two2the8

Hey @PhillipWestbrook, sorry to miss your comment. That Superlux sounds cool, I'll check it out. It's a great question you ask, about the goal of the stereo image. It's one I don't have a good answer for yet (though I'm all ears if anyone wants to make a suggestion!). I think my goal is probably more like your first option, though likely with some significant overlap between the two spatially. I'll have to listen to see what sounds OK. Thanks again to everyone who has pitched in. For anyone following along, here's where I'm at so far: I think I'll pick up four mics (4x Shure KSM 141s is my best guess so far) & two stereo bars. That will give me lots of options for setups, and having four of the same mic in the field will be great for redundancy & repairs, too. Plus the KSM 141s are switchable to omni, so they're versatile for all sorts of other situations I might encounter. Anyway, I'll run these into a 552 (in the process of purchasing now) and out to a minimum 4-track recorder, probably the F8. I'll try to do some experiments before I go to see how the various setups sound. After I read the stereophonic zoom, I did up some diagrams to picture the different setups for my application. In theory, for two choirs seated opposite each other, back-to-back spaced pairs appear to align the 'null' areas of each stereo pair to create the best rejection. I'll attach the diagrams. They're keyed to the pickup pattern of the MKH 40, roughly. I know there are problems with thinking about the nulls, but it was fun to make anyway, and maybe it's a little bit instructive? There's a little guide to the diagram below, if anyone's interested. If it *is* the case that spaced pairs would work decently well for this application, will I have problems when I go to mix? If I narrow the image of each AB pair, am I likely to introduce phasing problems? --- Guide to diagram: 1: an approximation of the cardioid pickup pattern. 2-6 (ORTF) 2&3: What each mic picks up in ORTF. Note the darker purple & brownish-green areas correspond to the SRA from the stereophonic zoom article: sources inside that zone will record in both mics; sources outside will record in just one. 4: What all mics are picking up. Note the areas of bleed. The next slides project out to show how this bleed encompasses both groups. 5: Projecting outward using the same angles to show how the bleed works for the top mics. Same is true for the bottom mics. 6: Projecting outward using the same angles to show how the bleed works for all mics together. It gets too messy here to show what's bleeding where. The upshot is that, with this arrangement, there are basically no null areas. Every mic catches about 2/3 of the off-channel group. 7-11 (XY) 7&8: What each mic picks up in XY. Again darker purple & brownish-green areas correspond to the SRA from the stereophonic zoom article. The considerable overlap is part of why XY sounds less interesting than ORTF—XY looks wider, but it sounds narrower because there's nothing in your sound source that will sit on the far side of either channel. 9: What all mics are picking up. Note the areas of bleed as above. The next slides project out to show how this bleed encompasses both groups. 10: Projecting outward using the same angles to show how the bleed works for the top mics. Same is true for the bottom mics. 11: Projecting outward using the same angles to show how the bleed works for all mics together in XY. Again, it's too messy here to show what's bleeding where. Bleed is not really any better here: with this arrangement, there are still basically no null areas. Every mic catches about the same amount of the off-channel group. 12-16 (AB) 12&13: What each mic picks up in AB. Again darker purple & brownish-green areas correspond to the SRA from the stereophonic zoom article. Overlap is comparable to ORTF. 14: What all mics are picking up. Note the smaller areas of bleed as compared to those above. The next slides project out to show how this bleed encompasses both groups. 15: Projecting outward using the same angles to show how the bleed works for the top mics. There's almost none. Same is true for the bottom mics. 16: Projecting outward using the same angles to show how bleed works for all mics in AB. It's relatively easy to see what's bleeding where: almost nothing of your desired sound source is bleeding. Null areas align so that you get maximum rejection. Every mic catches only about 1/8 of the off-channel group, if that. Microphone_Nulls_V2.pdf

Hey, thanks again @The Immoral Mr Teas! (Sorry to leave you hanging, I was off traveling for the week). I'm reading the stereophonic zoom now & thinking on all of this advice. I also came across some ideas this week that might give me another reason to go F8 or 680 or something like to use the extra inputs. I'm not sure yet, there's lots to think about. In the meantime, that article is really great, and I sure appreciate your help! @JackHenry thanks for the tip... I'll pop by there & see what I can learn.

