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  #31  
Old 01-06-2015, 02:07 PM
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To add to Fran's comments, doing really valid comparisons is really hard. Even when I think I'm doing a controlled comparison, I still have to think about whether the results are "real", and what might be responsible for the results - it may not be what I believe.

For one thing, we can get fooled easily - lots of sound engineers have experienced making EQ tweaks until a mix sounded better, only to discover the knob they were turning was de-activated!

And there are always elements we can't control. I once got a sound I really loved with my ribbon mic. I know exactly where I was sitting, how the mic was setup, what guitar I was using, etc. I can't get that "magic" sound again, tho. Who knows why. Maybe the strings were a perfect age, maybe my nail length was different, or the humidity was different. Or maybe the mic was an inch closer or further away.

When I first got my Brauners quite a few years ago now, I tried every possible mic setup I could think of, and one that really didn't work well was MS, so I concluded those mics just weren't a good match for MS. I could leap further and conclude that LD's don't work well for MS, and so on, but I just left it as "those mics and MS don't mix". But a few weeks ago, I gave them another shot (I posted an example here), and I really liked the sound. What changed? Who knows, maybe I set them up differently, maybe it was a different guitar, or a different spot in the room. Or maybe my taste has changed. So another self-generated myth bites the dust.

There's also theory vs practice. Those DPA charts are very interesting, but we still have to figure out if and how measurements made in lab conditions relate to recording a guitar, if there's a difference there we can hear, and if so, if it's a good thing or a bad thing.
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  #32  
Old 01-06-2015, 06:50 PM
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Doug and Fran,

Thank you. You guys are providing a real service.

Jim McCarthy
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  #33  
Old 01-06-2015, 08:57 PM
HighAndDry HighAndDry is offline
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I could tell little difference. Maybe the last one was not quite as sparkly but I don't know. They all sounded good Very nice playing!!
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  #34  
Old 01-07-2015, 11:25 AM
bbrown bbrown is offline
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Great comments Doug.

This is certainly true in my experience. With my ridiculously simple set-up, there are just not that many variables. Yet I can get very different results when I thought everything about the set-up was identical. Perhaps it's slight changes in mic angle, who knows. I get a wee bit suspicous when folks are too scientific about recording.
Your mention of humidity is interesting. Anecdotaly, just based on what I have observed, I am convinced that humidity changes the transmission of sound waves and there is a noticable difference in clarity based on changes in humidity.


Quote:
Originally Posted by Doug Young View Post
To add to Fran's comments, doing really valid comparisons is really hard. Even when I think I'm doing a controlled comparison, I still have to think about whether the results are "real", and what might be responsible for the results - it may not be what I believe.

For one thing, we can get fooled easily - lots of sound engineers have experienced making EQ tweaks until a mix sounded better, only to discover the knob they were turning was de-activated!

And there are always elements we can't control. I once got a sound I really loved with my ribbon mic. I know exactly where I was sitting, how the mic was setup, what guitar I was using, etc. I can't get that "magic" sound again, tho. Who knows why. Maybe the strings were a perfect age, maybe my nail length was different, or the humidity was different. Or maybe the mic was an inch closer or further away.

When I first got my Brauners quite a few years ago now, I tried every possible mic setup I could think of, and one that really didn't work well was MS, so I concluded those mics just weren't a good match for MS. I could leap further and conclude that LD's don't work well for MS, and so on, but I just left it as "those mics and MS don't mix". But a few weeks ago, I gave them another shot (I posted an example here), and I really liked the sound. What changed? Who knows, maybe I set them up differently, maybe it was a different guitar, or a different spot in the room. Or maybe my taste has changed. So another self-generated myth bites the dust.

There's also theory vs practice. Those DPA charts are very interesting, but we still have to figure out if and how measurements made in lab conditions relate to recording a guitar, if there's a difference there we can hear, and if so, if it's a good thing or a bad thing.
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  #35  
Old 01-07-2015, 01:31 PM
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Quote:
Originally Posted by bbrown View Post
Great comments Doug.

