Real Mic from a Chinese Toy

[Guest]

[quote author="Martin B. Kantola"]

Will read the whole thread again, but Wavebourn, what do you think is wrong with the Schoeps circuit? (sorry if the question has been asked...) EDIT: If you can, please reply in terms of how it affects sound (which is far easier for me to understand) Mikes are for listening to, yes?
[/quote]

Once again: harsh sound that got the nickname "Broken Glass". The whole project started in attempt to investigate the cause of that famous "Chinese Harsh Sound" and eliminate the effect. There was a strong opinion of self-appointed Gurus who taught us that the "harshness" belongs to capsules. My investigation revealed that it is not: the capsule itself makes a peak on 9.5 kHz while the electronics distorts the sound. Highs intermodulate with fundamentals on pn-junctions of emitter followers causing the phenomena.

In my design the amp itself is very clean in respect to psycho-acoustical cleanness, also it is loaded on high impedance of the primary of the transformer; a peak is equalized by a simple RC network with 6 dB/oct slope. I know that LC equalization would be better, but have no appropriate acoustical measurement equipment needed for such precise work.

When I mean "Equalize inside of the mic" I don't mean to squeeze into the mic body the whole famous rack mount EQ with many opamps, input/output transformers, whistles abd bells...
No, I mean to build the mic amp and treat a mic body such a way so the frequency response will be equalized.

By the way, in best German microphones such equalization always presented: properly selected transformers, resistors, capacitors, even Miller effect in tubes was utilized properly, no complex EQ networks are visible on schematics', tha's why you may think that it is easy to borrow a capsule from one mic, body from the second mic, and electronics from the third one. No, no and no! Without understanding of what's going on it is impossible to get good results by simple combination of "borrowed"! However, with understanding such "borrowing" is not needed: it is always easier and better to optimize the whole system than try to glue parts that were not developed for each other.

Did I answer your question?

 

[Martin B. Kantola]

Thank you, really appreciated your answer! Would you say the "broken glass" effect is the same as I hear in many microphones unable to reproduce a close-miked tambourine undistorted?

What you refer to as equalizing could perhaps be named "tuning" instead, since we are talking about more subtle shades, and a ruler flat response might not be what sounds best (to be precise, how does one define "flat" in a microphone anyway, with sounds arriving from multiple and unpredictable angles in normal use?)

Regarding your suggested circuit I was wondering if 48V is enough to get the best S/N from the capsule?

Thanks for an interesting thread and experiment!

Martin

 

[Guest]

[quote author="Martin B. Kantola"]Thank you, really appreciated your answer! Would you say the "broken glass" effect is the same as I hear in many microphones unable to reproduce a close-miked tambourine undistorted?
[/quote]

I don't know what you hear, in my case it distorted singer's voice, especially on sibilances.

What you refer to as equalizing could perhaps be named "tuning" instead, since we are talking about more subtle shades, and a ruler flat response might not be what sounds best (to be precise, how does one define "flat" in a microphone anyway, with sounds arriving from multiple and unpredictable angles in normal use?)

Sure, it may be called "fine tuning". That 10 dB boost presents on any angle.

Regarding your suggested circuit I was wondering if 48V is enough to get the best S/N from the capsule?

Plenty!
However, I would add more till the membrane stick to the plate, but I did not want to add a source of noise modulated RF energy inside of a mic body so decided to live with what I have from a mixing console.

Thanks for an interesting thread and experiment!

You are welcome Martin!
I love to experiment...

 

[Martin B. Kantola]

[quote author="Wavebourn"][quote author="Martin B. Kantola"]Thank you, really appreciated your answer! Would you say the "broken glass" effect is the same as I hear in many microphones unable to reproduce a close-miked tambourine undistorted?
[/quote]

I don't know what you hear, in my case it distorted singer's voice, especially on sibilances.[/quote]

Could be the same thing, except the tambourine also produces an ugly low thump on some mikes... Try it if you have a chance. Sure sounds like broken glass to me. Jingle jangle, it's Xmas now.

