Low Cost PCB's Low Cost Components

Author Topic: EEVblog #602 - Introduction to Microphones  (Read 11111 times)

0 Members and 1 Guest are viewing this topic.

Offline EEVblog

  • Administrator
  • *****
  • Posts: 24564
  • Country: au
    • EEVblog
EEVblog #602 - Introduction to Microphones
« on: April 12, 2014, 02:39:12 PM »
In the first of a series of videos tutorials on microphones, Doug Ford, former head designer at Rode Microphones explains the basics of how microphones work, the different types - carbon, dynamic, ribbon, condensor/electret, and how the omnidirectional pattern works.
Also, the internal construction of a high end measurement microphone.

 

Offline DutchGert

  • Regular Contributor
  • *
  • Posts: 247
  • Country: nl
Re: EEVblog #602 - Introduction to Microphones
« Reply #1 on: April 12, 2014, 08:44:47 PM »
Nice one, this was a topic that I litterly knew nothing about until now :). Thx!
 

Offline woox2k

  • Contributor
  • Posts: 38
  • Country: ee
Re: EEVblog #602 - Introduction to Microphones
« Reply #2 on: April 12, 2014, 10:02:41 PM »
Yes, finally some audio stuff.  :clap: Looking forwards for follow-up videos to take this even further, this one was fairly detailed but got cut short in the end.
 

Offline lewis

  • Frequent Contributor
  • **
  • Posts: 685
  • Country: gb
Re: EEVblog #602 - Introduction to Microphones
« Reply #3 on: April 12, 2014, 10:07:09 PM »
Woo hoo! Doug's back!  :-+
I will not be pushed, filed, stamped, indexed, briefed, debriefed or numbered.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 24564
  • Country: au
    • EEVblog
Re: EEVblog #602 - Introduction to Microphones
« Reply #4 on: April 12, 2014, 10:14:22 PM »
Yes, finally some audio stuff.  :clap: Looking forwards for follow-up videos to take this even further, this one was fairly detailed but got cut short in the end.

Yeah, unfortunately there wasn't a huge amount of structure to the whole shoot, being very off-the-cuff and jumping over the place. Going to be hard to edit into sensible sections that flow.
But in the end it'll be essentially a big dump of info.
 

Offline Sionyn

  • Frequent Contributor
  • **
  • Posts: 848
  • Country: gb
Re: EEVblog #602 - Introduction to Microphones
« Reply #5 on: April 12, 2014, 11:26:48 PM »
loved this glad Douglas has shown his head again (more please) especially his beastly power supply
eecs guy
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 24564
  • Country: au
    • EEVblog
Re: EEVblog #602 - Introduction to Microphones
« Reply #6 on: April 12, 2014, 11:50:23 PM »
loved this glad Douglas has shown his head again (more please) especially his beastly power supply

I'll be visiting his new lab shortly to check out what he calls "The Death Star". No, not a power supply, something a lot more exotic...
 

Offline David Aurora

  • Regular Contributor
  • *
  • Posts: 153
  • Country: au
Re: EEVblog #602 - Introduction to Microphones
« Reply #7 on: April 13, 2014, 12:05:35 AM »
Definitely looking forward to more, great stuff.

I don't mean to bust your balls here Dave (seriously, I love your work), but as a recording engineer I gotta admit I got a laugh out of seeing you walk into mentioning/suspecting audiophoolery a few times there haha. I see it on the forum a bit, where if anyone seems to mention the possibility of higher fidelity than an op amp stage on a coin cell they're assumed to be snake oil buying, magic rock placing, $5000 power cord using weirdos. Was really nice to hear Doug talk as a respectable authority on the matter and point out that high quality audio really is a complex topic, and not necessarily all bullshit. I'm really interested to see where the future videos go, both of you are great at explaining things but you also seem quite different in the angle you're coming from so I think it's going to make for some killer videos.
 

Offline delmadord

  • Regular Contributor
  • *
  • Posts: 78
  • Country: sk
Re: EEVblog #602 - Introduction to Microphones
« Reply #8 on: April 13, 2014, 05:55:11 AM »
Yeah our almighty Dave looks like he is actually learnig instead of teachnig us..I LIKE IT  :-+
 

Offline hi-Z

  • Newbie
  • Posts: 1
Re: EEVblog #602 - Introduction to Microphones
« Reply #9 on: April 13, 2014, 07:39:47 AM »
Fascinating subject, loved it.

I'm surprised nobody mentioned anything about piezoelectric elements.  That's the good stuff.
 

Offline dentaku

  • Frequent Contributor
  • **
  • Posts: 825
  • Country: ca
Re: EEVblog #602 - Introduction to Microphones
« Reply #10 on: April 13, 2014, 08:17:44 AM »
It's great to see Dave learning about stuff from a field of technology he's not very familiar with.
Sometime it would be great to see a video about and electronic instrument of some sort, beyond Sagan's Yamaha keyboard. Modular (mostly analog) synths are very interesting and so are effects pedals which are very similar. Maybe you could do a teardown of one of Fran Blanches audio effects boxes if someone is willing to lend you one.

