Fifty dollar mics

[TyphoidHippo]

Here's a comp, I hesitate to post these because my kit is crap and I'm not a drummer, but hey, I can beat out quarter notes . . . I can't hit as hard as a real drummer though.

One channel is the K-Micro and the other is another condenser microphone of the same basic type. Don't try to guess which, because I won't tell you, and your guess will likely be wrong anyway.

I'll post which channel is the K-Micro this evening.

Both mics about 1" from each drum. The last sample is a front side kick with the pillow removed, and I'm beating it as hard as I can with a mallet. Not a particularly musical sound, but I like it for testing drum mics because a) it's really loud, and b) it's a bit easier to hear distortion--if present--on the peak.

Preamp is ART Digital MPA, which can take severely loud input levels with no trouble. No pad used on either mic. Each channel was normalized (the K-Micro started off about 4dB louder), but no other processing other than .mp3 conversion.

Well... the left side sounds much cleaner, brighter, and more "airy". The transients seem to have more balls and don't linger around after their time is done.

The right side sounds dead and mushy...and distorted on the transients, which, I guess, in turn, accounts for the mushiness. Based on the earlier descriptions of the K-Micro, I am guessing that this is it...

Clearly a big difference, and just based on these clips, I can see the mic on the left being much, much more useful for recording drums...or anything, really. So if it's not the K-Micro, I hope you change your mind and tell us what it is. (I also hope it's something awesomely ridiculous like a 22 cent electret soldered to a coat hanger duct-taped to the input on the preamp. I love it when that happens )

 

[TyphoidHippo]

After listening again... it kinda sounds like the left mic is on top of each drum, and the right one is on bottom...is this a trick? Are both mics K-Micros, just on different sides of the drums? I suppose that may also account for the apparently-nearly-perfectly-out-of-phase signals that just about suck my eardrums outta my head when I listen to it.

I look forward to the unveiling this evening...

 

[mshilarious]

Well again, the K-micro is reverse polarity. So reverse polarity on one of the channels to compare, if you like. I guess I should have done that for you to disguise which was which, but I forgot Both mics were mounted in the same clip, with their capsules less than 1/2" apart, 1" from the top side of each drum (beater side on the kick).

 

[TyphoidHippo]

Well again, the K-micro is reverse polarity.

I remember you saying that now.

So reverse polarity on one of the channels to compare, if you like.

That's what I did for my initial comparison/guess, I just hit the phase/polarity/99pagethread button on the left channel. After thinking about the 22 cent electret/coathanger/duct-tape I guess my mind started reeling on about devilish trickery.

I guess I should have done that for you to disguise which was which, but I forgot

Is it actually possible to tell which is which? I mean... they are obviously reversed from each other....but how can you tell which is which, I wonder... Will the very first cycle on the waveform be negative for the K-Micro or something? Then how would one know the first cycle(s) haven't just been cut off, so the K-Micro is actually going up? I'm puzzled by this comment... Then again, I bet it's something really simple that I should know, heheh...

 

[TyphoidHippo]

...One channel is the K-Micro and the other is another condenser microphone of the same basic type. Don't try to guess which, because I won't tell you, and your guess will likely be wrong anyway.

I'll post which channel is the K-Micro this evening.

Is it evening enough yet?

 

[mshilarious]

I remember you saying that now.

That's what I did for my initial comparison/guess, I just hit the phase/polarity/99pagethread button on the left channel. After thinking about the 22 cent electret/coathanger/duct-tape I guess my mind started reeling on about devilish trickery.

Actually the capsule the K-Micro uses would be about 22 cents, probably. And a cheap capsule isn't necessarily bad. I think that capsule is OK, I think the circuit could stand some improvement. I don't think it makes the best drum close mic, not because of its performance, just because of its sound. For the record, I don't think the mystery mic makes a great drum mic either. More on that later. I think the K-Micro could be a serviceable overhead mic, but 7 of them on a kit is going to be way too much high-end.

Is it actually possible to tell which is which? I mean... they are obviously reversed from each other....but how can you tell which is which, I wonder... Will the very first cycle on the waveform be negative for the K-Micro or something? Then how would one know the first cycle(s) haven't just been cut off, so the K-Micro is actually going up? I'm puzzled by this comment... Then again, I bet it's something really simple that I should know, heheh...

Yes, it is possible, but no, it's not simple. The concept is simple: when you hit a drum, the batter head moves away from you. That should lower the air pressure in front of it momentarily, creating rarefaction, which is the negative side of the cycle.