Sure, it may be called "fine tuning". That 10 dB boost presents on any angle.

Yes of course, but what I meant was you can never make the total mike response "flat" since you can't predict the amount and spectrum of reverberation in the recording space...

However, I would add more till the membrane stick to the plate, but I did not want to add a source of noise modulated RF energy inside of a mic body...

Have you considered other solutions for producing a higher voltage, such as the clever optical one used by Gefell? Maybe not worth the trouble?


Martin

 

[Guest]

[quote author="Martin B. Kantola"][quote author="Wavebourn"][quote author="Martin B. Kantola"]Thank you, really appreciated your answer! Would you say the "broken glass" effect is the same as I hear in many microphones unable to reproduce a close-miked tambourine undistorted?
[/quote]

I don't know what you hear, in my case it distorted singer's voice, especially on sibilances.[/quote]

Could be the same thing, except the tambourine also produces an ugly low thump on some mikes... Try it if you have a chance. Sure sounds like broken glass to me. Jingle jangle, it's Xmas now.
[/quote]

Distorted thump?

That feedback that I took from Germans, tried but not implemented, meant exactly to eliminate overload of the amp on thumps and pops. I've figured out how to make that easier and more elegant than Germans did. :grin:

Sure, it may be called "fine tuning". That 10 dB boost presents on any angle.

Yes of course, but what I meant was you can never make the total mike response "flat" since you can't predict the amount and spectrum of reverberation in the recording space...

That's why I carry damping panels and graphics EQ with me.

However, I would add more till the membrane stick to the plate, but I did not want to add a source of noise modulated RF energy inside of a mic body...

Have you considered other solutions for producing a higher voltage, such as the clever optical one used by Gefell? Maybe not worth the trouble?

What do you mean, LED/solar battery pair?

 

[CJ]

semi related- i took apart a torroid at work becuase 16 henries was not the 20 we wanted.
The turns were good, but the tape wound core had been wound so that the last lap was welded off center, so that when the epoxy formed, there was a considerable air gap cuased by the outer lump.

so to drain all the energy off the capsule, you need a low insertion loss xfmr, thus then beyer "wind the wire on the center leg" trick. you want that first layer as tight around the core as you can get it, to link up the B> field with the core. especially since the primary is of very few turns.

i took apart a couple of badly wound Telefunken torroid transformers that were the worst pieces of junk i have ever tested. lousy curve and big time core loss. so winding quality and response can sometimes go hand in foot.
peace out from the woo tan clan see ya at van halen oaktown.
no one will ever top eddy in this planets life, so the hell with transformers.
and equipment.
why bother as long as him and page are still at it.

i am waiting for page, richards, clapton and beck and halen to kick it so i can make my move, but dang, these guys are stubborn!
satch and vai can lick my sack, derivitive bastards.

worse than Mike Wallace.
:green:

 

[Marik]

[quote author="Wavebourn"][quote author="Marik"]
I am not sure why would you EQ them in the mic itself, when in any case, any recording will be EQed during mastering stage. It seems you'd just introduce additional distortions, while it would not take care of the problem, anyway.[/quote]

Any signal path distorts. And there is a big difference, when to EQ: before distortions added, or after.

Now teach me please how to EQ intermodulations during mastering stage, I'm drooling waiting for your answer...
[/quote]

I am not gonna teach you anything. It seems you know it all, yourself.

PS: SERGEY ZADVORNY just has been announced as a

FIRST PRIZE WINNER IN 2008 BARRY ALEXANDER INTERNATIONAL VOCAL COMPETITION IN NEW YORK. (speaking of that "Baritone" you've criticized before...)

It seems you confuse me with somebody else, as I have never critisized him before. If I remember correctly, after listening to his recording I said that he is a VERY GOOD.
Indeed, I have critisized his accompanist, but it is completely different matter, if it makes any difference.

Best, M

 

[Guest]

[quote author="Marik"][quote author="Wavebourn"][quote author="Marik"]
I am not sure why would you EQ them in the mic itself, when in any case, any recording will be EQed during mastering stage. It seems you'd just introduce additional distortions, while it would not take care of the problem, anyway.[/quote]

Any signal path distorts. And there is a big difference, when to EQ: before distortions added, or after.

