Mobile rig for choral recording - any suggestions?

[David Spearritt]

How would you think the DPA measurement would translate into the figures provided by other manufacturers? Would you say the self noise of a 4091 is on par with a KM130, MK2, or something similar?

We got a loan of a demo pair of 4091's and directly compared them side by side with the KM130's. I am afraid that they were discounted for serious classical recording immediately because the self noise is so high. They are much noisier than the KM130.

They sound very neutral and omni, but the noise was a deal killer for us.

[mosrite]

This DPA noise thing is bugging me. Im on the verge of buying a pair of 4091's or 4090's and will sort out a demo to hear for myself. Its interesting though that many different people on this forum have had different experiences regards their self noise. Could those people with negative experiences please clarify what application they used the DPA's on in order to reach their conclusion? Could this information also include whether it was a studio recording or a location recording? As Rich has pointed out before there is an inherent difference in the 2 scenarios regards a microphones self-noise.

I stumbled across this info from DPA and it might shed some light on the noise figures. Rich has already touched on some of this but I believe this to be from the horses mouth:

A last note regarding noise: The 4090 and 4091 mics have a very low noise floor, inaudible in virtually any application. Please remember this: there
are currently no standards for measuring noise. As our background and
heritage is that of a test and instrumentation company, we use very
scientific and conservative methods for specifying the performance of our
products. We have found that looking at a wide range of very respected
manufacturers, the variations in measurement methodology results in the same
mics having as much as 8 to 10 dB difference depending on whose method is
used.

We have seen mics from other companies that they state, say, a 20dBA noise
spec that when we measure that same mic using our methodology, we find the
noise to be 28dBA or greater. Also, when others measure a mic from DPA that
has, say, a 20dBA noise floor, their methodology finds our mic measuring at
12dBA or even less. Don't take published noise figures and use them as
absolutes. I do not believe that you can compare them in an apples to
apples fashion. You will find the noise floors on these new models of mics,
the 4090 and 4091, to perform way below what you have come to expect from
other mics that measure in the mid 20's (dBA) in noise.


Best Regards,
Bruce


Bruce Myers
President
DPA Microphones Inc.
2432 N. Main Street, Ste 200
Longmont, CO 80501
303-485-1025
866-DPA-MICS

I will of course listen for myself. If I am satisfied with the self noise is there anything else to be concerned with if attempting to use these as a main spaced pair? Someone suggested they darken up considerably with the diffuse sound field compared to others?

I think it's only fair to warn you that many commercial choir recordings have a fair amount of Lexicon reverb mixed in post session.

Not something I would personally ever do.

[mosrite]

One more thing. Rich, IYO, for a main pair would you go with the less sensitivity and lower noise floor of the 4090's or the higher sensitivity/noise floor of the 4091's? Cheers.

[sonare]

That's a tough one as I used them with Millenia micpres which introduce no objectionable noise themselves.

I went with the lower sensitivity because the output seemed fine in the uses to which I put them. Dave Spearritt tried 4091--perhaps you could arrange for a trial of 4090 and see for yourself-- that is really the only way you can know for sure.

For a main pair I would likely try the 4090. Someone earler mentioned the Shure omni/cardi (KSM141?)-- they have been described to me as being OK for spots.

As you can see by now, everyone has a different threshold of noise and non-linearity!

Rich

[David Spearritt]

Correction, looking at my notes, the mics I listened to were 4090, the hi-sens ones. Sorry for the confusion. I plugged them into my Nagra V as I did with the KM130's in a quiet domestic environment with my typical gain settings for recording concert chamber music. They were so noisy I didn't even think about trying them on a real concert.

With louder sound sources than string quartets and closer distances than 3m away and 3m in the air, I am sure they will be very useful mics. But I am totally convinced that the self noise eliminates them from main pair applications for classical music recording.

The DPA self noise specs seem to correlate with listening tests and the Neumann specs on self noise. The 4090's are about 8-11dBA noisier than the KM130. This is significant for digital recording.

[DaveD]

Originally Posted by mosrite

I will of course listen for myself.

Let us know how the demo goes. I'm very keen to hear a further opinion re the noise of the low sensitivity 4091s.

[mosrite]

Just to clarify (been on the DPA website):

DPA4090 - NOISE 23 dB(A), SENS 20 mV/Pa, MAX SPL 134 dB

DPA4091 - NOISE 26 dB(A), SENS 6 mV/Pa, MAX SPL 144 dB

So the 4090 is less noisy AND more sensitive while the only advantage of the 4091 appears to be its max spl handling.

[David Rick]

Originally Posted by sonare

I am curious what you are thinking of. The Brits almost never need to add reverb, and they do most of the choral recording.

Rich

Yeah, but they're good at it! And more to the point, they have good halls. People who don't have good halls do what they have to do.

For the record, I seldom use artifical reverb either.

David

[sonare]

Originally Posted by David Rick

For the record, I seldom use artifical reverb either.

You might change your mind after trying Altiverb-- now for Mac and PC.

Rich

[DaveD]

Originally Posted by sonare

You might change your mind after trying Altiverb-- now for Mac and PC.

Rich

Mate, I just changed my mind! Altiverb 5 sounds amazing ...