Near Coincident Mics - phase problems?

it's only a Blumlein equivalent inasmuch as it picks up as much from the rear as it does from the front. Bruck's comment that it only works if it's a cardioid is only really relevant to using the technique as a main pair, and I think that it's unlikely to be used that way in most recording situations. Where it can really come into its own is as a rear pair, and if I was going to use it for real, that's probably the only way I would seriously consider it.

I suppose the only way to to check on this is to use the omni M-S where I have successfully used Blumlein in the past.  One other difference that would have to be taken into consideration is vertical directivity - the omni getting more from above and below than is the case with the crossed fig-8s.

But thanks for the remarks about using it as a rear pair - could be an improvement over the dangled spaced omnis.

But thanks for the remarks about using it as a rear pair - could be an improvement over the dangled spaced omnis.

I can put a bit of context on it from my POV... Recently I had to make a recording in a church with what could only be described as a 'muted' acoustic (due to brick cladding instead of the more usual stone), and I wanted to capture as much of the acoustic of the nave as possible. The main mic was the Soundfield - that was quite straightforward. But for the rear pair I was going to experiment. I had several potential options - basically as many combinations of two C414s and two DPA 4006's as you could think of, although a spaced pair of the 4006's at a sensible height would have been a little tricky, as it turned out. I'd seriously thought about a C414/4006 combination but having listened to the C414's as a fig-8 crossed pair (sounded stunning) I simply went with that, and didn't try the other combination, which would have required dematrixing to listen to anyway. And that's ultimately the snag with it - it's very flexible but requires a little forethought if you are going to use it for real. Since I'm actively contemplating what to do about monitor mixers, in whatever I end up with, I'll probably include all of the dematrixing options anyway, I think.

Which particular C414s, Steve?

Which particular C414s, Steve?

I have an AKG-matched stereo pair of C414B-XLS's.

I have an AKG-matched stereo pair of C414B-XLS's.

Very good!  I have been thinking on and off about a pair of those for some time.  However, I swore I would not buy them until AKG honours its commitment to produce the remote control for them (which will be never if the Harmonites continue to have their way - AKG is now an American company!).  Noise figure and other features VERY nice, but the more I go back and check with my C414EBs - now 20 years old - the more I think "why would I trade these in for the new ones".  Of course the C426B (now discontinued - thank you Sidney) is the first call mic, and the very early C460Bs with CK61s and CK62s serve their purpose (and I can upgrade them by getting a couple of C480 bodies if I feel inclined).   

 I have tended to stick with AKG -by assuming a consistent 'family' sound - since I first bought a pair of AKG D202s (from an establishment somewhere in Enfield?) in 1972/73.  Crossed at 90° these worked extremely well with the Uher 4200 (poor man's Nagra IV-S) which was only retired in 1997 when I bought my first MiniDisc (the MZ-R30 which still gets dragged out on occasions).

The exception is the Schoeps CMC54/58 combo, which has a really lovely sound on the Nagra with string quartets (and other class acts like the Harp Consort) in our Concert Hall - it has fabulous 'reach'.  The national broadcaster tends to use MK41s (hypercardioids) spaced about ORTF but much narrower angle, with MK2S outriggers for 'air'. (I tend to think I get a better sound all round with the C426B in Blumlein, but I'm not getting paid what they get paid, so they must be right).

I have used a MkIV Soundfield once but was not overly impressed on that occasion (and this at the time when it was a shootout between it and the C426B for my next acquisition - the Sales Prevention department in the local distributor was dominant).  I fully understood the mic (and I assisted in getting Michael Gurzon out here for an AES Convention) but at the time it didn't reveal its potential to me.

So I am set up for co-incident (C426B, MK4/MK8) or spaced (C414EBs, C460Bs).  Coincident always rides high in my preferences mainly due to considerations of mono compatibility,  If I am considering further mic purchases, right now I think I would get a second Schoeps MK4 capsule (I can only afford one at a time), though my colleague's devotion to his pair of MK21s suggests it could be an interesting path.

