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If I gave you a poorly recorded acoustic guitar, could you tell me...
Old 11th February 2013
  #1
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Scott Whigham's Avatar
 

If I gave you a poorly recorded acoustic guitar track, could you tell me...

Could you tell me whether or not the problem was:
  • Proximity effect
  • Boominess from mic placement
  • Body resonance
If so, how?

I'm curious. I recorded a really killer performance the other day yet the final result was that I'd done something wrong - there's a muddiness somewhere in the 200-600hz range (I won't say which so as not to "spoil" the answers). The question then is, "What caused it?"

Can you tell, from listening, the difference between PE, boominess from bad mic placement, and an obnoxious body resonance? If so, how?

And, if it matters, later this week I will get the chance to record it again and I'll be able to tell empirically. The question is not, "Can you tell by process of elimination?" though...
Old 11th February 2013
  #2
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Without knowing about the room, there is no way of telling.
Old 11th February 2013
  #3
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If you provided mic and guitar specifics, I could make a pretty good guess.
Old 11th February 2013
  #4
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skyshaver's Avatar
 

There are far too many factors in play to give any kind of reasonable answer based just on a recording. Room, mic, mic placement, guitar, player, etc. etc. The muddiness is probably a combination of things.
Old 11th February 2013
  #5
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ontariomaximus's Avatar
 

Quote:
Originally Posted by Andy_R View Post
If you provided mic and guitar specifics, I could make a pretty good guess.
I get the impression he's giving away a free guitar. Doesn't matter to me that it was poorly recorded.
Old 11th February 2013
  #6
Gear Guru
 

Quote:
Originally Posted by Scott Whigham
If I gave you a poorly recorded acoustic guitar, could you tell...
Quote:
Originally Posted by Andy_R View Post
If you provided mic and guitar specifics...
AND the aforementioned poorly recorded guitar!

Quote:
Originally Posted by Scott Whigham
Can you tell, from listening, the difference between PE, boominess from bad mic placement, and an obnoxious body resonance? If so, how?


Let me see if I have this right:
based on a vague written description we are to say whether we COULD GUESS the source of a problem IF we were able to hear the recording?

Any of those things might be guessable - with a little detective work and a clip. for example if the mic was "too close" there would also be a narrowing of the 'geography' of the guitar. Lots of "hole" and no "bridge" for example. If there was a sharp attack and then some silence the reverb might reveal something about the room. If you know that mic, you might hear a specific resonance is not coming from that mic.

Of course none of that information is available from your written description of the problem.

Quote:
And, if it matters, later this week I will get the chance to record it again
Again? So you have already stood in the room in question, chose the microphone in question, know where you placed it, and you were in the physical presence of the specific guitar?

Quote:
(I won't say which so as not to "spoil" the answers).
Oooh! Is this a contest? Are there prizes? Why are we 'guessing' if you already know the 'answers'? Not only do we not get a clip, but even the written description of the problem is "censored"? That makes guessing pretty difficult. Hopefully the prize is "worth it"!
Old 11th February 2013
  #7
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Scott Whigham's Avatar
 

I'm just trying to understand the differences between these three problems, and whether or not they can be empirically identified as such by someone who knows almost nothing about the actual session. For example, we can all listen to a solo piano recording and identify the "problem" as being "the piano is out of tune" without having to know anything about microphones, the room, etc. I'd even go so far as to say we'd be able to say "The mic is too far away - there's too much room sound" if we were given a recorded piano track yet no other details. So can we do the same things with an acoustic guitar track w/ respect to boominess, proximity effect, or body resonance?

To those talking about the room, I'm interested in how you are considering the room. If I said, "It was recorded in a 13x18x12' room", is that enough information? I can't really see how that's relevant so I'm curious as to (a) what info you'd need, and (b) how you would use that info in identifying the problem.

For those who asked about the guitar, that's another curious request. If I said it was a guitar in which you were intimately familiar with, would you say something along the lines of, "Oh yeah, everyone knows that there's a 230hz resonance on that guitar." Or is for another reason that you'd like to know the particular guitar?

As for the mic question, yet again I wonder if that is actually relevant here? I would have thought that, since I included proximity effect, that would imply we're talking about a mic that can have proximity effect. If it was an M149, would that change your answer to the base question? If it was an SM57, how does that change your answer? I can't see how the choice of mic - as long as it experiences PE - changes the answer to the basic question.

