Omnis Spaced about 12" for classical recording?

[Bradley Steenkamp]

Hi all,

Has anyone tried Omnis spaced about a foot from eachother?

I ask this as I'm looking for a way to mount two stereo pairs on a single bar on a single tall stand for live recording. Something like the Sabra ST4 or the studiospares version would work. I could use my beyer mc930 pair in XY or ORFT in the center and then Omni pair of NT55 on the outer. But, the bar is only about a foot in length and this might not be quite wide enough for a pair of spaced omnis!

The other option would be to use the NT55 with the cardiod capsule in NOS config with the Beyer's in XY or ORTF on the center two.

Main reason for doing this is to have one pair feeding a seperate recorder so I have a backup when recording live. It would also give me an option of two setups to choose from post recording.

So, if anyone has tried Omnis spaced this close then please let me know! I've seen it used at a live recording at Guildford Cathedral (I'm guessing it was a Tonmeister course recording) but have no idea how it sounded.

Thanks
Bradley

[Ariosto]

Hi all,

Has anyone tried Omnis spaced about a foot from eachother?

I ask this as I'm looking for a way to mount two stereo pairs on a single bar on a single tall stand for live recording. Something like the Sabra ST4 or the studiospares version would work. I could use my beyer mc930 pair in XY or ORFT in the center and then Omni pair of NT55 on the outer. But, the bar is only about a foot in length and this might not be quite wide enough for a pair of spaced omnis!

The other option would be to use the NT55 with the cardiod capsule in NOS config with the Beyer's in XY or ORTF on the center two.

Main reason for doing this is to have one pair feeding a seperate recorder so I have a backup when recording live. It would also give me an option of two setups to choose from post recording.

So, if anyone has tried Omnis spaced this close then please let me know! I've seen it used at a live recording at Guildford Cathedral (I'm guessing it was a Tonmeister course recording) but have no idea how it sounded.

Thanks
Bradley

I have a studiospares bar which is 30cm (about 20 inches) long and will take 4 mics. (Cost about £11 incl. VAT and postage)

What size group are you recording?

I have recorded a piano trio using two omnis on a bar which put them about 8 inches apart. About two feet out from the violin and cello positioned left (vln) and (cello) right. Piano about 2-3 feet back and centre, with lid fully open. Worked OK but the room was small and accoustic not brilliant. It was a last minute setup and the only room with a decent piano available that day, for a rushed competition entry.

Ideally in a better accoustic a couple of feet further away would have been better I think.

[Aural Reject]

You need to get someone to make you an equivalent of one of

these which are 1m wide...although mine is, um, a little shorter than that

.

[Guest]

A cheap and very easy but slightly inflexible option:
If you get three of the long (4-mic) K+M stereo bars, you can join them together to get wider spacings than may be achieved with a single such bar. The assembly is easy to do (just take the mic bolts out of the left end of one bar, and the right end of the other, then screw them onto the mic bots of the third bar to extend it left and right) and strong. Disadvantages are that spacing isn't flexible - you have a choice of two holes at each end, and the whole thing is rather heavy. I do still use this sometimes but now use it less having got some longer single piece bars that are more elegant. You can also (on most stands) screw another mic holder onto the top of the stand thread after screwing it though the bar, so a centre mic/extra stereo mount becomes an option - handy for rigging an AEA R88/Royer SF12 or Schoeps UMS20 short stereo bar with a pair of spaced omnis on the wider bar on a single stand

More elegant but more expensive:
AEA "Microphone Array Positioners" come in various lengths and configurations and allow for multiple mic holders on each bar. There's also a kit of parts to allow these bars to be mounted in various ways, or slung, and to be bolted together to from hybrid mounts for Decca Trees. They are etched with distance markings for spacings.

The new Grace Design "Spacebars" are available in two lengths and are extremely well made. They come in two lengths, the longer particularly allowing more than two mic holders (extra holders are available from Grace) and are marked for distances (spacings) with the mic holders being marked for accurate settings of angles (something I've not seen before on an off the shelf product). They even incorporate a mechanism for tilting the bar front-back, to allow mics accurately to be angled up/down whilst the stand remains vertical and supply a modified mic holder to allow for positioning of capsules/mics one above the other in co-incident/near co-incident arrays.

Schoeps do a 1m stereo bar ( MAB-1000 ) with two or three mic holders and engraved markings for spacings. The bar may also be expanded with an extra kit of bits for OCT and/or OCT surround. You can also buy the mic holders alone if you want lots of mics on the same bar.

