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City rumble is driving me crazy ... m/s shotguns the answer?
Old 14th June 2014
  #1
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City rumble is driving me crazy ... m/s shotguns the answer?

Seems where i am recording, SF bay area, the city rumble has increased everywhere i shoot and it is driving me a bit crazy. Even when i point a shotgun into a dead area like the dirt i hear the city rumble. I have been pondering if the fancy cmit m/s scheops would help, but that would be a major step for me ... since i do only low budget and corporate stuff. Am i missing something obvious, is the sound level of the entire bay area, even outer hill regions, increasing?
Old 14th June 2014
  #2
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City rumble is endemic in urban areas
Thats what low frequenct attenuation is all about
The only eq you really need.
Old 14th June 2014
  #3
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MS won't do anything about rumble, except that the rumble is stereo then.
If you're using a 416 or NTG now, the Schoeps might even output more LF rumble since it is more linear.

Use a hi-pass at around 60 or 80 Hz. If it's intended for laptop speakers, your HP frequency can be even higher.
Old 14th June 2014
  #4
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Quote:
Originally Posted by pkautzsch View Post
MS won't do anything about rumble, except that the rumble is stereo then.
Although the two mics involved, particularly the side, have LF rolloff, so it can help a lot.

LF propagates and re-radiates beautifully from structural walls and floors, so aim away from them if possible.
Old 14th June 2014
  #5
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Quote:
Originally Posted by David Spearritt View Post
Although the two mics involved, particularly the side, have LF rolloff, so it can help a lot.
OP's statement about low-budget corporate lets me infer he is using a shotgun mic already. As especially the less expensive shotguns have that LF rolloff, and the CMIT is more linear than an ME66, NTG-1, or 416, it won't help much.
A true (dipole) fig-8 mic has a strong rolloff indeed, and I've used a KM120 successfully in a few situations involving rumble. However the strong rear lobe makes it not suitable as a universal boom mic. It's just another special tool for special cases, as is the 816, a PZM, or an Omnigoose.

The "one size fits all" lo-budget/ENG/corporate way is: use a 416 and engage mixer's high-pass as needed. And don't worry about LF content, it won't come out of the TV or laptop speakers anyway.
Old 14th June 2014
  #6
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As you probably already know, the lower the frequency, the less directive the sound is. That makes the directivity of "shotgun" (let call them interference tube mics) more worthless the lower the frequency goes.

My experience has been the the Sanken CS3e is pretty brilliant at reducing the low end rumble in general and I find it really good for taking the noise of location power plants, generators, out of the track. They are manufactured using multiple capsules and although I probably should, I am not up to speed on the "whys" of that technology. It does seem to work, however.

Also, lo-cut filters, either at the mic end or at the mixer/recorder end are almost always used by me in recording dialog. I tend to roll off everything below 60Hz as sharply as I can, preferably at 18bD/octave. Some roll off even higher, 75Hz or even up to 100 or so. Remember, the dialog doesn't get affected dramatically (sorry ) certainly at 70Hz, and post doesn't want that crud below that in any case.

Music, at least for me, is different. Never any lo-cut. I try and more selectively take out the rumble with post tools such as Izotope RX3.

D.
Old 14th June 2014
  #7
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City BG and etc is one reason why I've gradually moved from the hypercard boom mics I used to use to much more directional mics like CS3e. It's a noisier world out there now. The other thing, of course, to do is get the mic closer to the source…

philp
Old 15th June 2014
  #8
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Thanks a ton for these answers guys, helps a lot!
Quote:
Originally Posted by Rolo 46 View Post
City rumble is endemic in urban areas
Thats what low frequenct attenuation is all about
The only eq you really need.
Your right Rolo, normally i just record things straight and clean it up in protools. Problem is when i do something in the field, and come home and it is taking me forever to clean it up ... and I can hear the scrubbing off of the noise. I was listening carefully, and there is something around Low C with a pink noise "whack" around it. There is also a bit of like high noise, like leaves ruffling in the wind ... that's harder for me to put a handle on, so i would have to carve that out too.

Quote:
Originally Posted by pkautzsch View Post
MS won't do anything about rumble, except that the rumble is stereo then.
If you're using a 416 or NTG now, the Schoeps might even output more LF rumble since it is more linear.

