Recording Accessoiries

[Emmathom]

Hi Folks

I thought that a topic on the microphone and recording accessories that we make (or adapt in the case of purchases) could be interesting. We could share our "tips".
Most often we are led to make these accessories which cannot be found in stores or at prohibitive prices. In French (and rather in the cinema) we call all of these personal accessories with which we work and which belong to us "our jewelry".

I will start with a problem that I encountered during my last recording. The alto violin was quite close to the piano and the piano was bleeping into the violin track. (see photo). No need to ask the violinist to move: the musicians are used to their positions and are reluctant to change them. And the mic has to be quit far away from the violonist (60cm at least) because she wanted to be free to move her bow without risking hurting it on the mic (bows can coast hundred of euros and even much more).

So I thought of making a kind of "cap" which could reduce the bleed (while knowing that it would not eliminate it completely). But each dB gained is important.

So I started with a base made of a plastic binder that I cut so that it encompassed the microphone at 180°. In fact, 180° is not necessary and I reduced the curve.
I chose to use an aquarium filter to dampen the recorded sounds hitting this cap and which could bounce and create unwanted artifacts. These filters exist in different densities: I chose a very low density and therefore a rather airy and large mesh. I glued it with neopren on the plastic cap.
The cap is held on the microphone suspension by small document clips. You can see some picts below.

I haven't made audio tests for now but will do asap and let you know how much unwanted sound it can reduce.

 

[Emmathom]

Since I'm alone to do some tests, I will proceed so (see pict) :

Without cap :
- I will play some acoustic guitar in axis 60cm from mic
- I will then move off axis (by ~ 90°) but still 60cm from mic (as if another musician was playing aside)

And do the same with the cap, of course without changing a thing between the 4 recordings.

I will be able then to compare the bleed (in dB) with and without the cap in the 2 recordings off axis AND also how the cap may influence the sound in the axis mode.

 

[zamproject]

Hey

That's my personal thoughts... don't take it as absolute fact or discouragement for your try...

I don't think your panel assembly will work that well, too close from the mic (possible comb) and probably useless at mid to low freq. I suspect you won't have that much overall rejection (especially from a big omnidirectional instrument like piano), but filtered bleed that may give you an even worst piano sound in that mic.

Don't you have mobile acoustic panel to place behind the alto ? seem there is room , and alto player already turn the back to the piano so no constant eyes contact required.

In situation where there is no placement option and obvious bleed unavoidable, I'll try to make the bleed nice, by mic choice and orientation according to polar pattern and -natural- rejection.

 

[Emmathom]

Hey

That's my personal thoughts... don't take it as absolute fact or discouragement for your try...

I don't think your panel assembly will work that well, too close from the mic (possible comb) and probably useless at mid to low freq. I suspect you won't have that much overall rejection (especially from a big omnidirectional instrument like piano), but filtered bleed that may give you an even worst piano sound in that mic.

Don't you have mobile acoustic panel to place behind the alto ? seem there is room , and alto player already turn the back to the piano so no constant eyes contact required.

In situation where there is no placement option and obvious bleed unavoidable, I'll try to make the bleed nice, by mic choice and orientation according to polar pattern and -natural- rejection.

Hi @zamproject ! Thank you. Your observations are wise and certainly true. I believe your are used to these situations... You're right saying that the piano is loud and omnidirectionnal and so I won't get a lot of rejection... That was impossible to put some screen on stage because I was shooting a vidéo clip. I also recorded live this orchestra with an audition, so no way to put an acoustic screen on stage, unfortunately.
About the filter comb I'll make some tests and post them. Once again the goal is to try to win a few dB's

 

[ubxf]

Could a piezo mic on the viola help adding a bit of direct sound in the mix ?

 

[Emmathom]

Could a piezo mic on the viola help adding a bit of direct sound in the mix ?

Or a dedicated miniature SDC on flexible, yes, but I do with what I own for the moment...

 

[Emmathom]

I think about posting an excerpt of the recording concerned : the main mix and the same part with the alto violin in solo, which means :
- we can ear the level of the instrument solo vs the whole mix level
- we can ear the bleeding in the mic
Will do that quickly...

 

[Emmathom]

Here we are...
The orchestra was composed by a piano, a violin, an alto violin and a cello.
Below an excerpt of the whole instruments together and one of the alto track in solo (in where we can ear qiet much bleeding of piano & lead violin).
In the same time, we must not forget that this recording is destined to be heard with all instruments in together ! If the balance is satisfying, then the result is ok...

Alto solo

All instruments

 

[zamproject]

Ho ! I don't get it was a concert recording...so nothing we can help afterward unfortunately.

Transparent panel are frequently used, which are good for audience and video capitations, but this add high reflective surfaces

I suppose you uses one or two ambient pair (whatever type) in addition to close mic ?
I'll probably use them as a first layer, assuming it's pro musician that have a good global balance.
Then open close mic if needed to add little precision...

Could a piezo mic on the viola help adding a bit of direct sound in the mix ?

Don't know where is the technology around piezo today, but in my mind that's not the sound I'll expect to have from a
-classical- performance

 

[Emmathom]

I suppose you uses one or two ambient pair (whatever type) in addition to close mic ?
I'll probably use them as a first layer, assuming it's pro musician that have a good global balance.
Then open close mic if needed to add little precision...

Unfortunately I should have done so (and I regret). I hadn't enough mics to add an ambiance couple... but effectively a good ORTF pair in front of the orchestra would maybe have provided better results.
I did so on a cello quartet with one SDC omni pair + a LDC M/S + an SDC ORTF (for choice) and I chose the omni pair (but the ORTF was very interesting too).
I should stick now to ambiance pairs as it's the most academic way to record classical music (any acoustic music in fact)

 

[zamproject]

Here we are...
The orchestra was composed by a piano, a violin, an alto violin and a cello.

Very informative !

In fact I don't find the bleed on alto mic that problematic ...considering the recording condition...
And to my ear the piano sound good on it (better than the violin but this one is less prominent)
I'm sure you'll find the proper balance to mix this recording, musician seem good, which is the most important part...
If this job is not for a very demanding classical label you'll be fine I suppose.

Unfortunately I should have done so (and I regret)

Lesson learned

At this point you should reverse your mind and look at the crosstalk/bleed as a chance !!!
To give you some space an the natural sound you miss without ambient mic.

By the way what is the name of the quintet ?

 

[Emmathom]

The quintet is composed by musicians which play here and there, with other musicians, in duo, trio, etc...

No it's not for a classical label but for my pleasure and to train myself. I began "outside recordings" 2 years ago in my region and since then "follow" the cello player in his different bands & recitals. He plays classical, baroque and sometimes eastern music, film music... so it's interesting & challenging since he never plays the same works twice.

I planned to set-up my pro Facebook page this winter to post my photo shootings, vidéo recordings and (of course) audio recordings and will add it to "my signature" here in diyaudio.