DPA do a long-ish (iirr about 540mm) bar with a couple of holders and you could get more holders from DPA (I think the bar is part no UA0836 (or 7) if you want to look it up).. Again, engraved markings and clever hanging tricks with a lovely finish but the bar is really balanced for DPA mics and imo you only get the full benefit from it if you use DPA mics. They also do a very pretty Decca Tree mount but again it's really at it's best with DPAs (though in all cases you can use what you like if you change the mic clips - DPA clips are rather small for most mics)

All of the above are in the hundreds of pounds bracket (some well into it!) and they all have their uses. Somehow, along the way, I've picked up all except the DPA tree mount and new Grace bars (though they're high on the shopping list ) and they each have their advantages and disadvantages. Mostly the disadvantages are cost related

A year or two back there was a guy in Switzerland selling some bars he'd had made which were a nice enough, relatively budget, product (about £70-£80) which are about 700mm long and have basic distance markings and four mic mounts. They're not bad at the price, though a little light and bouncy for heavy LDCs at the widest spacing (though they settle down when left alone). I've got a couple and they're great for flying pairs )or quads) of SDCs as they're nice and light and can accommodate quite wide spacings. I've probably still got his contact details somewhere if you want to see whether he still has any available.

Sabra Som bars aren't bad (though not great looking for live work) and you very cheaply can get hold of the hex profile steel rod they use in more or less any length from most decent steel stockholders. Buy a coupld of short bars (if the mounts aren't available on their own - they might be) and a length of rod to get the wider spacings. Then all you need is a tape measure and a Sharpie

There are probably others.

Alternatively, build your own - or draw it and take the drawing to a fabricator/engineering workshop and get them to make it up for you.

If you don't care what it looks like, a length of Dexion (or similar) punched steel angle will work fine. You can saw it to an appropriate length then get some 3/8* Whitworth nuts and bolts (Canford sell them if you can't find them locally) and slip them through the bar more or less wherever you like (you might need a file to open out the holes a bit). You can also add some bits of metal (Dexion used to have a suitable bracket in their range) to join two bits in a T shape for use as a Decca Tree. (That's how I made my first Tree mount after seeing pictures of some early Decca sessions using Dexion-like mounts; I've still got it somewhere )

Or get yourself down to a kite shop and pick up some carbon fibre kite spar and the little plastic/metal fittings and widgits used to put it together. Add some Araldite/metal loaded epoxy (or whatever they recommend), odds and ends of mic clips, nuts, bolts, etc., and a little ingenuity and you'd be surprised what you can come up with.

You could also get hold of some carbon fibre fishing rod blanks (they're often sold as flag poles/whips at music festivals) and use the tubes to make up something useful. I've got some very tall lightweight stands, some low profile booms, and a Decca Tree mount made out of these, and they're great for things needing light weight and comparatively thin tubes. You can even route cables through them if you get the right cable and do a bit of fiddling with the mounts. (Caution - they tend to be rather springy so weight of mics is limited, especially on the very small tubes, and devising a method of adjusting height/length isn't as simple as it might be. They also snap without warning and quite spectacularly if overloaded so over-spec and use some common sense. Also, cutting carbon or glass fibre needs some care and the dust can be dangerous if inhaled.)

Omnis at 8"-12" (200-300mm), imo, is fine for things like pianos and some chamber music, though some people deride such small spacings and claim that anything less than about double that is anathema. There again some people hate baffled omnis, e.g. Jecklin OSS disc, and I use that quite often; similarly, I usually find X-Y Blumlein rather unsatisfactory, especially on larger scale things (though when it works, it works brilliantly) and usually prefer to use MS Blumlein (if I use it at all). For larger scale things with spaced omnis I usually prefer a Jecklin OSS Disc or spacings somewhere between about 600 and 750mm as I find either integrates better with spot mics. For single pair work, that's irrelevant but spacing, angle and positioning becomes much more critical overall.

I used quite often to use a four mic array of ORTF and spaced omnis (often with subcardioids at ORTF spacing so not really ORTF) but about eleven or so years ago it evolved into playing with a hybrid array of (wider than ORTF and smaller included angle) spaced subcardioids with wider spaced omnis outside these. The difference is that I'm not using them as two separate pairs, e.g. main and backup/alternative, rather considering them as a single array. If I lost either then what was left wouldn't carry the balance alone but together they work quite well. I've not yet pinned down a single spacing/angle setup which works for every source/room/mic setup but the variation is fairly narrow.

