R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1] 2  All   Go Down

Author Topic: Not to be outdone, I now have a sticky at my forum  (Read 19569 times)

hargerst

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1458
Not to be outdone, I now have a sticky at my forum
« on: May 17, 2004, 10:18:34 am »

I just noticed that unlike all of the other forums, I don't have a sticky or an announcement at the start of my forum. Not to be outdone, here's mine:

About 2 years ago, I started posting to a thread at the homerecording forum about how mics work and what to use when, and it grew into this monstrous thread, often called simply, "The big thread". Once you get rid of all the wows and thanks, it still runs about 78 pages long and takes about 1 meg of space. The actual full length thread at homerecording.com is here:

     http://homerecording.com/bbs//showthread.php?s=&threadid =27030

A PDF of the thread (minus all the "Wow, great thread!!" stuff) is at:

HarveyThread.pdf

Worst case, it'll at least keep you busy for an evening.  Best case, it might clear up some questions you've had about what mic to use when, and why.
Logged
Harvey "Is that the right note?" Gerst
Indian Trail Recording Studio

MASSIVE Mastering

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 604
Re: Not to be outdone, I now have a sticky at my forum
« Reply #1 on: May 17, 2004, 04:24:23 pm »

Harvey, I'm honored and humbled to be the first to congratulate you on your new sticky.    Very Happy  

Here's to several more.  (clink! - gulp, gulp)
Logged
John Scrip
Massive Mastering - Chicago (Schaumburg / Hoffman Est.), IL - USA

Antonw

  • Newbie
  • *
  • Offline Offline
  • Posts: 10
Re: Not to be outdone, I now have a sticky at my forum
« Reply #2 on: May 20, 2004, 05:53:18 am »

As i was the first on recpit to reply to the sticky on the big mike thread, i thought to let somebody else have that honor, but still feel the need to be somewhere in this mighty thread.

Anton
Logged
Anton Woldhek
Utrecht School of Music Technology - Sound Design student
Latest Freesound: Coot in the City. http://freesound.iua.upf.edu/samplesViewSingle.php?id=7916

Chris Fitzgerald

  • Newbie
  • *
  • Offline Offline
  • Posts: 8
Re: Not to be outdone, I now have a sticky at my forum
« Reply #3 on: May 22, 2004, 09:02:09 am »

As the person who started that thread and have been trying to learn from it ever since, I just want to thank Harvey once again and say that I'm very pleased to have found this forum. The difference in my recordings after reading the info in that thread is tremendous.
Logged
Wherever you go, there you are



www.chrisfitzgeraldmusic.com

Fulcrum

  • Newbie
  • *
  • Offline Offline
  • Posts: 35
Re: Not to be outdone, I now have a sticky at my forum
« Reply #4 on: June 28, 2004, 09:13:21 pm »

Yes, congrats on your sticky. Might as well.

Here's a thought for maybe another sticky. Back at the old Rec Pit you had one for all the Jedi Mind tricks engineers play on the public in the course of making a recording, i.e., the celebrated cowbell trick, recording with woofers as microphones, etc. It might even be a candidate for the Whatever Works forum, though it initially appeared in yours. Any thoughts about reviving that for those who came in late (present company excluded-- I learned a bunch from that thread)?
Logged
http://home.no.net/nightguy/images/TEAM-GALACTIC.gif

Lee Tyler

  • Full Member
  • ***
  • Offline Offline
  • Posts: 148
Re: Not to be outdone, I now have a sticky at my forum
« Reply #5 on: October 28, 2004, 11:17:14 pm »

Twas' a great thread and should make a FINE sticky. Some sticky things in life are the best.  Shocked  No further elucidation on that comment! WTG Harvey!!!   ---Lee
Logged
Nurse to doctor: "Doctor, there is a man in the waiting room who thinks he's invisible".

Doctor to nurse: "Nurse, tell him I can't see him"

micguy

  • Newbie
  • *
  • Offline Offline
  • Posts: 37
Re: Not to be outdone, I now have a sticky at my forum
« Reply #6 on: December 29, 2004, 05:23:28 pm »

Quoted from quite a while ago in a forum far far away...

