testing out my new microphones.............what do you think?

[mkaykov]

my friend loaned me a matched pair of Rode NT55, and told me to put on the cardioid capsules, and to use the ORTF configuration. The results are pretty amazing. I recorded this onto a Hi-MD Minidisc in PCM mode..............

this is just a random improv,has some excerpts of Liszt Mephisto Waltz 1, and Chopin Ballade 1 (ending).


I am quite happy with the sound.........

[goldentone]

Indeed.

[rachfan]

Hi mkaykov,

I listened to your recording.  Unfortunately, you gave no information about the piano, which along with the mics and the pianist, is a key component of any recording.  From listening, it sounds like it might be an upright, although I could be wrong.  Perhaps you could clarify that point.

Rode NT55 pencil mics are certainly quality equipment. 

As far as ORTF configuration goes, I experimented with it at home (along with X-Y and AB) with my Baldwin parlor grand... and as a result do not use it to make my recordings.  ORTF is a nuance of X-Y confguration.  X-Y has the mics close in to the piano (usually with in 3 feet) with the mic capsules nearly touching and forming a 90 degree angle.  Visually it looks like a V.  ORTF does basically the same thing, only one capsule is very slightly elevated over the other, crossing it from above and almost touching the lower one.  Except for the crossover of the capsules, it too visually looks like a V. 

X-Y and its variants like ORTF are most effective with pops and jazz music.  Because it is close in, anywhere from the rim of the open grand to three feet or so away, cartioid capsules are obligatory.  The cartioids are directional only and often work in tandem with a "lo-cut" setting either on the mics themselves or on the recording unit, such that if the volume of sound or a burst is too intense and the mics being so close to the piano, the lo-cut feature will dampen the sound sufficiently to prevent unpleasant distortion.  Close-in recording tends to emphasize "music in the making", such as the percussive sound of hammer on string in staccato jazz chords.

By contrast, when it comes to classical music, listeners generally prefer a more refined, fully formed, and completely blended sound that has exited the piano out into the room.  For grands, therefore, small diaphragm condenser mics should be equipped with omni-directional capsules and be placed in parallel AB configuration on separate mic stands 5 to 8 feet away from the piano (depending on the piano and room acoustics) and be separated 12 inches apart.  This is what I use now, as do many others.  The omni capsules pick up both the directional sound emanating from the piano plus musical ambiance all around the mics allowing for a rich, vibrant sound.

Having said all this, I am, admittedly, unsure of optimal mic positioning techniques for recording uprights--and there may be differences.  I once read that some people learn how to remove the front panels to open up the sound, while others place the mics behind the soundboard, if the piano can be moved out and away from the wall.  Again, if you could say more about the instrument, that would help you to get the best feedback from listeners and pianos who record.

Of course, in any case, what is most satisfying to you is what you should use, whether it's considered right or wrong.  After all, they're your recordings!   

 

[mkaykov]

The funny thing is that the piano is: a Yamaha C3......   

That means that the ORTF configuration that my friend suggested is not suitable. For my next recoding, I will put on the omnis..........

[rachfan]

Hi mk,

As I said, I could be wrong and was on the piano.  Sorry about that.  .  Is it perhaps possible that the C3 had not been tuned recently?  (I've done that a few times, and members here let me know. )   

On mic positioning, yes, definitely change over to the omni-directional capsules.

Create a paper chart to capture your evaluations: i.e., test number, distance from piano, comments, and score  (could be 1 to 10). 

Then start about 5 feet away from the front leg of the piano and center the parallel mics on the curve of the case rim.  In testing, move the mics farther from 5' to 5' 6", 6', 6' 6", and 7'.  If you need more bass, move the parallel mics a few inches only sideways in the direction of the tail of the piano, while strictly maintaining the 12" separation between parallel mics. 

The piano lid should be fully open.  Incline the mics such that they point upward toward the edge of the raised lid.  As you move back from the piano in your tests, you'll need to remember to decrease the incline angle slightly at each step backward. 

During tests, always use the exact same excerpt from a piece to keep that as the constant.  The mic positions will be the variables. 

Listen to your outtakes carefully, putting your comments and scores on the chart.  Once you decide on the winner, find a surefire way to always be able to replicate that positioning.  You might simply use a yardstick, or it might coincide and can be lined up with the leg of a couch, or whatever.  Just remember, a difference of just a very few inches can significantly change the sound.  So you need to be as precise as you can be to get consistent results in each future recording.

I hope this helps.