This is an interesting question to me. We all talk about boominess and proximity effect and we like to think we can identify it on our own recordings. I'm in a situation where I recorded a guitar and yet I can't tell which is the problem without further "process of elimination" which involves re-recording. So the question still is valid, I think: can you identify whether a specific poorly recorded acoustic guitar track is boominess (from improper/poor choice of placement), proximity effect (ditto), or a resonance in the guitar without being able to go through that process of elimination?
Old 11th February 2013
  #8
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I don't know why you are being so vague. If you really want assistance I suggest you post a clip and provide some information about the chain and room.

Speculating about what we *might* hear is not very helpful or interesting.
Old 11th February 2013
  #9
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Karloff70's Avatar
 

Hey joey q, don't bite him. He didn't say that DAW's sound different or anything of the sort.
Old 11th February 2013
  #10
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Scott Whigham's Avatar
 

But I don't see why it needs specifics. The question is general by nature: can you tell which the "problem" is just by listening and, if so, how?

If the answer is, "No, you need either more specifics or you need to go through a process of elimination", then fine. But if you insist on adding specifics, then it changes the question away from being a "general question about recorded acoustic guitars" to being a "specific question about that scenario/situation". I don't want that - I'm asking the question at a general level specifically
Old 11th February 2013
  #11
Quote:
Originally Posted by Scott Whigham View Post
But I don't see why it needs specifics. The question is general by nature: can you tell which the "problem" is just by listening and, if so, how?

If the answer is, "No, you need either more specifics or you need to go through a process of elimination", then fine. But if you insist on adding specifics, then it changes the question away from being a "general question about recorded acoustic guitars" to being a "specific question about that scenario/situation". I don't want that - I'm asking the question at a general level specifically
Why not provide a test file? It's easier for people trying to help you.

The lack of qualities in a poor recording are detectable...that's how engineers improve the sound. The first thing that will be detactable (prior to recording) is the room sound in relation to the guitar...once this is fixed and engineer will typically listen to the guitar being played whilst monitoring the signal and moving the microphone in proximity to the guitar.

There are other factors: several mics might be tried, different preamps, temporary reflective surfaces in the room, etc.

Sometimes it's good to think OTB. Hope this helps : )
Old 11th February 2013
  #12
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Karloff70's Avatar
 

Quote:
Originally Posted by Scott Whigham View Post
But I don't see why it needs specifics. The question is general by nature: can you tell which the "problem" is just by listening and, if so, how?

If the answer is, "No, you need either more specifics or you need to go through a process of elimination", then fine. But if you insist on adding specifics, then it changes the question away from being a "general question about recorded acoustic guitars" to being a "specific question about that scenario/situation". I don't want that - I'm asking the question at a general level specifically
How do you pull apart mic positioning and proximity effect? As in, if you stick any directional mic on the soundhole up close it would be both, right?
Old 11th February 2013
  #13
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It is a strange question??? ALL mics have some proximity effect, so that doesn't help. If you move the mic away from the guitar, the room becomes quite important. Different guitars probably want the mic placed in different places to get the best sound, so the model may be helpful. But since all those factors interact, with NO information I suspect it's going to come down to: use a brighter mic and/or place it farther away and/or move it to the end of the fingerboard where the sound is brighter...
Old 11th February 2013
  #14
Deleted 651cf92
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I think everybody is saying that it depends on the clip, if it was recorded with a laptop built in mic, then the problem would be easy to say it was the mic, likewise if it was recorded in a water tank. Or it might have been a pretty avarage recording of an alright guitar, with a not great player but a quite good engineer, in a reasonable room. And then nobody will know anything

Edit

Screw bling shoot outs, someone should record something badly, and then everybody guesses what's wrong and the correct way to fix it
Old 11th February 2013
  #15
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Scott Whigham's Avatar
 

If you have to have a test file to be able to even answer the question, then that tells me that the answer is, "No, you cannot answer the question as asked without knowing more specifics and/or troubleshooting." Which is fine.

If I had asked this question, the responses would've been quite different I bet:

Quote:
Can you identify the problem without knowing session specifics between (1) a stereo recording of an acoustic guitar in which the two mics were out of phase, or (2) a stereo recording of acoustic guitar in which the two mics were in phase but there was too much room sound? And if so, how?
People would've been all over that. Why? We have definite ways we describe phase problems and we all know how to move the mics around. But this question - can you identify boominess from proximity effect when all you have is a sound file - is perplexing, no?

Or maybe if I'd asked it a different way:
  • Please write a one sentence description of what boominess sounds like and how it sounds different than proximity effect
Maybe that's how I should have phrased it.

