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Gear / Technical Help => Microphones & Setup => Topic started by: tgakidis on December 09, 2008, 06:10:59 AM
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I know this is nothing new, but I made some bars for my Jk Labs AKG Actives set up. Total cost less then $8.00 with left over tubing.
I made a 3' split omni Bar, a DIN Bar and a DINa bar. I have screws in the angle sections so I can pull them off and slide the shock mounts on and off. The screws also ensure proper placement.
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:coolguy:
No war wounds on the fingers or thumb either! Nice job!
I have a dumb question...when people run split omni's, do you run the capsules pointing forward or upward? I may have been messed up by seeing some Schoeps capsules, but I thought I saw someone once running some omni's with the capsules pointed towards the cieling??
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Great idea with the locking screws! I'm totally stealing your idea. 8)
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I thought I saw someone once running some omni's with the capsules pointed towards the ceiling??
I did this recently.
(http://www.soundonsound.com/images/forum/www_hotlinkfiles_com_files_361767_jxdzb_RM2020KMD20Piano20for20web.jpg.png)
This was because I was using diffuse-field omnis in the nearfield (only 2-metres from the piano).
A diffuse-field omni has a high frequency boost to compensate for the lack of HF in the diffuse field beyond the reverberation radius.
If you look at the polar pattern and frequency response of such a microphone, you will notice how, because of the physical size, a normal omni gets a bit directional at higher frequencies.
If you use the mic. in a vertical position, you will see that the natural roll-off at high frequencies to sound coming in at 90º off-axis compensates for the rising top-end - the result is a flat frequency response at 90º off-axis when using the mic. in the nearfield.
Which is what I did for the piano recital recording pictured.
It worked perfectly well - we did four CDs with an initial run of 3,000 of each.
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I made some bars for my Jk Labs AKG Actives set up.
Nice work. Simple, clean and effective. Not sure about the active cable and connectors and it may be too much of a PITA, but it would be totally trick to run cables through the tube for the 3'er.
I like the low profile color of charcoal ABS tubing. If you care to, you can knock the remaining glare off the slightly shiny, satin surface with some emery paper or fine grade sandpaper. I've done that before and the resulting matt finish makes the tubing and especially the fittings visually 'disappear' even better by eliminating the highlighting reflections of lights. If you want the things to look all 'spensive and less like plumbing you can use a courser grade first to smooth down the mold lines & surface features of the fittings before applying the finer emery finish.
I did this recently.
Pretty blue lights and labels.. are those the digital output Neumanns, John?
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Very cool. I will try to make something similar to this when I get my Busman actives. (2009?)
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ser epic
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Pretty blue lights and labels.. are those the digital output Neumanns, John?
Yes, the KM 183-D.
But I now also have the KM 131-D (flat omni) heads as well, but those were not out when I made the piano recording; hence using the 183s vertical.
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I now also have the KM 131-D (flat omni) heads as well, but those were not out when I made the piano recording; hence using the 183s vertical.
Ahhh, yes. Just noticed your avatar.
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schoeps also makes the mk6, which is a side address capsule (like an mk4v), which is switchable to omni
:coolguy:
No war wounds on the fingers or thumb either! Nice job!
I have a dumb question...when people run split omni's, do you run the capsules pointing forward or upward? I may have been messed up by seeing some Schoeps capsules, but I thought I saw someone once running some omni's with the capsules pointed towards the cieling??
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tonedeaf, you wrote:
> I have a dumb question...when people run split omni's, do you run the capsules pointing forward or upward? I may have been messed up by seeing some Schoeps capsules, but I thought I saw someone once running some omni's with the capsules pointed towards the cieling??
John Willett's reply has the essential information in it, but jerryfreak also has a point: Sometimes it only looks as if a microphone is pointed upward (away from the main sound source).
The summary is that omnidirectional condenser microphones are generally pressure transducers, and if you want one with "flat frequency response" there are four basic design alternatives, which differ mainly in their behavior at high frequencies (say, 2 kHz and above):
(a) those which give flat response on axis, with reduced high-frequency response off axis;
(b) those which give flat response off axis, with elevated high-frequency response on axis;
(c) those which give flat response if you integrate all angles of sound incidence; and
(d) those which give flat response for all directions of sound incidence--literally the same frequency response on axis as off axis unlike (a), (b), or (c)--but are noisy.
Most people, given a choice, prefer some version of (c) for general music recording, except in special circumstances which call for (a) or (b). Few people prefer (d), but there are some such people, and there are also special circumstances in which their approach could make more sense than usual.
If you had (b)-type microphones, such as John Willett's KM 183Ds, then to use them at medium or close miking distances you would need to point them away from the main sound source to avoid the elevated high-frequency pickup which is characteristic of their type. The newer omni capsules which John mentioned are of type (a) and are very suitable for close, direct pickup without emphasizing the highs and without having to aim them away. In fact, if he aimed those mikes up at the ceiling, he'd get a sound that was deficient in the high frequencies.
On the other hand for distant pickup in a highly reverberant sound field, you really need something like a (b)-type microphone or else you'll notice the lack of highs right away. It's not exactly brightness or dullness since it's occurring mainly an octave or so higher than the range that determines ordinary brightness or dullness, but it's very noticeable when that range is out of balance with the rest of your sound pickup. An excess is more disturbing to most people (they hear it as "metallic" or "artificial" sounding) than a corresponding lack would be, but the lack is no fun, either.
For most music recording with omni mikes at moderate distances in moderately reverberant environments, an in-between response is usually preferred--but that type of microphone can't have flat frequency response on axis, unless it's so small that it would be unacceptably noisy. Instead it will have some moderate elevation (say 2 - 4 dB) at high frequencies on axis, rather than the 6 - 8 dB elevation of a (b)-type microphone.
--best regards
P.S.: For those desiring extra credit, acousticians would call (a) a "free-field" type of microphone and (b) a "diffuse-field" type. For recording in an anechoic chamber (a) is ideal, while for recording in a dreamspace where the echoes go on forever and there's no localizable direct sound, (b) is ideal.
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D,
As usual you've done an outstanding job of clearly exlpaining things - even for those of us that know the principles you're explaining but aren't always able to state or catagorize as succinctly. Thanks for that!
...Few people prefer (d), but there are some such people, and there are also special circumstances in which their approach could make more sense than usual...
Care to go into more detail on this one?