I would use the 930 as stereo pair in a x/y configuration. Move them in the room until you find the sweet spot.
as for the 420 and 910 they can get Inside the lid to get a more direct sound.

thanks for your quick answer.

so you would use the opposite way i was thinking?
Interesting approach: i though it would have been better to use the panoramic for the room.
about the 930: i will try out your idea about moving in the room looking for the sweet spot.

Other answers are also welcome :)

Using a stereo pair is a good way to avoid phase problems. Having 2 identical mics to do a stereo capture is also recommanded because they have the same frequency response.

In the end the right way is the way it sounds good to you. Experiment and adapt your technic to the instrument and the room ;)

You didn't say anything about the size of the grand piano, the room in which you will be recording, or whether you will be tracking the piano separately from other instruments and vocals. Assuming you are tracking just the piano under studio conditions, you don't need to worry about bleed or (hopefully) unwelcome acoustic reflections.

In addition, if the piano track is to fit into a recording where the sum of all the other tracks already occupies much of the frequency spectrum, you have to think this out first about where you want the sound to fit, both spatially and in frequency spread. You also must decide whether you want a "rock piano", a "ballad piano" or a pseudo-classical sound and mic the piano accordingly.

The lowest octave on a full-size grand does not come out well on most cardioid microphones, but would be captured by your MC910 omni in the right acoustic surroundings. If you have some experience in these things, a 3-mic MS configuration where the MC910 is the M (centre) mic and the two MC930s are opposite-facing S mics could provide a very good capture for the ballad or classical styles.

[[url=http://[/URL]="http://www.soundons…"]Here [/]="http://www.soundons…"]Here [/]is a good article on piano miking.

Thanks for your detailed answer.

The room is a 5x5m room, with almost no acoustic treatment, so yes, reflections will be an issue.
I am going to record the piano solo.
It is a for an avantgarde/experimental album, so let's say i want a pseudo-classical sound.

I never recorded with MS but I know that you mean and it might be right situation to try that out :)

Thanks for the link too.

Hmm.... in an untreated 5m square room (how high?) you may well be better off with the cardioid pair, a little closer in than you would normally place for classical work. Make sure the instrument is not centrally sited in either of the room's horizontal dimensions - more across a corner but away from the walls might be a place to start. Put several rugs on the floor under the instrument and out to the microphone position. If the room has curtains you can draw, that may help to break up standing waves.

The genre of music is absolutely critical - a lovely sounding recording that makes the piano sound real and expensive might be great for a classical recital style, but fail to sit in a pop mix because the room sound overpowers. Close miking might well be better, or worse. What kind of music and playing will be going on?

The room is about 3,5m high, i know, standing waves will be a problem. I'll try to reduce that with curtains and carpet.

Here is a recording of what we usually do:
[MEDIA=soundcloud]soelaccousticelectro/27052014-1
[[url=http://[/URL]="https://soundcloud…"]View: https://soundcloud…]="https://soundcloud…"]View: https://soundcloud…]

Hard to describe otherwise

I suspect I'd close mic, and then do eq and effects to suit the rest of what is going on. To blend all the weird sounds, you need as clean as you can get - I'd have thought. I don't think I could describe it at all - rather reminds me of the old Music Concrete we used to do with loads of tape loops and weird sounds.

buscon, post: 420396, member: 47271 wrote: I was thinking to put the two 930s on the side of the piano, to get a good stereo image.
Then the AKG between the two 930s and the 910 a bit far away from the piano to get some more room.

My two cents here...

It all depends on how the room itself sounds. If you listen to how the piano sounds in the room, or, listen to other genre-related music in the the room, and what you hear is pleasing to the ear, then you could look into an M-S array. But, if the room is reflective in a negative way, or just simply sounds bad, then I'd steer clear of the M-S route, or, for that matter, any multi mic array placed at a distance from the instrument in which to capture the room.

Just to be clear, here, I love M-S arrays, I use M-S all the time; but ... you have to have a pretty decent sounding room for it to be beneficial, and, you can run into a lot of issues; flutter/echo "ringing" or "pinging" that can encompass a broad band of frequencies, or even be specific to a particular frequency. Or, it can just sound bad. Hollow, one dimensional, empty, thin.
If this is the case, the benefit of having an MS array - which is to pick up the sound of a nice instrument in a nice space - gets lost, and is overcome by other issues that detract from the original purpose of using a multi-mic array like this to begin with.

buscon, post: 420415, member: 47271 wrote: The room is about 3,5m high, i know, standing Waves will be a problem. I'll try to reduce that with curtains and carpet.

Carpet won't help standing waves. Curtains might, a little, depending on how thick they are, where they are placed, and, what is between them and the wall. The materials you mentioned might tame upper end flutter echo and ringing, probably from around 1k and up.... but they won't help you with low end standing waves and nulls. The lower the frequency, the more mass you need to tame its potential problems. BUT... it's not just about randomly throwing up just any type of acoustic treatment, either.... be it professionally fabricated or homemade.

You might want to check this out: http://www.amazon.com/dp/143545717X/?tag=r06fa-20 by RO member
Rod Gervais .

You'll be amazed at the information in this book, and what you can do on your own to improve the sound of a space... not only for mixing, critical listening and sound pollution, but for recording environments as well.
Many members here on RO consider Rod's book to be their "Bible" in terms of acoustical room treatment and soundproofing.

In the end, you may have to tight-mic the piano, and obtain your ambiance and space through artificial methods such as convolution or algorithmic reverb.

FWIW

d.

Thanks for the great answers, tomorrow I will do the recording and let you know!