So, one way or another, I think I have to be persuaded out of my comfort zone with co-incident techniques.  The only issue is that I have no real opportunity to use speaker monitoring on location, and headphone monitoring for image is severely compromised by the collapse of the high frequency response in my left ear.  Hence I am wary about optimising spacing etc in these circumstances

Anyway, I'd be interested in how you characterise the -XLS pair compared to your previous large capsule mics.  Have you tried them in the wide cardioid (hypocardioid) position, especially in spaced mode?

Since I'm actively contemplating what to do about monitor mixers, in whatever I end up with, I'll probably include all of the dematrixing options anyway, I think.

A colleague of mine is very satisfied with his solution - basically a balanced summing amplifier.  As he reported to me on a session recording a chamber choir, straight down to stereo:

"MK4 ORTF into AMEK 9098 and MK2s outriggers into TC Gold Channel, both mic amps then into my new little minimalist line mixer .... I am astonished at the sound quality. I have not heard such a low noise floor or such silky smooth sound from our mic amps ever before, this is one of the biggest changes in sound quality I have made in my recording rig."

You will find a link to the "Hux Balanced Buss Summing Amplifier" at :

http://www.hux.com.au/products.htm

4 stereo ins on XLR5s, fixed gain, panning of the L/C/R variety depending on how you wire the input cables (additional pads may give you more options, and M-S/sum-diff matrixing is also possible).  But his opinion may give you some encouragement as you explore your solution.

Very good!  I have been thinking on and off about a pair of those for some time.  However, I swore I would not buy them until AKG honours its commitment to produce the remote control for them (which will be never if the Harmonites continue to have their way - AKG is now an American company!).  Noise figure and other features VERY nice, but the more I go back and check with my C414EBs - now 20 years old - the more I think "why would I trade these in for the new ones". 

Well I didn't have the problem of older ones - I used to borrow a pair occasionally, but the B-XLS's are the first ones I've owned. I do have quite a collection of other AKG SD mics though. I wondered about the remote control too - but since the mics' memories are non-volatile, anything you set remains that way - fortunately! If they don't actually produce the remote, then I think that as a matter of good faith, they should at least release the control protocol.

Anyway, I'd be interested in how you characterise the -XLS pair compared to your previous large capsule mics.  Have you tried them in the wide cardioid (hypocardioid) position, especially in spaced mode?

I have made a direct comparison with an older pair - but not with the much older brass capsule ones, which are supposed to sound completely different. The new ones are significantly quieter, but as far as I'm concerned the sound is quite similar. Most of the time, the lower noise floor doesn't matter, but since the first thing I recorded with them was a clavichord, I was rather pleased about it, at least on that occasion, because clavichords are seriously quiet instruments needing all the help they can get. I did use the hypercardioid setting for the recording, but didn't space the mics any more than minimally, because there wasn't room to, and I don't think that it would have achieved anything significant anyway.

I have used a MkIV Soundfield once but was not overly impressed on that occasion (and this at the time when it was a shootout between it and the C426B for my next acquisition - the Sales Prevention department in the local distributor was dominant).  I fully understood the mic (and I assisted in getting Michael Gurzon out here for an AES Convention) but at the time it didn't reveal its potential to me.

I'm one of those people that the ambisonic crowd probably look down their noses at, because I use my MkV as a steerable stereo mic, although I do have the decency to record in B-format and make the adjustments afterwards... like all mics, you have to be aware of its good and bad points. And when you get used to it, most of them are indeed good points, not bad ones. And not the least of them is that it's always dead easy to come up with a good mono-compatible signal from it.

So, one way or another, I think I have to be persuaded out of my comfort zone with co-incident techniques.  The only issue is that I have no real opportunity to use speaker monitoring on location, and headphone monitoring for image is severely compromised by the collapse of the high frequency response in my left ear.  Hence I am wary about optimising spacing etc in these circumstances.

