Miking a violin

[DickN]

I'm now using 15 nF across the pickup. With the 2.2 k load of the board on the dbox, which probably expects a 600 Ohm load, the input impedance is in the 50-70 k range over most of the spectrum. It's capacitive above, and inductive below, 2 kHz. The 15 nF cap results in a 2-pole response with -3dB point at 100 Hz and has very little effect on the high frequencies. It's pretty close to a Butterworth response curve, at least in simulation. The experiments with the violin are not consistent enough to compare spectra with any real precision. Now the downside: I sometimes hear a kind of nautical creak like the rigging of a sailboat but much more rapid. Turning down the bass on the channel eliminates most of it, but that defeats the purpose of adding the capacitor. I've never noticed this sound with a microphone. The pickup is at the E string end of the bridge, and the sound occurs mainly with the high strings.

[emmah]

Hi there!

Why don't u use programed violins? They are so much easier to mix than real ones and the sound is so realistic nowadays...

[steve]

Why don't u use programed violins?

Have you ever heard of live music?

[DickN]

@Steve: My wife says "Thanks"!

@Emmah: This was her great-great-grandfather's violin. 'nuf said?

@Paxtonbt: The multipoint pickup sounds like the way to go. Also sounds expensive (we're on a zero-income budget). Do the 3 transducers have separate cables for external mixing? I don't have a good mental picture of the vibration modes of the body under the bridge, although I'm reasonably sure the transmission from strings to body would be of opposite phase in the two feet. Are the foot elements connected in phase opposition? If so, I would think this would tend to cancel some of the acoustic feedback. The sound post makes the body asymmetric, so the cancellation would be compromised.

As far as equalization for my recordings, I've really enjoyed the RCA Victor 1947 setting in Audacity. It's beaten all of the custom work I've done, although I'm sure I could find a better setting.

Our situation is church service, so using Audacity to eq the violin wouldn't help during the service. I also don't have a separate violin channel in the recording, so can't do it later unless she plays a solo or a duet and I put her in one channel. Might try it electronically when I get around to building that phantom-powered DI box - looks simple enough. Thanks!

General question: Could the rapid "sailboat rigging" noise I mentioned in my Feb 28 post be a matter of bowing technique? Lisa has never had lessons, although she's been playing now for about 12 years.

[DickN]

Just tried the RCA 1947 eq on my test recordings. It really boosts the "rigging noise" although it does restore the missing bass in the recordings without the added capacitor. Sound is too muffled though. I agree one could come up with a better setting.

[steve]

General question: Could the rapid "sailboat rigging" noise I mentioned in my Feb 28 post be a matter of bowing technique?

Bow pressure, during normal playing, will cause mechanical distortions in the bridge. These are normally inaudible, but bridge pick-ups can pick them up. Depending on how rapidly the bass rolls off, sub-sonic frequencies will be at a very low level, but the better the bass response of the pick-up, the more low frequency thumping, creaking and other weird sounds will become apparent. A steep low-cut filter can often reduce these effects, but it's a careful balance to avoid making the sound "thin" again. When playing with other instruments these unwanted sounds will usually be masked by other sounds, so it is generally only a problem with solo playing. Barbera pick-ups get round this problem by using an almost solid and very rigid bridge that flexes very little, but the downside is that the violin will then be very quiet with a heavily "muted" sound (like playing with a bridge mute) so they are only really suitable for an instrument that is dedicated to being plugged in. Barbera pick-ups are also rather expensive. http://www.barberatransducers.com/violinpickups.html

[DickN]

A gold mine of information here. Many thanks! I think my DI box design will include a tunable 2-pole HPF. The rest of the spectrum I can take care of satisfactorily with the channel eq on the board.