Some things to think about when choosing mics.

Harvey Gerst

New member
I'm not really sure where this fits in(maybe in the big thread), but maybe it deserves its own thread:

Each mic design has trade-offs, usually accuracy for noise. The most accurate mics are small omnis, but as the size decreases, the noise goes up. Ya don't hafta be a rocket scientist to figure out why; the smaller diaphragm doesn't put out as much signal as a bigger diaphragm, so you hafta crank it more and you amplify the noise along with the signal.

Condenser mics can only do certain things very well, especially when you get into different patterns. Large diaphragm mics get wonky off axis (which means they can be shitty on sounds coming from a lot of different directions at once). That's why large diaphragm condensers are best as a vocal mic; the mouth is a pretty small source, and ocassionally very quiet. Large condensers are great for picking up quiet sources. Trade offs.

Small diaphragm condenser mics have better off-axis response, so they're "usually" better for miking bigger stuff (guitars, drum kits, choirs, etc.), in other words, anything where the sound is coming at you from a lot of different places. But, because they're smaller, they won't be assensitive as large condenser mics. Trade offs, again.

So what's the best vocal mic? Usually a large diaphragm mic is the first thing the pros reach for.

What's the best mic for larger instruments? Unless you own a very well designed large diaphragm condenser mic, usually a small diaphragm will work better (unless it's a very quiet source and you're willing to give up some accuracy for extra low noise output).

Finally, most mics aren't truely flat - most have little spikes and dips that occur all over the place. The frequency response charts that you see are smoothed to eliminate those short peaks and dips, but they're still there. And they're different for every mic - even two that are exactly the same brand and model.

Now here's the important part: When you happen to sing or play a note that corresponds to a peak or dip, the sound is gonna change. So, what does that mean? It means that a mic that sounds great on one voice, one guitar, or even in one key, may sound very different on another voice, another guitar, or even in a different key.

And that's where the problem lies when people try to compare a mic to other mics, and especially when you hear people say things like "this Chinese mic sounds identical to a U87", or whatever. For that singer, that guitar, or in that key, that may be true. It just means that the peaks and dips in the two mics didn't get pushed so hard that you could hear the differences between the two mics. On something else, the differences can be night and day.

The other factor is that, unless you've been doing this stuff for a long time, you're ear isn't trained to hear some of the differences, and you'll think only in terms of louder and brighter, or more bottom. It's really easy to miss hearing the small peaks and dips, which only comes with longer listening sessions and some ear training. When you compare mics, if a mic sounds "brighter", or "more detailed", make sure you're not confusing high frequency peaks and/or treble boost for those qualities.

While it's not cut and dried, be suspicous of louder mics - it usually means that accuracy has been sacrificed, and try to figure out where that "extra loudness" is coming from. Remember, "bigger" means "louder", but it also means "less accurate". "Less accurate" is not in itself a bad thing, if it's more flattering, but just be aware that it is less "accurate".

There are always trade offs in choosing equipment; try to make those trade offs work for you over the long haul, and you'll be fine when choosing a mic for a particular task.

The "big thread" covers a lot more detail about those trade offs, but remebering these points (that we've just discussed) may just help you hear "better", faster.
 
As always, very insightful, Harvey.... it all depends on the application. Great points for anyone in the market to increase their microphone library... Like me!!:D

p.s. I listened to 'Not at Home on the Range'... very nice. Left a couple of questions for you on the TLM-103 thread, if you'd be so kind... Thank you!:D
 
Good post and informative. I know absolutely nothing about medium and large diaphram condenser mics other than how they are constructed. I have never used one and have only seen them behind glass in the high-end stores that I have been to.

What are your opinions on using high-end dynamic mics in a vocal application? Or others?

I've been recording on and off for the last 17 years and honestly, other than a month that I used a cheap-assed RS mic, I have been using the Sennheiser MD441U for everything. I mean everything.

I first saw this mic in a still photo being used in a studio where Tom Petty and Stevie Nicks were recording. I was fascinated with the asthetics of this mic and I had never seen a square mic before. I didn't know squat about it's characteristics or properties.

I drove down to the high-end place and showed a picture of this mic to the guy at the counter. "Oh yeah, we got that one, it's over here." Well after the sales pitch and a lesson on dynamic microphones I was sold. He said that's the last dynamic mic you will ever need. And I believed him.

Am I missing anything by limiting my recordings to this one mic? I've used it on stage as well and the sound guys love it. I have always been very happy with the results I have gotten with this mic. I used to have four at one point in time. Two strays and a serial numbered sequenced pair. It is very versitile as well with the bass roll-off and the attenuator.

Opinions? Advise?
 
Wow Harvey thanks!
I learned a couple of new things to think about.

Chris

P.S. Sennheiser, the 441 that bears your "namesake"
is one of the all-time great dynamic microphones.
 
Thanks for the tip. I have read many threads here before I started posting. Many long threads, but not all, tend to turn into a pissing match, or the thread turns in a different direction. It really doesn't matter what the subject is. But I guess that is the nature of a message board. It's not just here.

I guess I just need to get out and hear what I'm missing. Sound is very subjective and is different for everyone.

Maybe I should rephrase my question and ask, should I try experimenting with another type mic and see if I like it?

If condenser mics are the choice of most studios, why did I see them using this mic? Why would the engineer have chosen this mic over a condenser?

I'd really like to know if anyone could take a guess at an answer.

Thanks, Michael
 
Sennheiser said:
Thanks for the tip. I have read many threads here before I started posting. Many long threads, but not all, tend to turn into a pissing match, or the thread turns in a different direction. It really doesn't matter what the subject is. But I guess that is the nature of a message board. It's not just here.

