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Hallo,

next week I will track a string quartet for a pop recording. So far I'm planning to use a Schoeps ORTF System for the overall ensemble sound and some room information as well as close Micing each player individually with a Schoeps cardiotic mic.
Since I'm more used to classical recording techniques I have the following questions:

1. How close is close Micing strings for a pop music recording?

2. What is a got spot for close Micing violin/ viola/ cello?

3. Any other suggestions or experiences?

Thanks a lot,
Daniel

Comments

JoeH Fri, 03/18/2005 - 11:52

For the violins and viola, you'll probably want to come in behind each player with a boom & get directly overhead of each instrument, looking down at the top of the instrument - remember that the sound of a violin blooms/blossoms out of the top - almost like a fountain. You can probably end using the close-up mics for punch & detail, but add the ORTF room mics for a better blend of natural sound.

How close can you get with the mics?

Well, you could go as far as a clip-on mic on the bridge of the strings - IF they'll let you, and IF you want to risk even touching an expensive violin (If they've brought their GOOD axes to the session, that is...) Some players who do this sort of thing all the time even have their own mics, or at least a work-a-day instrument that they'll let you do such things to it. DPA, AT and AMT make good contact mics for this sort of thing, but it's an added expense, and it's probably better suited for live onstage applications where you need a LOT of gain before feedback.

If not, (and I'm NOT a big fan of clip on mics at all), then you can work your way in as tight as you dare with individual mics (again, usually overhead for each of the violins and viola, and out in front, looking slighty down & above the bow for the cello). But be aware of the bowing action for everyone (They'll no doubt TELL you that as well.....or poke your mic boom with it! :twisted: Good bows are often expensive as well....some cost as much as $12k, so avoid that too).

Perhaps you can spread them out just a tiny bit as well - a compromise to the point where they can still see and hear each other comfortably, yet give you room to work with your mics and stands - maybe giving you a little more isolation too - but not to the point of compromising their sound & perf.

DavidSpearritt Sat, 03/19/2005 - 14:02

Danju wrote: Anybody with a suggestion how to close mic a cello? Should the microphone point towards the soundhole other rather towards the strings?

Neither the strings nor the soundholes (f holes) make any sound, so they are not good candidates for mic placement.

The wooden top itself makes the sound. As it is large, close micing never works well, you will only get what the local section of the top is doing and this does not have a wide frequency radiation.

If anything, use a close omni like the little DPA's and stick it near the bridge, ie the middle of the wooden top, this is the best compromise.

Cucco Tue, 03/22/2005 - 10:23

DavidSpearritt wrote: Neither the strings nor the soundholes (f holes) make any sound, so they are not good candidates for mic placement.

The wooden top itself makes the sound. As it is large, close micing never works well, you will only get what the local section of the top is doing and this does not have a wide frequency radiation.

If anything, use a close omni like the little DPA's and stick it near the bridge, ie the middle of the wooden top, this is the best compromise.

Okay Dave, I just have to be a smart ass here - technically the strings do make sound. They vibrate as the bow passes over them or as they are "pizz'ed." However, they are not the single point source for the sound that we consider as the "cello's sound." Of course, holes are incapable of creating sound, so you are correct there, however, it is through the holes that the back waves from the vibrating soundboard vent. So, technically, sound does pass through the F-holes.

However, I do agree with you completely, mic'ing just above the bridge with the small dpa is probably the best solution. If you don't have the DPAs, you may point a SDC just slightly above the bridge from a distance of 6 to 12 inches. This will give you a bit more bow noise, but can sometimes be considered a nice sound.

J...

DavidSpearritt Tue, 03/22/2005 - 13:15

Cucco wrote: Okay Dave, I just have to be a smart ass here

Sigh ...

- technically the strings do make sound. They vibrate as the bow passes over them or as they are "pizz'ed."

All things make some sort of "sound" when you hit them or pizz them, thats not the point. Its not a sound you want to hear, if it was, the cello would be 4 strings stretched across a bit of 4x2. An electric guitar is the only "instrument" where the string motion is directly tapped to create sound, again, the strings themselves on a guitar do not make any sound. Try playing one without the amp plugged in.

However, they are not the single point source for the sound that we consider as the "cello's sound."

They have no acoustic significance at all, they are simply used as a vibration source to excite the top into vibration. Its the top you hear. A vibrating small diameter cylinder (string) in air cannot create any sgnificant audible sound power as it cannot move air significantly. This is basic acoustics theory.

Of course, holes are incapable of creating sound, so you are correct there, however, it is through the holes that the back waves from the vibrating soundboard vent.