Now teach me please how to EQ intermodulations during mastering stage, I'm drooling waiting for your answer...
[/quote]

I am not gonna teach you anything. It seems you know it all, yourself.
[/quote]

Swear to God I don't know how to eliminate intermodulations during mastering stage... But I know how to minimize them and their impact from the entire very critical beginning of the signal path.

PS: SERGEY ZADVORNY just has been announced as a

FIRST PRIZE WINNER IN 2008 BARRY ALEXANDER INTERNATIONAL VOCAL COMPETITION IN NEW YORK. (speaking of that "Baritone" you've criticized before...)

It seems you confuse me with somebody else, as I have never critisized him before. If I remember correctly, after listening to his recording I said that he is a VERY GOOD.
Indeed, I have critisized his accompanist, but it is completely different matter, if it makes any difference.

Best, M

Oh es, you've call him "baritone". Probably he can do both: bass and baritone, you are right...

 

[Martin B. Kantola]

[quote author="Wavebourn"]Distorted thump?[/quote]

Not exactly, more like distorted highs plus a very ugly thump, clearly created by the mike circuitry not able to handle all that energy...

That's why I carry damping panels and graphics EQ with me.

You are joking, right? Get the idea of tuning the room with panels, but graphics EQ? Horrible thought. Even if you could make the response "flat" frequencywise from one single direction, it'll be anything but if you consider other directions not to mention phase... Sorry if I missed the joke...

What do you mean, LED/solar battery pair?

Yes, that's the idea.

Martin

 

[Guest]

[quote author="Martin B. Kantola"][quote author="Wavebourn"]
That's why I carry damping panels and graphics EQ with me.[/quote]

You are joking, right? Get the idea of tuning the room with panels, but graphics EQ? Horrible thought. Even if you could make the response "flat" frequencywise from one single direction, it'll be anything but if you consider other directions not to mention phase... Sorry if I missed the joke...
[/quote]

No, it's not a joke.
When mics, mixing console, amps, speakers are as clean as possible, a room is damped, and the path from speakers to mics is properly equalized I can place mics on virtually any distance from a singer / guitarist, provide very clean amplification and record the live concert directly from mics that capture minimum colorations from the room. There is a big difference, whether to record a dead performance in a studio, or a live performance in front of public.

What do you mean, LED/solar battery pair?

Yes, that's the idea.

Good idea, I like it!

Speaking of tambourines, I did not try to record them using modified mics, but I am absolutely positive that there will be a big difference. My design is free from wide specter "Farting"/"Broking Glass" type of distortions. It has very low THD, almost the 2'nd harmonic, that is the lower the quieter is the sound.

Condenser mics are very different from ribbons. Mechanical distortions and distortions of emitter followers are very different things and sound very differently. If mechanical distortions of ribbons may be used to add dynamics to singer's voice, condenser mics have to be as neutral and as transparent as possible.

Electrical distortions may be different as well. If some type of distortions are used to add dynamics to electric guitars, some other specific types of distortions have to be avoided by any means: when guitarists discovered them they called them "Farting". It was the result of rectification of a signal on grids of output tubes when signal level was enough for a grid current. Capacitively loaded emitter followers generate very similar distortions by nature that can't add dynamics neither to voice, nor to a musical instrument. What sounds as "Farting" on fundamental frequencies sounds as "Broken glass" on harmonics, especially when they are highlighted before distortion.

 

[Marik]

[quote author="Wavebourn"]
Swear to God I don't know how to eliminate intermodulations during mastering stage... But I know how to minimize them and their impact from the entire very critical beginning of the signal path.
[/quote]

Wouldn't the use of capsule which does not need EQ first thing, be quite a sensible approach? :shock:

Oh es, you've call him "baritone". Probably he can do both: bass and baritone, you are right...