   

[mkaykov]

Dear Rachfan,

I tested out the omnis. The sound is spacious, and the bass is captured very well. I set them out at around 6 feet, pointing them up towards the piano lid, like you suggested.
This is exactly the kind of piano sound that I've wanted.

There is one problem, though. My Minidisc recorder (rec level set on manual) starts "clipping" as soon as a play a little bit louder. The sound level is just normal through the headphones, the the recorder still clips. The level on the mixpad is not set high at all - it is actually a bit too low. Still, the recorder clips.

This happens only with the omnis............

Do you have any suggestions?

[rachfan]

Hi mk,

One thing you can try is to move the mics back even farther from the piano.  The power of my Baldwin L plus the acoustics in my living room require a mic distance of 8 feet for optimal sound.  Try that first.

If still a problem, try lowering the lid from the full stick down to the singer stick.  That too can make substantial difference if the C3 is overpowering the room.  Decline the angle of the mics accordingly.

Also, on the back of your recorder, is there a gain setting switch?  If so, what is it set on?

Finally, is there a lo-cut switch either on the mics or on the recorder?  If yes, is it on or off?

[mkaykov]

I think I figured it out - the problem is only in the minidisc recorder. When I listen directly from the mixpad (I had my father play), there is no overload noise. I turned down the level on the recorder itself - it is a bit quiet, but I can always add gain...............


 

[daniloperusina]

Just to set some facts right, if you don't mind, dear Rachfan:

ORTF, the french radio, developed the idea to mimic the distance between our ears: hence the mic capsules are placed 17cm apart at a 110 degree angle outwards, which is also not really a variant of XY.
(the purpose of XY is to have the capsules at the same spot, variants of this are Blumlein and M/S)

Neither XY nor any other set-up specifies any particular distance to the source. It could only be said about the "Decca-tree", which was specifically conceived with a large ensemble, like an orchestra, in mind. But then the distance was rather left to right, and rather the size of the source, not the distance to it.

No set-up is more effective with any particular style of music. Actually, it's only when you want to record a soloist or an ensemble "live" that you really try to record in stereo. For all other purposes they record separate tracks in mono, artificially made into stereo later with the help of a mixing console.

Interesting to note is that Mr Blumlein, mentioned above, gave us many of these theories, in the 1930's. But it wasn't music that he had in mind; it was sound for films. He basically wanted the sound to correspond to the scene: if someone was walking from left to right, the sound should do the same. Blumlein was an engineer and an inventor with many patents to his name. I'm just trying to illustrate how neither he nor anyone else thought of any particular style of music, distance or anything else when these theories were worked out.

Similarly, Cardiod, omni, figure-of-eight, hyper-cardioid don't require a specific distance to source.
The first mics were omni-directional, or figure-of-eight (ribbon microphones). Then they figured out how to acoustically make the capsule directional by building little valves behind it. Then they figured out how to put two directional (cardioid) capsules in the same microphone and electronically combine them back to omni, or figure-of-eight. That became the "multi-pattern microphone".
However, the ideas were based on solving logistical problems, like how to get rid of unwanted sound from anywhere but the front of the mic, not, again, thinking about any specific style of music or instrument.

It's actually almost opposite of what you say. Cardioid is not specifically for close-up. What decides the limit of distance from source is when ambient sound becomes equal or more prominent than the sound from the source, and a cardioid can actually be used a bit further away than an omni for the very reason that it only picks up sound from the front. 

The lo-cut cuts low frequencies; it does not prevent overload. There's another switch called "-10dB Attenuation", which lowers the sensitivity by 10dB, and therefore makes it safer to close-mike loud sources.
What the lo-cut does is: if the mic is perfectlly sensitive in picking up frequencies down to 20Hz, lo-cut will stop that sensitivity at already 75Hz, or 150Hz, or whatever. Frequencies below that will be severely reduced in level. This is handy for some noises, like someone stomping his feet, or twisting his hands around the mic. It also compensates for the "proximity effect", ie when a cardioid is really close to a source: the bass gets boosted.

If you activate lo-cut when recording a piano, it will sound like a.....banjo. So, avoid!

Anyway, when the engineers were developing these things, in the 30's and 40's,  classical music was usually their main concern, as no microphone company or recording label were seriously interested in how to record a screaming teenage non-musician, but rather how to faithfully reproduce the sound of....Jascha Heifetz. Today, a microphone can be advertised as "great for electric guitar", while the truth is that it's a copy of a microphone designed before electric guitar was even invented!

Otherwise, I agree with your advise!

[rachfan]

Hi danilo,

Thanks for adding this additional information and the historical context as well.  If I have a day when I don't learn something new, then it's a bad day.  I got a lot out of your explanation.