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AB: 3' panned-in vs 27" hard L/R
Old 22nd December 2021
  #1
Lives for gear
 
🎧 5 years
AB: 3' panned-in vs 27" hard L/R

Has anyone directly compared the later 'Decca Tree' mains of 2 M50s at 36", panned-in a bit (Decca book recommends 50%; referred to as the four-mic tree - main pair plus flanks) with a pair at what Faulkner usually uses, 27" panned hard left and right? Not necessarily with M50s, but with other APE omnis.

The 'four mic tree' was preferred by Wilkinson later in his career, and was often used by Dunkerley. I didn't know till the book came out, that the main 36" pair were panned-in. I assume what attracts Faulkner to the 27" spacing is that it avoids a hole in the middle, without requiring panning-in.

The only similar comparison I've made is 27" APE omnis vs Onno 'double AB' on the same orch, same day. On that occasion the Onno won out for my taste, but on a smaller ensemble I could see preferring the slightly 'purer' sound of the single 27" AB. But I've never tried the 36", panned-in. I've wondered if the extra spaciousness from the greater time delay is worth the slight comb filtering that would result from the panning.
Old 22nd December 2021
  #2
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surflounge's Avatar
 
🎧 15 years
avoid comb filtering
Old 22nd December 2021
  #3
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king2070lplaya's Avatar
Listen to most of John Dunkerley or Simon Eadon’s orchestral recordings from the mid-80s to present for an idea of how the 4 mic setup sounds in-practice. You can also hear it employed on Wilkie’s last year or two of recordings for Decca.

I’ve used the 4-mic setup, and would use it again in the right situations, but the mics have to be in the right place for it to work correctly. 27” AB is definitely an easier thing to rig up, but doesn’t sound the same at all. For a more forgiving “Decca” sound and setup, nothing beats the 3-mic tree and outriggers.

Don’t think of the 2 inner mics of this setup as an AB. It’s not designed to work independent of the flank mics.
Old 22nd December 2021 | Show parent
  #4
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🎧 5 years
Quote:
Originally Posted by king2070lplaya ➡️
Don’t think of the 2 inner mics of this setup as an AB. It’s not designed to work independent of the flank mics.
So, you think one of the attraction for TF to the 27" spacing is that it's sounds fine w/o flanks for smaller ensembles, but the 36" panned would be too narrow on it's own? If the three mic tree works fine on it's own for smaller groups, w/o flanks, why would the 36"/panned not?
Old 22nd December 2021 | Show parent
  #5
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king2070lplaya's Avatar
Quote:
Originally Posted by M50k ➡️
So, you think one of the attraction for TF to the 27" spacing is that it's sounds fine w/o flanks for smaller ensembles, but the 36" panned would be too narrow on it's own? If the three mic tree works fine on it's own for smaller groups, w/o flanks, why would the 36"/panned not?
As I understand it, Decca used the ubiquitous 3 mic tree and outriggers setup for orchestras with the L and R tree mics panned in slightly. In the late 70s, around the time that Decca switched from Tannoy to B&W monitoring, Wilkie began experimenting with a narrower 2-mic tree to fill the center of the image, and following the established Decca convention of panning the L and R tree mics in. You can see photos of this setup employed by Wilkie at the Strauss “Egyptian Helen” sessions in Detroit.

As this was at the time of his retirement from Decca Wilkie’s preferred method of recording an orchestra, it was adopted by his protégée John Dunkerley for his own orchestral work at Decca, and later by Simon Eadon, who continued to employ it until his recent retirement. You can see photos of this setup in the recent Gramophone interview and article on Mr. Eadon (It should be noted that other Decca engineers continued using the 3 mic tree, with Lock, Pellowe, Moorfoot, and Goodall among them). John does a great job in his book, I feel, of explaining why he would employ any given tree setup in one circumstance or another. And you can see from the photo on the cover of the book that John teaches the 3-mic setup to his students at Abbey Road Institute.

From this historical perspective, you can understand how that 4-mic setup came empirically to be. Decca viewed the entire front array (tree and outriggers) as a complete unit, not as separate primary and secondary elements, similar to the Onno 4-mic setup, or even the Fine or Philips M3 setups. Unlike the approach of building the sound around a single pair of mics, as many engineers would, these arrays work to compose a stereo image in a somewhat artificial way, with no single element or pair contributing a majority of the sound. Make of that approach what you will, but there are many many great-sounding records made that way to justify their employment.