This is certainly true in my experience. With my ridiculously simple set-up, there are just not that many variables. Yet I can get very different results when I thought everything about the set-up was identical. Perhaps it's slight changes in mic angle, who knows. I get a wee bit suspicous when folks are too scientific about recording.
It's definitely an art, but there are a lot of "scientific" principles to it, and an understanding of the core concepts can help. I've lost track of how many people I've helped who had the phase of one channel reversed, for example. There are some concrete things that make a difference between good and bad recordings, and you can mess those up no matter how much or little you spend on gear. Also understanding some basic principles of testing, like "only change one variable at time", as well as being aware of our human biases and perception challenges can make it a lot easier to understand and evaluate what's happening and make consistent improvements, even if you're trying to be "artistic". It's really easy to say "I'm not getting a good sound, I must need to buy new gear". Maybe, maybe not. Approaching things a bit analytically can help answer that with necessarily buying lots of things to randomly try.

Quote:
Your mention of humidity is interesting. Anecdotaly, just based on what I have observed, I am convinced that humidity changes the transmission of sound waves and there is a noticable difference in clarity based on changes in humidity.
I just threw that out as an example of one of the many variables we don't have under tight control (as in "only change one variable at a time"). But we know that humidity affects the speed of sound, and perhaps more importantly, it also affects our guitars, so it's one possible wild-card when you're trying to nail that last 0.01%.
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  #36  
Old 01-07-2015, 03:15 PM
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Originally Posted by Fran Guidry View Post
Years and years ago Doug and I did some not-at-all-scientific comparisons of a bunch of mics and noticed that every mic sounded just like they said they would on Gearslutz. Amazing!

Then a while later I started testing in a more scientific way, with controls on as many variables as possible, and suddenly all those clear and obvious differences were gone!!! It's nearly impossible to overstate the importance of making comparisons in a careful manner by:

using exactly the same source
level matching with painful precision
blinding the samples

There are well established psycho-acoustic reasons for each of these and it's simply not humanly possible to avoid these issues.

So next time you're comparing your SD and LD mics, set one of each up in the same spot, use a test tone to tweak the levels, record the test tone followed by one performance on both mics at the same time, fine tune levels in post using that test tone, then do a double-blind comparison of the samples in an ABX comparator.

This is a lot of work. Unfortunately, doing a less careful job gives _bad_ information, which I consider worse than no information at all.

Fran
Just to be clear, Fran, what I was recording and comparing was simply the sound of the room as picked up by the mic. There was no input into the mic other than ambient noise (and self noise from the mic). An unscientific method, I know, but one could hear some very significant differences from mic to mic. Tried 9 different mics (4 SD and 5 LD) and the Shure KSM 137 stood out as providing a very low amount of self-noise and room noise. Interestingly there were certain frequencies where the differences really stood out. The boiler (water heated furnace) in the basement two floors below this room could not be heard on the Shure test track yet was very present in some of the LD mics I tried. And this was not because of there being drastic gain differences between the comparative recordings. Rather, certain mics were better at picking up the sound of the boiler (the sound of which travels up through the wall spaces and joists of this 1900 house). The same was true for the sound of the surf on Lake Michigan, which can be a bit like the ocean.

Now of course, the quietness of any mic is useless if the recorded sound of the instrument is displeasing, in this case if the sound of the acoustic guitar is muffled or restricted. But I'm quite pleased with the acoustic tone. Again, not scientific and no claims of this being true for all folks, but in my old house, different mics seem to behave very differently.
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  #37  
Old 01-07-2015, 03:46 PM
Fran Guidry Fran Guidry is offline
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Originally Posted by ukejon View Post
Great posts, Doug. As you know from our past discussions, for me the biggest difference between SD and LD has had to do with the amount of ambient or room noise they pick up. Since I'm not in the best recording situation (old houses are kind of generally noisy) there is a need for a mic that focuses on the guitar and not on the room. For whatever reason, the LD mics I've tried tend to pick up a lot more room noise than a cardiod SD mics.
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Originally Posted by ukejon View Post
Just to be clear, Fran, what I was recording and comparing was simply the sound of the room as picked up by the mic. There was no input into the mic other than ambient noise (and self noise from the mic). An unscientific method, I know, but one could hear some very significant differences from mic to mic. Tried 9 different mics (4 SD and 5 LD) and the Shure KSM 137 stood out as providing a very low amount of self-noise and room noise. Interestingly there were certain frequencies where the differences really stood out. The boiler (water heated furnace) in the basement two floors below this room could not be heard on the Shure test track yet was very present in some of the LD mics I tried. And this was not because of there being drastic gain differences between the comparative recordings. Rather, certain mics were better at picking up the sound of the boiler (the sound of which travels up through the wall spaces and joists of this 1900 house). The same was true for the sound of the surf on Lake Michigan, which can be a bit like the ocean.

