Topic: Best time to use omnis vs. cards

[jasonw]

Just wanted to see...what everyones thoughts were.  I want to play around with my caps but I dont want to goof up a recording that I also will want to listen to / distribute later on.

[cleantone]

speaking only about ambient audience recording...

you would mostly want to use them when a crowd will be respectful and not chatty. When you can record from close to the sound source, onstage and such.

[wbrisette]

As mentioned already, you need to get fairly close or use them to augment mics, I did some demo mixes for people at one point. Maybe we need to find a location to post those for good. It was several clips of a show I recorded for Black Rebel Motorcycle Club. I ran six channels that night two were using the Earthworks SR-77s (cards), two were using the Earthworks QTC-1s (omnis), and two were of the board itself. I put together samples of the cards and omnis by themselves, the combined omnis and cards, and the final six channel master.

I recently recorded a 40 piece steel drum band using three earthwork QTC-1/QTC-40 mics in a Decca tree that turned out great. But for the most part I always use the omnis to augment other mics. Rarely do I use them by themselves.

Wayne

[Shawn]

I like to run split omnis in open air outdoor venues. Even by themselves they can yield pretty good results.

[Roving Sign]

Omnis work very nicely outdoors - a nice choice for festivals - I think outdoor cards can color the sound a little too much - they also seem to emphasize air/wind motion - more of that swirly phase shifty sound.

Sometimes indoors - when a room has nice ambient "ding" to it - I like to use omnis - especially if you have good spot.

[wbrisette]

omni sample.... I put the omni samples up on my site if you want to check out nothing but omnis. This is acoustic (where I think omnis tend to sound better) and these were in a Decca tree...

http://www.wbwoodworks.com/samples/hothothot.mp3 (5.3 MB)

http://www.wbwoodworks.com/samples/hothothot.flac (130 MB)

The MP3 is 16/44.1, the flac is 24/96.

Wayne

[Brian Skalinder]

As mentioned already, you need to get fairly close or use them to augment mics, I did some demo mixes for people at one point. Maybe we need to find a location to post those for good. It was several clips of a show I recorded for Black Rebel Motorcycle Club. I ran six channels that night two were using the Earthworks SR-77s (cards), two were using the Earthworks QTC-1s (omnis), and two were of the board itself. I put together samples of the cards and omnis by themselves, the combined omnis and cards, and the final six channel master.

The samples are still up on tapers.org:

ftp:   tapers.org
port:  21
dir:   /drive1/_gear_comparisons/omni_v_cardioid_v_sbd_v_mixes.flac16
login: ftp4all
pass:  ftp4all

[BayTaynt3d]

You'd want conditions that have some or all of the following when using omnis: (1) you can get relatively close so you can get a good direct to indirect sound mix, (2) you want a decent sounding room that isn't too wet or boomy, and (3) you want a relatively quiet room where there isn't a lot of drink-clanking and gabbing, etc. Also, omnis are great compared to cards/hypers when it's windy.

[gratefulphish]

I agree with BayTaynt3d, particularly regarding the noise in the room.  Omni means omni, meaning all of the yapping, clanking, bottle breaking or whatever that occurs behind the mics.  That is why I like subcard as an option in a lot of these situations.

[jasonw]

I agree with BayTaynt3d, particularly regarding the noise in the room.  Omni means omni, meaning all of the yapping, clanking, bottle breaking or whatever that occurs behind the mics.  That is why I like subcard as an option in a lot of these situations.

What do you mean by subcard? 

[rowjimmy]

sub-cardioid is also know as wide cardioid...

From Schoeps' site for their mk21 wide card caps:

This type of capsule has a directional pattern between omni and cardioid.

The basic idea in designing this capsule was to combine the advantages of the cardioid with those of the omni. This results in a pickup pattern which blends the two sets of characteristics in a useful manner. It has fuller and more extended low-frequency response than a cardioid, with less proximity effect, while attenuating side- and rear-incident sound less than a cardioid.

The polar diagram shows the directivity of the MK 21/
CCM 21 to be only slightly dependent on frequency. This contrasts with omnidirectional microphones, whose directivity increases with rising frequency, and with cardioids (at least smaller ones), which tend to accentuate high frequencies that arrive at oblique angles. The MK 21/ CCM 21’s orientation is less critical than with a cardioid, since direct sound arriving on axis and reverberant or other sounds off axis are both reproduced accurately. This lack of coloration in the off-axis pickup produces a “warm” and natural sound image.

When used as a spot microphone it must be placed somewhat closer to the sound source than a cardioid would be, due to its lower directivity.

Its uniform off-axis response helps to blend nearby instruments seamlessly into the overall mix. For wide pickups where some directivity of the microphone is advantageous, as in acoustically difficult rooms where the bass would be too strong when using omnis, the MK 21/ CCM 21 can be especially helpful.

The low directivity of this microphone type prevents it from generating large enough level differences for X/Y use, though M/S and near-coincident spacings are often successful.

[ghellquist]

Truee pressure omnis has several advantages over cardioids. (Non switchable omnis, the switchable mics are generally a little different)
- less sensitive to structure born noise
- less sensitive to wind
- goes lower in the bass frequencies

They also receive sounds equally (more or less) from all directions.

To get the same ratio between direct and indirect sound, if you put an omni at distance 1 you will have the cardioid at distance 1.6. So get closer with your omnis. At the same time put them higher to diminish the audience noise. But then you might get closer to the ceiling instead.

In the end, go ahead and test.

Gunnar

[wbrisette]

In the end, go ahead and test.

Agreed. Testing is the only way to really know how and where to use certain mics and how best to place them.

Since Brian was nice enough to post the link to the sample files I put together, take a listen to those too, they will give you a feel for cards vs. omnis, and combining them to get a different sound.

Wayne

[wbrisette]

whenever the cards have to go back to the manufacturer for repairs........

Moke: I think the general idea is not to break the cards, so they don't have to go back for repairs. 

Wayne

[gratefulphish]

whenever the cards have to go back to the manufacturer for repairs........

I would hazard a guess that Moke does not run Omnis very often.