Congas... What your favorite mic?
- Thread starter Matt Vivlamore
- Start date
Re: Congos... What your favorite mic?
As Quoted from the Sweetwater Audio Glossary:
As Quoted from the Sweetwater Audio Glossary:
Re: Congos... What your favorite mic?
In the little rooms in which I work, I often need one that can turn them down below un-amplified - one of them always seems to be tuned to a room node/mode.
In the little rooms in which I work, I often need one that can turn them down below un-amplified - one of them always seems to be tuned to a room node/mode.
Re: Congos... What your favorite mic?
Not that I would consider Sweetwater's stuff to be definitive on anything, but I think the question is WHY does changing the distance minimize phase cancellation. Any time two signals are combined you need to consider both level and timing. The rule can't simply be based on arrival timing because no matter what distance you choose, some frequencies will cancel. Instead my understanding, based on Bob McCarthy's book, is that a large enough SPL difference in the signals being combined reduces how noticeable the cancellation is. Moving the second mic three times further from the source reduces the signal from the source enough that when combined with the first signal the cancellation is not as significant.
Of course I may be due for a reread of that section of Bob's book, but I think that is a better explanation of WHY the rule works. What the Sweetwater note addresses is the result of applying the rule, not an explanation of why the rule works.
Not that I would consider Sweetwater's stuff to be definitive on anything, but I think the question is WHY does changing the distance minimize phase cancellation. Any time two signals are combined you need to consider both level and timing. The rule can't simply be based on arrival timing because no matter what distance you choose, some frequencies will cancel. Instead my understanding, based on Bob McCarthy's book, is that a large enough SPL difference in the signals being combined reduces how noticeable the cancellation is. Moving the second mic three times further from the source reduces the signal from the source enough that when combined with the first signal the cancellation is not as significant.
Of course I may be due for a reread of that section of Bob's book, but I think that is a better explanation of WHY the rule works. What the Sweetwater note addresses is the result of applying the rule, not an explanation of why the rule works.
Re: Congos... What your favorite mic?
Jay, I wouldn't consider sweetwater to be the definitive answer on anything either, it was just an easily quotable online reference. The most important part of which, may be just clarifying that it is a 3:1 rule and NOT a 3' rule. Even you made an example of placing MIC A at a distance of 1' from te source and then MIC B at a distance of 3' from the same source... which would NOT be a correct implementation of the rule... that would be a 2:1 relationship.
I too need to re-read Bob's book for sure.... along with a few others. I just finished with "Electricity for the Entertainment Engineer" (Richard Cadena) and am starting "Control Systems for Live Entertainment" (John Huntington) which are both great books, and it's always nice to learn a few things that aren't strictly audio.
Jay, I wouldn't consider sweetwater to be the definitive answer on anything either, it was just an easily quotable online reference. The most important part of which, may be just clarifying that it is a 3:1 rule and NOT a 3' rule. Even you made an example of placing MIC A at a distance of 1' from te source and then MIC B at a distance of 3' from the same source... which would NOT be a correct implementation of the rule... that would be a 2:1 relationship.
I too need to re-read Bob's book for sure.... along with a few others. I just finished with "Electricity for the Entertainment Engineer" (Richard Cadena) and am starting "Control Systems for Live Entertainment" (John Huntington) which are both great books, and it's always nice to learn a few things that aren't strictly audio.
Re: Congas... What your favorite mic?
Electro-Voice N/D 468... Tight polar pattern keeps separation and they are fairly flat in freq response, also very maneuverable on kits with a bunch of toys (cowbells, chimes etc)
Just make sure you put LOC-TITE on the nuts and bolts that hold them together and secure the nuts FIRMLY or they will eventually fall apart, and the bolt is easily stripped if adjusted more than a couple of times.
Electro-Voice N/D 468... Tight polar pattern keeps separation and they are fairly flat in freq response, also very maneuverable on kits with a bunch of toys (cowbells, chimes etc)
Just make sure you put LOC-TITE on the nuts and bolts that hold them together and secure the nuts FIRMLY or they will eventually fall apart, and the bolt is easily stripped if adjusted more than a couple of times.
Re: Congas... What your favorite mic?
Interesting thoughts on this rule. Seems to me if you know the actual phase response of the mics you plan to use you can decide whether or not cancellations are going to be a problem. Moving one mic 3 feet away is just not practical in a live situation unless you were using iso-boxes on an amp. I have always thought of microphones in the same way I think about speakers in terms of placement and the phase relationship. If we know the phase response is the same, it becomes about time.
When I first heard someone tell me that my mics were too close in the studio and that it wouldn't work they tried to recite the principles behind this idea. I knew they knew nothing about phase of transducers- the person had a strong understanding of Polarity, but not Phase. This engineer was a drummer and I told him he better rethink how he mics his drum kit if that was the principle. He was more concerned about the phasing of his room mic on the drum kit rather than the sound. I showed him how to get the sound he wanted out of the room mic based on it's proximity and then add a little delay to clean-up the phase interaction. Although this is a controlled studio environment you could apply the same principles to the live stage. You just have to have a tool for showing you phase display across the frequency scale that will show you the manipulations.
It's just not a simple as the rule implies, which is why I'm so baffled by it.
And thanks for the great discussion!
Interesting thoughts on this rule. Seems to me if you know the actual phase response of the mics you plan to use you can decide whether or not cancellations are going to be a problem. Moving one mic 3 feet away is just not practical in a live situation unless you were using iso-boxes on an amp. I have always thought of microphones in the same way I think about speakers in terms of placement and the phase relationship. If we know the phase response is the same, it becomes about time.
When I first heard someone tell me that my mics were too close in the studio and that it wouldn't work they tried to recite the principles behind this idea. I knew they knew nothing about phase of transducers- the person had a strong understanding of Polarity, but not Phase. This engineer was a drummer and I told him he better rethink how he mics his drum kit if that was the principle. He was more concerned about the phasing of his room mic on the drum kit rather than the sound. I showed him how to get the sound he wanted out of the room mic based on it's proximity and then add a little delay to clean-up the phase interaction. Although this is a controlled studio environment you could apply the same principles to the live stage. You just have to have a tool for showing you phase display across the frequency scale that will show you the manipulations.
It's just not a simple as the rule implies, which is why I'm so baffled by it.
And thanks for the great discussion!
Re: Congas... What your favorite mic?
Kip the rule goes back to micing choirs so the foot length was based on that. It is the ratio that matters. To follow the rule if one mic is 2 inches from an amp speaker, another mic should be 6 inches from the first mic. Most places I have seen the rule they show the mics on a line perpendicular to the line to the source.
Kip the rule goes back to micing choirs so the foot length was based on that. It is the ratio that matters. To follow the rule if one mic is 2 inches from an amp speaker, another mic should be 6 inches from the first mic. Most places I have seen the rule they show the mics on a line perpendicular to the line to the source.