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)
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.
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.*
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.
10 років тому
The High energy multimeter destruction video kicked ass... Nice to have Doug back on the stage :-)
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.
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.
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!
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)
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
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.
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...
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.
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)
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)
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.
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.
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
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.
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.
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.
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.
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!
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
***** 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.
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.
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.
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?
Certainly. And you can take a quick trip to the market in your Lamborghini, also. But lab mics are much more expensive than "ordinary" microphones because of the calibration, so typically people don't use them for "ordinary" applications. Chances are, with all the other variations, you wouldn't hear the difference, anyway.
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.
Thanks to Doug for sharing his knowledge, great to see him again. I would like to see more videos on sound reproduction please. Having been interested in audio for years both as listener and as part of my degree, i find the term audiophool kind of distasteful and un-informing to be honest. What is really needed is a, what is good engineering and what is mutton dressed as lamb or bad engineering, discussion. Clarifying what products sex up , confuse the issue, or plain lie and those that really do the job they purport to do. Thanks again Dave for the videos.
It sensibly acknowledges Beats and other unparticular musical components that make up a highly variable and substantial hunk of markets, which are otherwise unexplained (or tells to interdiction, bellwethers, RFQ gaming, illicit trades...) Your suggestion of categorical brand/ad-agency/inventor/OEM/trope/patent-by-patent/licensing-agency-by-licensing-agency sorting is surely more distasteful (though not a big problem for Hadoop users,) if I take it like that! Perhaps you're suited well by the RED (camera/cue/sound capture and edit in camera) licensed capability-rolling sites, or other sound engineer kin? No wait, he said that once, and bad-mouthed one kind of mic. (potential across a diaphragm in a magnetic field; vocal pop shields in place; the bag camera of directional sensitivity) which is a particular $(1-80)k sort of foolishness more about gig safety and session fidgetproofing than engineering. (As for lamb fancy; what?) If you want to pipe in with an explanation of how highly selective shotgun mics work with low profile, that's kind of thrilling audio telescope work that freed artists from wearing multiple mic/radio boxes.
The measurement microphones are very interesting! Why do they use an unbalanced signal via BNC connector instead of a balanced signal via XLR? Most measurement microphones I've seen so far were microphones with a balanced XLR connector. Or are these microphones providing an balanced signal through the 2 pins of the BNC connector and earth comes from the chassis? And what about the directional pattern reffering to the chassis design of the microphone capsule? Many unanswered questions in this video.. won't you invite him again to answer the questions? :D Best regards from germany!
BNC is the science/laboratory standard for test equipment. A reference or calibration microphone like that is closer to a piece of test equipment vs. a piece of audio gear (which would have XLR, etc.) Reference microphones are typically designed with small diaphragms so that they are pure pressure-transducers, and they are constructed long and thin so that they reduce the impact (=distortion) to the audio waveform in the air.
Ah! Thank you very much for your respond Richard! :) But are these microphoes providing a balanced or unbalanced signal? And if they provide an unbalaced signal so can you tell us why they don't provide a balanced signal?
With a BNC output, clearly they are unbalanced. The traditional low-impedance, balanced connection scheme used for pro microphones are optimized to go long distances (as long as several kilometers) with minimal noise-susceptibility along the way. Not always optimized for flat frequency response because of the unknown qualities of the cable inbetween. And typically signals are used internally as single-ended, so some scheme must be used to convert balanced to unbalanced. And, furthermore, in mic input circuits, to provide common-mode rejection to implement that lowered susceptibility to ambient interference. But that balanced to unbalanced circuitry is just another barrier to really ruler-flat frequency response which is the major point of a laboratory microphone. And laboratory situations rarely have long distance runs of cable between the microphone and the test equipment. So for those reasons laboratory mics tend to have unbalanced BNC connections vs. traditional audio-grade mics intended for studio, stage, remote applications.
I love any video with Doug in it, he just makes complex explanations so easy to understand, along with a sense of humour :)
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.
I love Doug. He's always so informative and easy to understand.
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)
Excellent documentary on microphones Dave & Mate who doing all work,thank's.
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 🤷🏻
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.
I like it when there's a guest in the lab, Good talk.
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
Very informative video--looking forward to the next ones.
As a hobbyist audio engineer, i find this very interesting! thank you!
At 2:06 the gentleman refers to an Italian engineer who developed the telephone before Alexander Graham Bell. His name was Alessandro Meucci.
Love this guy!
*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.*
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.
The High energy multimeter destruction video kicked ass... Nice to have Doug back on the stage :-)
i love the way you people enjoy sharing information
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.
My brother is a former broadcaster and still a musician. He will love this video.
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.
Yay Douglas is back
UA-cam have changed the comment system again.....(end of 08 2017).
Watching this series again, this is pure gold. If only we had more.....
Please invite a guest like this for fundamentals Friday at least once in two months, IT WAS AWESOME.
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.
Thanks Dave for this very interesting lesson I look forward to more with Mr. Ford. As always your efforts are both educational AND entertaining.!
Can't wait for the next part!
These are incredible videos Dave, thanks for posting this ! Now I wanna tear apart all of my microphones
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!
Cant wait for part 2!
Thank you for this! looking forward to the rest of the series!
The eevblog never fails to impress.
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)
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
Excellent.
Definitely looking forward to the rest of these.
Thank you Doug for all the info.. you are the man!
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.
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...
Thanks for showing. A microphone is definitely a physics project, let alone the electronic amplification efforts!
I like this discussion like format... more guests like this! :)
Can't wait for more microphones videos!
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!
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)
Fantastic, I have wonted information on microphones for a long time.
brilliant. I look forward to more audio-related vids!
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)
Really enjoyed that Dave! keep 'em coming!
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.