I don’t want to speak for Tony, but I would imagine he arrived at the 27” AB pair after his own empirical and professional journey of making records. I imagine his early career of using fairly minimal setups to record classical music led to his preference to build a sound around a single pair of mics, with embellishing spots only as needed.

I don’t think a panned-in main stereo pair is a good idea. The 4-mic tree only works because of the proximity of each mic to the others in the setup, and to each mics individual part of the string section. Listen to recordings done that way, and try doing one following the books specific instructions, and you will better understand how and why it works.
Old 23rd December 2021
  #6
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🎧 5 years
It's not specifically mentioned in the Decca book, but sounds like you doubt that 36"/panned was likely to have ever been used for smaller ensembles w/o flanks, as was often done with the three-mic tree.

As I mentioned in another thread, I tried 3' spacing with middle fill once but did it in the worst possible way - by summing L+R then mixing that mono in; I needn't describe what the result sounded like! Dumb !! Was a choir too - double ouch (fortunately it was just a back-up experiment). Something to play for students to demonstrate what comb filtering sounds like. I have to say, though -despite the awful tonality, the sound stage was gorgeously enveloping, and the left to right imaging was seamless. Made me curious what 3' properly panned (I would imagine much less than 50% when used without flanks, so combing would be even less) would sound like, but never got around to trying it.
Old 23rd December 2021
  #7
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🎧 10 years
The attraction of a single 67cm bar, 4 mic phased array for TF vs a central AB plus outriggers as per Decca ?

Easy....it's 2 fewer mic stands (primarily), which is a big deal if you're a 1man show battling limited setup time, limited stand placement options (or a hostile concert manager telling where you can't place those 2 outrigger stands !)....not to mention grumbles about visual landscape pollution by a video cam operator !

As Kevin says, the 5 mic (3-tree, 2 outriggers) and 4 mic (AB centre, 2 outriggers) Decca arrays are systems, and work symbiotically with/against one another. In other words, the in-panned central wideAB works dynamically image-wise in the context of all 4 mics deployed in that array...and not in relation to itself as a standalone single pair.

It's true, the 3 mic tree (likely assisted by a spot mic or two) works well for small ensembles, like piano quartet, wind octet etc...but the same didn't apply to the 3 foot AB alone for Decca. The in-panning recommended of 5 and 4 mic trees was likely employed to give a solid yet spacious centre image...to complement the width afforded by the outriggers, and probably skates safely on the right side of audible comb-filtering, while still being aesthetically satisfying, like so many of Decca's approaches.

In addition, if you study the DAW recommendation tables for the 5 and 4 mic trees, you'll see very specific mix level itemisation figures for each mic...not just panning %'s alone. Thus each 'system' is a finely balanced combo of horizontal dimensions, stand heights, output level and panning parameters (including Pan Law bias configurations).

Decades of empirical experimentation, trial and error and logging of session charts across numerous recording locations and teams have been done by Decca....to save you the trouble of needing to do so today !

Visualisation tools and charts for SRA such as those compiled by Williams and Sengpiel will assist you in creating new formulas for AB arrays (without outriggers).

If you wind up with a choice of two contenders (with differing widths) as a result, the one that employs no panning-in is theory-bound to avoid comb-filtering !

Last edited by studer58; 23rd December 2021 at 01:14 PM..
Old 24th December 2021 | Show parent
  #8
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king2070lplaya's Avatar
Quote:
Originally Posted by M50k ➡️
FWIW, here's a bit of 3' spacing I just remembered I did many a moon ago (in this case with cards, due to the room).

At the time, I hadn't a good way to pan them in, so I just did it my DAW; 30%.

Even though it was done with my very humble pres of the time, and MC012s, I don't hear any disturbing combing, and the image is quite solid. The singer was performing Broadway ditties, so was acting the scene out and moving around a lot.
Here’s a track that I recorded and mixed following the 4-mic tree conventions described in the book:

https://open.spotify.com/track/6aGUu...TUa_yU77jAmVyQ
Old 24th December 2021 | Show parent
  #9
Lives for gear
 
🎧 5 years
Quote:
Originally Posted by king2070lplaya ➡️
Here’s a track that I recorded and mixed following the 4-mic tree conventions described in the book:

https://open.spotify.com/track/6aGUu...TUa_yU77jAmVyQ
Any other way to hear this without having to sign up with Spotify?
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