Small and large diaphragm Mic Differences - Continued

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darnold

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This was brought up again in another thread. Its possible this is ALL discussed in the big mic thread but...its just so long how am i supposed to find it. It might have been brought up elsewhere too.

The argument was brought up that large diaphragms pick bass frequencies up better than small diaphragms. Everyone put there input in that these facts were not true which is quite well known around here. But night'schild responded to me with a private message with statements from Microtech Gefell tells otherwise. I will give a copy and paste of the message and what i replied back with what i could muster up as justification :D. But its probably best left to people who really know.

Sorry night'schild if you wanted to be kept anonymous. But since it would be pretty easy to figure out which argument i was talking about i didnt think it would really be anonymous anyway.



night'schild said:
If I am wrong why do the engineers at Gefell agree with me?

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Type of capsule Advantages
Small diaphragm (16mm or about ½”) Better directivity
More even response curves
Better for live performances
Less feedback on stage
Less sensitive to solid borne noise
Less handling noise
Less proximity effect
More accurate and critical
Better for instruments

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Large diaphragm (25.4mm or 1”) More musical
Better low frequency response
More sensitive
Lower self noise
Greater proximity effect
Warms up the source
Smooth and complimentary
Better for voice

You can read the article for yourself it is under diaphragm size.

http://www.gefell-mics.com/capsules.htm
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darnold said:
Hey Night'schild.

Really glad you brought this up. But i think it would really be best to be bring this up on a thread. If you dont mind ill start a new one and bring up these facts that you have presented. If you dont want your name brought into it i wont bring it up. But it is a worthy and respectable thing to bring up. There are many people more worthy than me to try and give a proper explanation for you.

I think the main argument you have is they say that large diaphragms have better bass response. This might be true to an extent but I believe its unrelated to the diaphragm size. The thing is, the statement is not completely true. The reason being is that small diaphragms pick up just as much bass as a large diaphragm, and infact it picks up the bass frequencies more accurately. I remember hearing that there is a microphone that recieves down to 2Hz or something, maybe even 1Hz. And it is smaller than a half an inch. Even small omni measurement microphones pickup to 20Hz and they are smaller than half inch diaphragm. If they didnt pick up bass frequencies as well then they couldnt be used as room analyzer microphones. Infact they pick up bass probably better than large diaphragms because of the accuracy.

So really the larger picks up more bass is basically a false statement. What could be true about the large diaphragm because of its accuracy issues that it colors the bass frequencies in a pleasant way. This would give you the perceived effect that it picks bass frequencies up better. And infact those bass frequencies could be boosted in the frequencies to give the bass coloration. But it really has nothing to do with how much the diaphragm is picking up. So really the statement isnt totally incorrect, but its not really correct either.

Infact, that is why there are actually some smaller diaphragm microphones that have more bass than some large diaphragms because its really irrelevant. Its not as common for that to happen because the small diaphragms are usually pretty accurate on the frequency curve so its not going to do that. But the engineer of the microphone could easily tune it to be that way.

And it also looses the argument that it picks up more sound in general because it even says the small diaphragm is more directional. That is why it is more common to see small diaphragms in a stereo pair because the accuracy and the direction of the mic is more accurate. Large diaphragms dont work as often for this because the coloration is stronger off axis of the mic. If the coloration is bad in the off axis areas of the polarization then the stereo imaging in the center is going to be weaker. So thus you could say that because the off axis coloration with large diaphragms is so great that its actually pulling less energy into the microphone from the sides.

The statement about the large diaphragm having more proximity effect is also a false but true statement. The EV RE20 is a large diaphragm dynamic mic and it has very minimum proximity effect. This is one i probably cant explain which is why we need to pu this in a thread. But im sure it has more to do with the polarization in the back diaphragm then with the large diaphragm.

As far as the sensitivity goes. That probably has more to do with the way they are mounted. Small diaphragms are mounted pretty tight which would make them less sensitive to both movement of air and breaking. Where as the large diaphragm is normally suspended where a windblast could dislodge it. Again, not really related to diaphragm size.

