Topic: Neumann Omni Question

[anhisr]

Bean, I didn't start "fixing" my AK50 tapes until recently.  The shows I sent you were not "fixed" yet. I will post my setting as soon as I have time too. 

[stevetoney]

Bean, I didn't start "fixing" my AK50 tapes until recently.  The shows I sent you were not "fixed" yet. I will post my setting as soon as I have time too. 

...and does this 'fix' satisfy you regarding the needed/desired amount of warmth, balance, or whatever?

[anhisr]

yep.  More of a warmth thing. 

[anhisr]

Bean, you are quite the slut 

[DSatz]

tonedeaf, a lack of "warmth" in a recording is one thing that can often be improved with fairly simple equalization. A friend of mine built what he called a "warm filter" once, which was just a Radio Shack box containing a couple of op amps with a shelving boost at around 250 Hz as I recall.

Let me just say that when I was active as a studio engineer, the older guys all used EQ with a degree of skill that I think has become almost a lost art. As far as I could find out, they used EQ as a matter of course on nearly all the live recording that they ever did, often in relatively small amounts such as 2 dB here or there, but knowing when and where to apply it was a thing which they'd learned through decades of practice.

I see that EQ has a bad reputation today--people seem to think that it spoils the "purity" of their sound--but I chalk that up to using too much in the wrong place, and also to some wishful thinking about how "pure" their sound is to begin with.

--best regards

[illconditioned]

Hey DSatz, I've got another question for you about "warmness":

I'm been recording with DPA 4060 lately, and find there is some kind of "harshness" in the sound.  All the frequencies seem to be there, and there is tons of detail, but I find the guitar amplifier, in particular, to sound harsh.  I don't think this is how it sounded in the room, either.  The mic seems to be doing something to it, but I can't say what.

The clip is at: http://soundmann.com/2007-11-10-NathanColes_clip_dpa4060_eq.mp3
I'm not sure if I applied EQ or not, but it didn't really change the sound.

Comments?
  Richard

[DSatz]

The clip sounds a bit "glassy" to me. Spectrum analysis shows a sizable bump in the octave around 2 kHz, and I'd prefer less of that, or maybe none. I say that with caution since my computer loudspeakers are nothing serious and I don't know what kind of sound you like. But if your reaction resembles mine, you could try reining in the 1.5 to 3 kHz region by a couple of dB to see whether that gets at what's bothering you.

--best regards

[illconditioned]

The clip sounds a bit "glassy" to me. Spectrum analysis shows a sizable bump in the octave around 2 kHz, and I'd prefer less of that, or maybe none. I say that with caution since my computer loudspeakers are nothing serious and I don't know what kind of sound you like. But if your reaction resembles mine, you could try reining in the 1.5 to 3 kHz region by a couple of dB to see whether that gets at what's bothering you.

--best regards

Thanks!  I'll try to play with the EQ.  I'm wondering if there is more to it, though.  These mics are constructed quite differently than "classic" electrets.  They have a thin gold plated (mylar?) sheet, but it is rectangular, and not tensioned.  Instead it is just resting on the (articulated) backplate.  This probably accounts for the detail, but may be causing some of the weirdness as well.

 Richard

[illconditioned]

The clip sounds a bit "glassy" to me. Spectrum analysis shows a sizable bump in the octave around 2 kHz, and I'd prefer less of that, or maybe none. I say that with caution since my computer loudspeakers are nothing serious and I don't know what kind of sound you like. But if your reaction resembles mine, you could try reining in the 1.5 to 3 kHz region by a couple of dB to see whether that gets at what's bothering you.

--best regards

Hmm.  On second thought, could this 2k boost be caused by having the mics on my hat?  Anyway, even if reduce the frequency near 2k, it still sounds a bit "sharp" for my liking.  Maybe it did sound like that in the room, I don't know.  But it doesn't sound good on the recording!

 Richard

[KLowe]

I see that EQ has a bad reputation today--people seem to think that it spoils the "purity" of their sound--but I chalk that up to using too much in the wrong place, and also to some wishful thinking about how "pure" their sound is to begin with.

--best regards

This is THE MOST QFT statement I've read all year.  I'm firmly in the EQ to taste camp.  I have never understood all of the "EQ ruins the tapes" B.S.

DSatz...... you are a man among men.

[Tim]

I see that EQ has a bad reputation today--people seem to think that it spoils the "purity" of their sound--but I chalk that up to using too much in the wrong place, and also to some wishful thinking about how "pure" their sound is to begin with.

--best regards

This is THE MOST QFT statement I've read all year.  I'm firmly in the EQ to taste camp.  I have never understood all of the "EQ ruins the tapes" B.S.

DSatz...... you are a man among men.

My reservation is that many people don't know what they are doing and don't have good monitors to do the work on.

[Gutbucket]

The clip sounds a bit "glassy" to me. Spectrum analysis shows a sizable bump in the octave around 2 kHz, and I'd prefer less of that, or maybe none. I say that with caution since my computer loudspeakers are nothing serious and I don't know what kind of sound you like. But if your reaction resembles mine, you could try reining in the 1.5 to 3 kHz region by a couple of dB to see whether that gets at what's bothering you.

