Sound timbre question

[lherrm]

Hello ASR,
When a speaker produces a sound of, say, a piano, then a violin (or whatever) at the exact same frequency (and SPL, duration, etc.), is the difference of produced sound caught in measurements (with everything else other than instrument/timbre being the same) ?
How do we know the speaker produces, timbre wise, the sound it is supposed to do ?
Maybe, more generally, is the distance between the recorded timbre and produced timbre measurable ?
Thanks.

 

[RayDunzl]

Maybe, more generally, is the distance between the recorded timbre and produced timbre measurable ?

Yes. But difficult to quantify the analysis.

Example:

A single electric Bass guitar note - electrical signal spectrum:

Findamental is 96.5Hz, with harmonic multiples - 96.5 x 2, x 3, x 4 etc

Red is the peak level, black is the current level - the note decays after you play it.

Compare to what a microphone captures in-room.

It would look "about the same" with high fidelity reproduction.

A different instrument, with different timbre, would look different.

 

[GimeDsp]

Hello ASR,
When a speaker produces a sound of, say, a piano, then a violin (or whatever) at the exact same frequency (and SPL, duration, etc.), is the difference of produced sound caught in measurements (with everything else other than instrument/timbre being the same) ?
How do we know the speaker produces, timbre wise, the sound it is supposed to do ?
Maybe, more generally, is the distance between the recorded timbre and produced timbre measurable ?
Thanks.

A flat frequency response with low distortion throught your system will be your best bet.
A frequency response that is way off will lead to many issues of "unnatural" sound, timbre included.
I've been a drummer for many MANY years and one thing that is hard for speaker to get right is the sound of a rim shot, I am sure guitar players are highly attuned to the sound of a guitar too. a hyped up speaker will sound lively or "energetic" but will likely be unnatural too.
A good recorded violin is excellent for judging a system's/speaker's timbre.

 

[PaulD]

When a speaker produces a sound of, say, a piano, then a violin (or whatever) at the exact same frequency (and SPL, duration, etc.), is the difference of produced sound caught in measurements (with everything else other than instrument/timbre being the same) ?

Yes. Everything that can be heard can be measured. We can measure far beyond the limits of our hearing.

How do we know the speaker produces, timbre wise, the sound it is supposed to do ?

By the system (speaker) having a flat frequency response and low distortion.

Maybe, more generally, is the distance between the recorded timbre and produced timbre measurable ?

Yes. The SMAART system for live sound PA system correction does exactly that, in real time, to provide correction.

By far the weakest link in the reproduction chain are the speakers and the room. Microphones (in the recording chain) are the next largest source of problems.

If you are so intensely interested in timbre, then reading on music acoustics and how instruments work might be useful for you. Timbre differences are most noticeable in the attack phase of a musical note, say the first 10mS. The timbre of a clarinet and piano note are most different during the first 10th of a second, the sustained portion of a note is far less distinguishable between instruments than the attack portion.

 

[lherrm]

Thanks everyone for you answers.
From what I understood from your messages, timbre accuracy is somehow only a function of FR of the system (thus the flatter the better).
As per your advice, I'll look more into musics acoustics.

 

[March Audio]

Thanks everyone for you answers.
From what I understood from your messages, timbre accuracy is somehow only a function of FR of the system (thus the flatter the better).
As per your advice, I'll look more into musics acoustics.

Yes but also distortion can have an impact. It will generate harmonics of the original signal components and additional spurious intermodulation signals in between those harmonics of the original sound.

 

[Archaea]

Yes. Everything that can be heard can be measured. We can measure far beyond the limits of our hearing.


By the system (speaker) having a flat frequency response and low distortion.


Yes. The SMAART system for live sound PA system correction does exactly that, in real time, to provide correction.

By far the weakest link in the reproduction chain are the speakers and the room. Microphones (in the recording chain) are the next largest source of problems.

If you are so intensely interested in timbre, then reading on music acoustics and how instruments work might be useful for you. Timbre differences are most noticeable in the attack phase of a musical note, say the first 10mS. The timbre of a clarinet and piano note are most different during the first 10th of a second, the sustained portion of a note is far less distinguishable between instruments than the attack portion.

A local enthusiast group has blind tested level matched speakers on the same source equipment several times. In each occasion speakers especially of different designs sound different. (I do realize even the same speakers can sound different if not placed in the same position and toed in identically, but I’m speaking more to timbre differences). A horn based compression driver like the JTR speaker vs a ribbon tweeter like the Salk. A soft dome tweeter on a studio monitor vs either of the others discussed for example. A coaxial driver. All sound different.

I think there is more at play than frequency response alone. And perhaps more than harmonic distortion, and yes more than even room affect. What measurements would be needed for an expert to tell what kind of speaker technology was being used by looking at the data? A frequency response profile would not. A harmonic distortion or distortion profile? A room study would not, at least not alone. Not to hijack the post, but I’ve been long curious about this. I think timbre difference is a reasonable way to express this delta, and I’ve never read how that is accounted for in objective measurements.

 

[richard12511]

A horn based compression driver like the JTR speaker vs a ribbon tweeter like the Salk. A soft dome tweeter on a studio monitor vs either of the others discussed for example. All sound different.

Indeed, but they also all measure different. You're right that a simple on axis frequency response is insufficient to characterize a speaker's sound, but ASR measurements go way beyond simple frequency response.

