Grand piano (5 questions and replies)

How do I mike a grand piano with CM-700 microphones?

Reply: Here's a suggestion. Put the lid on the long stick. Aim one CM-700 straight down over the treble strings at the metal bar, 8 inches horizontally from the hammers, and 8 to 12 inches above the strings. Aim another CM-700 straight down over the bass strings, about 2 feet horizontally from the hammers, and 8 to 12 inches above the strings. To reduce boominess, cut 1 to 2 dB at 250 to 400 Hz.


I have two Crown PZMs and I understand that they are good for recording piano. Are they suitable? Where should the mics be located? What models would you recommend?

Reply: PZMs work really well for recording the piano. Gaffer-tape them to the underside of the raised lid. One PZM goes over the treble strings about 8 inches horizontally from the hammers, and another PZM goes over the bass strings, a couple feet toward the tail of the piano. The treble-strings mic goes over the strut. The two mics divide the sound board in thirds. If you have just one PZM, place it about 8-12 inches horizontally from the hammers in the middle of the keyboard, gaffer-taped to the raised lid.

If isolation is a problem, close the lid and cover it with moving blankets. The sound will be tubby with the lid closed, so cut a few dB around 300 Hz until the sound clears up.

The first choice is the PZM-6D because it is lightweight and has a wide, smooth frequency response. Second choice is the PZM-30D because it sounds the same as the PZM-6D. Last choice is the PZM-185.

Reply from Harold: The information you gave about using the PZM mics on the piano worked great. I couldn't tape the mics to the underside of the top. The Young-Chang uses natural wood with an oil finish. The tape just would not stick to it. I attached the mic by the XLR connector to a boom stand with electrical tape tightly stretched around the connector and boom, then positioned the mics in place with the top raised a little. I was surprised at the stereo spread. The mics picked up the sound of the piano almost no ambient sound, even as the singer was doing a scratch vocal while playing. I'm able for her to come in and overdub the main vocal track without "ghosting" from the scratch vocal leaking into the PZMs.


I am looking for an affordable way to record my daughter's piano playing. I have a limited budget and can't afford a PZM-6D. Can I use a Sound Grabber II to do a grand piano recording? I am using a Tascam digital mixer connected to a PC. The mixer comes with two XLRs and two 1/4" plugs. And what does it mean by "high-Z unbalanced output"?
Joe Wong  

Reply: The Sound Grabber is intended mainly for recording conferences and videos. It normally plugs into a miniature cassette recorder or camcorder.  

"High-Z" means "high impedance", or a high resistance to AC current (about 1500 ohms in the Sound Grabber). However, most recorders are designed to work with low impedance microphones (about 250 ohms). An "unbalanced" output is a signal on a cable with a shield and one conductor. An unbalanced output picks up more hum than a balanced output, which has a shield and two conductors.  

If your recorder has a 3-pin professional XLR mic connector, it is designed to work with a low-impedance balanced microphone. All Crown mics except the Sound Grabber and GLM-100E are low-impedance balanced.  

Costing $99 or less, a Crown GLM-100E mini microphone can produce studio-quality recordings. However, it needs a connector and a 9-volt battery.  

A wiring diagram is below. To reduce cost, the GLM-100E has no connector, but you can solder on your own connector.  

1. Solder the red lead to the + wire of a 9-volt battery clip.
2. Solder the shield to the wire of the 9-volt battery clip.
3. Also solder the shield to pins 3 and 1 of the XLR male 3-pin connector.
4. Solder the white lead to the + wire of a 10 microfarad electrolytic capacitor.
5. Solder the wire of the 10 microfarad electrolytic capacitor to pin 2 of the XLR connector.


If you don't want to do the wiring, you could buy a GLM-100 microphone, which already has an XLR connector. It is phantom powered and costs about $200.  

If you are using the GLM-100E, plug the XLR connector (that you soldered) into your mixer's XLR connector. Be sure phantom power is turned OFF in your mixer.  

If you are using the GLM-100, plug its XLR connector into your mixer's XLR connector. Turn ON phantom power in your mixer.  

As a starting point, tape the microphone to the underside of the raised piano lid, in the middle. 


I have two PCC-160 microphones. I am looking for the best way to mike a grand piano and an upright piano with one mic each. Sound leakage is a big issue. How would you mic them?

Reply: Here are some suggestions. For the grand piano, use gaffer tape (not duct tape) to attach the PCC-160 to the underside of the raised lid. Place it about 8 inches to 1 foot horizontally from the hammers over the middle strings, aiming at the hammers. Experiment with the height of the lid. If you get enough isolation with the lid on the full stick, use that. If you need to close the lid, do that (but the sound will be a little more boomy). Aim the hinged side of the lid at the upright piano for isolation.

With the upright you have a number of mic-placement options:


I'd like to permanently mike a grand piano with a PZM, but I don't want to gaffer-tape the mic to the underside of the lid. Are there any other placements that work?
Jeff Rodabaugh

• Place a PZM on the soundboard under the strings.
• Place a PZM under the soundboard on top of the cross brace, about 2/3rds up the keyboard. With a little high-frequency boost it sounds great.
Thanks to Peter Patrick and Ivan Beaver of Syn Aud Con for this advice.