If an acoustic instrument (A small one that's easy to get with single mic) was close mic recorded in an anechoic chamber in mono and played back on a single extremely accurate loudspeaker with high dynamic capabilities in the middle of a normal room (Where a typical musician would be standing) and with a window open, would someone walking by think it was a live instrument being played?
I have a fair amount of "real world" experience with your "thought experiment".
If the dynamic, frequency and polar response of the speaker match what was recorded, it can be very hard or impossible to tell the difference between the live source and playback when listened from outdoors or another room through a window.
Even within the same room, it can be difficult to determine.
That said, most instruments and vocals have a radiation pattern that is not similar to a loudspeaker, so the "room sound" will betray the substitution.
If the dynamic, frequency and polar response of the speaker match what was recorded, it can be very hard or impossible to tell the difference between the live source and playback when listened from outdoors or another room through a window.
Even within the same room, it can be difficult to determine.
That said, most instruments and vocals have a radiation pattern that is not similar to a loudspeaker, so the "room sound" will betray the substitution.
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Thanks for the response. What you said makes total sense. The reason I bring up the anechoic aspect is due to the normal superimposition of one "acoustic" on top of another with all normal recordings that are played back in a different room than the original. A close mic'd anechoic recording would keep this from happening. You would only get one acoustic environment on playback.
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A great question. Pity it is arm-chair only.
Curiously, it is the reverse of the "threshold" criterion for HiFi: sitting in your chair, could you believe the Toronto Symphony Orch. is playing outside your window?*
And esp interesting to read Art's post. His reply might mean "easy" or "never" depends on how you read it. But I have to say, it is a very good answer to OPs question... although I am in the "never" camp myself since you can't meet the requirements, as he suggests himself.
For decades I've been proposing the down-the-hall test. Frankly, I have almost never ever thought Renee Fleming was singing in my music room when listen from down the hall.... or any other record of anything more challenging to imitate than a cellphone ringer.
Sure, folks swore Edison's cylinders were great. Toole has an interesting history in his book.
B.
*pedestrians fooled on the street - maybe possible. But no qualified audiophile would ever seriously ask if you can imitate the real thing right in your living room: ridiculous (and that includes headphones)
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As has already been mentioned, uniformity of polar response plays a role. A huge role. This is an area in which the drivers in a box paradigm particularly fails.
Before that, however, there is an predicate question: Which is the more preferable, for an reproduced instrument to sound convincingly live in your listening room, or rather for you to be convinced that you have been transported to the original live event? The former effect depends on a speaker's ability to uniformly radiate in to the room in all directions. Conversely, the latter effect depends on the speaker's ability to remove/minimize the reflective sound of the room.
Before that, however, there is an predicate question: Which is the more preferable, for an reproduced instrument to sound convincingly live in your listening room, or rather for you to be convinced that you have been transported to the original live event? The former effect depends on a speaker's ability to uniformly radiate in to the room in all directions. Conversely, the latter effect depends on the speaker's ability to remove/minimize the reflective sound of the room.
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I played tricks on my father like that. I recorded someone talking and played it back later, fooling him that person was around. I made him go to the door because i recorded doorbell and played it back.
My early recording years put me on right path.
That is a pretty accurate description of what's going on. I will only add that an instrument's sound (both timbre and volume) changes with direction. Some instruments change less than others. For example, a flute or a clarinet changes less than a French horn or a trumpet. This is easily demonstrated by the OP's "thought experiment". Rather than making a single mono recording with a single very accurate microphone, make a three track recording (for example) - one microphone in front of the instrument, one 90 degrees to the side, and one behind. Each track will sound different!
In the OP's original hypothetical experiment, the recorded sound is the sound which was picked up at only one point, and remember, it's being done in an anechoic chamber. As a result, none of the sound radiated in other directions is recorded. So, we have a recording of, say, a trombone, where the only sound played back is the sound of the trombone in that direction. It should be no surprise that, played back through a loudspeaker, it doesn't sound like a trombone being played in that room.