Quote:
Originally Posted by Karloff70 View Post
How do you pull apart mic positioning and proximity effect? As in, if you stick any directional mic on the soundhole up close it would be both, right?
Finally - that's in the vein I'm looking for. So by your definition, boominess and proximity effect are inseparable with directional mics?
Old 11th February 2013
  #16
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Quote:
Originally Posted by Scott Whigham View Post
I'm just trying to understand the differences between these three problems, and whether or not they can be empirically identified as such by someone who knows almost nothing about the actual session.
such as someone who has not even heard a clip?
someone from whom even the frequency of the resonance is being 'hidden'?

Quote:
So can we do the same things with an acoustic guitar track w/ respect to boominess, proximity effect, or body resonance?
not from a verbal description, no

Quote:
To those talking about the room, I'm interested in how you are considering the room. If I said, "It was recorded in a 13x18x12' room", is that enough information?
conceivably someone with a room mode calculator could predict the resonances of the room. Is the information about the room treatment being "withheld" from us too?

How about if you give us just the walls and not the ceiling height? Would that make the game more exciting?

There had better be prizes!


Quote:
I can't really see how that's relevant so I'm curious as to (a) what info you'd need, and (b) how you would use that info in identifying the problem.
It's relevant because experienced engineers have an idea of what to realistically expect a room will contribute to a close miked acoustic guitar. What info I would need? The more info the better. IMO, it is not a matter of applying some 'rules' to some raw 'data'. It is a matter of listening to something and hearing how that matches up to previous decades of experience.
Quote:
..you'd like to know the particular guitar?
Of course. If I know that guitar, I might know it is a well-made guitar that doesn't have any particularly ugly resonances. The more info the better.

Quote:
..If it was an M149, would that change your answer to the base question?
Certainly. Some mics have more proximity effect than others, some cardioid mics are more cardioid than others. The more info the better.

Quote:
This is an interesting question to me. We all talk about boominess and proximity effect and we like to think we can identify it on our own recordings.
but not other people's secret recordings where we only get verbal information on a need-to-know basis

If you want to know if I can tell you 'resonant guitar', 'ugly room' or too much proximity effect from your verbal description, no I can not. No need to even "hide" the clues.

If you want to know if I can tell boom, room, or zoom from listening to YOUR audio clip, maybe. It might even be obvious.

However, I am quite certain that if I were in your situation - i.e.
I was the guy who made the recording
I chose the mic
I know the mic
I was physically present in the room in question
I was in the physical presence of the guitar while it was played

that 95% of the time I would be able to correctly "guess" the cause of the boominess - listening back to MY recording at a later date. How? I would say it was 1000 little things and not any one big "clue".
Old 11th February 2013
  #17
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Karloff70's Avatar
 

Quote:
Originally Posted by Scott Whigham View Post

Finally - that's in the vein I'm looking for. So by your definition, boominess and proximity effect are inseparable with directional mics?
Well, all directional mics have some sort of proximity effect, and if you put them close up and AT THE SAME TIME in a place where it just sounds boomy, like in front of the hole, then there is no way to say which is causing the problem, because both are. Together.

But you might recognise some of the shape of sound you end up with from a certain mic you use a lot and knowing what it does when pulled up too close to stuff. However, this should happen WHEN you position the bugger and adjusted for. To state the obvious.

So if you say dreadnought with a U87 right up on the hole in cardioid I would expect a few people will recognise the shape of the wrongness it will cause together.

Not sure how any of this helps you though??
Old 11th February 2013
  #18
Is there a point to this post? I mean what does it matter if someone can tell why a recorded sounds sucks? If it sucks, it sucks, redo it or make it sound as best you can.
Old 11th February 2013
  #19
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Scott Whigham's Avatar
 

Quote:
Originally Posted by joeq View Post
If you want to know if I can tell boom, room, or zoom from listening to YOUR audio clip, maybe. It might even be obvious.
Well, cutting through all the BS, you've answered the question. Your answer is "maybe".

I really don't understand what happened to this thread - why the vitriol, bull****, and unhelpful responses. I think it's both an interesting and a worthwhile question: if you're given an acoustic guitar clip that is poorly recorded, can you tell what the problem is without having to be spoonfed every little detail about the session?