Indeed, I confused his voice. On that particular recording he did not sound like a bass to me.
Since I worked a lot with both, bass and bariton singers, I believe I know a little bit how they should sound.
The only explanation for the confusion I can give is the recording itself. IIRC, I wrote in that thread there was something wrong with the sound of low register, and that there was a wrong choice of the mic for the application, but that is only my opinion.

Best, M

 

[Guest]

[quote author="Marik"][quote author="Wavebourn"]
Swear to God I don't know how to eliminate intermodulations during mastering stage... But I know how to minimize them and their impact from the entire very critical beginning of the signal path.
[/quote]

Wouldn't the use of capsule which does not need EQ first thing, be quite a sensible approach? :shock:
[/quote]

Yeah, and Ferrari for shopping in Wallmart... The topic is about modification of one particular very cheap condenser mic, how to make a usable thing from it redesigning electronics and treating a body. Period.

Oh es, you've call him "baritone". Probably he can do both: bass and baritone, you are right...

Indeed, I confused his voice. On that particular recording he did not sound like a bass to me.
Since I worked a lot with both, bass and bariton singers, I believe I know a little bit how they should sound.
The only explanation for the confusion I can give is the recording itself. IIRC, I wrote in that thread there was something wrong with the sound of low register, and that there was a wrong choice of the mic for the application, but that is only my opinion.

Best, M

Marik, difference between bass and baritone is in diapason of the fundamental frequency, it has nothing to do with harmonics. No mic can change a fundamental frequency. I did a trick back in 1970'th connecting a mic and output of a German electric organ Matador to an analog multiplier, so playing one octave below I could sing as a bass. Later the thing was evolved into a multiple filters and modulators, so I could sing accords applying formants of a human voice to an electronic instrument.
Changing pitch of voice requires more than a simple filtering by any mic or EQ, it requires to change a fundamental frequency.

 

[Martin B. Kantola]

[quote author="Wavebourn"]No, it's not a joke.
When mics, mixing console, amps, speakers are as clean as possible, a room is damped, and the path from speakers to mics is properly equalized I can place mics on virtually any distance from a singer / guitarist, provide very clean amplification and record the live concert directly from mics that capture minimum colorations from the room.[/quote]

Room colorations is what I love about recording acoustic instruments, but I guess everyone has their own preferences...

[quote author="Wavebourn"]Speaking of tambourines, I did not try to record them using modified mics, but I am absolutely positive that there will be a big difference. My design is free from wide specter "Farting"/"Broking Glass" type of distortions. It has very low THD, almost the 2'nd harmonic, that is the lower the quieter is the sound.[/quote]

Sounds like I might have to try to build your circuit some day and have a listen... BTW, why did you decide not to use a center tap configuration to extract the phantom voltage from the Altran transformer (but resistors instead)?

[quote author="Wavebourn"]Capacitively loaded emitter followers generate very similar distortions by nature that can't add dynamics neither to voice, nor to a musical instrument. What sounds as "Farting" on fundamental frequencies sounds as "Broken glass" on harmonics, especially when they are highlighted before distortion.[/quote]

Are you saying "highlighted" as in boosted or amplified? (by capsule properties?)

Martin

 

[Marik]

[quote author="Wavebourn"]

Marik, difference between bass and baritone is in diapason of the fundamental frequency, it has nothing to do with harmonics. [/quote]

With all due respect, I think you are wrong here. Officially, baritone and bass difference in the range is quite small, and is only a minor third (on the bottom G, vs. E second octave below middle C), and the whole range is very much overlapped.
I saw baritones which can easily sing down to E. The main difference is in the timbre of the voice, which I believe is a function of harmonics.

Likewise, if you take for example cello and double bass, even when played in the same "overlapped" range, you will always unmistakably recognise "which is which".

Best, M

 

[Guest]

[quote author="Martin B. Kantola"][quote author="Wavebourn"]No, it's not a joke.
When mics, mixing console, amps, speakers are as clean as possible, a room is damped, and the path from speakers to mics is properly equalized I can place mics on virtually any distance from a singer / guitarist, provide very clean amplification and record the live concert directly from mics that capture minimum colorations from the room.[/quote]

Room colorations is what I love about recording acoustic instruments, but I guess everyone has their own preferences...
[/quote]

It is fine without feedback that highlights reverberation. With feedback from speakers more damping is necessary.