Wow, Jez (@The Immoral Mr Teas), thanks for the great response. Reading about B-format is blowing my mind! Well, my primary aim is to create good documentation for archival purposes and for music analysis, but I am also interested in working toward some kind of limited release CD/DVD publication if I can manage to get good recordings. Galleries/museums are an option, too. Most of the market for this stuff will be fairly local to the area where I'm working, which is pretty low-tech—not much likelihood of rendering ambisonic recordings in surround-sound. Fortunately I don't own much equipment yet, so I can kind of build up my kit with this project in mind. All my previous work in field-recording has been working with other folks' gear, which has been a wonderful luxury & a great learning experience. For myself, I'm looking at multi-track field recorders & mixers: I'm seriously considering the F8, maybe with a 422 in front for the nice preamps, or if I can get the scratch together maybe a used Zaxcom Maxx or 744 or something like (I wish the 552 recorded four tracks!) If you have thoughts about others to consider, I'd be interested to hear them. For mics, I'm considering two of the NT4s or BP4025s, for ease of use as I mentioned, but I'm a bit torn as to whether to go with integrated stereo mics or to pick up single mics which could prove more versatile. A hard decision—I'll have to do a bit of testing to see how I like the sound of the stereo mics before I can decide. This is all very helpful, too. I will look into making MS out of XY—that's an intriguing option for fixing imperfect setups later. Is the idea that you re-encode the two mics to approximate a centre and a figure 8 instead of the X & the Y? That's neat. If you're up for it, I'd be interested to know more about the challenges of L-CR & CL-R that you mentioned. Thanks again!

Well, I guess I'm trying to use option a) to get to option b), but maybe that's silly. I want to record both groups relatively cleanly—like mic'ing single instruments for a live band, but in stereo—and then use those clean recordings, created separately, to create a mix that gives an impression of the overall event. I have done a bit of experimenting with throwing up just one ORTF on the whole event, and while the stereo image is really nice, the chatter in the off channel gets really overwhelming at times. That's good to know, thanks! @jhharvest, thanks! Great to know, and thanks for the advice on mixing. I guess I'll do some experimenting before I go out & see what sound right.

Thanks for the replies! @Philip Perkins, that really would be ideal, but unfortunately in this case that's not really an option most of the time. For the most part I'll be recording singing that is associated with ritual events, and the singing is largely improvised, so I can't really do it over again or record the groups one at a time. The choirs in these events are non-professionals, and the singing is not really a performance, it's more part of the festive ritual atmosphere, so the singers are not particularly concerned about quiet. I do love ORTF, though—I find it a bit of a pain to set up in the field, but I think it sure sounds *great*. My concern about ORTF in a setup like I describe is that, if the groups are sitting opposite one another, pairs of ORTF cardioids will each pick up more of the 'off' group than pairs of X-Y (or M-S) would. (At least, I *think* that's the case, when I plot it out in my head. It's a bit confusing). @jhharvest, sometimes, ya! The chatter can range from being interesting commentary on other singers, to folks practicing bits to sing next, to singers conspiring together about a verse, to mundane talk about lunch. There's often coughing and the like in the off-choir, too, which I'd like to minimize. (I do usually shoot video, too, but I'm not too concerned about keeping the mics out of the frame. If it's easy to do, then sure, but since it's principally documentary I mostly don't mind). The pieces are typically quite long. Do you have thoughts about ways to mix the two choirs that wouldn't be so distracting? Left-centre, centre-right is really just an example I used to explain, but I actually have been thinking about starting with something more like L-CR & CL-R, giving a lot of overlap to the two groups, but keeping them just a little bit spatially distinct. In any case, from your comments it sounds like it's possible to muck about with the stereo width after the fact without making too much of a mess? My previous recording gigs have all either used two channels straight to stereo or multiple mono ISOs, so I've never really had to wrestle with adjusting stereo width in post.

Hi all, I'm new to the forums, so I hope this is the right place to post this. I'm a beginning ethnomusicologist, and I'm about to embark on a long field-recording project that will often involve recording two choirs that take turns singing to one another. The choir that is not singing at any given moment, though, is often very chatty (and I can do very little to control this). I've been thinking that I would like to record the two groups separately so that I can reduce the chatter when making a mix later. I have done some previous work with similar choirs, and I really like how they sound in stereo, so I would also like to make stereo recordings for each group. I am just beginning to think through my kit and approach, and here's what I'm thinking so far: Set up two stereo rigs, one for each choir (maybe using a single-point stereo mic like the rode nt4 or bp4025, for simplicity). Set the rigs up facing opposite one another, to maximize rejection of the 'off' group. Use a 4-track recorder to capture each stereo pair separately. Later, when mixing, duck the volumes on the 'off' group with each alternation, and mix down to a clean stereo recording. Assuming I've explained my problem clearly, does this approach seem feasible? Are there other/better/smarter approaches that I'm missing? Also, a related question: say I've recorded each group as an XY stereo pair, with each channel mixed hard-left and hard-right. When mixing later on, can I narrow the respective stereo field of each group? For example, can I place group A on the left side by mixing them hard left & centre, and then place group B on the right side by mixing them hard right & centre? Or will narrowing the field like that destroy the stereo effect for each group? Thanks very kindly for any and all advice you can give.