Blumlein for Acoustic Guitar?

[7rojo7]

I have an AKG contact mic that's a figure 8, when it's mounted as suggested the poles of the 8 are towards the body and away from the body on the same plane as the strings. I sometimes mount it on the brace inside between the hole and the bridge, one lobe picking up the hole and the strings and the other the bridge, I prefer this although I usually have to apply a lo shelf cut with the shoulder at 160 hz.
How and where would I have to mount a similar mic to make a usable blumlein array?
It's oval shaped!
How would mounting one inside and one outside go?

[NorseHorse]

Hmmm... well for starters, the mics have to be in essentially the exact same place to eliminate phasing.

Anyone tried surface mounting a Blumlein? Certainly unconventional, but what if we've been missing the Holy Grail of guitar recording??!?!?!?!

[David Spearritt]

The holy grail of guitar recording or any recording is understanding the techniques, and using them correctly.

You cannot surface mount Blumlein. Do a bit more reading around the technique. Its a superb way to capture the guitar, but it needs to be at least 1m away from the instrument.

[NorseHorse]

Sadly, I think DS is probably right. I'd like to hear someone show him up though!

Anyone rebelious enough?

[7rojo7]

Maybe matrixed in M-S, where should be the best spot? I guess one of them should be mounted sideways, what happens if you mount them to each other, would they have (acoustical) crosstalk or obstruct each others plane of pickup? There's plenty of different information around the guitar, a source to be mic'ed in stereo by many.
I wasn't aware of the 1 meter rule, I've used B on bkg vox and everyone was about a half a meter from the mics and a pane of glass was on the other side at about the same distance (would that make a meter?), I'm not really sure though because I didn't bring my laser rule, sounded great though (C-24> Langevin AM16s> LA2A's> I don't remember the mark of the glass but it could've been Owens-Corning).
I didn't realize I was breaking the rules, I guess I'll have to read the rule book again.
I like xy, x=top strings, y=bottom strings hypercardiods and a cardiod behind the bridge or an xy to capture the horizontal plane between the 12th fret and the bridge (in front of you).
Maybe 2 45 degree wedges would work or I could just angle them on the putty,
come on guys help me make this work. this is important.

[JEGG]

Originally Posted by David Spearritt

You cannot surface mount Blumlein.

Speaking generally, and apart from the issue under discussion here, there is no reason why surface mounting a Blumlein would not work.

Any pattern of mic will work with surface mounting, it retains its pattern and merely looses one half of its polar pattern, and acts otherwise like any mic placed on a boundary.

With Blumlein, there is a little physical difficulty to be worked out, but MS is easy. Both mics need to be in the pressure zone, which varies in depth by frequency.

In principle, there's no problem at all.

[7rojo7]

Yeah I want to try it out with 2 of these AKG, to hear the effect, as there's not much happening with stereo on the gtr anyway, I'm hoping it might make somekind of voodoo. I use this mic mainly for supporting the monitor of Ac Gtr and I'm being forced to get another, just want to throw aruond the idea, I could do it without asking but I though it might be a fun topic since all I read about on the board theses days is about blumlein or M-S and wanted to open it up a bit.
if they're mounted at 90° on different sides of the sound board they'll still be a coincident pair.
When I get the other one I'll just move it around to hear it and then probably never use it, just like I almost never use them for anything else. B for problems and M-S if the mic has to move during recording.
Thanks for the response

[Audiop]

Originally Posted by JEGG

Speaking generally, and apart from the issue under discussion here, there is no reason why surface mounting a Blumlein would not work.

Please tell me how it COULD work.

Any pattern of mic will work with surface mounting, it retains its pattern and merely looses one half of its polar pattern, and acts otherwise like any mic placed on a boundary.

I don't get it. A fig 8 mic or a dipole loudspeaker depends on the active moving element being open in both directions. If you put it up against a surface and close the back off you turn it into an omni.

With Blumlein, there is a little physical difficulty to be worked out,

A little..? Blumlein means 90 degrees between a pair of transducers open on both sides (single diaphragm or dual) how that could work with surface mount is above me.

but MS is easy. Both mics need to be in the pressure zone, which varies in depth by frequency.

What is your definition of pressure zone in this context and depth from/to what?

In principle, there's no problem at all.

Sorry for sounding harsh here but somehow I get the feeling you missed physics class in school.


/Peter

[David Spearritt]

Sorry for sounding harsh here but somehow I get the feeling you missed physics class in school.

Indeed.