Reality is more complicated. The speed of sound is faster through the drum head than it is through air. So if the mic is close to the edge of the drum, the edge of the skin will vibrate the air near the mic before the larger rarefaction from the stick will get there. Thus, you get a complex waveform.

However, the largest peak is usually negative, because the drum head loses energy every time it vibrates back and forth. If you are micing a resonant head, it would be the opposite.


OK, before the answer, a couple more things--I should have done this earlier, the same drums (not the same hits, sorry) with a Shure 55SH--yes, the Elvis mic, but it has the same capsule as the SM57, an important reference when talking about close-micing drums.

The 55SH has one other advantage: truly high SPL handling, at least the K-Micro's "rated" 145dBSPL, probably more.

I think in the context of a drum mix, the dynamic mic wins here. My rattle-y kick drum is nicely quieted down. The extreme energy from the snare wires is dampened. On the other hand, a cardioid dynamic mic does not have the profound low-end of a small diaphragm condenser (SubKick users, take note!) But I think all three mics on kick drum would need significant EQ to fit in a mix.

Finally, can you see distortion on a waveform? Often you can. Have a look at one of the pillow-less kick drum hits (with the polarity fixed), and there is your answer--both mics are distorted until about 38ms, but one is still distorted at 100ms. Compare to a 55SH hit for a distortion-free example.

 

[TyphoidHippo]

This is fantastic information, thank you very much.

The waveform on the bottom in your pic looks entirely unnatural, like it's been clipped off, but why the slant like that? Is that the mic actually, like... sort of "spazzing out" as it distorts? The only sort of clipping I'm really familiar with is the compression kind that makes fairly flat plateaus in a waveform.

I like the sound of the newest clip, and I do see what you're saying about the high end in the K-Micros. I imagine I might have come to that conclusion as well, if I heard a whole kit miced up with nothing but K-Micros. Judging by the amount of snare-rattle it picked up (I actually initially thought I was hearing loose high-hats shake as you hit the snare, lol), I'm sure the bleed during an active-drummers session would be way less than ideal...bordering on unmanageable.

 

[mshilarious]

The waveform on the bottom in your pic looks entirely unnatural, like it's been clipped off, but why the slant like that? Is that the mic actually, like... sort of "spazzing out" as it distorts? The only sort of clipping I'm really familiar with is the compression kind that makes fairly flat plateaus in a waveform.

The simplest answer to that is that analog clipping isn't like digital clipping, especially we are talking about a single transistor here as the source of the distortion (the K-Micro has two transistors, but the second one isn't the problem). The capsule FET doesn't "hard clip", but begins to distort asymmetrically as the signal gets louder.

(I actually initially thought I was hearing loose high-hats shake as you hit the snare, lol), I'm sure the bleed during an active-drummers session would be way less than ideal...bordering on unmanageable.

There is no hi-hat set up at the moment; my drumkit is in pieces and I never seem to get the time to put it back together

 

[dgatwood]

This is fantastic information, thank you very much.

The waveform on the bottom in your pic looks entirely unnatural, like it's been clipped off, but why the slant like that? Is that the mic actually, like... sort of "spazzing out" as it distorts? The only sort of clipping I'm really familiar with is the compression kind that makes fairly flat plateaus in a waveform.

I'm not 100% sure why it is happening, but it looks to me like the highs frequencies are getting obliterated by an excessively strong lower-frequency component. In effect, that slanted line represents the average of the actual signal across a period of time. My first guess would be that the capsule doesn't respond to high frequencies well when at or near maximum extension, but that's pretty much a wild guess. Could also be something in the circuit behaving that way. No idea which.

 

[mshilarious]

I'm not 100% sure why it is happening, but it looks to me like the highs frequencies are getting obliterated by an excessively strong lower-frequency component. In effect, that slanted line represents the average of the actual signal across a period of time. My first guess would be that the capsule doesn't respond to high frequencies well when at or near maximum extension, but that's pretty much a wild guess. Could also be something in the circuit behaving that way. No idea which.

No, actually it's the opposite, it's the result of additional high-frequency content generated by harmonic distortion. Basically, it's like a sawtooth wave--the fundamental sine wave is still there, but now it's got lots of friends

The technical explanation has to do with FET pinch-off voltage and gate-source capacitance and things like that, but my transistor theory isn't the strongest, so at that point I get confused . . .