Use a hi-pass at around 60 or 80 Hz. If it's intended for laptop speakers, your HP frequency can be even higher.
Will do pkautzsch... i think a serious notch at 67 hz is a starting point.

Quote:
Originally Posted by David Spearritt View Post
Although the two mics involved, particularly the side, have LF rolloff, so it can help a lot.

LF propagates and re-radiates beautifully from structural walls and floors, so aim away from them if possible.
Thanks David, I will pay more attention to that, i think there's pockets between buildings where this noise evens out a bit more ... i hunt for spots like that a lot more.

Quote:
Originally Posted by pkautzsch View Post
OP's statement about low-budget corporate lets me infer he is using a shotgun mic already. As especially the less expensive shotguns have that LF rolloff, and the CMIT is more linear than an ME66, NTG-1, or 416, it won't help much.
A true (dipole) fig-8 mic has a strong rolloff indeed, and I've used a KM120 successfully in a few situations involving rumble. However the strong rear lobe makes it not suitable as a universal boom mic. It's just another special tool for special cases, as is the 816, a PZM, or an Omnigoose.

The "one size fits all" lo-budget/ENG/corporate way is: use a 416 and engage mixer's high-pass as needed. And don't worry about LF content, it won't come out of the TV or laptop speakers anyway.
You nailed my equipment problem pkautzsch, the only shotgun mic i have is a 416 ... and use it to death. I've really never used another shotgun mic in the field, i think i need to broaden my horizon one of these days ... i've been eyeing the cmit but have never used one extensively. Also field mic's aren't something that i understand real quick, i need to play with them in a lot of circumstances to understand them (i.e. i find picking studio mic's way easier then field mics).

Quote:
Originally Posted by tourtelot View Post
As you probably already know, the lower the frequency, the less directive the sound is. That makes the directivity of "shotgun" (let call them interference tube mics) more worthless the lower the frequency goes.

My experience has been the the Sanken CS3e is pretty brilliant at reducing the low end rumble in general and I find it really good for taking the noise of location power plants, generators, out of the track. They are manufactured using multiple capsules and although I probably should, I am not up to speed on the "whys" of that technology. It does seem to work, however.

Also, lo-cut filters, either at the mic end or at the mixer/recorder end are almost always used by me in recording dialog. I tend to roll off everything below 60Hz as sharply as I can, preferably at 18bD/octave. Some roll off even higher, 75Hz or even up to 100 or so. Remember, the dialog doesn't get affected dramatically (sorry ) certainly at 70Hz, and post doesn't want that crud below that in any case.

Music, at least for me, is different. Never any lo-cut. I try and more selectively take out the rumble with post tools such as Izotope RX3.

D.
I am taking this to heart D., I'm use RX3 advance, not that i'm a expert with it since i'm primarily running off of presets. I think i need to walk myself through using it more carefully. Normally i don't like what it does with the sound, i'm probably hitting it to hard. I like the idea of the Sanken CS3e as a 2nd shotgun mic to slowly replace my mkh 416. I was also looking at the mkh 8070, but my boom skills aren't good enough. Reading this again the probably easiest thing for me to do is whack below 75 hz in protools.

Quote:
Originally Posted by philper View Post
City BG and etc is one reason why I've gradually moved from the hypercard boom mics I used to use to much more directional mics like CS3e. It's a noisier world out there now. The other thing, of course, to do is get the mic closer to the source…

philp
Thanks Philp, The bay area noise is definitely increasing, i think the high ways are a lot more busy ... seems like things would calm down around 10 pm ... but the city noise doesn't drop off until 2 am and starts up again around 5 am. On the getting the mic closer, one thing i've started to do is use a tlm67 outside close to a source. I really love bringing my m149 outside but it's just too much of a hassle. I've been waiting for a pair of elam 260's microphones with the field power source, can't wait to try that out and get close to things. Another weirder thing i do is use a talinga parable, i think what it's doing is increasing the high's while the lows are about the same (i bet the low frequency doesn't bounce back from the thin plastic parabola). As a real weird thing i've been doing recently is placing contact microphones and hydrophones(in a glass), next to things ... completely removes the city noise but takes forever to setup correctly. If i get my act together i would love to have a production lot between some valley's, there is always dreaming.
Old 17th June 2014
  #9
I hear continous low freq hum where I live. I hear it in my right ear only.
I live in Ghent, belgium, but can hear it in Bochum, Germany, Kleve, Germany, and in Zeeland, Holland as well.
any idea what this might be?
Old 17th June 2014
  #10
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Quote:
Originally Posted by monitor View Post
I hear continous low freq hum where I live. I hear it in my right ear only.
I live in Ghent, belgium, but can hear it in Bochum, Germany, Kleve, Germany, and in Zeeland, Holland as well.
any idea what this might be?
Sounds like a prime symptom of tinnitus. Recommend consulting a medical specialist ASAP. In the US, they are called "otolaryngologists" or "ENT" (ear, nose, throat specialists).
Old 18th June 2014
  #11
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PatrickFaith's Avatar
 

