Stereo Techniques with Supercardioids

[CGBrian.M]

Next week, I will be doing a recording with some supercardioid mics that I just purchased, and wanted some input on what stereo recording techniques are used for best pick-up. I'm thinking DIN or DINa at the moment, or perhaps closely spaced?
The recording will be done in a medium(ish) size hall with a 3 1/2ft. lipped stage. I'll have the mic stand on the floor just in front of the lip for sure, and hopefully if my new mic stand arrives by then (Quik-Lok A85), I'll be able to go up about 10-12 feet.
Thanks for any help.

Brian

Updated files below.

[hughesmr]

I think Jerry Bruck used to recommend 25 cm spacing and 103º for MK41s as a quasi-ORTF setup. You may need to pull back further than you would with cards or subcards. As with most stereo techniques, adjust to taste.

[David Spearritt]

To assist with your reading on this subject, this is valuable.
http://www.davidgriesinger.com/spati...on_and_loc.doc

and interesting stuff in here.
http://www.davidgriesinger.com/recording_verdi.ppt

both from http://www.davidgriesinger.com (obviously)

[David Rick]

In the classic Williams Stereophonic Zoom paper there is a chart specifically for near-coincident supercardioids.

I use supercardioid/hypercardioid pairs a lot. In many distant miking situations, you can't get a decent stereo spread using cardioids without using such an extreme angle that you get bad coloration due to their off-axis response. OTOH, if you're recording a full orchestra, you often can't get a wide enough working angle using supercardioids. That's when I turn to cardioids -- with omni outriggers.

David L. Rick
Seventh String Recording

[Sheikyearbouti]

The Michael Williams curves are very useful for such pairs. The AES paper has a graph for fig8 pairs as well. As far as I know he uses hyprcardioids a lot for surround recordings. The point is that you get a great separation between the channels and when arranged correctly you get great localization with less stereophonic distortion. The biggest problem would be the bass response but I heard that he uses some sort of "very special" mics.

David, I know that the point here is to use as few mics as possible, plus why making things unnecessarily complicated, but maybe the stereo width problem can be solved with 3x hypercardioids (L, C, R) used again according to the curves? Has anyone tried something like that maybe in a different situation?

[pkautzsch]

This might help too, as to recording angles:
Image Assistant

[Sheikyearbouti]

pkautzsch, this is a great tool. Thanks for sharing. There is another one online but the application itself is written bad and it crashes all the time. This one looks quite functional and much more professional. thumbsup

[CGBrian.M]

Rather than start a new thread, I'll update this one with samples from the recording with the supercardioids.
Look at my first post in this thread for a description about the hall. I ended having the mics about 6-8 feet out from the performers, and another few feet from that from the piano lid. The mics were about a few feet above the performers, with the stand on the floor below the lip of the stage. Total height for the mic stand was about 12 feet, maybe a little less.
There are three samples here. The first two flute samples are the same flutist and accompanist in the same hall. The first example is last year with ADK TL (Stock) matched pair set to omni. The set-up then had the mics on two different stands about 3 feet apart and 3 feet below the performers. The second example is this years with the above set-up and CAD E100S' pair.
The violin example is also this years with the same set-up.
The whirling noise you here in all examples is the A/C unit (I live in Phoenix after all, and it's already into the 90's regularly). Having said that, I still think the E100S' are noticeably quieter, although it's difficult to say whether the omni setting with more ambiance pick-up is accounting for most of the extra noise.
Again, keep in mind that these are students, and only the flutist is going to make a career in music (he's attending Indiana's Jacobs School of Music in the Fall).
Let me know what you think.

Brian

Updated with edited files. Please let me know if you hear any improvement, and what else might be done to make them better.

[didier.brest]

Too much room in the first sample. Piano too thin in the second sample and sound too dry, an issue that you could solve by means of digital reverb.

Cardioid mics could be nice here.

[CGBrian.M]

Originally Posted by didier.brest

Too much room in the first sample. Piano too thin in the second sample and sound too dry, an issue that you could solve by means of digital reverb.

Cardioid mics could be nice here.

I'm aware that the piano sounds thin. Result of where I had to place the mics, among other factors. I'm experimenting with EQ (and reverb) to try to restore some of the low end lost on the piano.

What did you think of the sound of the flute and violin?

