is off-topic for this thread, so contact me by PM or otherwise.

 

[Kal Rubinson]

the surround speakers should not be at the side wall.

??? What is the source of that pic? Standard recommendations are 90-120deg.

 

[abdo123]

??? What is the source of that pic? Standard recommendations are 90-120deg.

Dolby. which is already a rather lenient recommendation.

The real 'standardized' positioning is agreed upon by the industry in the ITU-R BS.775-1

Equal distance between you and all the speakers.

 

[tuga]

No, but I have a small surround system set up in my office, which is 10' x 10' (3m x 3m). Are your rooms typically smaller than that?

This is the most typical layout for a 3-bed 2-storey house here in Oxford, a tiny sitting room with 2.4 m high ceiling and a chimney breast taking up one of the walls.