Your 'GOTO' stereophonic mic. technique

[Gary Nattrass]

One big factor for using M/S in broadcast is very simple, if you have an X/Y or crossed pair and lose one leg you either have left or right content only, if you lose a leg from an M/S mic fed to you in A/B you still have a mono capsule pointing in the right direction for the action!

Also on a boom the M capsule will always be pointing at the action where a crossed pair can do some very strange things to the stereo image in the hands of a boom op.

We had loads of bad examples on our broadcast ITV stereo sound training course in the 80's including tests on soap operas and BBC drama and using an M/S or mono mic on a boom was always the best option.

[Ty Ford]

Depends on the job.

I just recorded a 20-person flute choir in a church. I used a pair of Schoeps cmc641 in coincident XY and a pair of TLM103 in AB to the four channels of a Sound Devices 744T. In post, having both sets up equally and pulling down around 6 kHz a bit for the TLM 103 worked very nicely.

I have used the Audio Technica BP4025 to really good effect on nat sound and ambience.

The AT4050ST is another fixed position XY solution. Like the BP4025, large capsules making for quieter selfnoise.

I have a review of it and the Sennheiser 418S on my blog.
Ty Ford Audio and Video: Audio-Technica AT4050ST Stereo Studio Condenser Microphone

Regards,

Ty Ford

[James Kuhn]

Mr. Ford...as always, your insight is greatly appreciated. My initial foray into 'stereo techniques' will be the 'BlumLein Array'. My friend is an excellent guitarist and singer/song writer, I plan on using him as a Guinea-Pig. Heh, heh! Since my Sound Devices SD-302 has three 'primary' Inputs, I think I'll use the AKG C 414 XLS in the 'Blumlien' configuration and mic the sound hole or bridge with a small diaphragm Cardioid, either my AKG C451 B or the AT4053b. We'll see how that works out. I don't feel 'confident' in my skills to employ 'M/S' at this juncture. All things with time, eh?

Thank you for your input.

Regards,

J.

[Ty Ford]

Mr. Kuhn,

I have had great success with a specific config with guitar playing singer-songwriters.

If you find Blumlein unsatisfactory, you might give this a try.

C414 in figure of eight. Positioned horizontally, parallel to the ground.

WHile listening on headphones, get the performer to play guitar. Twist the C414 in the suspension mount so that the acoustic guitar is in the lower null of the figure of eight.

Cooch the C414 into place for vocals and check the rotation to make sure you have the guitar in the null.

AT4053 or 451 aimed toward the floor but with the capsule just a few inches off from where the neck joins the body of the guitar. The voice will be in the back null of the mic.

This will work very nicely unless the player has to be looking at his/her fretting hand a lot.

To hear what this sounds like, go here: Ty Ford Music Production

Listen to Neil Harpe's "Elder Green" and Chris Bailey's "Someone Help Me." Both were recorded that way.

Regards,

Ty Ford

[James Kuhn]

Sweeetttt!!! Thanks Ty, you are a very generous person. I'll try your technique and let you know how it works out. I'll go one better, 'your' technique will be in my 'quiver' from this point forward. Every-time I set it up, you'll get credit. : )

Thanks to ever one for contributing to this thread, I received a lot more than I ever expected when I asked the 'GOTO' question.

Just a great group of people, thoughtful, generous, and knowledgeable. Thank you all.

Best regards,

J.

[Christian Brown]

XY receives a thumbs-down here for recording any type of ambient or ensemble recording:

Recording the Wren Organ TechDeck: XY and MS

[Ty Ford]

Here's the Audio Technica BP4025 XY, large diaphragm, stereo mic ambi recording.

https://www.dropbox.com/sh/7f0qg6se5...4025ambi08.wav

Works for me.

XY also provides mono compatibility, which can be extremely important.

Regards,

Ty Ford

[Brian P. Reynolds]

Originally Posted by Christian Brown

XY receives a thumbs-down here for recording any type of ambient or ensemble recording:

Recording the Wren Organ TechDeck: XY and MS

Interesting listening test... they have recorded the sound of the hall rather than the organ. This is very evident with hearing of the footsteps.

Yes MS sounds huge and XY is narrower due to the distance the microphones probably were away from the sound source. AB (spaced omni mics) which they didn't do would have sounded even better.
It was noted in the link..."What I will demonstrate today is that MS is not the same XY with regards to imaging, and that XY is a poor choice for distant recording applications in comparison with MS." Why would anyone do a distance recording with a stereo mic anyway... use a shotgun mic!!!

I downloaded all 3 samples and had a look at them on a Stereo display (Lissajous display) the XY was in nice proportion of L/R + phase, the wide XY has a greater spread but still a good balance between L/R and phase but the MS sample has a VERY broad spread with lots of out of phase components in the signal. In fact it is much wider than I would broadcast safely, a signal that wide (depending on the TX path) could possibly cause problems with auto phase correct.

MS v XY is likely to be an ongoing debate for many years to come my suggestion is try lots of different combinations and find one YOU like.
Its a bit like art what you may like others may not.

[Paul R Johnson]

There seems to be conflict here between recording techniques used for recording high quality, stereo sound for CD release and high quality sound for video. The ideal place in virtually every case for SOUND is terribly wrong for video, because the damn microphones are right in the middle, in full view.