I'm confident that I'd be able to tell whether someone else's clip was out of phase without knowing every little detail. I'm confident whether I'd be able to tell whether there was too much room in someone else's clip without knowing every little detail. And in both cases, I would be able to communicate "How to fix it so it doesn't happen again" to them. I'm not confident, however, that I can tell whether or not the problem is boominess, proximity effect, or body resonance without more information. And even if I had more information, I'm not sure I could answer with 100% accuracy without troublshooting/re-recording. So I asked the question so that I could see whether I was deficient in my knowledge, or whether it was an "It depends" situation.
Old 11th February 2013
  #20
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Silent Sound's Avatar
Boominess and proximity effect are two completely different things. Proximity effect can create boominess, but so can many other things, such as the room or the instrument. Boominess is a symptom. Proximity effect is but one of many possible causes. So saying things like:

Quote:
can you identify whether a specific poorly recorded acoustic guitar track is boominess, proximity effect, or a resonance in the guitar without being able to go through that process of elimination?
it becomes confusing. Boominess is an adjective. Proximity effect is a noun.

In any case, you're talking about a build up of sound at a specific frequency range. It can have many different causes that all sound the same or very similar. However, an experienced engineer will usually be able to tell what the cause is if he/she is familiar with the equipment, instruments, and room, just by listening to a clip.
Old 11th February 2013
  #21
Quote:
Originally Posted by Scott Whigham View Post
Please write a one sentence description of what boominess sounds like and how it sounds different than proximity effect?
Boominess is too much bass in relation to the rest of the signal; boominess is constant (room/guitar body) whereas proximity effect is variable (mic position).
Old 11th February 2013
  #22
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Quote:
Originally Posted by drbob1 View Post
It is a strange question??? ALL mics have some proximity effect, so that doesn't help.
All directional mics have some proximity effect, omnis do not.
Old 11th February 2013
  #23
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My answer is "maybe" and "who cares?"
Old 11th February 2013
  #24
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Scott Whigham's Avatar
 

Quote:
Originally Posted by Silent Sound View Post
Boominess is an adjective. Proximity effect is a noun.

In any case, you're talking about a build up of sound at a specific frequency range. It can have many different causes that all sound the same or very similar. However, an experienced engineer will usually be able to tell what the cause is if he/she is familiar with the equipment, instruments, and room, just by listening to a clip.
I like that - thanks. Since you said "an experienced engineer will usually be able to tell what the cause", do you think an experienced engineer who is listening to someone else's clip be able to tell which is which? And if so, what is he/she listening for? That's sort of the "point" of this post if I had to put a "point" to it.

In other words, what are the words that you use to describe "the sound of boominess" vs. "the sound of proximity effect"? I like Arthur Stone's version but I'm not sure that really covers the difference in sonic between the two. Like I said earlier, I could tell someone, "Here's how you know something is phasey" or "Here's what to listen for when something is recorded from too far away". I don't quite know how to tell someone else what to listen for when it comes to boominess vs. proximity effect vs. body resonance. The only way I know how to tell is to good ol' trial and error.
Old 11th February 2013
  #25
Gear Guru
 

Quote:
Originally Posted by Scott Whigham View Post
I really don't understand what happened to this thread - why the vitriol, bull****, and unhelpful responses.
there are no helpful responses because there is no "help" that you need. You are not asking to "fix" your guitar track. You are asking a vague, theoretical question and then refusing to provide specifics.

If you really wanted to KNOW in the 'abstract' if people are truly able to "guess" these issues or not, you would simply put up the damn clip and solicit the damn guesses! Then when you do your re-recording and troubleshooting you could find out for certain if the guesses were correct or not! Then you would KNOW if people can "tell" from a recording or not! And which people! Everything else is hot air. Annoying hot air.

You could easily learn the information you claim you are seeking. But you are not doing that. You are setting up some kind of convoluted "thought experiment" and on top of that, you keep changing the rules. I am truly surprised that you can not see how irritating that is.

You are playing a game with the 'information' that nobody else wants to play. Is that clear enough? What is our motivation for playing with one hand tied behind our backs?

Where are the prizes? heh


Quote:
I think it's both an interesting and a worthwhile question: if you're given an acoustic guitar clip that is poorly recorded, can you tell what the problem is without having to be spoonfed every little detail about the session?
It IS an interesting and worthwhile question! But we have not been given any clip! Maybe everyone would go "oh too close to the sound hole!" or "oh, ugly room". Or maybe everyone would go: "gee I can't tell". But since there is no clip, it is just an annoying intellectual exercise.

Quote:
I'm not confident, however, that I can tell whether or not the problem is boominess, proximity effect, or body resonance without more information. And even if I had more information, I'm not sure I could answer with 100% accuracy without troublshooting/re-recording.
Did you record the original clip or did you not? If so, you have all the information -including all the subconscious "feel" stuff about the room guitar and mic that can not be written down.