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.
awesome! Love the channel, any more content on audio/audio electronics/processors is more than welcome!
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.
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
Very interesting and unique Dave,
Thanks!
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.
really interesting video, thanks a lot, especially to doug for sharing his knowledge :)
Excellent. Adore this channel!
Brilliant episode, very informative!
It's a very interesting 'lecture', thanks!
Really excellent and fun to absorb.
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!
Had no idea Rode was an Australian company! Love this featured video
Many thanks for these!
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.
well that was pleasantly different, thanks guys - great talk :)
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.
17:35 : Why small capsule condenser mics have a stronger low-end freq response than a large capsule.
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!
It was my father who created the radio quality headset for telephones and gave it to AT&T/Bell
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
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
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.
Keep up the good work! Thanks!
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.
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.
lol I didn't realize you guys were sitting til I saw this ep.
Premium, industrial grade, AAA rated content right there. Wow. Loved it
A somewhat recent issue of QST had a ribbon microphone construction project.
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?
Please show more things like this!
maths is beautiful and that's what people don't understand, i'm a musician and able to see the correlation of maths and reality.
Youre such a special snowflake
Can those laboratory microphones to be used for vocal recordings and podcasting?
Certainly. And you can take a quick trip to the market in your Lamborghini, also. But lab mics are much more expensive than "ordinary" microphones because of the calibration, so typically people don't use them for "ordinary" applications. Chances are, with all the other variations, you wouldn't hear the difference, anyway.
Thank you for another educating video
Doug's a cool guy. I'd sure like to hear him explain how a single tube shotgun mic works!
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.
Yay, audio engineering!
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".
Nice video! Could we also have at some point amp and speaker design?
Slams imperial and then pulls out favourite half inch mic :)
AWESOME! want MOAR!
Thanks to Doug for sharing his knowledge, great to see him again. I would like to see more videos on sound reproduction please. Having been interested in audio for years both as listener and as part of my degree, i find the term audiophool kind of distasteful and un-informing to be honest. What is really needed is a, what is good engineering and what is mutton dressed as lamb or bad engineering, discussion. Clarifying what products sex up , confuse the issue, or plain lie and those that really do the job they purport to do. Thanks again Dave for the videos.
It sensibly acknowledges Beats and other unparticular musical components that make up a highly variable and substantial hunk of markets, which are otherwise unexplained (or tells to interdiction, bellwethers, RFQ gaming, illicit trades...) Your suggestion of categorical brand/ad-agency/inventor/OEM/trope/patent-by-patent/licensing-agency-by-licensing-agency sorting is surely more distasteful (though not a big problem for Hadoop users,) if I take it like that! Perhaps you're suited well by the RED (camera/cue/sound capture and edit in camera) licensed capability-rolling sites, or other sound engineer kin? No wait, he said that once, and bad-mouthed one kind of mic. (potential across a diaphragm in a magnetic field; vocal pop shields in place; the bag camera of directional sensitivity) which is a particular $(1-80)k sort of foolishness more about gig safety and session fidgetproofing than engineering. (As for lamb fancy; what?)
If you want to pipe in with an explanation of how highly selective shotgun mics work with low profile, that's kind of thrilling audio telescope work that freed artists from wearing multiple mic/radio boxes.
Steve Nordquist psst. EEVBlog #611 continues the Condenser Mic discussion. Y'think he rolls into patents and other IP?
Lefty!! I've always wondered if there are more leftys that are into electronics than other fields.
What's up with the vignetting at ~25 minutes? Zoomed out on the macro lens?
yo talking about soildering,where did you buy yours, the yellow one? is it good to buy it on ebay?
The measurement microphones are very interesting! Why do they use an unbalanced signal via BNC connector instead of a balanced signal via XLR? Most measurement microphones I've seen so far were microphones with a balanced XLR connector. Or are these microphones providing an balanced signal through the 2 pins of the BNC connector and earth comes from the chassis? And what about the directional pattern reffering to the chassis design of the microphone capsule? Many unanswered questions in this video.. won't you invite him again to answer the questions? :D Best regards from germany!
BNC is the science/laboratory standard for test equipment. A reference or calibration microphone like that is closer to a piece of test equipment vs. a piece of audio gear (which would have XLR, etc.)
Reference microphones are typically designed with small diaphragms so that they are pure pressure-transducers, and they are constructed long and thin so that they reduce the impact (=distortion) to the audio waveform in the air.
Ah! Thank you very much for your respond Richard! :) But are these microphoes providing a balanced or unbalanced signal? And if they provide an unbalaced signal so can you tell us why they don't provide a balanced signal?
With a BNC output, clearly they are unbalanced.
The traditional low-impedance, balanced connection scheme used for pro microphones are optimized to go long distances (as long as several kilometers) with minimal noise-susceptibility along the way. Not always optimized for flat frequency response because of the unknown qualities of the cable inbetween. And typically signals are used internally as single-ended, so some scheme must be used to convert balanced to unbalanced. And, furthermore, in mic input circuits, to provide common-mode rejection to implement that lowered susceptibility to ambient interference.
But that balanced to unbalanced circuitry is just another barrier to really ruler-flat frequency response which is the major point of a laboratory microphone. And laboratory situations rarely have long distance runs of cable between the microphone and the test equipment. So for those reasons laboratory mics tend to have unbalanced BNC connections vs. traditional audio-grade mics intended for studio, stage, remote applications.
Just plausible! Thank you. :)
Why is the frequency response measured upto 40khz? I thought the human audible range was 20hz- 20khz
Thanks you. This is great.
Fantastic!
Did Doug work on the NT1?
Yes, you'll see that in an upcoming video.
He seamed a smart guy, can't believe he worked on such a horrible (especially in the top end) mic lRode Nt1.