SDC mic for recording pianos?

[quantum]

There has been a bit of recording discussion going on here recently.  I'd like to know a list of some recommended small diaphragm condensers for piano recording. 

Maybe there can be several price classes:
- best that money can buy
- under $1000
- under $500
- under $200
- under $100

[richard black]

Why small diaphragm particularly? Just curious....

The best SDC I know is the DPA 4003 - line-level version of the 4006. It's an omni so you're rather limited in stereo configurations you can use it in, i.e. no crossed pair! Price - a lot.

The best microphone I know, period, is the Royer SF12 stereo ribbon (though I've no doubt the mono versions are the same since they have all the same bits inside, I've just never used them).

Cheaper mics I'm not up to date on.

[quantum]

I've seen them used several times by the CBC in concert recordings.  Also have read recommendations and such for use on pianos.  But mainly I'd just like suggestions for specific models good for pianos.

I've got a pair of LDC's but no SDC's yet.  Might be looking to pick up a pair.

[m]

The best mics money can buy... well, you cannot buy those online or in retail store as they are whether custom made, or custom tuned.
Although very popular, I don't particularly like DPA 4003 and sold them long ago. The design is based on scaled up 1/2" B&K 4133 instrumental capsule, but due to the bigger 4003 capsule size the polar pattern sucks on the top of the range. The electronic circuit employs an opamp, with lots of negative feedback, which is responsible for dry, unmusical, and sterile sound. (BTW Richard, 4003 is not a line, but a 130V version of 4006, which has 48V phantom).

If you are into omni, instead, I would recommend Josephson 670, which uses Gefell instrumental capsules MK202 and MK221, which although identical to B&K, have much thinner (submicron) Nickel (vs. 5 micron stainless steel) diaphragm and sound much better. The Josephson head preamp circuit is also very nice.

For cardioid Gefell M294 are very nice. They are built around legendary M94 Nickel capsules.

For serious recordings I use whether ribbons (I have about a dozen), or mics custom built around Gefell MK202/221 and M94 capsules.

As for affordable stuff, I believe there are two models which stand out-- Studio Projects C4, and less expensive Oktava MK012. Both have interchangable omni and cardioid capsules (with Oktava you should purchase separately) and can be used in wide variety of miking techniques applications, are excellent designes, and sound good.
Unless you can afford Schoeps stuff, specifically for piano they are the best value on the current market.

Ribbons... well let's not even get there as I could write here a paper on the topic...

Best, M

[richard black]

Regarding the DPA4003:

The electronic circuit employs an opamp, with lots of negative feedback, which is responsible for dry, unmusical, and sterile sound. (BTW Richard, 4003 is not a line, but a 130V version of 4006, which has 48V phantom).

A couple of clarifications. The circuit inside the 4003 microphone is simplicity itself, a two-stage follower (FET and bipolar) and nothing more. The associated box of electronics (model number was something like 2812 when it was a B&K, don't know if it's changed) is indeed op-amp based. I've always used 4003s without it, powering them either from a stack of 10 lead-acid rechargeable batteries (!) or a custom-made regulated supply. The output is actually sort-of line level - it swings the full 130V p-p at the capsule's maximum SPL of 138dB (that's from memory, I may be a couple of dB out) which translates to about 1V-ish at the SPLs you expect off a nearby piano. You can run that into quite a few bits of electronics, and certainly the domestic CD recorder I use, without any amplification. All you need is a coupling capacitor to block 65V of DC. Of course the output from the mic is unbalanced but if you're not running long lines that's not such a problem at the voltages you're dealing with.

On tonal grounds, if you're not using ribbon mics I would _strongly_ advocate omni rather than cardioid condensors, as they have a much higher primary resonance, and indeed in SDCs this is higher than in LDCs. The 4003, according to my own measurements about 20 years ago, resonates at 25kHz.

Interesting what Marik writes about B&K vs Gefell diaphragm materials. I actually thought B&K used nickel but could easily be wrong.

[m]

Regarding the DPA4003:

A couple of clarifications. The circuit inside the 4003 microphone is simplicity itself, a two-stage follower (FET and bipolar) and nothing more. The associated box of electronics (model number was something like 2812 when it was a B&K, don't know if it's changed) is indeed op-amp based. I've always used 4003s without it, powering them either from a stack of 10 lead-acid rechargeable batteries (!) or a custom-made regulated supply.

Doesn't it prove my point about custom tuned equipment?
Yes, indeed the PSU was 2812. When they came to the market at first they were using a 5532 opamp in the circuit, which later was modified for AD797. The later model had much less noise and the sound was much improved.

The output is actually sort-of line level - it swings the full 130V p-p at the capsule's maximum SPL of 138dB (that's from memory, I may be a couple of dB out) which translates to about 1V-ish at the SPLs you expect off a nearby piano. You can run that into quite a few bits of electronics, and certainly the domestic CD recorder I use, without any amplification.

In fact, quite a few mics have enough sensitivity and can be used directly, without MIC preamp.

Due to the high voltage supply the 4003 is capable of 154db SPL, which is about 10db more than 4006 headroom.

The sensitivity is 40mv/Pa, or -27db in reference to 1V/Pa.

On tonal grounds, if you're not using ribbon mics I would _strongly_ advocate omni rather than cardioid condensors, as they have a much higher primary resonance, and indeed in SDCs this is higher than in LDCs. The 4003, according to my own measurements about 20 years ago, resonates at 25kHz.

Well, here I could argue. Not all "true" omnies have a high tuning (I think that you are refering to) resonance. While it is true, the omni is a stiffness controlled system and need to be tuned into the top of the bandwidth, in fact, MOST of them in order to get low noise figures are tuned somewhere in the middle (usually around 2-3K) and then effectively dampened with low volume backchamber. In this respect, they not very much different from cardioids.

On the other hand, your measured 25KHz, is not accurate, either, as the figure includes dampening effect of the backchamber. Since the 4003/4006 have a rather large one, its influence is not as prominent, but still needs to be taken into account, but indeed, the tuning resonance of the diaphragm itself is out of bandwidth, which explains the capsule's very linear phase response on the top ot the band.

Also, because of rather large spacing between diaphragm and backplate the linearity of capacitance to voltage transfer is much improved, resulting in very low distortions.

Interesting what Marik writes about B&K vs Gefell diaphragm materials. I actually thought B&K used nickel but could easily be wrong.

No, you are right. Indeed, B&K/DPA also uses Nickel (much thicker though--5micron). For some reason when writing, I was thinking of Aco Pacific... or is it Larson Davis
One of them uses Stainless, and another Titanium. I never can remember which is which.