This is one reason why good studio designers go to great lengths to provide a desirable (and often, variable) acoustic environment, and why recording engineers typically don't place microphones directly in front of most instruments - a better tonal balance and more representative sound can be achieved with good placement in a good room.
Ah, here it is: Comparison of different microphone positions for orchestra instruments
An excellent resource - you can listen to the directivity of a variety of instruments.
It's easy to get bogged down in the theoretical stuff - I've gone around in circles on this path many times.
The only right answer I can find is to get multi-track recordings of the music you want to listen to, and put together a Grateful Dead-style setup, with speaker directivities (and positions) that match the instruments you'll be putting through them.
As it happens, I have the equipment to pull that off, but lack the time or inclination.
Chris
An excellent resource - you can listen to the directivity of a variety of instruments.
It's easy to get bogged down in the theoretical stuff - I've gone around in circles on this path many times.
The only right answer I can find is to get multi-track recordings of the music you want to listen to, and put together a Grateful Dead-style setup, with speaker directivities (and positions) that match the instruments you'll be putting through them.
As it happens, I have the equipment to pull that off, but lack the time or inclination.
Chris
Most normal recordings aren't of a single instrument. Imagine an orchestra recorded in a similar way, would it sound right with only your room's acoustic imposed?
What you're aiming for there is binaural sound. The microphones should include a HRTF for accuracy when playing back via headphones.
Stereo micing for reproduction via speakers is a huge topic. Spaced mics give phase information, while directional (but coincident - see XY, M/S) give level information. ORTF is an attempt (there are others) to include both phase and level information.
Chris
Stereo micing for reproduction via speakers is a huge topic. Spaced mics give phase information, while directional (but coincident - see XY, M/S) give level information. ORTF is an attempt (there are others) to include both phase and level information.
Chris
No, because number one, you can't get a full orchestra into an anechoic chamber, and number two, you can't close mic it. That's why it wasn't included in the thought experiment
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Not exactly on topic, but some of the best sounding orchestral records I've heard or owned were recorded by RCA and Mercury in the lats 50s, with I think just three microphones and of course analogue tape. Do I think the orchestra is in the room? No - but do I enjoy the music - of course.
Geoff
Geoff
@ Chris661,
A couple of very useful posts there! Thank you.
Thanks for the link to the microphone positioning comparisons! That's something which I've always wanted to do, but simply do not have the resources for that kind of intensive effort.
With regard to "normal simple stereo" recording techniques, you're absolutely on the right track. I'll just say that, whether A-B, X-Y, ORTF, or other variation on simple/basic mic choice/placement, the "bottom line" is venue and ensemble. A recording engineer must live within those constraints, regardless. I'm fairly certain that you know this, and am mostly talking to those who are getting their feet wet.
Back to comparisons, your linked source is excellent. I've not seen anything comparably high quality.
Just fyi for everyone, way back as a study several decades ago, I did a microphone comparison, but the focus was on comparing various "high end" microphones, for various instruments. Sometimes, the difference was rather subtle - even hardly noticeable, sometimes it was obvious. I still have the original tape.
Your link does a great job of highlighting the importance of microphone positioning! Thank you for the link!
A couple of very useful posts there! Thank you.
Thanks for the link to the microphone positioning comparisons! That's something which I've always wanted to do, but simply do not have the resources for that kind of intensive effort.
With regard to "normal simple stereo" recording techniques, you're absolutely on the right track. I'll just say that, whether A-B, X-Y, ORTF, or other variation on simple/basic mic choice/placement, the "bottom line" is venue and ensemble. A recording engineer must live within those constraints, regardless. I'm fairly certain that you know this, and am mostly talking to those who are getting their feet wet.
Back to comparisons, your linked source is excellent. I've not seen anything comparably high quality.
Just fyi for everyone, way back as a study several decades ago, I did a microphone comparison, but the focus was on comparing various "high end" microphones, for various instruments. Sometimes, the difference was rather subtle - even hardly noticeable, sometimes it was obvious. I still have the original tape.
Your link does a great job of highlighting the importance of microphone positioning! Thank you for the link!
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