Brian

[David Rick]

Originally Posted by Sheikyearbouti

David, I know that the point here is to use as few mics as possible, plus why making things unnecessarily complicated, but maybe the stereo width problem can be solved with 3x hypercardioids (L, C, R) used again according to the curves? Has anyone tried something like that maybe in a different situation?

I've a fair amount of LCR recording, but it was destined for LCR playback. An interesting array of this sort is Theile's OCT tree, which I use a lot. It has two side-facing hypercardioids (Schoeps 41V's are recommended) and a (slightly forward) front-facing cardioid. The stage width is controlled by changing the spacing between the hypercardioids, which is quite easily done when you have a good mic bar such as those from AEA, Grace, or Schoeps.

Theile mentions that this array is not optimal for downmix to stereo -- for that he recommends the OCT2 configuration which pushes the cardioid much farther forward. You can experiment with these and similar configurations using Image Assistant.

Williams did attempt to expand his design methodology to 3, 4, and 5 mic arrays. There are several AES preprints available, and he eventually released a CD of design tables which helps choose among the many configurations that he analyzed. I use this tool occasionally, but in my opinion he was overly concerned with full-circle imaging, and insufficiently concerned with the conflicting virtual images that result when (for example) a stage right instrument is also heard through the Center+Left mic pair. When using an OCT tree, that same right instrument is mostly in the null of the left-facing hypercardioid.

David L. Rick
Seventh String Recording

[CGBrian.M]

Bump for feedback on updated files.

[CGBrian.M]

I'd really appreciate it if I could get some feedback on the new flute/violin files compared to the originals. It was the first time I really experimented with EQ and reverb in my DAW, and I tried to restore the low-end and low-mids from the directional mics being so far away from the source. I also tried to remove some of the A/C and PA noise that was present, although the drone, I think from the PA, was at about 129hz, and it took to much away from the piano, so I left that in.
I used a graphic EQ to remove the A/C noise, and experimented a lot with a Linear Phase EQ to restore the sound of the piano. I then added reverb from one of the presets in the reverb built into my DAW.
Thanks in advance for any help provided.

Brian

[didier.brest]

I much pefer the flute sample 2010 no. 2.
Good enough. The piano is not yet beautiful, still a bit thin. I suspect that it was like that ?

[CGBrian.M]

Originally Posted by didier.brest

I much pefer the flute sample 2010 no. 2.
Good enough. The piano is not yet beautiful, still a bit thin. I suspect that it was like that ?

It definitely sounded a little thin overall. I think the mics were just to far back from the piano (something I could not help). The piano used was this one: Grand Piano 187
I have several solo piano recordings from the concert, and I'm having a hell of a time getting them to sound at anywhere near a satisfactorily level. WHY IS PIANO SO HARD TO RECORD?(!)
I'm quite satisfied with the sound of the other solo instruments (flute, violin, french horn), whether with piano accompiament, or not. The E100S' show a flat response from 40hz-4khz, with a slight rise and then dip. Of course, this was probably from about 1 foot away (0.3m). From the distance of 10-12 feet that I recorded, that response is probably meaningless.
I'll keep trying to make it better.

Brian

[Oli_W]

I do like the 2nd flute sample - i think the piano still needs thickening - some large/broad boost at about 60Hz?

I feel it is all a little skewed to the left aswell, anything you could do to just move it over a little bit?

[CGBrian.M]

Originally Posted by Oli_W

I do like the 2nd flute sample - i think the piano still needs thickening - some large/broad boost at about 60Hz?

I feel it is all a little skewed to the left aswell, anything you could do to just move it over a little bit?

Still experimenting. There was a lot of low level noise (from a/c and pa systems) from about 20hz-75hz, and I'm trying not to exaggerate that noise, while at the same time trying to thicken the piano sound.

I didn't hear anything skewed to the left, although the flutist moved around quite a bit while he was playing. Is that what you're hearing?

Brian

[CGBrian.M]

Ok. I recorded a middle school piano recital last week, and placed the mics about 2 feet or so (0.5m) away from the lid of the piano. Mics were placed away from the crook of the piano in a DIN sorta set up-capsules about 8 inches (20cm) but angled more like 75 degrees instead of 90. Basically, one mic pointed towards the hammers, and the other towards the end of the piano. The piano was a Yamaha C5. recording venue was a small church with decent sound, although with the close miced situation, you won't really hear that. I added a small amount of reverb so it's not so dry. Ideally, I would've liked to have placed the mics about another foot out (1 meter total) so to not make it so intimate. But nevertheless, I think the results are pretty good.
I have to say that I'm much happier with this result, and feel these mics are very capable of achieving a wonderful sound when placed properly (although that can be said for almost any mic).
Let me know what you think.