Speaking of tambourines, I did not try to record them using modified mics, but I am absolutely positive that there will be a big difference. My design is free from wide specter "Farting"/"Broking Glass" type of distortions. It has very low THD, almost the 2'nd harmonic, that is the lower the quieter is the sound.

Sounds like I might have to try to build your circuit some day and have a listen... BTW, why did you decide not to use a center tap configuration to extract the phantom voltage from the Altran transformer (but resistors instead)?

I can match resistors to avoid DC bias of a transformer. They are cheap.

[quote author="Wavebourn"]Capacitively loaded emitter followers generate very similar distortions by nature that can't add dynamics neither to voice, nor to a musical instrument. What sounds as "Farting" on fundamental frequencies sounds as "Broken glass" on harmonics, especially when they are highlighted before distortion.

Are you saying "highlighted" as in boosted or amplified? (by capsule properties?)

Yes, I mean the 1'st tooth of a comb that is about 10 dB high.

 

[Guest]

[quote author="Marik"][quote author="Wavebourn"]

Marik, difference between bass and baritone is in diapason of the fundamental frequency, it has nothing to do with harmonics. [/quote]

With all due respect, I think you are wrong here. Officially, baritone and bass difference in the range is quite small, and is only a minor third (on the bottom G, vs. E second octave below middle C), and the whole range is very much overlapped.
I saw baritones which can easily sing down to E. The main difference is in the timbre of the voice, which I believe is a function of harmonics.

Likewise, if you take for example cello and double bass, even when played in the same "overlapped" range, you will always unmistakably recognise "which is which".

Best, M[/quote]

Cello and double bass have different formants. All singers have the same. 2 of them are well known since antiquity "Belkanto" formants. If microphone peaks are tuned to around them they are less audible than peaks on other frequencies.

 

[Guest]

Here is the sample of "Room ambiance highlighted by Makie boomboxes": yesterday on my friend's party I've recorded him putting this modified mics around his microphone. Hum from his gear is audible, also is audible room ambiance colored by his Makie boomboxes and microphone.

http://wavebourn.com/music/diego/01.mp3

Latrer I'll record him singing through my speakers and amps without any additional mics to compare.

Here is the photo of the setup:

 

[Guest]

The same mics in a living room; no amplifiers, no speakers, no damping panels:

http://wavebourn.com/music/zadvorny/sample.mp3

 

[Marik]

[quote author="Wavebourn"][quote author="Marik"][quote author="Wavebourn"]

Marik, difference between bass and baritone is in diapason of the fundamental frequency, it has nothing to do with harmonics. [/quote]

With all due respect, I think you are wrong here. Officially, baritone and bass difference in the range is quite small, and is only a minor third (on the bottom G, vs. E second octave below middle C), and the whole range is very much overlapped.
I saw baritones which can easily sing down to E. The main difference is in the timbre of the voice, which I believe is a function of harmonics.

Likewise, if you take for example cello and double bass, even when played in the same "overlapped" range, you will always unmistakably recognise "which is which".

Best, M[/quote]

Cello and double bass have different formants. All singers have the same. 2 of them are well known since antiquity "Belkanto" formants.[/quote]

While true, I don't quite see how it explains the fact the bass and baritone have different timbres in principle.

Moreover, if hypotetically assume the only diference between them is a diapason (range) of the fundamental frequency, then indeed, there would be very easy to confuse them, esp. when sung in the same range.

I never tried it, but I believe, it is possible to EQ a bass making it sound like a baritone... but I might be wrong here.

Best, M

 

[Guest]

By the way, Sergey Zadvorny will perform in Carnegie Hall January 27 at 1:30 pm.

Here is one more his sample from yesterday's home concert (the same mics):


http://wavebourn.com/music/zadvorny/22dec2007/22.mp3

Bass and baritone have different timbres because of how easy they take highest and lowest notes.