"Dynamic Mics

------------------------------------------------------------ --------------------

By far, the most popular mic on the market today is the dynamic cardioid mic, so that's as good a place as any to start. "How does it work, what exactly is a cardioid, and how and where would you use it" will be our focus today. Let's look inside one and see what we find:

Well, it has a cone (like a small speaker), a voice coil (like a small speaker), and it sits in a magnetic gap (like a small speaker), so isn't it just a small speaker in reverse? Yes, and no. The operating principle is the same, but the execution is very different. When's the last time you saw a 3/4" speaker that went down to 30 or 40 Hz? Here's how it's done:

The system resonance is chosen for a mid band frequency. By itself, the capsule's response looks something like this:

......./\
....../..\
...../....\
..../......\
.../........\
../..........\
./............\ - just one big resonant peak, with the response falling off rapidly on each side of the peak. Now you can tame that peak by putting in a resonant chamber that's tuned to that peak, which will give you two smaller peaks on either side, like this:

..../\..../\
.../..\../..\
../....\/....\ And if you add two more resonant chambers, tuned for each or those peaks, you wind up looking more like this:

./\../\../\../\
/..\/..\/..\/..\ And if you make the chambers a little more broad band, the response starts to really flatten out:
._..._.._..._
/..\/..\/..\/..\ but remember, it's still a lot like a bunch of tuned coca cola bottles inside there.

Now ya gotta do all of this stuff JUST to get the response usable - never mind about the mic pattern yet!

A lot more to come!! Everybody still with me at this point? Any questions?

------------------------------------------------------------ --------------------
Last edited by Harvey Gerst : 05-04-2001 at 14:46. "




OK, I quoted this because I've seen it one too many times, and it just plain bugs me at this point.

My objection to this "common wisdom" is that, in plain truth, it's plain wrong.

Dynamic mics are like little moving coil loudspeakers, yes, but... like moving coil loudspeakers, they have one primary resonance - not in the middle of their operating range, but at the bottom (typically 50 to 150Hz for a modern dynamic microphone). Above that bottom resonance, up to 5 to 10 KHz, they are remarkable linear devices that are NOT relying on resonances to work. Yes, at the very highest frequencies, there are peaks and dips on the curve, some due to housing diffraction (which is also present in large diameter condenser mics) and diaphragm breakup modes (which make more dips than peaks.

I know this is counter to common wisdom, but it's true - dynamic mics, though not perfect, do not rely on multiple resonances stacked on each other carefully (like a house of cards) to work. They're actually a little simpler (and hence more robust) than "common wisdom" implies.


Logged

hargerst

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1458
Re: Not to be outdone, I now have a sticky at my forum
« Reply #7 on: December 30, 2004, 12:24:20 pm »

Well, yes and no, kinda, not exactly. Above the resonant peak (and up to where the diameter of the diaphragm equals 1/2 wavelength), the mic can be reasonably smooth. But the games that manufacturers play to get the resonant peak down to an acceptable level, and trying to extend the high end and low end is where the problems start.

Unfortunately, my ASCII drawing didn't allow for much detail to show the finer points, but the concept is still pretty valid for the extremes of the response curve.  And the point that I was making is still pretty valid: A lot of it is done with smoke and mirrors.

I knew when I was writing this, that some of the analogies I made weren't perfectly accurate, but overall, the thread holds up pretty well as an introduction to microphones and why things aren't always as they seem to be. But you're right; I did paint a somewhat bleaker picture than neccessary to get some attention.
Logged
Harvey "Is that the right note?" Gerst
Indian Trail Recording Studio

micguy

  • Newbie
  • *
  • Offline Offline
  • Posts: 37
Re: Not to be outdone, I now have a sticky at my forum
« Reply #8 on: December 30, 2004, 03:21:52 pm »

The resonant peak is indeed damped by things around it, but to a knowledgeable manufacturer (yes, I work for one), there's no real voodoo involved - it's mostly acoustical resistances that can be measured, modelled, etc. Extending the low frequency end isn't really ever done beyond the engineering of the diaphragm's mass and compliance - the low frequency limit is set by the main resonant frequency (the pistonic one of the coil and diaphragm mass on the spring of the diaphragm surround), and below that, it's a 12 dB per octave dropoff. At the high frequency end, managing diffraction is a large part of the job, and doing some extension with a resonator is a well established part of the art.
So there's a second intentional resonance (beyond the low frequency one) in a typical design - for a net of one at each end of the pass band. In most designs, any other resonances are things that are engineered out of the design, not intentionally put in, and for a reputable manufacturer, that means you won't see (or hear) them much, if at all.