I'm more interested in synths and their VOCs, VCAs, VCFs, LFOs etc. than guitar pedals though.
 

Offline don.r

  • Frequent Contributor
  • **
  • Posts: 529
  • Country: ca
Re: EEVblog #602 - Introduction to Microphones
« Reply #11 on: April 13, 2014, 01:27:11 PM »
I wonder how tubes (valves) microphone?
Shippers: for the love of Pete and all that is holy, STOP USING UPS INTERNATIONAL!
 

Offline calexanian

  • Super Contributor
  • ***
  • Posts: 1718
  • Country: us
    • Alex-Tronix
Re: EEVblog #602 - Introduction to Microphones
« Reply #12 on: April 13, 2014, 01:49:31 PM »
I wonder how tubes (valves) microphone?

Are you referring to micro phonics in a tube? Well, Vibrations wiggling a grid rather than a diaphragm. Although a grid can be seen as a diaphragm with slots cut in it. There are two modes of transduction. One is direct action of altering plate current through physical vibration of the grid (The most common) and capacitive changes in the grid with the basic same effect. There have actually been purpose built microphone tubes for specific frequencies and measurements.
Charles Alexanian
Alex-Tronix Control Systems
 

Offline sdscotto

  • Contributor
  • Posts: 43
Re: EEVblog #602 - Introduction to Microphones
« Reply #13 on: April 13, 2014, 03:49:17 PM »
I got a real kick out of all the metric this and metric that followed by "this is a 1/2 inch reference mic"

Can't wait to learn more, in metric of course!
 

Offline 99tito99

  • Regular Contributor
  • *
  • Posts: 54
  • Country: us
Re: EEVblog #602 - Introduction to Microphones
« Reply #14 on: April 13, 2014, 04:09:50 PM »
Hey, I'm a Yank and I understand meters and feet!





Cheers,
Mark
********************
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 24564
  • Country: au
    • EEVblog
Re: EEVblog #602 - Introduction to Microphones
« Reply #15 on: April 13, 2014, 05:28:04 PM »
I don't mean to bust your balls here Dave (seriously, I love your work), but as a recording engineer I gotta admit I got a laugh out of seeing you walk into mentioning/suspecting audiophoolery a few times there haha. I see it on the forum a bit, where if anyone seems to mention the possibility of higher fidelity than an op amp stage on a coin cell they're assumed to be snake oil buying, magic rock placing, $5000 power cord using weirdos.

Because that's were the laughs are, it's called taking the piss.
No, I do not assume everyone who wants good audio performance is an audiophool. Any indication you have of that is incorrect and of your own making.

Quote
Was really nice to hear Doug talk as a respectable authority on the matter and point out that high quality audio really is a complex topic, and not necessarily all bullshit.

Doug thinks exactly the same way about audiophools as I do.
But because I've done a video poking fun at audiophools, and love to poke fun constantly, I get incorrectly pigeon holed as thinking that anyone who listens to music and asks a question is an audiophool.
« Last Edit: April 13, 2014, 05:32:14 PM by EEVblog »
 

Offline DrGeoff

  • Frequent Contributor
  • **
  • Posts: 641
  • Country: au
    • AXT Systems
Re: EEVblog #602 - Introduction to Microphones
« Reply #16 on: April 13, 2014, 06:12:36 PM »
Was Doug involved in the design of the original NT-1?
That's one of the quietest condensor mics ever made and still very handy for recording some vocalists.

BTW, some dynamic mics sound much better when terminated with a particular load impedance. For example, the SM57 is great into a 600 ohm load. A lot to do with the termination of the internal transformer to stop ringing.
Was it really supposed to do that?
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 24564
  • Country: au
    • EEVblog
Re: EEVblog #602 - Introduction to Microphones
« Reply #17 on: April 13, 2014, 06:15:30 PM »
Was Doug involved in the design of the original NT-1?

Yes, and he goes into the circuit design in a future video, and why it is so quiet.
 

Online G7PSK

  • Super Contributor
  • ***
  • Posts: 3463
  • Country: gb
  • It is hot until proved not.
Re: EEVblog #602 - Introduction to Microphones
« Reply #18 on: April 13, 2014, 06:40:15 PM »
Very interesting on the old carbon microphones, a balanced carbon rod microphone was one of the first electronic things I built (well more electro mechanical really) it was so sensitive that you could hear a fly walking with just a set of high impedance headphones.
 

Offline fcb

  • Super Contributor
  • ***
  • Posts: 1161
  • Country: gb
Re: EEVblog #602 - Introduction to Microphones
« Reply #19 on: April 13, 2014, 06:54:54 PM »
I wonder how tubes (valves) microphone?
Tube mikes - the tube/valve is just the local amplifier/buffer for the pick-up, in place of a FET.
 

