Topic: Comparing OctoMic's Polar Patterns to the World's Best Mono Mics

[Len Moskowitz (Core Sound)]

If you compare Core Sound OctoMic's first-order polar patterns (e.g., omni, cardioid, hypercardioid, dipole (figure-8) to the best ones from microphones that tapers here use, you'll see that OctoMic's are better.

Here's one: Omnidirectional

Attached are two polar pattern graphs. One from OctoMic, and the other from a very popular mono mic used my many tapers here.

On request, I will post similar pairs of patterns for cardioid, hypercardioid and dipole (figure-8).

[heathen]

What are the measuring protocols of each?  Without knowing that, comparing the graphs doesn't really tell anyone much.

[Len Moskowitz (Core Sound)]

What are the measuring protocols of each?  Without knowing that, comparing the graphs doesn't really tell anyone much.

Measured every five degrees at 1-meter from the sound source. Log sweep.

[Gutbucket]

Seems to me this is comparing apples to oranges. 

What is the response of the OctoMic above 10kHz? Say at 16kHz as plotted for the other mic?
What is the diameter of the very popular mono mic? 

It is not especially difficult to maintain omnidirectionality to higher frequencies by use of a smaller capsule, assuming a fully omnidirectional response up top is the desired goal.

Not trying to be contrarian here, just keeping it real.  Rather than straight omni and bi-directional patterns, I'd expect the off-axis behavior of cardioid range patterns to be where significant differences might be found,

[EmRR]

True, different because it's a derived pattern with the advantage of elements pointing in every direction.  Each has it's advantages.  Is there a simple path with ambisonics to model the changing directionality with frequency for various patterns, if desired?  Just thinking out loud.  I'm sure it CAN be done, just whether the 'convenience' tools are there. 

What that perfect omni pattern tells you is that you can then derive any other pattern pointed in any direction; it's the ultimate test for weak spots. 

The other mic looks a lot like the MKH 20.  I've used the high frequency directionality to advantage with an MKH based native array, though to be clear I was setting out to do so. 

[heathen]

If it is the MKH 20 then I think I would quibble with saying it's used by many tapers here.

Why not tell us what mic the other graph is from?  Inquiring minds want to know 

It's the Schoeps MK5.

[Len Moskowitz (Core Sound)]

Not trying to be contrarian here, just keeping it real.  Rather than straight omni and bi-directional patterns, I'd expect the off-axis behavior of cardioid range patterns to be where significant differences might be found,

Did you want to see the two cardioid polars?

Also, keep in mind that OctoMic offers all of the excellent first-order and second-order patterns simultaneously, as many as you please, and each pointed in whatever direction you please, all defined in post.

A mono mic is one pattern pointed in one direction.

[Gutbucket]

I think that's likely to be a more useful comparison for most folks here, as long as the basis of comparison is equivalent (similar measurement methodology, polar resolution, frequency points, smoothing, etc)

[Gutbucket]

Is there a simple path with ambisonics to model the changing directionality with frequency for various patterns, if desired?  Just thinking out loud.  I'm sure it CAN be done, just whether the 'convenience' tools are there.

Can be done.  Schoeps Polar Flex like.  I've thought much about that for use with TetraMic and wish that functionality was included in the included VVMic conversion/polar-manipulation software.. most useful placed there for the convenience factor as you mention because one does not have to convert to B-format first to play around with listening and tweaking and direct stereo output from the raw A-format files.  I've not searched to find whatever 3rd party ambisonic tools are available to do this after conversion to universal B-format. 

That functionality is my second wish for VVMic (and/or whatever software is used for OctoMic), the first being the incorporation of an input gain-balance correction feature for recordings made using multichannel recorders that do not have linked channel input trims (Roland R44, R88, etc) which need levels matched using a test tone recorded to each channel during the session for trim calibration.

[Len Moskowitz (Core Sound)]

Here are the cardioids.

Note that the OctoMic chart goes down to -40  dB. The mono mic only goes down to -30 dB.

Also, the OctoMic goes down to 100 Hz. The mono mic only goes down to 250 Hz.

[kuba e]

Is there a simple path with ambisonics to model the changing directionality with frequency for various patterns, if desired?  Just thinking out loud.  I'm sure it CAN be done, just whether the 'convenience' tools are there.

Maybe you can try to eq omni component in B format (or other components except omni). I only read a discussions about ambisonic here and one article on wikipedia, so please take me with a grain of salt.

[Len Moskowitz (Core Sound)]

Is there a simple path with ambisonics to model the changing directionality with frequency for various patterns, if desired?  Just thinking out loud.  I'm sure it CAN be done, just whether the 'convenience' tools are there.

Maybe you can try to eq omni component in B format (or other components except omni). I only read a discussions about ambisonic here and one article on wikipedia, so please take me with a grain of salt.

That won't work.

[kuba e]

Why wouldn't it work? I will have to read in detail how the beam former works for higher order ambisonics. But for a first-order ambisonic, it should work, right?

[Len Moskowitz (Core Sound)]

This thread has strayed very far from the original post. I'm locking the thread.