Where some of the "chambers" actually come in is more in the area of polar pattern management - making the mic act as a cardioid over a wide range of frequencies. A typical cardioid mic will have fron and rear entries that, left to their own devices, will tend to want to make the mic a bi-directional at some frequencies. A chamber behind the diaphragm is often used to bring in some "omni" component, and steer things towards a consistent cardioid pattern.
Logged

hargerst

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1458
Re: Not to be outdone, I now have a sticky at my forum
« Reply #9 on: December 30, 2004, 04:58:51 pm »

And that explanation would have left most of the readers at homerecording in the dust.  Yeah, I made too big a deal of the major peak, but it was easier to draw in ASCII, and the concept of other little stuff in there (chambers, slots, and resonators) I did try to cover, probably a little too simplistically in my description.

There were some other areas where I screwed up even worse, but I was pretty ill during a lot of the writing.  Not much of an excuse, but it works for me.  Most of the questions there were along the lines of "Which is better, a cardioid or a condenser?".

Is the entire thread useful (warts and all)?  I think so - but only time will tell.
Logged
Harvey "Is that the right note?" Gerst
Indian Trail Recording Studio

micguy

  • Newbie
  • *
  • Offline Offline
  • Posts: 37
Re: Not to be outdone, I now have a sticky at my forum
« Reply #10 on: December 30, 2004, 09:38:35 pm »

Harvey,

I wasn't trying to undermine the usefulness of your thread - just one sticking point that got to me. You are in remarkably good company, though - the guys at Neumann (who know a heck of a lot about condenser mics, are really smart, and nice guys to boot) even share some misconceptions about the workings of dynamics (as witnessed in the referenced material). So you don't have to feel too bad Wink

Now, if you want to talk major peaks, we could move on to condensers, but for now, let's just leave it lie. OK?

Have a great New Year!
Logged

Empty Planet

  • Full Member
  • ***
  • Offline Offline
  • Posts: 158
Re: Not to be outdone, I now have a sticky at my forum
« Reply #11 on: August 23, 2005, 09:40:49 am »

Harvey,

I now have the pdf on my desktop.  Truly helpful.  I can only thank my lucky stars you feel compelled to "give back."

I'm back in school.

Thanks very much,
Seth

Cool

Logged

Former Oceanway drone

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 405
Re: Not to be outdone, I now have a sticky at my forum
« Reply #12 on: September 09, 2005, 04:36:12 am »

I want to congratulate you on your sticky and also warn you that stickies can be addictive and should only be used in the presence of adults.

Cheers,

Alan Tomlinson
Logged

tmoney

  • Newbie
  • *
  • Offline Offline
  • Posts: 5
Re: Not to be outdone, I now have a sticky at my forum
« Reply #13 on: January 09, 2006, 02:21:39 pm »

Harvey, just read finished up with the pdf, and I just wanted to say thanks so much. Made me a little sad when you said you were disappointed about how few people were reading it. But anyway, just from reading this series, I feel like I've had someone actually helping me understand sound and miking. That's a difficult world to enter, with all the studios around not even willing to take a free intern. I think one of the greatest things a man can do is not hold his knowledge as if it were his secret, cherished prize which only he is entitled to, but instead spread it so that it can be used for everyone's purposes. So thanks, man.  Very Happy

<3
Logged

mudflaps

  • Newbie
  • *
  • Offline Offline
  • Posts: 15
Re: Not to be outdone, I now have a sticky at my forum
« Reply #14 on: January 13, 2007, 12:02:51 am »

You the same Harvey that played in  band called Sweetwater at a pop festival back in the 60's ? And do you know a guy name Richard Hankey from McKinney TX? Just wondering if you use to record in a trailer house in Princeton TX? If not sorry I might of got you confused with a different Harvey from TX.
Logged
Pages: [1] 2  All   Go Up