Quote:
Originally Posted by monitor View Post
I hear continous low freq hum where I live. I hear it in my right ear only.
I live in Ghent, belgium, but can hear it in Bochum, Germany, Kleve, Germany, and in Zeeland, Holland as well.
any idea what this might be?
My left ear hearing is off slightly, is kind of useful in some ways in that it's a built in detector on some frequencies.

Quote:
Originally Posted by Richard Crowley View Post
Sounds like a prime symptom of tinnitus. Recommend consulting a medical specialist ASAP. In the US, they are called "otolaryngologists" or "ENT" (ear, nose, throat specialists).
+1 ... I try and go every few year to ENT. It's kind of weird in that most people have their eye's checked regularly ... but when you explain you want your hearing checked regularly people question you. I think most of us need to get our ears checked out much more frequently and not chicken out going to a ear doctor, lot of the problems are preventable if caught early. I have gotten fanatical in ear maintenance, but i'm afraid hearing loss is an epidemic which is "out of sight".
Old 18th June 2014
  #12
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Wyllys's Avatar
 

Quote:
Originally Posted by PatrickFaith View Post
Seems where i am recording, SF bay area, the city rumble has increased everywhere...
Old joke, but since you're from SF:

What does a Grateful Dead fan say when he runs out of pot?

"What's that noise?"
Old 18th June 2014
  #13
Quote:
Quote:
Originally Posted by monitor View Post
I hear continous low freq hum where I live. I hear it in my right ear only.
I live in Ghent, belgium, but can hear it in Bochum, Germany, Kleve, Germany, and in Zeeland, Holland as well.
any idea what this might be?
My left ear hearing is off slightly, is kind of useful in some ways in that it's a built in detector on some frequencies.


Quote:
Quote:
Originally Posted by Richard Crowley View Post
Sounds like a prime symptom of tinnitus. Recommend consulting a medical specialist ASAP. In the US, they are called "otolaryngologists" or "ENT" (ear, nose, throat specialists).
+1 ... I try and go every few year to ENT. It's kind of weird in that most people have their eye's checked regularly ... but when you explain you want your hearing checked regularly people question you. I think most of us need to get our ears checked out much more frequently and not chicken out going to a ear doctor, lot of the problems are preventable if caught early. I have gotten fanatical in ear maintenance, but i'm afraid hearing loss is an epidemic which is "out of sight".
I 've been visiting an 'ENT' 3 times when this started. he says a low freq tinnitus doesn;t exist, my wife and other people hear this low freq too when they visit our house.
it's a 12 Hz hum, but the city environment service claim it is below legal limit of 100 dB A weigthed on that freq.
Seems I will have to move though.
Old 18th June 2014
  #14
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I had a 20Hz hum when I moved to the country
My cottage is near to an underground gas national grid main (its 4m wide!)
Many could hear it
They changed the fan speed, its gone now
Old 18th June 2014
  #15
Quote:
Originally Posted by Richard Crowley View Post
Sounds like a prime symptom of tinnitus. Recommend consulting a medical specialist ASAP. In the US, they are called "otolaryngologists" or "ENT" (ear, nose, throat specialists).
Quote:
Originally Posted by Rolo 46 View Post
I had a 20Hz hum when I moved to the country
My cottage is near to an underground gas national grid main (its 4m wide!)
Many could hear it
They changed the fan speed, its gone now
Hi Rolo
i was thinking about gas also.
thanks for the tip!
Old 18th June 2014
  #16
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Yep, was suspecting something like gas pipes too. Have read about remote heating systems.

Here in Munich, I hear some very low rumble sometimes as well. Mostly in my left ear - which according to my ENT is perfectly fine. It must be some "civilization infrastructure" thing.