One of the advantages of the Soundfield in the no-loudspeaker monitoring environment is that you can always fix the results afterwards, and generally it's pretty easy to get an acceptable result as long as the sound is balanced when you listen in mono on headphones. But you still get a better bass response from the DPA4006's, and in many ways I prefer the sound from those anyway, although the differences are really pretty marginal.

If I get another windfall, I might well get some Schoeps mics - I've always fancied a pair, although they would be rather hard for me to justify in terms of a hard cash return, I think.

As far as monitoring is concerned:

A colleague of mine is very satisfied with his solution - basically a balanced summing amplifier.

This is certainly along the lines I was thinking of - although I will roll my own. I have the facilities...

[ If they don't actually produce the remote, then I think that as a matter of good faith, they should at least release the control protocol.

I have a sneaking suspicion it was based on the AES42 control protocol - AKG regarding it as a halfway house to their first digital mic.  And we will have to wait and see on that topic ... 

I did use the hypercardioid setting for the recording, but didn't space the mics any more than minimally, because there wasn't room to, and I don't think that it would have achieved anything significant anyway.

The wide cardioid (should be called hypocardioid for consistency) is interesting because of the greater pressure component, and possibly better LF response).  But Braunmuhl-Weber variable pattern dual diaphragms have a different LF characteristics compared to the single diaphragm fixed (almost pure pressure) pattern of the Schoeps

I'm one of those people that the ambisonic crowd probably look down their noses at, because I use my MkV as a steerable stereo mic,

Its probably how I would have used it, though ozpeter and I have occasionally made noises about having a crack at surround.  And with the Nagra I do frequently check the mono sound as a guide to correct balance.

If I get another windfall, I might well get some Schoeps mics - I've always fancied a pair, although they would be rather hard for me to justify in terms of a hard cash return, I think.

Luckily  as I pursue my recording activities as an avocation, return on investment - except in the satisfaction sense - doesn't come into it, only my allocation as part of the household budget.  Speaking of which, can you keep your ear to the ground about early real-world experience with the new Prism Orpheus - could be the next windmill in my Quixotic quest for aural satisfaction.

I'm one of those people that the ambisonic crowd probably look down their noses at, because I use my MkV as a steerable stereo mic, although I do have the decency to record in B-format and make the adjustments afterwards...

As my eyes have aged, I can no longer see the end of my nose!  Seriously, though - even those recording for the sake of the surround result know that most people will only ever hear it in stereo.

Paul

Even worse  ... I believe that over 90% of people listen to stereo material in a situation where stereo cannot be perceived - on mono equipment, or in the next room, or in the wrong position.  Cinema is probably the closest to a defined listening situation.   But then again you have the horrible imposed centre track for dialogue ...

Fact: in all the Beatles albums, according to Geoff Emerick, the mix that got the greatest degree of attention was the mono album mix.  At that time radio, TV and film were basically mono (Radio 3 would NEVER play that sort of thing!) - you would occasionally hear stereo at the cinema on roadshow releases and that was it.

You will always overestimate the proportion of listeners that takes what you do SERIOUSLY!

Even worse  ... I believe that over 90% of people listen to stereo material in a situation where stereo cannot be perceived - on mono equipment, or in the next room, or in the wrong position.  Cinema is probably the closest to a defined listening situation.

Given the ubiquitous iPod and equivalents (indeed, I do much of my listening that way), I think that 90% is probably pessimistic these days - but I take your point.

But then again you have the horrible imposed centre track for dialogue ...

Attempts to decode ambisonics for replay on a true ITU layout have found that it is necessary to leave out the centre speaker, and that the decode is still none too stable.  However, as approx 0% of domestic surround systems are arranged according to the ITU guidelines, I follow the line taken by Nimbus and decode for a square.

You will always overestimate the proportion of listeners that takes what you do SERIOUSLY!

Indeed.  Of all the people (including choir members) I have recorded in surround, only one has ever been prepared to take a surround DVD to play on a relative's system.  Anyone who thinks that surround is the next big thing for real recording is living in Cloud-cuckoo-land.

Paul