To the audio recordist the concept of recording stereo from a distance with a shotgun type mic just doesn't cut it because the polar response is narrow at the top and cardioid at the bottom causing huge amounts of image shift as the music content changes frequency. You can get audio that make you feel quite nauseous if you use them. A piano that with your eyes closed physically appears to move across the stage as the pianist moves from left to right - yuk!

I'm mystified by the comment that X/Y is not suitable, when it's the most common technique - although as in the example, put the pair in the wrong place or set them too wide and very odd things happen.

With my pedantic head on, could I suggest we refer to twin channel sound rather than A/B, because that's another established microphone technique that some people like - using spaced rather than coincident pairs of cardioids (or even omnis). I'm also surprised nobody even mentioned Blumlein pairs - although I suppose many people don't actually have two figure-8 mics in their kit.

For video work on certain things, A/B can work better because there's no central mic to spoil the pictures, but it can go badly wrong if the people in the studio don't quite understand what has been recorded. There's quite a famous (infamous?) recording from the 70s - The Syd Lawrence Orchestra playing Glenn Miller, where they separated the band in the studio and recorded in A/B - but too far apart so the saxes were all totally one side, with the trumpets and bones on the other - with drums, bass and solos central. On speakers it sounds pretty realistic - but on headphones, the total isolation makes you feel quite ill, especially when they do the doo-wah, doo-wah bits!


There is NO standard for recording stereo audio. We all have our favourite few, that we find work for certain circumstances - but to select the right one needs you to be there, in the building and able to clap your hands, and listen to what you hear. Only then can you decide which one will work best.


EDIT
With a while to spare today, I took the files into the studio, and did the same thing as others have reported - the vectorscope revealed for me, very similar information.

There is indeed a difference between the two recordings, and after a few listens I've come up with these comments.

The actual articulation in the playing in the second, louder section shows that the microphone placement was not ideal for the location of the rank used in the recording - the X/Y recording allows the particular rank of pipes to be heard better. The M/S recording suggests that the mid microphone was balanced too low - I'm not sure I agree that the M/S sounded bigger - I think it had more reverb content, that's all. I feel that in both recordings, the real issue was improper or inaccurate mic placement for both pairs of microphones. The organ sounded very small. Too much ambience, not enough source. The feel was very much a small rural church, recorded from too far away. I had never heard of the organ or chapel, so I looked it up, and it is a small organ. It's also a very small space, which also confirms the view that the mic positioning could have been improved. The RT60 of the space is probably not that long, so the more distant mic position made the space sound bigger, but removed clarity, accuracy and detail. There is also an issue with the organ - with it's single manual and limited number of ranks in the small casing - most ranks will be spaced across the width of the case, and each rank aligned in front of our behind the next. As such, the stereo width of the organ is probably only 8-10 feet. So in effect, when recorded from a distance, it is almost a mono source - making most of the stereo information a combination of reflections and comb filtering - so we are hearing stereo reverberation - VERY different from a stereo instrument.

I'm not certain the test was matched very well to the venue. From what I heard, I expected a much larger venue and instrument, but was surprised to find out it's real size. The recording seemed to have been planned to sound bigger than reality, and I feel this was a mistake.

[Ty Ford]

I consider myself a recording engineer (with enough technical chops to have been certified by the FCC many years ago with a First Class Radiotelephone Operator's License), but I'm also a musician and sound designer.

I think using vectorscopes is useful for post analysis is valid, but using them to create music or sound is very problematic. OK so you can see degree of in phase or out of phase info and to some degree. Yes, that is valuable. But your ears should tell you that.

Every venue and situation is different. The x/y brackets may work in one situation, but need a tweek in another. AB the same way, M/S similarly.

Again, it comes back to "what does it sound like?"

Regards,

Ty Ford

[Greg Miller]

OK folks, it's time to put this discussion to rest. Really, the answer is simple. Record everything in binaural, and play back only on headphones.

Dispense with all the world's loudspeakers. Think of the space this will free up in our listening rooms and home theatres. Admittedly, this will be a small inconvenience in the larger cinema, but inconvenience is a small price to pay for perfectly realistic sound reproduction.

[I can only pray that we won't start another sub-thread with serious replies to the above...]


P.S. to Ty Ford: You piqued my curiousity so I had to dig out my original First Phone ticket. I remember flying to DC to take the exam in '69. I still have my slide rule, too. ;-)

[Seth Bloombaum]

Originally Posted by Greg Miller

...Really, the answer is simple. Record everything in binaural, and play back only on headphones.

Dispense with all the world's loudspeakers...

This is really exciting! !!! !!!!!!!!!

Really, though, this will be great when we implant the transducers in our heads. How long will it be before we're so connected we have the, um, headPOD and retinalDISPLAY. Binaural recording will then come into its own, it's a technology before its time!

[Ty Ford]

Greg for President!

Problem solved, nothing to see here, move along, move along.

Did you get yours commuted to a General too?

Yes, a small room somewhere in DC. I was there in 1969 as well! Maybe early1970.

I was three years old then.

Regards,

Ty Ford

[Gary Nattrass]

Back to mono thats what I say as all this surround and stereo stuff just causes confusion!

[Greg Miller]

Originally Posted by Ty Ford

Did you get yours commuted to a General too?

Yes... sigh. That little cheesy wallet card really isn't very impressive.

Originally Posted by Ty Ford

Yes, a small room somewhere in DC. I was there in 1969 as well! Maybe early1970. I was three years old then.

Danged kids!