 

[dgatwood]

Really? In the picture I'm seeing, there's a lot of high frequency motion in the top sample from about 35-45 milliseconds that simply is missing entirely in the bottom sample, and a lot of the other swings are similarly reduced in intensity. I'm not saying there isn't additional high frequency crap being added, but it really looks to me like there's some being dampened as well.

 

[mshilarious]

Really? In the picture I'm seeing, there's a lot of high frequency motion in the top sample from about 35-45 milliseconds that simply is missing entirely in the bottom sample, and a lot of the other swings are similarly reduced in intensity. I'm not saying there isn't additional high frequency crap being added, but it really looks to me like there's some being dampened as well.

Yeah, that's true that when you clip, you will lose some information that can't be reconstructed. So when you will a bit that's missing, rather than just reduced in intensity, that's gone for good, but replaced with distortion products at high frequencies.

 

[hairylarry]

Cool graphics

mshilarious,

Cool graphics. It's great seeing those waveforms. completely over my head but great.

Are you using your DAW for the waveforms or do you have oscilloscope software or ???

Thanks,

Hairy Larry

Actually the capsule the K-Micro uses would be about 22 cents, probably. And a cheap capsule isn't necessarily bad. I think that capsule is OK, I think the circuit could stand some improvement. I don't think it makes the best drum close mic, not because of its performance, just because of its sound. For the record, I don't think the mystery mic makes a great drum mic either. More on that later. I think the K-Micro could be a serviceable overhead mic, but 7 of them on a kit is going to be way too much high-end.



Yes, it is possible, but no, it's not simple. The concept is simple: when you hit a drum, the batter head moves away from you. That should lower the air pressure in front of it momentarily, creating rarefaction, which is the negative side of the cycle.

Reality is more complicated. The speed of sound is faster through the drum head than it is through air. So if the mic is close to the edge of the drum, the edge of the skin will vibrate the air near the mic before the larger rarefaction from the stick will get there. Thus, you get a complex waveform.

However, the largest peak is usually negative, because the drum head loses energy every time it vibrates back and forth. If you are micing a resonant head, it would be the opposite.


OK, before the answer, a couple more things--I should have done this earlier, the same drums (not the same hits, sorry) with a Shure 55SH--yes, the Elvis mic, but it has the same capsule as the SM57, an important reference when talking about close-micing drums.

The 55SH has one other advantage: truly high SPL handling, at least the K-Micro's "rated" 145dBSPL, probably more.

I think in the context of a drum mix, the dynamic mic wins here. My rattle-y kick drum is nicely quieted down. The extreme energy from the snare wires is dampened. On the other hand, a cardioid dynamic mic does not have the profound low-end of a small diaphragm condenser (SubKick users, take note!) But I think all three mics on kick drum would need significant EQ to fit in a mix.

Finally, can you see distortion on a waveform? Often you can. Have a look at one of the pillow-less kick drum hits (with the polarity fixed), and there is your answer--both mics are distorted until about 38ms, but one is still distorted at 100ms. Compare to a 55SH hit for a distortion-free example.

 

[mshilarious]

mshilarious,

Cool graphics. It's great seeing those waveforms. completely over my head but great.

Are you using your DAW for the waveforms or do you have oscilloscope software or ???

Thanks,

Hairy Larry

That's Wavelab, but I would think any DAW is similar, just zoom in enough!

 

[hairylarry]

distortion

That's Wavelab, but I would think any DAW is similar, just zoom in enough!

I use SAW Classic and I just got a free Cubase with a purchase. I can zoom in close in SAW and I do when making edits. I never thought about looking at distortion though but it makes sense.

We used to play tunes on single board computers by programming square waves. Just getting them to play a tune was all we cared about and, of course, square waves have a lot of distortion. The clipped waveforms look kind of similar to square waves. Although they have a slope they look more like square waves than sawtooth.

Does the clipping action cause the distortion or the fact that the waveform is being compressed towards a square wave cause the distortion? Or both?

And what's up when you overload a digital input and the sound starts cutting in and out? That's not just compressed or distorted it can go to total crap.

Thanks,

Hairy Larry

 

[mshilarious]

We used to play tunes on single board computers by programming square waves. Just getting them to play a tune was all we cared about and, of course, square waves have a lot of distortion. The clipped waveforms look kind of similar to square waves. Although they have a slope they look more like square waves than sawtooth.