You seem to be UNABLE to decide if this is something YOU need to be able to do from listening to your own clip or if it is something WE need to be able to do from a clip which doesn't exist or maybe even from a censored verbal description. I am confident I could do it from my own clip.


In any case, if you actually need to 're-enact' your own "crime" to determine the cause of death, IMO you need more experience.
Old 11th February 2013
  #26
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Basically, boominess caused from room nodes is going to sound different than proximity effect in ways that are hard to describe. They both will cause lower frequencies to be exaggerated. Sometimes, room problems will also smear those lower frequencies a bit, but that's not always something you can hear. Some of the more commonly used mics, like an sm57 have a very familiar proximity effect. If you've used the mic enough times and experimented with trying to use the proximity effect to your advantage, then you're probably familiar with what it sounds like. However, each mic's proximity effect is going to be different, and it's possible to have a room that builds up in those same lower frequencies that an sm57 would also accentuate through proximity effect, thus making the distinction between the two fuzzy at best.

So if you're familiar with the room, then you know what that room sounds like and you can factor that into your answer. If you know the microphone and it's distance from the source, then you can factor that into your answer. If you don't have access to any of that information, then you may be able to hazard a guess based on how similar it sounds to your previous experiences. However, with each assumption your making about the mic/room/instrument/setup/everything, your lessening the probability of being right in your guess.

So the more experience an engineer has with different mics, instruments, and rooms, the more he/she has to draw from to come to an educated guess. But in the end, it's always going to be a guess, and some of those guesses may be extremely accurate, and others may be a shot in the dark. There's not a litmus test, however. So that's why you're getting the answers that you are.
Old 11th February 2013
  #27
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with an audio clip and any pre room noise, foot tapping, talking, setup, etc. I could tell you without knowing the specifics
Old 11th February 2013
  #28
This is an interesting thread in the sense that it's made me reflect on an implicit process...I deal with that implicit sense of boominess by doing things I can make explicit (verbalise) e.g. move the mic, cut at 80 Hz, etc. - this is all pretty current in neuroscience.

The implicit sense of boominess is the same as the theoretical 'qualia' e.g. the sense of 'yellowness' or the taste of melon: Qualia - Wikipedia, the free encyclopedia

Boominess is like qualia because although we can agree that it is an excess of particular frequencies we cannot precisely and objectively explain how we perceive it's quality compared to how others experience it.

I'm not a proponent of qualia but it does offer some explanation in this context.
Old 11th February 2013
  #29
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Quote:
Originally Posted by Scott Whigham View Post
I'm curious. I recorded a really killer performance the other day yet the final result was that I'd done something wrong - there's a muddiness somewhere in the 200-600hz range (I won't say which so as not to "spoil" the answers). The question then is, "What caused it?"
...
later this week I will get the chance to record it again and I'll be able to tell empirically.
What I find very strange about this thread is that one on hand you seem to have a very practical problem in which you are seeking the advice of other engineers so you can improve next time. Great. This is one of advantages of the GS community.

But on the other hand you seem to want to engage in some academic and esoteric exercise in which you deliberately withhold information that may help someone actually help you address your boominess problem.

I think you have your answer - with enough information about the instrument, room, chain, and placement, as well as a clip, someone might be able to identify the source of the boominess. If I am your client I hope you chose to share this info before I pay for another boomy track.
Old 11th February 2013
  #30
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Quote:
Originally Posted by Silent Sound View Post
So the more experience an engineer has with different mics, instruments, and rooms, the more he/she has to draw from to come to an educated guess. But in the end, it's always going to be a guess, and some of those guesses may be extremely accurate, and others may be a shot in the dark. There's not a litmus test, however. So that's why you're getting the answers that you are.
Good stuff, thanks SS. So it takes it back to "trial and error" or "experience" are the ways to know the difference. Although I can absolutely solve my own problems by playing around, trying new mics, new positions, new room placements, etc, what I really wanted to know was whether there was a "litmus test" as you say to help determine which is which just by listening to any random track. We all like to save time and, ultimately, that's what I was hoping to do - to be able to immediately hear one vs. another and know how to explain the problem/sound to someone else (just like we can w/ phase issues, comb filtering, too much room sound, etc).

And Arthur - love that qualia analogy.

Quote:
Originally Posted by neirbod View Post
What I find very strange about this thread is that one on hand you seem to have a very practical problem in which you are seeking the advice of other engineers so you can improve next time.

But on the other hand you seem to want to engage in some academic and esoteric exercise
Noted. Perhaps that's what led to some folks being very rude and disrespectful. I'll apologize in hindsight for not having written this as clearly as I should have.
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