Bear in mind that using an ORTF pair and an omni pair on the same bar will lead to some compromise on positioning (that's why I ended up changing what I did). The optimum position for an ORTF pair is normally quite different from that of an omni pair and putting the two in the same place will mean that (at least) one is in the wrong place for it to work at it's best. Sod's law says that if an equipment failure leaves you only one pair, it'll be the 'wrong' one. If you use both in the mix, then you'll be mixing one optimumly set pair with a (probably inferior sounding) misplaced pair. The alternative is to positionally compromise both so that neither is ideal but both are doing something which blends usefully. Then you can no longer afford to consider one a backup as losing either leaves the balance flawed. (Arguably, with neither pair in the optimum place, a balance of the two will never be anything other than flawed but the sunm can be greater than the parts.)

Anyway, it's all pretty subjective so experiment and find what suits you/your clients.

[Aural Reject]

Damn, beaten to the long answer again

[Bob Bickerton]

I explored using close spaced omnis with small mic mounted baffles when I was recording a recent chamber music festival which is discussed in this thread

This is a variation on the Jecklin disc method (and is more discreet). The initial results were encouraging, but I'd be reluctant to recommend it unless you have time to experiment before hand. I prefer the more 'expansive' sound of omnis and this method seemed to deliver the results.

As to making your own bars, it's easy enough if you have access to a drill! I've made several variations using square or 'U' section aluminum extrusion, drilling holes to suit (using a 10mm bit) and then kitting out with 3/8 bolts etc. It's even easy enough to have them powder coated matt black.

Bob

[Bradley Steenkamp]

Thanks everyone,

Some very useful information there! Ovu, thanks for the very informative post. I might try out the three in a row studiospares mount idea.

Part of my idea for using two pairs on the stand if for experimentation but, as was mentioned, the positioning for ORFT and Spaced omni would likely be quite different so it isn't really ideal! The next concert I'm recording is as a favor for a friend so I might try out both the spaced omni and ORFT setup. The main issue is that I can't put up a variety of mic stands as it starts to look a little messy! Think the music will be a small chamber ensemble, nothing too big.

[John Willett]

The new Grace Design "Spacebars" are available in two lengths and are extremely well made. They come in two lengths, the longer particularly allowing more than two mic holders (extra holders are available from Grace) and are marked for distances (spacings) with the mic holders being marked for accurate settings of angles (something I've not seen before on an off the shelf product). They even incorporate a mechanism for tilting the bar front-back, to allow mics accurately to be angled up/down whilst the stand remains vertical and supply a modified mic holder to allow for positioning of capsules/mics one above the other in co-incident/near co-incident arrays.

I have just ordered the Grace Spacebar 30/66 kit with two extra mounts and case - Grace are also doing the standard 3/8" Whitworth threads for it.

Back to the original question - I often use spaced omnis at around 20cm - it's my preferred method for recording a grand piano.

I also have Jecklin and Schneider Disks for recording with omnis ad head-reference spacing.

[JeanMarie]

I also have Jecklin and Schneider Disks for recording with omnis ad head-reference spacing.

Hi John,
You received your Schneider disk ? How does it compare to the Jecklin ?

Thanks to share with us.

[Guest]

I have just ordered the Grace Spacebar 30/66 kit with two extra mounts and case - Grace are also doing the standard 3/8" Whitworth threads for it.

I'm awaiting news as to whether or not they can make me some 750/800mm bars instead of a 660mm before I order If not I'll probably make do with the ordinary ones.

[Guest]

I also have Jecklin and Schneider Disks for recording with omnis ad head-reference spacing.

Hi John,
You received your Schneider disk ? How does it compare to the Jecklin ?

Thanks to share with us.

I'm not John but I've used a Schneider Disc on maybe a hundred or so recordings over several years (and a Jecklin Disc on over a thousand recordings since 1994/5) and imo the Schneider Disc produces recordings which are more convincing on headphones than those of the Jecklin Disc* but which translate less well to speaker listening. I regard it as an interesting novelty item for use when a recording is needed specifically for headphone listening rather than a useful all round tool which works in a range of applications.

(*When either is used alone. I do, however, find it much harder convincingly to integrate a Schneider Disc main pair with spot mics in a multimic setup, which can present problems.)

I do quite a lot of recording for hospital radio, the listeners to which are almost all restricted to headphones. It works well for these.

[John Willett]

I also have Jecklin and Schneider Disks for recording with omnis ad head-reference spacing.

Hi John,
You received your Schneider disk ? How does it compare to the Jecklin ?

Thanks to share with us.

Only got it last week and have not had a chance to try it out (still searching for a suitable transit case).

[JeanMarie]

Thanks 0VU for your interesting report and we will wait for John testings.

[Jeraldo]

Over here, at least, you can get Sabra bars of any length. I've got a 1 meter bar, a 2 foot bar, and the one that comes with the ST4.