Most people don't hear it, or don't mind.
Some soundies do. I try to think "it's not a bug - it's a feature".
Old 19th June 2014
  #17
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Monitor/pkautzsch/Rolo ... i think u guys nailed it. Where i normally do a lot of my field recordings, in a creek area, they put in this massive municipal building about 500 feet away(my studio is also about a half a mile away). No one ever goes into this building, but i've noticed big pipes and stuff. I can hear this grumble liking drilling from a mile away too(it's goes late at night), but the sound is hard for me to localize. I fortunately have enough bases traps in my recording rooms and studio that i can't hear it, but when i open a window late at night i hear the grumble. Also i've noticed it changes frequency in the mourning, especially when there is some fog.

As a side note, I think the worse thing about getting into field recording is you get sensitive to things that you just ignored in the past.
Old 19th June 2014
  #18
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I do a lot of recording in big downtown office buildings. An infinite palette of interfering noises always audible--thus directional mics, lavaliers and furni pads strategically placed, always. And then in post…noise reduction. It's a noisy world out there.

philp
Old 19th June 2014
  #19
Quote:
Originally Posted by PatrickFaith View Post
Monitor/pkautzsch/Rolo ... i think u guys nailed it. Where i normally do a lot of my field recordings, in a creek area, they put in this massive municipal building about 500 feet away(my studio is also about a half a mile away). No one ever goes into this building, but i've noticed big pipes and stuff. I can hear this grumble liking drilling from a mile away too(it's goes late at night), but the sound is hard for me to localize. I fortunately have enough bases traps in my recording rooms and studio that i can't hear it, but when i open a window late at night i hear the grumble. Also i've noticed it changes frequency in the mourning, especially when there is some fog.

As a side note, I think the worse thing about getting into field recording is you get sensitive to things that you just ignored in the past.
is it possible to make a bass trap in a bedroom to diminish a 12 Hz rumble?
Old 20th June 2014
  #20
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Quote:
Originally Posted by monitor View Post
is it possible to make a bass trap in a bedroom to diminish a 12 Hz rumble?
Rolls of oil paintings (large ones - old 10 feet wide ones). I have about 7 large rolled paintings per corner. It's kind like a rolled tar/lead/rubber but thinker(like those hanging rubber weighted base traps). It's not the most cost effective way to go though, using old large oil paintings. (the old paintings are really heavy too, there is a lot of ground rock mixed with the oil, some are almost a 1/4 inch thick on the cloth - they stay gummy forever too)
Old 20th June 2014
  #21
Quote:
Originally Posted by PatrickFaith View Post
Rolls of oil paintings (large ones - old 10 feet wide ones). I have about 7 large rolled paintings per corner. It's kind like a rolled tar/lead/rubber but thinker(like those hanging rubber weighted base traps). It's not the most cost effective way to go though, using old large oil paintings. (the old paintings are really heavy too, there is a lot of ground rock mixed with the oil, some are almost a 1/4 inch thick on the cloth - they stay gummy forever too)
thanks for the advice. will this also help in an old house, where the problem is that the house itself resonates on this freq? (wodden floors, thin walls,...)
Old 20th June 2014
  #22
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Look at Tom Hindleys bass traps for the BOP studios
youtube.com/watch?v=ZjKVndZSZqE
Old 20th June 2014
  #23
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Quote:
Originally Posted by Rolo 46 View Post
I had a 20Hz hum when I moved to the country
My cottage is near to an underground gas national grid main (its 4m wide!)
Many could hear it
They changed the fan speed, its gone now
wow - i've never thought of this - I and others in my village (uk midlands) hear a low rumble, and we do have a gas main going up the road... also we have a dual carriageway about 500m away... :(

our solution... "don't think about it"...that way it stops buggin ya.
Old 20th June 2014
  #24
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Thank you for the pointer to possible gas mains. It could explain the rumble I used to hear in Berlin. ( On Sundays it would increase and rattle kitchen shelves, though, which I guess must have been some other kind or source.)

There exist `conspiracy theories´aboutt LF used as means to communicate with submarines, which are reported to be perceivable enough for to make people ( like in Berlin) nauseating and having head aches; and another one called HAARP. High Frequency Active Auroral Research Program - Wikipedia, the free encyclopedia

Further, also in Berlin I was hearing some HF for most of the day, which appeared to be emissioned from a military air craft station near by. Don´t know whether I got my tinnitus from that or from my mixing with headphones at that time.