And the warms up the source and better for vocals is again because of the coloration it provides. It normally colors the voice in a more flattering way than a small condenser. But still, small diaphragms are used on voices quite often too. My Neuman TLM 193 isnt a true large diaphragm, its a 3/8". But its coloration is awesome.

Im gonna go ahead and put this up in its own thread for more comment and comfirmation that my own statements are correct. I could be feeding a bunch of bull shit too.

Danny
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I think the main argument you have is they say that large diaphragms have better bass response. This might be true to an extent but I believe its unrelated to the diaphragm size.

You are right, it is unrelated. Since SD have less proximity effect, many take it as a "worse" bass response, which is not correct.

I remember hearing that there is a microphone that recieves down to 2Hz or something, maybe even 1Hz. And it is smaller than a half an inch. Even small omni measurement microphones pickup to 20Hz and they are smaller than half inch diaphragm.

In fact even 1/4" omnies can go down to 3-5Hz, depending on back-chamber construction

The statement about the large diaphragm having more proximity effect is also a false but true statement. The EV RE20 is a large diaphragm dynamic mic and it has very minimum proximity effect. This is one i probably cant explain which is why we need to pu this in a thread. But im sure it has more to do with the polarization in the back diaphragm then with the large diaphragm.

RE20 has very elaborate back chamber construction, where phase shift network is divided into three ranges--low, mid and top, each having it's own path. It was specifically designed for low proximity effect, and is rather an exception. Polarization of the back diaphragm is applied only to condenser mics, and affects pickup pattern, but it is true in a sense that the closer to omnie we get, the less proximity.

As far as the sensitivity goes. That probably has more to do with the way they are mounted. Small diaphragms are mounted pretty tight which would make them less sensitive to both movement of air and breaking. Where as the large diaphragm is normally suspended where a windblast could dislodge it. Again, not really related to diaphragm size.

Sensitivity depends on three things: 1) Area of capacitor (diaphragm, in our case, so the smaller diaphragm, the less signal coming out of it) and 2) polarization voltage--the higher, the more sensitivity, but there is a limiting factor, which depends on mechanical construction, where if you are going beyond a certain point, the capsule loses headroom and can collapse, and 3) Spacing between diaphragm and backplate.

And the warms up the source and better for vocals is again because of the coloration it provides. It normally colors the voice in a more flattering way than a small condenser. But still, small diaphragms are used on voices quite often too. My Neuman TLM 193 isnt a true large diaphragm, its a 3/8". But its coloration is awesome.

The coloration depends very much not only on capsule itself, but also on all electronic circuit.
 
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I too received a PM regarding my response to this statement:
night'schild said:
If you know anything about how a diaphragm works you would know that larger area = improved pick-up of subtleties. That was all I was trying to imply.
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crazydoc said:
Sorry. If that were so, we'd all be using 18 inch woofers as microphones. :)
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I think that night'schild is confusing "subtleties" with "pleasing distortion". I myself would define "pick-up of subtleties" as a more accurate representation of sound. I think he may mean that they sound more musical, or are more sensitive to SPL (other things like diaphragm thickness and material, polarizing voltage, spacing, etc. being the same). However, they impart more distortion to the signal, which I think is the "subtleties" he refers to. This distortion can be pleasing in many cases, which is why some of these mics sound more "musical" or "warm" and are in demand. However, they are less accurate the larger the diaphragm.

Yes, folks are using speakers as kick drum mics, but not (as far as I know) as the only mic on the kick. The output is mixed with the signal from another kick mic, not to impart any subtlety to the sound but rather to color it.
 
Originally Posted by night'schild:

If you know anything about how a diaphragm works you would know that larger area = improved pick-up of subtleties.

