C12 Style Mics for Orchestras & Choirs?

[Audiop]

Originally Posted by didier.brest

You had never seen.

And as you see, flat frequency response means no phase distortion. In the top where the FR rolls off you see the associated phase roll as you can expect from a MP device.

Thanks for helping me building my case. :-)


/Peter

[Audiop]

Originally Posted by didier.brest

[B]Could you provide us with the phase vs. frequency response of a Neumann TLM50, the amplitude frequency response is given by the attached graph. How many degrees deviation between 20 Hz and 20 kHz ?

If you send me a unit I'll be happy to run some measurements on it.


/Peter

[didier.brest]

You said

Originally Posted by Audiop

Transient response follows frequency response.

Originally Posted by Audiop

Transient response depends on phase and frequency response. Phase follows frequency response in minimum phase (MP) systems.

You can download the frequency response of the TLM50 from Neumann. Just tell us what is the phase deviation between 20 Hz and 20 kHz. Since you need the mic for answering, you acknowledge that this curve is useless forr assessing the transient response of the mic. So we agree.

Originally Posted by Audiop

And as you see, flat frequency response means no phase distortion. In the top where the FR rolls off you see the associated phase roll as you can expect from a MP device.

I actually see that there is a phase deviation at 6 kHz where the amplitude curve is dead flat and a amplitude bump at 15 kHz where the phase deviation is null. What happens beyond 20 kHz is of smaller interest, if any, for audio. I think that you would be much embarrassed for demonstrating on this example the relation between both curves.

[Audiop]

Originally Posted by didier.brest

You said
You can download the frequency response of the TLM50 from Neumann. Just tell us what is the phase deviation between 20 Hz and 20 kHz. Since you need the mic for answering, you acknowledge that this curve is useless forr assessing the transient response of the mic. So we agree.

I never said that curve was enough (for me) to calculate PR, only that phase follows FR in MP-devices.

I actually see that there is a phase deviation at 6 kHz where the amplitude curve is dead flat and a amplitude bump at 15 kHz where the phase deviation is null.

Do we know the smoothing of the FR-graph?

Also phase roll starts before the deviation you see in FR. The steeper the flank of the roll of the further down (or up) in frequency you start to see phase deviation.

That's part of why early digital sounded so so. It's not enough with flat FR to 20kHz if you have a brickwall filter after that. Such a steep filter cause severe phase distortion way down in the audio band.

What happens beyond 20 kHz is of smaller interest, if any, for audio.

Not at all, it's very important for phase response below 20kHz.

Perhaps you should spend some time reading up on this before suggesting that I should be embarassed?


/Peter

[Audiop]

One more thing..

Even if there were some in band phase deviation of a device that was supposed to be a MP-system we need to understand the audibility of phase of human beings.

The phase deviates aprox. 6 degrees at 6kHz in that graph of the DPA mic.

Have studied this so you know such a deviation is audible? No I thought so! :-)

In fact we are relatively insensitive to phase distortion and I would not be afraid to bet my car that no one would be able to hear that.


/Peter

[didier.brest]

Originally Posted by Audiop

I never said that curve was enough (for me) to calculate PR, only that phase follows FR in MP-devices.

So what ?

When a microphone is available to me and I am interested whether it sounds good or not, I record and I listen to the take. Why would I measure the frequency response, only its amplitude, for deriving its impulse response by means of suspicious and cumbersome computations ?
Did you ever do that ?

The only issue at stake to me in our discussion was whether one could judge about the transient response of a microphone from its published frequency response. I am happy that we agree that the answer is negative.

Originally Posted by Audiop

Not at all, it's very important for phase response below 20kHz.

We see directly from the DPA amplitude and phase curves what happens below 20 kHz. That's why I do not care of what happens beyond 20 kHz.

[Adebar]

Originally Posted by myferalprofessor

I'm wondering whether using spaced stereo C12 style mics in omni mode is a decent choice for choirs and orchestras. When I worked in the studio we used our pair of vintage C24 mics as go-to mics for small choirs in the live room all the time. But that's quite different than using them in large halls.

Is using C12s for classical just crazy talk or a reasonable alternative?

Thanks!

With the Josephson C700 - the LD capsule is derived from C12 - it is even more than a reasonable alternative. Not that it only sounds great, it also offers very versatile approaches in conjunction with the SD omni capsule in the C700A.

[narcoman]

Originally Posted by myferalprofessor

Indeed. I've heard some great recordings done with LDCs.

like pretty much every major hollywood recoding !! Various '67s as spots, and C12s as surrounds - on my gigs as well as the usual M50s {yes I know !!} etc etc