 

[MattHooper]

I've found the phenomenon of "timbre" to be fascinating and prominent in my own impressions of speakers. All reproduced sound coming from speakers, even "neutral" ones, sound homogenized to me relative to real voices and instruments. But some speakers seem to produce a certain timbres in a way that remind me of the real thing where others do not (e.g. the way a "wood-based" instrument can actully sound like wood, rather than some electronic version of the instrument). Even the most "accurate" speakers sound monotonous to me - once I hear drum cymbals, or trumpets etc through those speakers I generally know what the timbre of that sound is like and there are no surprises, as there are in real life.

On first hunch it seems almost ridiculous to expect a few metal or paper/plastic drivers in a box to reproduce accurately every vibrating material in a symphony orchestra.

On the other hand, that's kind of how things work anyway: all the sounds of a symphony ultimately aggragate to the single vibrations of your ear drum (simplifying things of course). So it's sort of a reverse-speaker-driver situation in our actual hearing. So the question left for me is why our sound systems seem to fail in reproducing the range of real world timbres. Probably issues through the whole chain, from microphones onward.

 

[paddycrow]

When you can hear the difference between a Stradivarius and a Revelle violin through a pair of speakers, you will know the timbre is correct!

 

[richard12511]

When you can hear the difference between a Stradivarius and a Revelle violin through a pair of speakers, you will know the timbre is correct!

Have there been double blind tests with Strads vs modern violins? If not, I'd love to see someone perform such a test. I don't follow that scene very well, but it does smell of snake oil a tiny bit. I watched a documentary about Strad himself, and I see a lot of similarities to high end audio reproduction in the way modern musicians describe his instruments. Like I said, I don't follow it as closely as I do the reproduction side, so perhaps it's very different. I suppose part of me finds it hard to believe that modern engineers, with all the advantages they have, are incapable of making a violin that sounds as good as those made hundreds of years ago.

Also, are Steinway piano's really that much better? Would love to see double blind tests there too.

 

[Frank Dernie]

I think there is more at play than frequency response alone. And perhaps more than harmonic distortion

Personally I disagree.
Since timbre is the number and level of harmonics a change in frequency response will alter timbre. Harmonic distortion adds signal at the harmonics, so could effect timbre.
Nothing else alters the level of harmonics or their number, hence nothing else has the ability to alter timbre.
All those different sorts of tweeters will have different frequency response to each other and different harmonic distortion profiles so it would be expected that they would alter timbre differently. No other explanation is necessary.

 

[Frank Dernie]

Also, are Steinway piano's really that much better? Would love to see double blind tests there too.

Steinway, Bösendorfer and Fazioli have different timbres to each other all are beautifully made and have an action giving the pianist lots of control. Take your pick, there are certainly far more Steinways about!

 

[richard12511]

Steinway, Bösendorfer and Fazioli have different timbres to each other all are beautifully made and have an action giving the pianist lots of control. Take your pick, there are certainly far more Steinways about!

Gotcha, so would you say those brands are similar to Genelec, Neumann, and Me-Geithain in that sphere? Also, is there snake oil in the high end instrument business the same way there is in the high end audio reproduction business?

 

[Raindog123]

Does anyone know if [neural net] machine learning (ML) techniques are being used to classify variously-sounding instruments/sources? As well as applying the findings to synthesize the instrument sounds and filter imperfections/unwanted distortions? The AI/ML is widely used in many sensing areas, so why not in sound engineering?

 

[pozz]

Have there been double blind tests with Strads vs modern violins? If not, I'd love to see someone perform such a test. I don't follow that scene very well, but it does smell of snake oil a tiny bit. I watched a documentary about Strad himself, and I see a lot of similarities to high end audio reproduction in the way modern musicians describe his instruments. Like I said, I don't follow it as closely as I do the reproduction side, so perhaps it's very different. I suppose part of me finds it hard to believe that modern engineers, with all the advantages they have, are incapable of making a violin that sounds as good as those made hundreds of years ago.

Also, are Steinway piano's really that much better? Would love to see double blind tests there too.

Controlled study of violinist preference: (2017) Claudia Fritz - Stradivarius: Myth or Reality?

 

[Frank Dernie]

Gotcha, so would you say those brands are similar to Genelec, Neumann, and Me-Geithain in that sphere? Also, is there snake oil in the high end instrument business the same way there is in the high end audio reproduction business?

I don't think snake oil but definitely luxury brand marketing
There are very good volume production instruments at much lower prices because of manufacturing economies.
I wouldn't compare 3 different instrument manufacturers, who intend to produce a product with its own characteristic sound, with monitor manufacturers who presumably do their best to be a neutral "window" not add a brand specific colour.

 

[richard12511]

Controlled study of violinist preference: (2017) Claudia Fritz - Stradivarius: Myth or Reality?

Awesome! I'll have to watch that later.

 

[richard12511]

I wouldn't compare 3 different instrument manufacturers, who intend to produce a product with its own characteristic sound, with monitor manufacturers who presumably do their best to be a neutral "window" not add a brand specific colour.

That is an important distinction.

 

[paddycrow]

Controlled study of violinist preference: (2017) Claudia Fritz - Stradivarius: Myth or Reality?

Can you give us the Cliff Notes version? Almost an hour and a half video exceeds my attention span!