I don't believe you'll find that the thread I reffered you to turns into either a pissing match or turns in a different direction. If I didn't think it might be directly helpful to you, I would never have even bothered to search out the link to it.

I guess I just need to get out and hear what I'm missing. Sound is very subjective and is different for everyone.

I don't believe it's that simple; if it were, it wouldn't explain why producers and engineers like Al Schmitt and George Massenburg are continually nominated for Grammys for about 4 decades now, doing everything from rock to country to jazz.


Maybe I should rephrase my question and ask, should I try experimenting with another type mic and see if I like it?

Experimenting is a great way to learn as long as you understand what your doing and how to interpret the results.

If condenser mics are the choice of most studios, why did I see them using this mic? Why would the engineer have chosen this mic over a condenser?

Michael Jackson used a Shure SM-7 dynamic mic to record the biggest selling album of all time, Thriller.


I'd really like to know if anyone could take a guess at an answer.

I really don't like to guess.

Thanks, Michael
You're quite welcome.
 
As always, so VERY helpful! What you said about a microphone sounding different in one KEY as opposed to another, really makes sense to me now. See, I have had some really nice results (mostly attributed to this bbs) with mic "A" on one particular source, but when using this same mic on another song, in a close, but different key, well, the results were not quite a stellar. It's obvious to me now, why that is.
Thanks Harvey.
Could you (or anyone else) explain this: It seems to me that the small dia. condensor mics I have used on my grand piano, seem to lose definition in the A2 - A3 octave. Why is that?
 
Grasshoppa has been enlightened!

What an outstanding source of information on microphones.

Harvey, I had never ventured that many pages back in the history to see that thread.

Now I understand. Your explanations and examples blew me away. I have an AEE degree and I was able to make sense of much of the material. Not that I needed it with the easy way you explain complex technical material, but it helped.

And now I know why the 441 is so damn good and how they got it that way.

I think that the Sennheiser MD441U was chosen for Nicks because of the timbre of her voice and her style of singing. I would have never been able to figure that out before. She used that mic for three albums and always used it live until 1997. That is just my opinion based on the information that was presented and being very familiar with her vocal style and her timbre.

I have noticed her voice has changed slightly since then and other mics have been used. Her voice has deepened and is slightly rougher than it was in her younger days.

Thank you for what I believe to be the equivilent of an entire semester of college. It is much appreciated.

Someone on that thread compiled all of your material in Word format and I bookmarked it for reference for the times I get stuck.

Whew...I'm still sitting here with my jaw practically down to the keyboard.
 
Michael Jones said:

Could you (or anyone else) explain this: It seems to me that the small dia. condensor mics I have used on my grand piano, seem to lose definition in the A2 - A3 octave. Why is that?

mic positioning?
 
littledog said:


mic positioning?
Well, I mean... it... but...if....

You might think that, but I have tried a multitude of mic positions, and while it may sound slightly less pronounced on some positions, it's still there,(that lack of detail in that range) or... ummm... not there.

I feel, and of course, I may be completely wrong, but the results I have had from numerous experiments with positioning, and various small diameter condensors, yeilds this lack of definition in the low - low mid range. With LD condensors, this problem is
non-existent.

I could of course keep using LD condensors on my piano, they work well, and sound very nice, I'm just trying to learn the technical aspects of whats happening.
 
If you are getting the results you want with other methods, than the question is somewhat moot.

But in general, small diaphragm condensers are more accurate across a wider frequency range than large diaphragm. Perhaps the large diaphragms are giving you a boost in the region which you are interpreting as the small diaphragms cutting. Or maybe you are just using some dogs for small diaphragm mics.

What specific mics you have tried? I can say that I have used Earthworks QTCs (about as small a diaphragm as you can get) on almost every piano recording I have done in the last few years in my studio, and get a stellar sound. (The piano helps a lot with that, unfortunately, the room does not!) But I have a buddy who uses a pair of M149's on his very similar piano, and he is rhapsodic about the result. Two VERY different mic choices... with excellent results for both.
 
littledog said:
If you are getting the results you want with other methods, than the question is somewhat moot.

But in general, small diaphragm condensers are more accurate across a wider frequency range than large diaphragm. Perhaps the large diaphragms are giving you a boost in the region which you are interpreting as the small diaphragms cutting. Or maybe you are just using some dogs for small diaphragm mics.

What specific mics you have tried?
Shure SM81's primarily. Not a mic I would consider a dog.

Well, I posted this before , and you were very helpful in your response; saying something to the affect that "...you might be hearing a low mid presence peak...from the large diaphrams"

Could very well be, but that still doesn't explain the loss of definition from the small diameter condensors.

In the linked thread, scroll down to my post that appears right after yours.
 
If the problem isn't the mics or mic placement, maybe it's time to start looking at the piano.

Has a tech looked at the hammer felts lately or checked the regulation and trapwork?

Just a thought.
 
Michael Jones said:

Shure SM81's primarily. Not a mic I would consider a dog.

Not necessarily a dog, but not my favorite mic for pianos either. Try a pair of omni small diaphragms if you can - especially in light of your specific problem. You won't get proximity effect from the strings nearest the mics like in a cardioid mic. That alone may "solve" your problem.
 
Sennheiser said:
If the problem isn't the mics or mic placement, maybe it's time to start looking at the piano.

Has a tech looked at the hammer felts lately or checked the regulation and trapwork?

Just a thought.
I don't think the problem is the piano.
It's a 7'-2" Boston Semi Concert Grand. I have it tuned and regulated 4-6 times a year. So it's kept in top notch shape.
 
It's really no big deal guys. Like I say, I get very nice results with a pair of LD condensors. I'm just curious why the drop off in definition on the SD Condensors. I recently threw a pair of MC012's at it too. Better, but not perfect. Maybe if I took the lid completely off, instead of just full open?
 
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