Regarding the difference between the ears, mentioned above, there were discussions about hearing on GS long ago in which it was emphasized that the left ear is pitched to communication / voice FQ range ( which why most of us prefer to take tel.phones to the left side), whereas the right one was specialized on alarming about predators / thus being flat on FQs.

Ruphus
Old 20th June 2014
  #25
Kaotica Eyeball won't eliminate the problem, but it might help. It has certainly helped us, but we are using it in treated, isolated rooms.
Old 20th June 2014
  #26
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Quote:
Originally Posted by Ruphus View Post
Regarding the difference between the ears, mentioned above, there were discussions about hearing on GS long ago in which it was emphasized that the left ear is pitched to communication / voice FQ range ( which why most of us prefer to take tel.phones to the left side), whereas the right one was specialized on alarming about predators / thus being flat on FQs.
Ach, that was always a pretty fanciful explanation! Have none of those guys ever shaved with an Occam's razor?
I trained myself to hold the phone to my left ear so that I was free to jot down notes with pen in right hand.
Old 20th June 2014
  #27
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Quote:
Originally Posted by Tom McC View Post
I trained myself to hold the phone to my left ear so that I was free to jot down notes with pen in right hand.
Of course.

D.
Old 20th June 2014
  #28
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PatrickFaith's Avatar
 

Quote:
Originally Posted by monitor View Post
thanks for the advice. will this also help in an old house, where the problem is that the house itself resonates on this freq? (wodden floors, thin walls,...)
My area is similar, also i have sound blankets i put on the floor in some area's.
This is pure cheating, but I tune the instruments to a mode that is out of sync of my room resonance(i tune A to 437 hz instead of 440, amazing what a few hz difference makes if you have a frequency in a room that you just can't fix with sound conditioning - this is of course totally impractical if your not doing the recording as well as the mixing).

In general throughout the area I hang thick paintings on suspended wires( i.e. on adjacent walls, i hang 4x8 foot aluminum frame paintings on hanging wires). I'm not really sure the physics why the low frequency bass traps need to "float", my gut feel is they cloth/oil/rubber/rock_particles actually moves when the frequency hits it (and dampens it by converting the wave to heat), if the media didn't move it would not absorb the frequency.

edit ... ohh and another thing i did is use concrete siding instead of vinyl (the concrete siding looks like regular boards, but is made of concrete).

Quote:
Originally Posted by Rolo 46 View Post
Look at Tom Hindleys bass traps for the BOP studios
youtube.com/watch?v=ZjKVndZSZqE
I haven't seen that studio, it's AMAZING! I especially like the little resort in the back, WOW. Man that is a dream setup. A bunch of things suspended by chains in the walls ... very cool.
Old 20th June 2014
  #29
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Quote:
Originally Posted by PatrickFaith View Post
Seems where i am recording, SF bay area, the city rumble has increased everywhere i shoot and it is driving me a bit crazy. Even when i point a shotgun into a dead area like the dirt i hear the city rumble. I have been pondering if the fancy cmit m/s scheops would help, but that would be a major step for me ... since i do only low budget and corporate stuff. Am i missing something obvious, is the sound level of the entire bay area, even outer hill regions, increasing?
san franciscos rumbeling is increasing? sounds dangerous
Old 21st June 2014
  #30
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Quote:
Originally Posted by Tom McC View Post
Ach, that was always a pretty fanciful explanation!
I thought the different pitch of ears was a scientifical finding.
Just made a quick search:
Quote:
Your ears differ
Sing to your right ear and speak to your left. Your right ear hears differently than your left.
Your ears differ

Your left ear is better than your right ear at receiving sounds from speech, whereas your right ear is more sensitive to sounds of music and song, according to American researchers behind a study of the hearing in 3,000 newborns.

It has long been known that the right and left halves of the brain register sounds differently because of differences in the brain cells in each side. But the results from the study indicate that the ears play a much more important part than previously believed.

"We always assumed that our left and right ears worked exactly the same way. As a result, we tended to think it didn't matter which ear was impaired in a person. Now we see that it may have profound implications for the individual's speech and language development," said the leader of the study, Yvonne Sininger of University of California at Los Angeles.

The scientists inserted tiny probes into the babies' ears that emitted two different types of sounds and measured the amplified vibrations.
Your ears differ - hear-it.org

Ruphus
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