--best regards

Thanks!  I'll try to play with the EQ.  I'm wondering if there is more to it, though.  These mics are constructed quite differently than "classic" electrets.  They have a thin gold plated (mylar?) sheet, but it is rectangular, and not tensioned.  Instead it is just resting on the (articulated) backplate.  This probably accounts for the detail, but may be causing some of the weirdness as well.

 Richard

The interchangeable 'grids' on the DPA 4060 change the mic's high frequency response by creating a little resonant bump depending on the length of the grid tube.  The mics come with two different length grids, but some people also use them without the grids, presumably to get a flatter (possibly rolled-off?) high end response.  Below is a response chart showing curves for both grids for the DPA 4060. There is no published response data that I know of for the mics without any grid. The longer grid creates a bigger, peakier bump that is designed to help accommodate common lavaliere placement for announce/stage voice work.  I don't think many use the long grid for recording music.   

I wonder if the resonant tube design of the grids has something to do with what you're hearing, Richard.  I've thought about using some brass tube bits and experimenting with different tube lengths & possibly cutting the tube end at an angle to broaden the peak.  I've also thought about doing that to make the mic more side address oriented which would be beneficial for some of the ways I use them.  I realize that I probably shouldn't notice much directionality, given their extremely small size, the data from the DPA polar plot and my 4+ decade old ears, but I do hear some of the airy top end roll-off when off axis, so I point them appropriately. 

I almost always prefer the short grids. I do notice the emphasis which I often find useful at the distances from which I typically record, but can sometimes be a bit bright near cymbals for instance.  The only time I've found the long grid useful for music is when putting the caps flush on opposite sides of a 8" ball to emulate something like the Schoeps KFM6. I believe the omni caps in the KFM6 are diffuse-field eq'd or have some sort of additional high shelf boost (D.Satz, please correct me if I'm wrong), so it would seem that by using the longer grids perhaps I'm creating a more boosted diffuse field response curve suitable to a stereo sphere mic application? I only use that technique in the center of a circle of acoustic musicians, which is a different application than what the KFM6 is designed for in any case. 

Here's the polar plot & response graphs with the two grids, from DPA's site-

[Gutbucket]

Here's the 4060 polar plot-

[DSatz]

gutbucket, many thanks for the juicy diagrams but the frequency range that I find to be exaggerated in this recording is lower than where the peaks are in those diagrams. What I'm hearing is "too much of a good thing" in a frequency region near where most people's hearing is at its most sensitive.

That other stuff way up top is kind of--not the icing on the cake; icing is far more important than that. It's more like whether a few chocolate sprinkles on the whipped cream on top of the icing on the cake are glazed sprinkles vs. unglazed sprinkles.

I should really find out what type of microphone this is. The odd thing is that its polar diagram implies a rather small capsule (1/2" or maybe even smaller?) without much rolloff in its off-axis response at high frequencies. But when you have that characteristic, you no longer need a high-frequency boost in the 0-degree response (normally required in larger omni microphones that are intended for distant pickup, to bring up their diffuse-field response to something like flat). So the whole acoustical design is a bit of a puzzle to me--it seems like a special-purpose item which would only be needed in a hall full of overstuffed pillows (or people, perhaps).

--best regards

[Gutbucket]

^^^
That's why I figured I'd post the charts.. as you mention, the mic's response peaks are higher in frequency.  I just listened to the sample and hear the presence boost on the guitar but not the vocals, so maybe its due to the mic location more than the mic's inherent response? Could be directly on-axis with the guitar amp? Just a guess.

As for DPA's odd 4060 design- it's an extremely small back-electret lavalier mic, originally targeted towards stage and announce work and built to survive sweat, makeup, etc.  It has a very small 5.4 mm diaphragm that is oriented vertically, half of which protrudes from the cylindrical brass body of the mic. When one of the protective grids is installed the entire capsule in then 'inside the tube' facing to the side. Even though the capsule faces sideways, it's still a end address design and is measured that way in the polar plot. DPA makes several different sensitivities to match with different wireless manufacturers and most people around here have the lower sensitivity 4061 model which are commonly found used from stage productions.  The self noise and signal to noise figures are better for the hotter 4060 version however, and personally I find the 4061's a bit noisy for acoustic music. 

The mics became popular around here and for music recording in general because of their small size and their transparent sound.  Since their introduction, DPA has developed mounts to mic pianos, close-mic brass, guitars & violins, and now has a system of small preamp/stereo pan/summing boxes that chain together and feed a stereo mix to the board for the whole section.  Blasphemous as it may be for classical music, each members of a string section has their own small preamp and stereo sum buss chained to the next member with a single stereo feed for the whole section.

So it is a bit of a special purpose item and I'd guess that any frequency bump was initially engineered for 'on the actor' placement and happened to work out well for some music applications too.


4060 specs-
 
Sensitivity, nominal, ±3 dB: 20 mV/Pa; -34 dB re. 1 V/Pa
Equivalent noise level A-weighted: Typ. 23 dB(A) re. 20 µPa (max. 26 dB(A))
Equiv. noise level ITU-R BS.468-4: Typ. 35 dB (max. 38 dB)
Total harmonic distortion (THD): <1% THD up to 123 dB SPL peak
Max. SPL, peak before clipping: 134 dB
S/N ratio, re. 1 kHz at 1 Pa (94 dB SPL): 71 dB(A)
Dynamic Range: Typ. 100 dB

Microphone length: 12.7 mm (0.5 in)
Weight: 7.5 g (0.26 oz) incl. cable and connector