Online SeanB

  • Super Contributor
  • ***
  • Posts: 14336
  • Country: za
Re: EEVblog #602 - Introduction to Microphones
« Reply #20 on: April 13, 2014, 07:26:18 PM »
Microphones are available is various qualities, depending on how much you are willing to pay. Up to a point there is a near linear rise in performance, but if it is gold plated on the outside, and just junk on the inside it is Audiophoolery.

Carbon microphones are still in use in intercom systems, as they are pretty insensitive to hum on the supply lines, and survive lightning strikes nearby. I did upgrade a couple though using a spare electret insert and a single PNP germanium transistor along with a bias resistor across BE junction to set operating current into the speaker in class A in an intercom. More sensitive and less noise, but only done as the carbon no longer responded to banging and I could not get a replacement quick, as they were out of stock, and only offered a complete indoor unit at a price. Biggest killer of the carbon microphones are cleaners with spray furniture polish, which builds up a silicone oil coating on the granules.

Edit because I suddenly forgot how to spell correctly.
« Last Edit: April 13, 2014, 07:42:34 PM by SeanB »
 

Offline David Aurora

  • Regular Contributor
  • *
  • Posts: 153
  • Country: au
Re: EEVblog #602 - Introduction to Microphones
« Reply #21 on: April 13, 2014, 07:45:27 PM »
I don't mean to bust your balls here Dave (seriously, I love your work), but as a recording engineer I gotta admit I got a laugh out of seeing you walk into mentioning/suspecting audiophoolery a few times there haha. I see it on the forum a bit, where if anyone seems to mention the possibility of higher fidelity than an op amp stage on a coin cell they're assumed to be snake oil buying, magic rock placing, $5000 power cord using weirdos.

Because that's were the laughs are, it's called taking the piss.
No, I do not assume everyone who wants good audio performance is an audiophool. Any indication you have of that is incorrect and of your own making.

Quote
Was really nice to hear Doug talk as a respectable authority on the matter and point out that high quality audio really is a complex topic, and not necessarily all bullshit.

Doug thinks exactly the same way about audiophools as I do.
But because I've done a video poking fun at audiophools, and love to poke fun constantly, I get incorrectly pigeon holed as thinking that anyone who listens to music and asks a question is an audiophool.


Haha nah man, I'm not lumping you in the extremist category, that forum reference was in regard to a bunch of threads I've seen (and particularly one dude whose name evades me who always manages to steer high quality audio discussion into how much he hates tubes and people who use them).

Don't worry, us studio geeks think exactly the same about the audiophool world   ;D
 

Offline don.r

  • Frequent Contributor
  • **
  • Posts: 529
  • Country: ca
Re: EEVblog #602 - Introduction to Microphones
« Reply #22 on: April 14, 2014, 01:12:29 AM »
I wonder how tubes (valves) microphone?
Tube mikes - the tube/valve is just the local amplifier/buffer for the pick-up, in place of a FET.

LOL! Not what I meant. A tube can start to "microphone", i.e. acts like a microphone itself (act like a pickup) and I was curious about the physics involved there.

I wonder how tubes (valves) microphone?

Are you referring to micro phonics in a tube? Well, Vibrations wiggling a grid rather than a diaphragm. Although a grid can be seen as a diaphragm with slots cut in it. There are two modes of transduction. One is direct action of altering plate current through physical vibration of the grid (The most common) and capacitive changes in the grid with the basic same effect. There have actually been purpose built microphone tubes for specific frequencies and measurements.

Thanks. I thought it was the grid acting like a diaphragm.
« Last Edit: April 14, 2014, 01:14:51 AM by don.r »
Shippers: for the love of Pete and all that is holy, STOP USING UPS INTERNATIONAL!
 

Offline 99tito99

  • Regular Contributor
  • *
  • Posts: 54
  • Country: us
Re: EEVblog #602 - Introduction to Microphones
« Reply #23 on: April 14, 2014, 02:18:20 AM »
Hi Dave:  Thanks to Doug and you for the video (and I gather a few more to come).  I do not consider myself an audiophile nor an audiophool, but I do like good music reproduced well and I like learning about thing I don't know much about.  Cheers, Mark * * *


PS
When I was a kid (12 - 14?) I got hold of a carbon microphone and of course I did not "Plug It In, I Took It Apart."  It was a big sucker on a stand, probably from a Ham transmitter.  As I recall it contained about a teaspoon of carbon granules that were glossy black and about the size of table salt (~1/3 - 1/2 mm).
 

Offline [email protected]

  • Super Contributor
  • ***
  • Posts: 3938
  • Country: 00
Re: EEVblog #602 - Introduction to Microphones
« Reply #24 on: April 14, 2014, 02:41:31 AM »
When I was a kid (12 - 14?) I got hold of a carbon microphone

When I was a boy(TM) we built our own from the carbon rods of old batteries. A bit difficult today with almost only alkaline or rechargeable batteries around.
I delete PMs unread. If you have something to say, say it in public.
For all else: Profile->[Modify Profile]Buddies/Ignore List->Edit Ignore List
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf