EEVblog
ฝัง
- เผยแพร่เมื่อ 26 ส.ค. 2024
- 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.
www.dfad.com.au
Discuss on the Forum: www.eevblog.com...
EEVblog Main Web Site:
www.eevblog.com
EEVblog Amazon Store:
astore.amazon.c...
Donations:
www.eevblog.com...
Projects:
www.eevblog.com...
Electronics Info Wiki:
www.eevblog.com...
![[TH] 2024 PMSL SEA W2D5 | Fall | พลาดวันนี้ จะต้องเสียใจ](http://i.ytimg.com/vi/A5-Cuo12p6A/mqdefault.jpg)
I love any video with Doug in it, he just makes complex explanations so easy to understand, along with a sense of humour :)
I love Doug. He's always so informative and easy to understand.
One of the legendary episodes of EEVblog.
Always a pleasure to see Doug on the channel.
I absolutely love these types of videos that teach me how things work and about the design.
Hey you old convict, we're using metric over here in the old country except for cricket and horse racing. Loved the video, please do more Dave.
Cool stuff, when i was a technican in a audio recording studio a came across lots of miks. The ones that impressed me the most where the sennheiser MKH types. As they used RF modulation, like the theremin, to "recreate" the audio.
The "inventor" of the condenser mike was the "Neumann" company as they´ve done the first good working condenser mike ("The Bottle"), while the ribbon technique was first introduced by UK and US based companies (Royer, BBC and RCA)
i love the way you people enjoy sharing information
Carbon granule microphones are still produced and used in the last bastion of archaic audio technology: Harmonica Amplification
The abysmal frequency response and overall "lo-fi" sound is sometimes desirable when close mic'ing a source that could otherwise sound overly bright and harsh, like a harmonica. Same thing goes for diaphragm coupled "crystal" piezo microphones.
Harmonica or accordion?
@@karlohorcicka7388 I don't know much about accordion amplification. But an accordion is a giant harmonica with bellows, so maybe 🤷🏻
I like it when there's a guest in the lab, Good talk.
After working Doug at Jands and post era discussions, we all have afirmed the opinion that doug names his electrons and has successfully farmed them.
Yay Douglas is back
the major reason recording engineers and musos like ribbon mics is the polar pattern. they usually capture the sound of drums, guitars and what have you much better, or at least capture the preferred sound by most ears. condensers are great otherwise if the acoustics of the environment sound ok. alternatively if you want to imprint very noticeable characteristics on the recording, differentiate it sonically from other things or capture a dry sound and not so much background, dynamic mics are preferred.
Excellent documentary on microphones Dave & Mate who doing all work,thank's.
At 2:06 the gentleman refers to an Italian engineer who developed the telephone before Alexander Graham Bell. His name was Alessandro Meucci.
Very informative video--looking forward to the next ones.
The High energy multimeter destruction video kicked ass... Nice to have Doug back on the stage :-)
Thanks guys.That was amazing and helpful. I'm a 59 yr old Bass player and I've bought some equipment to record some original music as well as some of my old band mates music because I want to leave some documents behind when I buy the farm and take a dirt nap lmao.Seriously,I'm in bad health and wake up in the hospital once or twice a year
with tubes coming outta every orifice in my body,not cancer or anything,but I'm trying to learn how mics work and you guys tell it like it is and I'm gonna watch every
f#$%ing video in this series.Ty
*Despite what I already know, your Fundamental Fridays teach me much more.
A suggestion for a future FF episode: various oscillator circuits and how they work.*
As a hobbyist audio engineer, i find this very interesting! thank you!
Love this guy!
My brother is a former broadcaster and still a musician. He will love this video.
Nice - wasn't expecting this, this morning & just in time for coffee - nice job guys, You're a ledgebag for setting this up Dave, good to see some more audio stuff!
I do live event audio engineering. Found this set of videos very helpful. There is a reason the SM58 is a staple of live sound vocal microphones. Well done.
Can't wait for the next part!
Please invite a guest like this for fundamentals Friday at least once in two months, IT WAS AWESOME.
TH-cam have changed the comment system again.....(end of 08 2017).
Watching this series again, this is pure gold. If only we had more.....
Some people often ask why microphones don't simply mimic human hearing by measuring frequencies separately. In the human ear, there's a couple thousand neuron receptor cells that each respond to a different frequency. If it works for us, why dick around with measuring wobbly membranes?
It's interesting to consider that mammalian ears (including human ears) measure frequency and not time. This might seem like a pretty silly thing to do, because it takes a lot of effort to construct (biological) band-pass filters that are going to be accurate enough for musical hearing (cochlear implant designers had to learn this the hard way). Though thinking about the limitations of biology, it makes sense why hearing is based on frequency and not time. If you measure frequency separately, you can equalize by simple changing the gain of each frequency channel (biological gain), instead of having to do weird FFT or AC coupling mechanisms, which might as well be impossible in biology. This biological equalization happens all day long. If you endure a specific tone for some time, you'll be desensitized to it.
If you want to construct an electric variant of the ear.. you'd need some way to construct tens of thousands of little band-pass filters that are accurate to single hertz. Anyone knows if this is currently possible at all?
So, in a way, biological hearing is better as frequency-based, while electronic sound capture is best as time-based (currently)
Cant wait for part 2!
These are incredible videos Dave, thanks for posting this ! Now I wanna tear apart all of my microphones
Thanks Dave for this very interesting lesson I look forward to more with Mr. Ford. As always your efforts are both educational AND entertaining.!
Great video. There is a microphone that does sense sound that doesn't use 'Wobbly Diaphragm' it uses two heated wire filaments and the oscillations in the air causes the wires to cool and the resistance changes. I think the company is Microflown that make them in case anyone is interested.
+Matthew Dabin awsome. thats really cool. heh, get it. ......i have no life.
Thank you for this! looking forward to the rest of the series!
Can't wait for more microphones videos!
The eevblog never fails to impress.
Excellent.
Definitely looking forward to the rest of these.
Great Video Dave! FYI in America we use feet in the construction field and meters in the lab. Mainly because old people are too stubborn to change.
I like this discussion like format... more guests like this! :)
Didn't know Rode was an Australian company.
The last time I saw Rode microphones was when I was in a vocational skills competition, and they had a video news production competition in which the boom microphones used were twice as expensive as the cameras themselve
It was my father who created the radio quality headset for telephones and gave it to AT&T/Bell
also have a look at the Heil Sound web site for a great explanation of microphones and also how we hear. The fletcher munson curve explaines how we actually hear through our ears.
brilliant. I look forward to more audio-related vids!
lol I didn't realize you guys were sitting til I saw this ep.
Those of us doing the math for calculating speed of sound are capable of converting imperial to metric in our heads (or thinking in metric to start with, but that is still rare, even in younger users). There is really no need for using feet for anyone using these maths.
Most often, it is an off-the-cuff measurement by sight for calculating things like PA system delay, or using fixed-length things like floor tiles for calculating the expected resonant frequencies of a room.
Thanks for showing. A microphone is definitely a physics project, let alone the electronic amplification efforts!
Excellent. Adore this channel!
One thing I've learned is to NEVER remove that paper/cloth tape that covers the vents on a dynamic microphone element, it sounds crappy if you do that.
The noise filter!
Fantastic, I have wonted information on microphones for a long time.
Why do we design audio systems based around the eardrum.
Has there ever been a microphone that acts like the cochlear with its multiple simultaneous frequency receptors?
Yes, they do, but sometimes your not measuring sound waves for the "ear"... You can measure sound waves to determine if a bearing is going bad in a machine. (for instance) not necessarily things the ear can pick up. (tl;dr: Measuring sound is not always human centric)
Thank you Doug for all the info.. you are the man!
Really excellent and fun to absorb.
Really enjoyed that Dave! keep 'em coming!
This guy is marvelous I love good analog design but my favorite was his referring to a tube as a Fet with a pilot light ! Beauty his last design would make a great phono preamp plenty of gain for required RIAA equalization and still very quite
Great video Dave, keep them coming! Hope you have now learned a bit more about sound, acoustics and audio... and how it hooks together with electronics... pretty much same with preamplifies, amplifiers, speakers, etc... all have their distinctive sound depending on how they are mechanically and electrically constructed, topology, quality and material of parts, etc...
Can you do a video on audio basics? Sine wave, oscillascope, Nyquist, resistance, Ohms, all that stuff. I've seen a video on this kind of stuff but the one I saw assumed I was taking a class in audio engineering already or something, it lectured in Greek to me.
awesome! Love the channel, any more content on audio/audio electronics/processors is more than welcome!
17:35 : Why small capsule condenser mics have a stronger low-end freq response than a large capsule.
Please show more things like this!
Microphones can be pretty surprising actually, for example you can use a piezo as a microphone for guitars, as an extremely precise touch sensor or as a damn loud tweeter. A very smart use of speakers is when intercoms use the speaker as both a microphone and a speaker. (Electra intercoms in Romania are made like that, in a very old model you can actually short circuit the ground with the speaker to hear the speaker at the entrance without anyone calling)
Had no idea Rode was an Australian company! Love this featured video
Very interesting and unique Dave,
Thanks!
If it works as a mic it will generally work as a speaker....Take a look at the Apogee loudspeakers, they are a sight to behold. I was running a service dept. in a high end hi fi shop in the 90s when these arrived and a pair were in for service. A curious colleague was looking at one and had an allen key in his hand...As I watched I was too slow to react as he moved the allen key toward the ribbon...The massive magnetic field caught hold and whipped the key from his hand..and PLONK..stuck itself to the ribbon!
Microphone technology and outstanding quality recording technique and microgroove arrived together in the early 50s allowing us to hear close miked crooners on all their glory for the first time...Listen to Buddy Holly...Never been surpassed for quality, and it is obvious.
really interesting video, thanks a lot, especially to doug for sharing his knowledge :)
Brilliant episode, very informative!
A lot of USA military radios and communication equipment still use carbon microphones. Very robust.
I'm not really "into" microphone tech, but this video was surprisingly interesting. Nice one!
27:34 should have been the cover picture. I had never converted speed of sound to ft/s always have used m/s even though I am a Yank, but it is interesting to know that sound travels the distance of almost 4 football fields per second.
well that was pleasantly different, thanks guys - great talk :)
It's a very interesting 'lecture', thanks!
Many thanks for these!
Slams imperial and then pulls out favourite half inch mic :)
Hi Dave, can you guys talk a little bit about how bone conduction headphones work, limitations, etc? Things like Google Glasses uses them and I'm sure more future devices like that will use these.
A somewhat recent issue of QST had a ribbon microphone construction project.
Good video.
It cracks me up, how Dave periodically just smiles into the camera for apparently no reason.
18:25
Matt Heilman
Checking to make sure the recording is still ok. The joy of being a one-man-band and not have a camera person.
EEVblog You do quite a good job. I just added a Monitor to my Electronics Bench, so I can see my USB camera's output.
Doug's a cool guy. I'd sure like to hear him explain how a single tube shotgun mic works!
Premium, industrial grade, AAA rated content right there. Wow. Loved it
Keep up the good work! Thanks!
To me, you demonstrated the number one reason (most other) Americans find it difficult to deal with metric. They're obsessed with "what is that in inches?" It's as if their brains cease to function if you don't tell them what the measurement is in imperial. What you did is what they need to get off their collective duffs and do for themselves, and say "that" is 17mm.
The first time I seriously had to use metric was my first semester of physics in college. Ever since then, metric has been easy. I used to come home every day from classes or work, and before turning the thermostat up (winter) or down (summer), I would estimate what the (C) temp was, then go over to a (digital) thermometer to see how good my estimate was. All it took was about 2 months' practice to be within a degree. That's all anyone who doesn't know metric needs to do, is to practice, but they refuse to do it.
Units are really meaningless at the end of the day. As someone who grew up in the US, I am very comfortable knowing what an inch looks like. If a certain part is measured in mm, in my head I rapidly convert it to inches (25.4 mm = 1 inch). Even though I know intuitively that 50 mm is about 2 inches, and I know that its about the length from the tip of my index finger up two knuckles, my brain stores it as being about 2 inches. I would imagine native english speakers who are fluent in spanish still think in english. Its the same way that when I see a resistor I imagine a spring, a capacitor a damper, and a voltage as a pressure differential or a force (since I learned ME topics before EE topics).
People get so grumpy about which unit system to use, but really all it takes to convert a unit is one multiplication. I would assume that us Americans are generally better at using metric than the rest of the world is at using imperial on average.
...and if I simply just used a system (such as SI), no conversion or multiplication would be necesssary, which is my point.
As for thinking in English, not really. Near the end of my third year of high school Spanish, I started thinking of sentences in Spanish terms, not what is it in English then translate. I didn't and don't do that all the time, but there comes a point where concept goes directly to the target language with no intermediary of the first learned language. Actually, that's exactly the same thing in measurement, where one starts thinking in a given distance in terms of meters, or a volume in milliliters.
_I would assume that us Americans are generally better at using metric than the rest of the world is at using imperial on average._
That's because very close to the rest of the world is using SI, and imperial is "the odd man out." We should have finished what we started in the nineteen eighties.
Great video! I'd like to hear a little more about how the condenser mic is measuring capacitance. Why does it need +48v at the mic, etc.
If you charge up the condenser with some relatively high voltage (maybe somewhere between ~20V and >100V), then, when the capacitance changes (because sound waves impinge on the diaphragm), you can sense a change in voltage relative to the sound wave. That very tiny (and very high impedance) signal is amplified by a transistor (or firebottle) into something that can be sent through the wire. Technically, it is not "amplification" so much as "impedance conversion" or buffering.
The capsule must be charged with a voltage in order to sense the capacitance change (the diaphragm movement). Originally, this was done with a ~high voltage source, but then they discovered how to make permanently-charged capacitor capsules with Electret technology.
The 48V standard was stumbled upon when Neumann made some new transistorized mics for Norwegian Broadcasting Corp in the mid 1960s The voltage (whether 48V or some lower voltage) is required to power that transistor (or tube) that does the impedance buffering mentioned in the first paragraph.
Thanks for a very thorough explanation! You lost me with the impedance conversion - not amplification though. I have to read up on signal impedance. Funny to hear about the norwegian broadcast, as I am a norwegian :)
In effect, the impedance converter circuit amplifies the CURRENT, not the VOLTAGE. In a roughly similar way, a small power amplifier for a speaker may not put out much more than line-level voltage, but it amplifies the CURRENT to drive the very low impedance (4-8 ohm) of the speaker.
Freddie Mercury always used the Shure SM58 in concerts
Could you at some point do a "Cheap lab power supply" shootout like you did with the multimeters? I need buying advice :]
*****
Yea, I was designing my own and was using that as a reference, then decided it is probably not worth the effort and I'd rather build other stuff. Also, I would really want more than 1 A as I am toying around with stepper motors and such.
I have actually found a decent looking (for the price) lab power supply, the KA3005P, is it worth the ~100€ ?
*****
Oh wow, the first one is tempting, but sadly a bit too expensive (for a poor student like me at least) for a single supply. The second one seems incredible for the price though, I will definitely consider it. Thanks!
ungratefulmetalpansy
Well, in Germany at least, the average entry level salary for Bachelor absolvents is around 40k € per year, which seems decent enough, right?
ungratefulmetalpansy
well, i am working a student job for 600 € a month at the moment, I could support myself in a sufficiently small flat for that amount. As a reference, the quoted 40k € a year are around what a "highschool" teacher earns after working for a few years.
ungratefulmetalpansy I know people who've been EE's their entire life. Blanket statements are dangerous
Thanks you. This is great.
Very Good Video. I've been watching your videos for quite a while now Dave ! And im an Actual Musician. I found this Video very useful as its seen from a Designers perspective (on top of that from a very well respected company in the music industry) and its thoroughly explained :) Keep up the good work ! greetings Chris
Dave looks so excited lol
Thank you
You missed out the fastest-growing type of microphone in use today in portable electronic devices and likely in future wearable electronics, MEMS microphones. see - www.eetimes.com/document.asp?doc_id=1321756 and - www.digitimes.com/news/a20140410VL200.html
Are there any consequences from using an unbalanced connection for that reference mic? Is there anything special I am missing in comparison to a less expensive, but still phenomenal mic like a Earthworks QTC40?
Lefty!! I've always wondered if there are more leftys that are into electronics than other fields.
AWESOME! want MOAR!
Thank you for another educating video
Haha, audiofools! I'm going to start using that.
It's correctly spelled Audiophool. Monster will sell you a set of letters with hand carved wooden ends for £18000
I've heard of "fool" but not "phool", so I'd go with "fool".
Yay, audio engineering!
yo talking about soildering,where did you buy yours, the yellow one? is it good to buy it on ebay?
Does the uniformity of the response matter with sufficiently good DSP? Also, the size of the diaphragm and wavelength relatino sounds a lot like near field/far field in RF or photonics.
Oooooooooooooooooo Rode, Dug worked at rode? I love Rode mics. My fave though is the NT1-A. I'd love a stereo pair of those. Though it looks like they don't do that no more.
What's up with the vignetting at ~25 minutes? Zoomed out on the macro lens?
BRAVO!
Hi Dave! Love your channel mate! I learn so much from them and I enjoy the way you explain things. I can’t seem to find all the videos from the microphone series though :-/ is there a complete playlist somewhere online? Thanks in advance!
help me please... how do i connect a dynamic microphone to lapel microphones uhf transmitters? Can I connect directly, like a condenser lavalier microphone?
Ubber interested, Keep it up and thanks in advance