The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
Sm7B and room noize Condenser Microphones
Old 28th December 2010
  #31
Lives for gear
 

Quote:
Originally Posted by Nelson89 View Post
When i said condenser's were "traditionally" more accurate, i was referring to the fact that they're "typically" faster, as a result being able to reproduce more subtle nuances. Of course there are exceptions to the rule, but we're talking in a typical case here.
Fast is typically not a good word describing transducers.. at least without further explanations.

Quote:
But you know as i'm writing this i'm wondering if you truly believe that something like an sm7b wouldn't be more effective at rejecting off axis sound source than a condenser of the same polar pattern.
No I don't believe that and there's no rational explanation that I'm aware of that would describe such a phenomena.



/Peter
Old 28th December 2010
  #32
Lives for gear
Quote:
Originally Posted by Audiop View Post
Fast is typically not a good word describing transducers.. at least without further explanations.



No I don't believe that and there's no rational explanation that I'm aware of that would describe such a phenomena.



/Peter
Have you physically tried the sm7b? And compared it to a condenser?
Old 28th December 2010
  #33
Lives for gear
 

No, but I have studied physics including transducers such as microphones and loudspeakers.

My angle is if you don't understand the mechanisms behind stuff you should restrict yourself to "it sounds like" instead of giving explanations based on flawed understanding on laws of physics.

Nothing personal, cross my heart! :-)


/Peter
Old 28th December 2010
  #34
Lives for gear
Quote:
Originally Posted by Audiop View Post
No, but I have studied physics including transducers such as microphones and loudspeakers.

My angle is if you don't understand the mechanisms behind stuff you should restrict yourself to "it sounds like" instead of giving explanations based on flawed understanding on laws of physics.

Nothing personal, cross my heart! :-)


/Peter
Ok well put it this way, i own several condensers and several dynamics...and this is what happens when i use them, the effect is even more pronounced on the sm7b which is partly to do with its casing as well. I'm sure many other people will have experienced the same thing, if not with other dynamics, then at least with the sm7b...after all this is one of the main reasons people choose it in the first place...it used to be a hidden gem, now its kinda talked about way too much...but certain characteristics of it are true, and this particular characteristic is a big one.

Concerning the physics point of view, i should probably direct you to some of what Go Nigel Go was saying, some of which does flaw some of what you've been saying...
Old 28th December 2010
  #35
Gear Maniac
 
cporro's Avatar
 

sheesh lots of posts on this. i read some not all. trying to not duplicate.

so the noise is a click? it's not dull? if it's duller i'd take a look at how the mic is mounted. make sure it's decoupled from the keyboard.

make sure your placement it optimal. get some cheap iso earbuds and put some gun muffs over them. should give you a poor mans control room. turn up your monitor volume and then play. now move the mic around to find where it rejects the most keyboard noise and still works for your voice.

also, as others have said you can sing closer to it. but it will change the way you sound. just make sure you like that.

you can look at reflections from the keyboard to the mic. any hard surfaces where the clicks might reflect off? put something down to absorb. and i think it was said already but if it doesn't get in the way you could put something between the keys and the mic....foam or whatever.

most importantly listen (as above) as you place the mic and add absorption. then you'll know what the mic is picking up.

i wouldn't start looking at other mics until i figured out the optimum placement and took a look at the recording environment.
Old 28th December 2010
  #36
Gear Nut
 

[to OP] how are you setting the gain structure on the GAP? Start with the output level all the way up and then change your input gain very slowly - this will give you the clearest sound - I say this because if the pre is being 'driven' a bit by lowering output gain and increasing input gain, the natural compression that results from that may cause more exterior noise to be picked up than if your pre is set the other way.

I had a problem a while ago with a snare drum track picking up way too much bleed, and found that all I had to do was adjust the gain structure on the pre.
Old 28th December 2010
  #37
Lives for gear
 

Quote:
Originally Posted by Nelson89 View Post
Ok well put it this way, i own several condensers and several dynamics...and this is what happens when i use them, the effect is even more pronounced on the sm7b which is partly to do with its casing as well. I'm sure many other people will have experienced the same thing, if not with other dynamics, then at least with the sm7b...after all this is one of the main reasons people choose it in the first place...it used to be a hidden gem, now its kinda talked about way too much...but certain characteristics of it are true, and this particular characteristic is a big one.
I bet you find the answer in polar pattern if you investigate it.

Quote:
Concerning the physics point of view, i should probably direct you to some of what Go Nigel Go was saying, some of which does flaw some of what you've been saying...
Not what I see. I think you possibly misinterpret what he is saying.

The way I read his post I agree and also note that he mentions "linear".


/Peter
Old 28th December 2010
  #38
Gear Maniac
 
Malcolm Boyce's Avatar
 

To help with the 'dynamic mics are the fix for isolating' argument.

I agree that mics like the SM7B will help isolate, but it's not just because it is a dynamic mic.

A condenser like a Beta87 or (budget permitting) KSM9 will also do a fab job of isolating a vocal in a less than ideal situation. Many people discard these as possibilities in "the studio" but they are great at what they do. Several brands offer similar options, but I tend to use the Shures....

This should not be a "dynamic VS condenser" question, but which mics could be a solution to the poster's problem.

I also agree that you should try as many options as you can before you find a solution and buy something. My suggestion in this case would be to try a Beta 87A. They are usually easy to find which makes them easy to demo.

Good luck.
Old 28th December 2010
  #39
Gear Addict
 

Audiop, you're working very hard to reject the nearly universal experience of studios and individuals around the world when it comes to the SM7.

The housing of the microphone makes a large contribution to the pickup pattern. The capsule isn't floating in open air, sir. The SM7's housing was designed for this exact purpose, and radio professionals everywhere use them in large part because of this trait. It's not the only mic that offers good off-axis rejection, but it's one of the better ones.

You can hook one up to a matched preamp right next to a high-sensitivity cardioid condenser, then level match on your board or in your DAW, and then see which mic picks up soft sounds to the side and rear better.

Your claim is that polar pattern is everything (it's not what you've said, but that's the message that is getting delivered) ignores the fact that if you put a steel plate next to the mic, the pattern is altered. That's the value of housing.
Old 28th December 2010
  #40
Lives for gear
 

Quote:
Originally Posted by PFRfan View Post
Audiop, you're working very hard to reject the nearly universal experience of studios and individuals around the world when it comes to the SM7.
Hi there!

I think you totally miss my message.

I don't question the experiences with SM7B, I question the explanations some come up with to describe what they hear.

Quote:
The housing of the microphone makes a large contribution to the pickup pattern.
Well of course.

Quote:
The capsule isn't floating in open air, sir.
Did I write anything that was even close to suggesting I was under such an impression? Don't think so. :-)

Quote:
The SM7's housing was designed for this exact purpose, and radio professionals everywhere use them in large part because of this trait. It's not the only mic that offers good off-axis rejection, but it's one of the better ones.
Ok, I haven't used it or seen measurements of its polar pattern so I wouldn't know. I don't doubt for a second it's a superb mic and I am about to purchase one myself.

Quote:
Your claim is that polar pattern is everything (it's not what you've said, but that's the message that is getting delivered) ignores the fact that if you put a steel plate next to the mic, the pattern is altered. That's the value of housing.
But please! :-)

I do not ignore influences of steel plates, LCD monitors, beer cans, birthday cakes or big fury pets in close proximity to the mic but now we are talking about microphones and their pick up, not reflection/diffraction/diffusion/absorbtion of external objects.


/Peter
Old 29th December 2010
  #41
Lives for gear
 
enroper's Avatar
 

Quote:
Originally Posted by hereticskeptic View Post
If anyone knows, does the SM7B benefit a great deal from a treated room, or is treating a room when using an SM7B somewhat unnecessary? I'm still going to be treating my room, since I'll be mixing in there, but I was just kind of interested in this, since most everyone mentions the 7B as a mic that doesn't pick up a lot of noise not in close proximity. Will I be seeing a solid improvement in my recordings once my room is treated than when it was untreated? Of course, I'll be finding out soon enough myself, but thought I'd ask, in case any of you have knowledge on this subject.
YES!! Absolutely. Sing loud in an untreated room on an SM7 and you will definitely still hear the room.

Also goes the other way, sing quiet at high gain and compress, and you will hear the room.

And sm7b is not a panacea. It's a step in a right direction. I use it for rejection of outside noises, but before I started getting better at taming reflections, room sound was definitely heard over an sm7b
Old 29th December 2010
  #42
Gear Addict
 

Quote:
Originally Posted by Audiop View Post
I do not ignore influences of steel plates, LCD monitors, beer cans, birthday cakes or big fury pets in close proximity to the mic but now we are talking about microphones and their pick up, not reflection/diffraction/diffusion/absorbtion of external objects.
I was referring to the effect of the housing (or a metal plate) on the pickup pattern, not the reflections that it causes.

Anyway, thanks for staying friendly!

Jonathan
Old 29th December 2010
  #43
Lives for gear
 
hereticskeptic's Avatar
Quote:
Originally Posted by enroper View Post
YES!! Absolutely. Sing loud in an untreated room on an SM7 and you will definitely still hear the room.

Also goes the other way, sing quiet at high gain and compress, and you will hear the room.

And sm7b is not a panacea. It's a step in a right direction. I use it for rejection of outside noises, but before I started getting better at taming reflections, room sound was definitely heard over an sm7b
Word up. A lot better than when I was using an AT3035 in an untreated room right next to the refrigerator. This doesn't sound bad at all considering I'm, again, right by the fridge! The room I'll be using is actually upstairs, but I'm not moving things up there for a few more days, and thought i'd try out the setup anyway, just to check it out.

I'm using an SM7B, Apogee Duet, pair of Yamaha HS80M's, an iMac and Pro Tools 9. Treatment to come in the next week, but went ahead and recorded without treatment just to see.

I think it came out alright, but then again, I have yet to burn a copy and take it to the car to compare. I did no mixing whatsoever, so I'll really get a good feel for how quality the setup is without treatment as soon as I can snag some CD-R's. Sounds really nice on the ATH-M50 headphones, but of course, those are headphones. Nice to hear a difference in quality from past experiences though.

Overall, though, I am excited and content! Treatment will be a huge plus, and then when I get that Great River, I should be good to go for some time. I'd post the rough track I jus recorded for you guys, but I really am not sure how it came out at all. Sounds okay through the HS80M's/iMac speakers. Nothing special, but much better than any other stuff I've done in untreated studios. Soon enough, I'll up something.
Old 29th December 2010
  #44
Lives for gear
 

Quote:
Originally Posted by PFRfan View Post
I was referring to the effect of the housing (or a metal plate) on the pickup pattern, not the reflections that it causes.
But the housing is an integral part of the microphone and as such is part of the measured data. I'm not aware of any manufacturer or tech guy that measures the capsule on its own when the goal is to learn and collect information about a complete microphone.

That said a baffle or housing have acoustic effects such as reflection and diffraction and those affect the pick up pattern.


/Peter
Old 29th December 2010
  #45
Lives for gear
 

The polar pattern graphs are based on a fixed level of sound coming from different directions compared to the axis of the mic. I do not believe most of them contain any information in regards to sensitivity to various levels of sound from any angle. I have seen a few that had polar patterns for two or three levels of sound (they can be quite different), but most only have one sound level based on expected usage levels rather than weak or background noise levels.

The polar pattern is vital information for selecting a mic for pick up of ambient sound or off axis rejection, but it does not tell the whole story. Sensitivity and microphone type play a big role in how much room noise ultimately becomes signal or is rejected. Dynamic mics tend to be less sensitive, and all else being equal tend to not pick up weak or distant sounds nearly as well as other designs such as condensers. All mics will pick up room noise if it is loud enough, but how loud that is depends on sensitivity factors as much as polar pattern.

My AT-4040 will pick up a small battery powered clock ticking 40 feet away in another room 90 degrees off axis. My RE-20 simply will not, no matter how much gain you throw at it and no matter what the angle. The weak distant sound simply will not move the heavier dynamic mic diaphragm enough generate a significant voltage. I consider this difference useful in selecting a mic for room and off axis rejection. Polar pattern is simply a directional way of attenuating unwanted sound via mic placement in addition to regulating the distance and intensity of the unwanted sound.
Old 30th December 2010
  #46
Lives for gear
 

Quote:
Originally Posted by Go Nigel Go View Post
The polar pattern graphs are based on a fixed level of sound coming from different directions compared to the axis of the mic. I do not believe most of them contain any information in regards to sensitivity to various levels of sound from any angle.I have seen a few that had polar patterns for two or three levels of sound (they can be quite different), but most only have one sound level based on expected usage levels rather than weak or background noise levels.
You wouldn't have a link?

If this is significant it means gross distortion for sound coming from these angles which have a level dependent response.



Quote:
The weak distant sound simply will not move the heavier dynamic mic diaphragm enough generate a significant voltage.
If there's such a mechanism it is not dependent on weight since mass is linear. Possibly the suspension can have a nonlinear compliance causing this.


/Peter
Old 30th December 2010
  #47
Lives for gear
Quote:
Originally Posted by gcp View Post
I've had two figure 8 mics arranged on a sitting guitar player who was singing and had unbelievable attenuation just by pointing the vocal mic null at the guitar and vice versa.
+1

Great isolation can be had using fig8 mics with judicious pointing of the side nulls at whatever sound you want to eliminate.
Old 30th December 2010
  #48
Lives for gear
 

Quote:
Originally Posted by Go Nigel Go View Post
Acceleration = Force/Mass. It takes more energy to overcome inertia as the mass of a microphone diaphragm increases. Weaker sound = less change in velocity. (linear) ANY given sound level impacting a heavier mass = less change in velocity (also linear)

The Energy available to be transduced into an electronic signal =Mass x Velocity^2. This an exponential increase in available energy as velocity increases. A lighter mass moving at the same velocity as a heavier one will have less energy, but if the same energy is applied, a lighter mass it will accelerate to a higher velocity. and increase it's AVAILABLE energy exponentially.

Simply put, the heavier mass of a dynamic microphone's diaphragm means less available electrical output because the energy is lost overcoming inertia and mechanical resistance. As a result a weak sound impacting a lighter Condenser mic diaphragm will give a stronger electrical signal than the same sound energy impacting a heavier Dynamic mic diaphragm in a non-linear way.
Mass vs acceleration is linear, but velocity and available energy is non linear. This gives a lighter diaphragm an edge with weak signals because it accelerates to a higher velocity than a heavier dynamic given the same sound levels, and therefore has exponentially more energy available to be converted to an electrical signal.
Old 30th December 2010
  #49
Lives for gear
 

Quote:
Originally Posted by Go Nigel Go View Post
Mass vs acceleration is linear, but velocity and available energy is non linear.
Slippery slope when talking about linear vs nonlinear.

What I meant is if you increase the moving mass of a microphone or speaker you do not get extra spectral components such as HD and IMD. You only change the sensitivity and Q of the fundamental resonance.

Mass affects low level sounds the same way as high level sounds, if not you see HD and IMD.

Quote:
This gives a lighter diaphragm an edge with weak signals because it accelerates to a higher velocity than a heavier dynamic given the same sound levels, and therefore has exponentially more energy available to be converted to an electrical signal.
Not more energy but potentially higher sensitivity (due to increased motion) and only in the mass controlled area. Condensers are typically operated mostly in the compliance controlled area, the opposite to dynamic mic's which are operated mostly in the mass controlled area.


/Peter
Old 30th December 2010
  #50
Lives for gear
Quote:
Originally Posted by BigIzzy View Post
Hey guys!

Quick question (this is for anyone who OWNS a Shure SM7B and knows how it behaves in the studio).

I'm a singer/songwriter, I play piano and sing. Something that I've noticed while recording is that I tend to sing better when I'm playing piano at the same time (weird, huh?). I've done many recordings, and it ALWAYS sounds better when the two are combined.

The problem I'm having with my current mic (Shure KSM-27 going through a GAP-73 preamp) is that it picks up the noises that my keyboard makes (Yamaha KX-8) when I hit the keys. It's VERY annoying, and sometimes can be heard quite distinctly in the mix (even when other instruments are in the mix).

I've tried recording piano and vocals separate, but it never has the same "sparkle" as when I'm with my instrument.

Questions--I've heard GREAT things about the Shure SM7B. If I swap out my KSM-27 for a SM7B, will the noise my keyboard makes not be a problem anymore? Will the microphone pick up sounds like that if they're coming from directly below it? Would this solve this problem and allow me to sing/play piano at the same time?

Thanks!