Although this message was not directed to me, I will chime in with response, as this is probably one of widespreaded misconceptions ...
Nothing can rival good 1/4" omni capsule in term of accuracy of picking-up of all music subtleties. I think Crazydoc is right in that you are confusing it with distortions. The larger diaphragm (esp, with unsupported center), the more very complex resonanse modes it gets into, receiving signal. That's the source of distortions=coloration, very often perceived as "subtleties". It is exactly like using transformers in tube gear. Some can give very pleasing coloration, which has nothing to do with accuracy.
 
Ahh great to clear this up. I had the proximity effect envisioned in my head as to why but i couldnt write it out in scientific terms and facts. I tried but i ended up leaving it out. I knew it had alot to do with the polarization with the back plate. But does it need more voltage to polarize the back diaphragm because of the mass? Just curious.

I see now about the RE 20. Obviously it doesnt work that way because a dynamic doesnt use two diaphragms.
 
darnold said:
But does it need more voltage to polarize the back diaphragm because of the mass? Just curious.
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I am not quite clear what do you mean here. More voltage than what? Then existing one, or the one compare to front of the capsule? Once again, as I've already wrote, the polarazing voltage is limited by mechanical construction of the capsule, and besides, it changes its directivity pattern. In any multipattern capsule (except of some rare ones with mechanical control)directivity pattern is controlled by the right balance of polarizing voltage and its polarity between front and rear. In any case, voltage value on rear should not exceed that of front in omni pattern, and same but negative value in fig 8 pattern--two extreemes, between which all other patterns are.

Also, I don't exactly understand which mass are you talking about. Is it mass of air, loading the diaphragm, or mass of diaphragm itself, etc.?
 
I have been reading the posts and all seem to have good points but I still am wondering what kind of testing you guys have done to back up your points. I have done lots of testing using the e609 and sm57 and I have found that even though the diaphragm in the e609 is just a little bit bigger that it seems much more "musical." Of course I have used sdc's for over heads and now I am using the AKG c-200b's because they have the bigger diaphragm which to my ears sounds more open than the akg c100b. Maybe it all depends on the design of the sdc, but I have not yet heard a sdc that is better than any decent ldc is sonic representation.
 
I wanted to fix my last statement:
Maybe it all depends on the design of the sdc, but I have not yet heard a sdc that is better than any decent ldc IN sonic representation.
 
All you're really saying is that you tend to like LD's better than SD's.

Or at least of the ones you have direct experience with. Which isn't at all surprizing to me if all you've been using are AKG-1000's and SM-57's. :D No offense, but your point of reference is severely limited. An earthworks would blow you away in terms of sensitivity and accuracy . . . and a Schoeps or even a Groove Tubes GT-44 might make you sh*t your pants in terms of musicality.

As far as testing goes, it's kinda' gotten to the point of common knowlege. And based on my own experience with small-diaph. reference mics, it's very clear to me that those particular mics are about as sensitive as it gets, and go down about as low as you can go (a spectral analyzer will likely reveal the rumbling of your heater or air conditioner ... passing traffic, footsteps from another room, etc.). It's pretty obvious.
 
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>I have been reading the posts and all seem to have good points but I still >am wondering what kind of testing you guys have done to back up your >points.

Listening and AB'ing some of the best mics ever produced, including DPA 4006, 4011, Shoeps M221, CMC6, Gefell, almost all Neumann and AKG "high end" line, Ela m251, etc.

>I have done lots of testing using the e609 and sm57 and I have found that >even though the diaphragm in the e609 is just a little bit bigger that it >seems much more "musical."

You cannot base your judgement on dynamics, as they have completely different principle of working, where the diaphragm is rigid and works in piston-like mode.

>Of course I have used sdc's for over heads and now I am using the AKG c->200b's because they have the bigger diaphragm which to my ears sounds >more open than the akg c100b.

I guess you are talking about c2000 and c1000. Well, C1000 probably has its uses, but I wouldn't judge all SD microphones based on this mic, as it is not exactly one to compare to, IMHO.
 
Marik said:
Well, C1000 probably has its uses, but I wouldn't judge all SD microphones based on this mic, as it is not exactly one to compare to, IMHO.
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So in other words, you think it sucks. :D
 
Yo,

I guess to keep my question plain and simple. Why is it that large diaphragms has more proximity effect? I guess i missed it or miss understood. Is this part actually based on the size of the diaphragm or something else?