That's the way you had to do sound on an Apple ][ as well. In BASIC there was a single memory location that output to the speaker, you used a POKE command which triggered that memory on and off, and gave you a tone. I think there was a full byte dedicated to that, so you could assign a value of say 128 and it played middle C (this is before MIDI, or at least before it was common, so the value didn't correspond with a MIDI note). But you could also use assembly language and directly turn the speaker on and off quickly, and generate music or speech. That's how the classic game Castle Wolfenstein worked.

I was explaining sample theory to my daughter the other day, and demonstrated how changing sample rate and bit depth affected quality. I demonstrated by converting a 24/44.1 file to 8/8 Then I told her my Apple ][ only had 48K of memory, and 16K of that was reserved, so effectively you could do about 6 seconds of 8 bit/4kHz audio, and still leave enough memory to run your program . . . floppy disks were too slow to dynamically retrieve audio, as a hard drive can do . . .

Yeah, she's in fifth grade . . . I taught her Ohm's Law too, and she knows what all the basic circuit components are . . .

Does the clipping action cause the distortion or the fact that the waveform is being compressed towards a square wave cause the distortion? Or both?

A square wave is the resulting of clipping, which is a circuit that attempts to exceed its power supply, and of course fails. If you have an amplifier with a +/-15V power supply, and a gain of 10, and you feed it a sine wave input of 2V peak (1.4VRMS), it will attempt to output 20V peak--and fail. The portion of the sine wave above 15V will clip, you will have a flat line until the sine wave drops below 15V again.

The distortion in our capsule works a little differently. The capsule FET will be able to go about -1.5V or so before 'pinch-off voltage', where the FET stops conducting. But before it cuts off completely, it will become very non-linear. On the positive side, it can go up to a much higher voltage before similar distortion occurs. So this sort of assymetrical distortion occurs.

And what's up when you overload a digital input and the sound starts cutting in and out? That's not just compressed or distorted it can go to total crap.

Not sure about that one; do you have an example?

 

[Fishmed]

That's the way you had to do sound on an Apple ][ as well.

No way, the Commodore 64 was the way to go. There where 3 voices that could play at one time.

 

[hairylarry]

fifty buck kick mics

Hi,

This is a hard one. It's hard to find a good kick mic under $100. I have one candidate.

Superlux FK-2

I bought mine for $45.

It comes included in the 8 mic kit Superlux DRK-F5H3 Drum Microphone Kit which is $140 new. Let's see, that works out to $17.50/mic, average. Definitely qualifies for under $50.

This is a tailored kick mic rather than a general purpose instrument mic that's also very good on kick like my ATM25. I've used the FK-2 live and it worked well. It's really for kick drum only, maybe toms, but would not be recommended for anything else.

I prefer kick mics that are also instrument mics. I believe I could even record vocals on my ATM25. But that's more of a $100 mic.

There are many who prefer the tailored kick sound. Please weigh in.

If you have a kick mic you like to use that is available used or new in the $50 range please let us know.

If you have used the Karma kit or other inexpensive kits recording drums give us a post on how what you like and what you don't.

Generally speaking drums are expensive to record mic wise. When I set up to record "Blues For Peace" I used four mics on the kit. None of them qualified for this thread but they were inexpensive, that is in the $100 range.

Many use the Naiant's as drum overheads. Harvey Gerst talks about using them in his thread, Do you really need all that expensive stuff. They definitely qualify for this thread.

https://homerecording.com/bbs/showt...t=do+you+really+need+all+that+expensive+stuff

A kick and two overheads will make a good recording of a kit. This can be done under $150. What are your recommendations?

Thanks,

Hairy Larry

 

[Ed Dixon]

Another vote for speakerrepair.com GLS mics. We have a dozen or so of them and they've done very well.

Ed

 

[Toker41]

Just discovered the NIB Shure SM57 that I bought on Ebay for $52 is a fake. It's a really good fake, but a fake all the same. Was wondering why I couldn't get a decent tone when I mic'd up my Boogie with it. That was my first clue, so I did some reading up on it. It only weighs in at 240 grams, when an SM57 should come in at 284 grams. I contacted Shure, and they claim that they work with Ebay, and pull down 3000 to 4000 fake SM57's, and 58's a month from Ebay.
I contacted the seller, who had close to 300 positive feedback points on Ebay. He claims that the mic is 100% genuine, but was very, very quick to refund my payment through Paypal, without any mention of returning the mic, when I mentioned filing a claim, and reporting it to Ebay, and Shure.