Inside the grand piano: close miking techniques

[chris319]

Originally Posted by David Spearritt

These pictures demonstrate clearly why you shouldn't mike in the near field to a planar sound source. Acoustic guitar is not unlike a piano soundboard.
BBC News - In Pictures: Stringed theory

Wow! Nice find!

[chris319]

I have just ordered one of these for my closed-lid miking dilemma:

CBL 99

I like that it is lightweight (56 g). I'm not so skittish now about using blue painter's tape to tape it to the inside of a piano lid using eight strips of tape in an octagonal configuration.

[hbphotoav]

Just curious... unless the price was the determining factor... why would you choose the attached AKG CBL-99 FR over the DPA 4060/61 (see at: omni capsule question Post #11) ?

Off-axis response is pretty much identical... but +10dB at 7K...? Thatsalotsa "air"...

[chris319]

Four reasons:

1. Price

2. Price

3. Price

4. It is a non-paying gig and I'm treating it more as an experiment than anything. I wanted to try something specifically designed as a boundary mic.

[hbphotoav]

Kewell. Let us know what you think...

[chris319]

I have a Crown PZM-30D I could press into service but it is not light in weight, and it has one of the best Live Performance Detectors in the industry. If I'm using light-tack blue painter's tape to hold it on during a live performance ...

[John Willett]

Originally Posted by hbphotoav

Just curious... unless the price was the determining factor... why would you choose the attached AKG CBL-99 FR over the DPA 4060/61 (see at: omni capsule question Post #11) ?

Off-axis response is pretty much identical... but +10dB at 7K...? Thatsalotsa "air"...

Originally Posted by chris319

Four reasons:

1. Price

2. Price

3. Price

4. It is a non-paying gig and I'm treating it more as an experiment than anything. I wanted to try something specifically designed as a boundary mic.

I was surprised how inexpensive the DPA kit was - about £600 for the complete stereo kit when I asked a few weeks ago.

[Bechstein]

Originally Posted by John Willett

I was surprised how inexpensive the DPA kit was - about £600 for the complete stereo kit when I asked a few weeks ago.

Same price in the EU. I'm even considering buying a set.

[chris319]

Originally Posted by hbphotoav

Just curious... unless the price was the determining factor... why would you choose the attached AKG CBL-99 FR over the DPA 4060/61 (see at: omni capsule question Post #11) ?

Off-axis response is pretty much identical... but +10dB at 7K...? Thatsalotsa "air"...

OK Harry, you talked me out of it. I have cancelled the order for the AKG boundary mic and have ordered an omnidirectional one of these. It only has a 5 dB bump! The price is comparable.

http://www.shure.com/idc/groups/publ...o_mx391_ug.pdf

If it doesn't sound good it's YOUR fault!

[hbphotoav]

Originally Posted by chris319

OK Harry, you talked me out of it. I have cancelled the order for the AKG boundary mic and have ordered an omnidirectional one of these. It only has a 5 dB bump! The price is comparable.

http://www.shure.com/idc/groups/publ...o_mx391_ug.pdf

If it doesn't sound good it's YOUR fault!

I would be happy to accept blame if you'd ordered a DPA4061 and were not satisfied that IT sounded good in this application... I'd also likely offer to buy it from you since I think it might make for a cool, lightweight Decca tree. I've never used the Shure... but since the sound pressure level inside a concert grand piano can exceed 130 dB SPL peak 20 cm (8") over the strings (refer to: http://www.dpamicrophones.com/en/Mic...and-Piano.aspx )... the MX391's somewhat anemic "Maximum Sound Pressure Level (1 kHz at 1% Total Harmonic Distortion, 1 kΩ load)
Cardioid: 118.8 dB Supercardioid: 117.5 dB Omnidirectional: 110.7 dB " may leave you wanting the AT851RO's (which I own) 132dB, or, for a decent amount of headroom, the 4061's 144dB max before clipping.

I'm really not chiding you, or trying to force my choice upon you or anyone else. But I also hate to see money spent twice... and the DPAs are truly amazing mics. I'm going to try my pair on rack and floor toms tomorrow, to see if I can get a sweeter cymbal sound than we get through the "usual" Audix pair...



HB

Late edit: Here are up to 10 4061s with LEMO connectors for $150 each...

http://cgi.ebay.com/DPA-Microphones-...#ht_500wt_1156

MicroDot connectors are available for $99 here...

http://cgi.ebay.com/DPA-DAD6001BC-Mi...#ht_1581wt_907

$250 for a 4061 and MicroDot... sounds like a deal to me...

[chris319]

I'll have a Crown PZM-30D along in case the Shure doesn't work out. The Crown can take 150 dB SPL. As I said, I'm treating the mic in the piano basically as an experiment and it's plan "B" anyway. I can't be damaging the finish of a rented instrument and I can't have the mic go ker-plop during a live concert. And I can't have the lid open (unless the conductor changes her mind). The last time I did this, the lid was going to be open in a phone conversation with her the week before, then it was closed the day of. I wound up putting a mic on a low stand beneath the piano on the wrong side of the sound board. Suffice it to say, the sound was nothing to be proud of.

If there is an opening in the lid near the hammers, behind the desk where the sheet music is propped up, I will aim a Rode NT-1A at that opening. That is plan "A".

[hbphotoav]

Cool. At any rate, and especially if you need to use the PZM, have a fresh roll of 2" PermaCel ShurTape or ProGaff genuine gaffer tape (or its $20/roll equivalent in SoCal) as well as the paper painter tape. If you're concerned about the metal surface of the Crown, use the painter tape to cover the bottom, and use four 18" strips of gaff to tape it to the lid, once you've determined where you want it. I like about 18" behind the hammers, and centered (or cheated toward the bass strings, if anything) on 5' and 7' grands.

In 20 years of doing shows with closed grand pianos (some with RadioShack PZMs, some with Crown PZMs, some with AT851s, and most - recently - with 4061s) I have NEVER had an issue with either PermaCel or the ProGaff I source at Tour Supply here in Nashville. Never. Even through a week of rehearsal followed by a week of shows. Never an issue.

Truly... good luck, and break a leg.

HB

[chris319]

In reading the PZM patent (which has expired):

Pressure recording process and device - Google Patents

two properties of a proper boundary mic are that a) the diaphragm be parallel to the boundary, and b) that it be just a few millimeters away from the boundary (the piano lid being the boundary). Does the DPA 4061 satisfy both of these requirements? Of course if you're getting satisfactory recordings it's really a moot point.

Listening to the last recording I made of this group, one of my problems seems to have been the piano bleeding into the stage mic used for soloists. There's another problem to solve. Keep in mind that this is a YOUTH symphony. The playing -- let's not talk about that

[Bechstein]

And what about this ?

Blue Microphones | Ferras