Yah i understand the voltage part to the back diaphragm. I guess i might be a little confused on what causes the proximity effect is so i might hop into the big mic thread and re-read that part.

Danny
 
darnold said:
Yo,

I guess to keep my question plain and simple. Why is it that large diaphragms has more proximity effect? I guess i missed it or miss understood. Is this part actually based on the size of the diaphragm or something else?
Danny
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Any directional microphone is a pressure-gradient type, where sound wave reaches both, front and rear of the diaphragm. With close distances, pressure difference on LF can be substantional, because of relatively to front, rear path will be longer. Of course, the bigger diaphragm, the longer this path, the more pressure difference, the more proximity effect.
 
Whatever our personal beliefs are, that's a pretty serious statement for a company like Gefell to make. I've posted it as a question at Klause Heyne's forum for comments since he has most of the major mic manufacturers reading there. For those of you who want to follow along, it's at:

http://recforums.prosoundweb.com/index.php/t/2451/26/
 
DJL said:
Bummer... no response on your thread yet. :(
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Not so fast. Don't be impatient, DJL. The traffic there is much slower--guys there kinda take time to answer--unlike many other boards, they think before they write.

I won't be surprised if somebody will actually say completely opposite to what I wrote, and support Gefell's statement. But I feel good--at least it seems that Harvey thinks the same.
 
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Marik said:
Not so fast. Don't be impatient, DJL. The traffic there is much slower--guys there kinda take time to answer--unlike many other boards, they think before they write.

I won't be surprised if somebody will actually say completely opposite to what I wrote, and support Gefell's statement. But I feel good--at least it seems that Harvey thinks the same.
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They answered the question and basically, it's a flaw in "dual diaphragm" condenser mics that lets them make that statement.

Below a certain frequency, the rear diaphragm adds enough resistance to the delay network to change the mic from a cardioid into an omni at very low frequencies.

For direct comparisons between small, single diaphragm cardioids and large, single diaphragm cardioid mics, bass response would not be better with the larger diaphragm mics. The Neumann TLM103 is a single diaphragm mic, for example.
 
Sorry about referencing lower line AKG mics I forgot I am dealing with gear snobs. How about this test using a matched pair of km184 Neumann's and a pair of U87's to record an acoustic guitar. I heard both and a/b'ed the tracks over and over at my cousin's studios and the U87 recordings were far better. The U87's had better bass, more depth, and were overall more musical. Why use a sdc when you have great ldc's that are more effective.
 
Ahh that makes more sense. I new it had something to do with the bass hitting the back diaphragm but i didnt quite catch how that would make more bass than less. But that makes much more sense.

night'schild - thats all personal preference, and doesnt prove the fact that large diaphragms have more bass, just more colored bass. I own two Neumann KM184s and used to have (just recently got rid of them) two Neumann U87s. My personal preference would have never preferred the U87 on acoustics guitar over the KM184. Remember your not really looking for a perfect frequency balance in all the instruments you are looking to give each instrument its own sonic space. Do you really want a lot of bass frequency in acoustic guitar if you are putting it up with a bass guitar and vocals, with possibly drums? Chances are those bass frequencies arnt going to matter much so you might as well get the best color with the highs. You want to retain some mids and lows but when your putting it up with all that you need to find a place in the mix more in the high string frequencies. This all dependent on what your mixing with it. Now if it was acoustic guitar alone maybe a U87 would work pretty well and balanced. But i think even still i would rather do a small condenser right up close and a large diaphragm over the shoulder to get the warmth.

But i guess if the U87 is the way you like it, that totally cool too. But it still has nothing to do and neither does it prove that large diaphragms pick up bass better. Its just more colored. In fact in my opinion they pick up worse because of the proximity effect and the inaccurate colorizing that it adds. So in reallity its probably inbalanced to the source. But might be what your looking for.

Danny
 
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