Now of course, the quietness of any mic is useless if the recorded sound of the instrument is displeasing, in this case if the sound of the acoustic guitar is muffled or restricted. But I'm quite pleased with the acoustic tone. Again, not scientific and no claims of this being true for all folks, but in my old house, different mics seem to behave very differently.
Hopefully you can understand the need to match total system sensitivity between samples if this kind of comparison is to be meaningful. If one mic is 3 dB more sensitive than another it will "pick up more noise" if both mics are used with the same preamp gain.

How many times have we read the suggestion that dynamic mics "pick up less room" than condensers. Intuitively obvious and demonstrably false, but the demonstration takes some effort and very careful level matching.

Fran
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  #38  
Old 01-07-2015, 03:53 PM
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Jon, did you use a test tone to at least make sure the mics were all at the same level?

I had a weird case when I first got my Brauners, where I had them side by side with my Schoeps, and level matched, so when I played guitar they had the same basic levels. Then I noticed that if I flipped a light switch across the room, the VU meters on the Brauners jumped dramatically more than the Schoeps. That had me puzzled for a while: how could the mics have the same levels when I played guitar, but pick up a quiet signal differently? Maybe the Brauner's responded "faster"? That didn't seem right, the Schoeps SDs should be faster to respond, if anything. Fran finally came up with a convincing answer - differences in polar patterns or off-axis response. That makes perfect sense. If you read that DPA link someone posted, they also compare how different mics have different patterns at different frequencies. We think of "cardiod" as being a set pattern, but it's not, it varies by mic and by frequency. I'd expect that would have some impact on how each mic picks up Lake Michigan, but might have less impact on how the mics pick up a guitar right in front of it.
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Last edited by Doug Young; 01-07-2015 at 04:19 PM.
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  #39  
Old 01-07-2015, 04:13 PM
ukejon ukejon is offline
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Quote:
Originally Posted by Doug Young View Post
Jon, did you use a test tone to at least make sure the mics were all at the same level?

I had a weird case when I first got my Brauners, where I had them side by side with my Schoeps, and level matched, so when I played guitar they had the same basic levels. Then I noticed that if I flipped a light switch across the room, the VU meters on the Brauners jumped dramatically more than the Schoeps. That had me puzzled for a while: how could the mics have the same levels when I played guitar, but pick up a quiet signal differently? Maybe the Brauner's responded "faster"? That didn't seem right, the Schoeps SDs should be faster to respond, if anything. Fran finally came up with a convincing answer - differences in polar patterns or off-axis response. That makes perfect sense. If you read that DPA link someone posted, they also compare how different mics have different patterns at different frequencies. We think of "cardioid" as being a set pattern, but it's not, it varies by mic and my frequency. I'd expect that would have some impact on how each mic picks up Lake Michigan, but might have less impact on how the mics pick up a guitar right in front of it.
I did use a test tone (first time) based on Fran's advice to me at the time. Also, Doug that is a good point about different "cardioid" mics having different abilities to pick up side and back sounds. Lake Michigan sometimes thinks she is the Pacific Ocean, and it may be that some mics hear that better than others.

Quote:
Originally Posted by Fran Guidry View Post
Hopefully you can understand the need to match total system sensitivity between samples if this kind of comparison is to be meaningful. If one mic is 3 dB more sensitive than another it will "pick up more noise" if both mics are used with the same preamp gain.

How many times have we read the suggestion that dynamic mics "pick up less room" than condensers. Intuitively obvious and demonstrably false, but the demonstration takes some effort and very careful level matching.

Fran
Yes, and again you generously schooled me early on about being attentive to this when comparing mics. One good real life lesson in all this was when I got the Audix SCX-25A, which is about 6db more sensitive than my Shure mics. First few recordings were pretty goofy until I was alerted to the sensitivity of the Audix piano mic.
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Last edited by ukejon; 01-07-2015 at 04:36 PM.
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