Nope, the holes are not reflecting any back waves. The holes are there as helmholtz resonator "necks", where very woofly air moves back and forth elastically across the holes (like a loudspeaker port) and you would certainly not want to hear that or put a mic there. Its over a very narrow freq range, almost a "tone" ie low and very woofly. The helmholtz resonator helps the top radiate and vibrate at the very lowest of its modes, its still the top you want to hear. The back of the cello/violin is far too rigid to vibrate efficiently at acoustic freqs, it is there for structural significance, ie to support the sides and top and keep them from folding in or collapsing.

So, technically, sound does pass through the F-holes.

Nothing significant "passes through" the f-holes, there is no nett transfer of air out of the cello, thats why cobwebs and dust build up in there.

However, I do agree with you completely, mic'ing just above the bridge with the small dpa is probably the best solution.

Precisely because this point is the centre of the top where you are likely to be close to as many of the tops modes of vibration as possible. Nothing to do with strings or f-holes or sound reflections from rigid backs etc.

Cucco Tue, 03/22/2005 - 14:31

Dave, Dave, Dave...
So many things wrong here - I'll start at the top...

DavidSpearritt wrote:
All things make some sort of "sound" when you hit them or pizz them, thats not the point. Its not a sound you want to hear, if it was, the cello would be 4 strings stretched across a bit of 4x2. An electric guitar is the only "instrument" where the string motion is directly tapped to create sound, again, the strings themselves on a guitar do not make any sound. Try playing one without the amp plugged in.

Not true. The standard string instruments are ALL directly tappaed for their sound. Though the electric guitar uses a pickup, the stringed instruments use a bridge and a soundboard. The string itself vibrates quite a bit. The vibration is picked up by the bridge and then carried to the body of the violin where it is amplified. Thus -- "directly tapped."

They have no acoustic significance at all, they are simply used as a vibration source to excite the top into vibration. Its the top you hear. A vibrating small diameter cylinder (string) in air cannot create any sgnificant audible sound power as it cannot move air significantly. This is basic acoustics theory.

Wrong here too - try tensioning a violin string in mid-air and then bow it with a properly rosined bow. Surprise, you get quite audible vibrations. They even have a defined pitch center, surprise, surprise. Again - this "basic acoustics theory" is quite simple - you can't amplify it if it doesn't exist.

Nope, the holes are not reflecting any back waves. The holes are there as helmholtz resonator "necks", where very woofly air moves back and forth elastically across the holes (like a loudspeaker port) and you would certainly not want to hear that or put a mic there. Its over a very narrow freq range, almost a "tone" ie low and very woofly. The helmholtz resonator helps the top radiate and vibrate at the very lowest of its modes, its still the top you want to hear. The back of the cello/violin is far too rigid to vibrate efficiently at acoustic freqs, it is there for structural significance, ie to support the sides and top and keep them from folding in or collapsing.

So, technically, sound does pass through the F-holes.

Nothing significant "passes through" the f-holes, there is no nett transfer of air out of the cello, thats why cobwebs and dust build up in there.

Wrong here too.

The violin is not a Hemholtz resonator. True, it is similar, but it is most definitely not one. A Hemholtz resonator is tuned to one specific frequency and that's it. As well, they are usually designed to pick up air-borne sound waves. What the violin (et. al) is is an acoustic amplifier. It picks up all the frequencies and amplifies them. The vibration is transmited through the bridge from the vibrating strings. It is then passed on to the body of the instrument which vibrates sympathetically. This vibration excites the air on both the outside and the inside of the instrument. The excited air (in other words - air in motion) inside the instrument exits through the F-holes thus making sound. (moving air=sound).

Try plugging the F-holes on an instrument with a truly air-tight seal - silicone caulk, etc. (if you can find a violin that you don't mind destroying.) Magically, the instruments sound is still present, but at a far diminished amplitude.

Precisely because this point is the centre of the top where you are likely to be close to as many of the tops modes of vibration as possible. Nothing to do with strings or f-holes or sound reflections from rigid backs etc.

Nope, just cuz I don't get excess bow noise, player grunting, and cuz it's convenient. Frankly, I prefer the sound of the mic just outside the F-hole, but you find a violin player who will play a concert with a mic 3 inches from the F-hole.

Ironically, I was the guest speaker this weekend at the Belmont Bay Science Center and my topic was physics and how it relates to music. This was one of my big demonstration pieces was the art of the violin construction and it's timeless simplicity.

J...

Joe - Nope, I just can't help it. :?

Cucco Tue, 03/22/2005 - 17:51

That's a good article Dave, but understand that, first, they do not claim the violin is a Hemholtz resonator - simply that it exhibits the properties of one when sung into. Also, their concept of a string being quiet when played alone is simply a subjective concept. I've measured as much as 61 dB from a solitary string - no violin attached.

Overall, your article agrees that the sound produced within the cavity of the violin does make a great deal of difference - and how does that sound escape the instrument? Why, that's through the F holes.

:)

J