~Big Izzy
Hey Big Izzy,
If singing and playing at the same time delivers the best performance, yeah...you gotta go that route.
A dynamic mic would be the way to go, but it is hard to say the SM7b would be the best choice or not...
It "can" be good, great, but more often than not in my vocal shootouts before tracking a vocalist it is just o.k, and not the winner.....it is a bit veiled, flat, not much "air"....
The Senheiser 421 has more presence and clarity...
There are probably a lot of dynamic options that would work, it would be cool if you could find a local Gearslut Brotha to do a shootout for your voice with a few mics...
Good luck!
Old 30th December 2010
  #51
Lives for gear
Quote:
Originally Posted by Yetti View Post
Hey Big Izzy,
If singing and playing at the same time delivers the best performance, yeah...you gotta go that route.
A dynamic mic would be the way to go, but it is hard to say the SM7b would be the best choice or not...
It "can" be good, great, but more often than not in my vocal shootouts before tracking a vocalist it is just o.k, and not the winner.....it is a bit veiled, flat, not much "air"....
The Senheiser 421 has more presence and clarity...
There are probably a lot of dynamic options that would work, it would be cool if you could find a local Gearslut Brotha to do a shootout for your voice with a few mics...
Good luck!
Yeh he's right here, the sm7b has kind of a rolled off sound up top (upon hearing the recorded material) compared to the md421, however, using something like the Abbey Roads rs127 rack and boosting 10k by a couple of db cleaned that problem right up...i'm sure similar results could be achieved with the use of a high shelving EQ...the rest of it is pretty smooth...but yeh, the 421 and sm7b SOUND different...its hard to tell which would work better for you voice...but i have noticed that the sm7b will pick up less bleed than the md421...have you tried playing a weighted keyboard or something with it either off or the sound running through your headphones? It's not the same as playing a piano...but in your situation, it might get the job done?...just a suggestion.
Old 4th January 2011
  #52
Gear Nut
 

Hey everyone! Thanks for the responses, I really appreciate all of your input!

Nelson89, I run everything through headphones. It's not the "audio" from the piano samples, it's the sound from the actual keys on the keyboard. I tend to play with a lot of emotion (meaning, I sometimes bang on the keys) and you can hear it in the recordings!

I do use a weighted keyboard, it's a Yamaha KX-8 88key MIDI controller (has an AWESOME piano-like feel to it), but it's still very noisy when you play it hard (I have yet to play a MIDI-controller that's extremely quiet).

I think, for the time being, I'm going to keep the KSM-27. Like one of you said earlier, I should try and isolate the problem through soundproofing before I swap-out mics. Or, as one of you said earlier, I could play "air-piano" while recording vocals. I haven't tried this yet, but I'll give it a whirl and see if it helps.
Old 4th January 2011
  #53
Lives for gear
Quote:
Originally Posted by BigIzzy View Post
Hey everyone! Thanks for the responses, I really appreciate all of your input!

Nelson89, I run everything through headphones. It's not the "audio" from the piano samples, it's the sound from the actual keys on the keyboard. I tend to play with a lot of emotion (meaning, I sometimes bang on the keys) and you can hear it in the recordings!

I do use a weighted keyboard, it's a Yamaha KX-8 88key MIDI controller (has an AWESOME piano-like feel to it), but it's still very noisy when you play it hard (I have yet to play a MIDI-controller that's extremely quiet).

I think, for the time being, I'm going to keep the KSM-27. Like one of you said earlier, I should try and isolate the problem through soundproofing before I swap-out mics. Or, as one of you said earlier, I could play "air-piano" while recording vocals. I haven't tried this yet, but I'll give it a whirl and see if it helps.
Yeh the sm7b will pick up a lot less...but im thinking something like the sm pro audio mic thing or the rode vicoustic(i think thats what its called) could be something a bit more up your alley, they will isolate your mic a bit more depending on how you angle them. Here's a link to what i mean:

SM Pro Audio

Turramurra Music :: Acoustic Treatment : Rode Vicoustic
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Similar Threads
Thread
Thread Starter / Forum
Replies
carlrenaud / Electronic Music Instruments and Electronic Music Production
5
Alxi / Music Computers
0
rodge / Electronic Music Instruments and Electronic Music Production
8
ClaySchmitt / Electronic Music Instruments and Electronic Music Production
5
reinvention.of.man / Rap + Hip Hop engineering and production
2

Forum Jump
Forum Jump