Brian

[didier.brest]

Hi Brian,

the piano timbre is OK here but I just agree with you: it's too close. I don't get a spatial representation of the instrument by listening on earphones. Your digital reverberation seems lacking early reflections for giving a room feeling and making sound the piano more distant. Also I would have preferred a narrower stereo. Since the room was rather good, you might have try a pair of omnis, the ideal setting for piano recording.

Didier

[joelpatterson]

Originally Posted by CGBrian.M

...Let me know what you think.

Pretty damn gorgeous, I think... the one little quibble I would take to the gaming tables would be the sensationally crisp and active top end of these mics is just a little TOO revealing on the upper end, in this scenario, maybe-haps... the shimmers of the notes ringing out, the attacks and detacks (new word!) are carrying the actual signature of how those strings are responding, and somehow that's distracting me from the body and the currents of the music, it's snapping be back into reality, when I want to lose myself in a dream...

Nice job, I say!

[jnicholl17]

As in Joel's review of the E100S, I really like how the violin recordings turned out. The recording in Joel's review of the E100S is stunning, and the recording here is tonally similar, thought the violinist could have been a better performer. (No offense intended, I'm sure I'm much worse.) The flautist is obviously very talented. The flute recordings are excellent, but that seems more because of the skill of the flautist than because of the microphone (it's still a very good recording).

The new piano recordings are much better. The placement may be a little too close, perhaps due to overcompensation from the first effort (third time's the charm?). I very much like how the high notes cut through the chords. It might be a little exaggerated for Joel's taste, but I like the effect.

I think the choice of hyper cardioid mics might have been a good idea to keep crowd noise down to a minimum. Even with a hyper cardioid there are some minor distractions, I can imagine how cluttered the recording might have been with an omni.

I'm looking at picking up a CAD E100S myself. It's good to hear samples that were created by someone learning how to use the mic, rather than someone who helped design, test, and refine the mic, and then figure out every DSP trick to get the most out of the recordings... I'm much closer to the former than the latter.

Thanks!

James

[CGBrian.M]

Didier: Unfortunately, the only omni's I currently have are the CAD E70's that came free with the mics I used here. They sound like the cheap, off-the-shelf Chinese mics that they are. So no go with that option.

Joel: Thanks for the compliments. Yeah, my girlfriend (who is one of the piano teachers at this school) also thought that the percussive aspects of the high-end (from the hammers) was to prominent. Like I said before, even another foot out would probably cure all that.

jnicholl: Yeah, definitely still learning how to record, and use the equipment that I have to its fullest potential. One of the problems with recording live events all the time is that there are several factors that influence how the recording will turn out (i.e. sight-lines, scaring young people with all this equipment in their faces!, directors telling you what/where you can place the mics, etc...). Put simply, ideal situations in regards to performing live events are rare, and we have to capture the performance the best we can within those limitations.
Virtually all the recordings I post here on GS are of young people who mostly will never make a career in the music industry, are playing on VERY low end instruments, and haven't developed a mature sound on their instruments in any way. It's only for their reference, mine, and their schools.

In the piano recordings, while everything Didier said is completely true, I was still very happy with the timbre, balance, and articulation. Overall, I think there is more right with the recordings, given the limitations, than wrong.

I plan to keep working at this! Next step is to sell some of my current mics that I don't use or want, and purchase some good omnis.

Brian

[Matti]

I used Schoeps 41 pair for many doc. situations at the time, where I couldn´t show the mics on cameras and no possibility to rig, just narrow the angle and get further back.

Matti

[Tom McC]

Originally Posted by MATTI

....where I couldn´t show the mics on cameras and no possibility to rig, just narrow the angle and get further back.

Assuming the camera is zoomed in to fill the screen with the performers stage, wouldn't you perhaps have to _widen_ the angling of the hypercardioids as you move back?

Doing this would reduce the mics Sound Recording Angle (SRA), thus retaining a match with angle subtended from the stage

[Tom McC]

Originally Posted by Tom McC

Sound Recording Angle (SRA)

Stereophonic Recording Angle (Williams etc) - need to polish my acronyms :-)