Polar response of ribbons vs dual diaphragm fig-8s

[mixsit]

I've been experimenting with using fig-8 in multi micing situations, primarily for the purpose of taking advantage of the null characteristics, not to mention their being tighter at less than 90 deg.
Looking at the few polar patterns of mics I have (and others) that show more than the standard 1 kHz' (or limited frequencies) there seems to be an interesting trend in that the ones that do show multiple/extended plots, ribbons show a much less beamy top end than dual cap condensers.
121' pg18
http://www.royerlabs.com/pdf/manuals/R-121manual.pdf

I have a print out for the RCA Varacoustic' (a low ball general purpose' mic for it's time) that isn't well behaived on the back side but very broad up front, Cascade does 500, 1k, 5k, looks good for what's shown.. Don't have the KSM44, but this seems fairly the norm' for dual-caps from what I've seen ..hell for a lot of LDC cards' for that mater.
http://shure.com/stellent/groups/pu...documents/web_resource/us_pro_ksm44_en_ug.pdf

I've been aware of the general consistent patterns of ribbons but it never struck me before to the possible extent of it.
I was just wondering if this a rather very general trend?

 

[dementedchord]

sounds reasonable... the two diagphrams on the ldc work through phase cancellation etc to get all the different patterns... obviously they're interacting... where a ribbon has a single sheet suspended in between two magnets to each side... no interaction... maybe msh will respond... would'nt surprise me to only have half the story...

 

[mixsit]

Another thing I noticed is the 44' is the widest up top on axis in fig8.

 

[Marik]

I've been experimenting with using fig-8 in multi micing situations, primarily for the purpose of taking advantage of the null characteristics, not to mention their being tighter at less than 90 deg.
Looking at the few polar patterns of mics I have (and others) that show more than the standard 1 kHz' (or limited frequencies) there seems to be an interesting trend in that the ones that do show multiple/extended plots, ribbons show a much less beamy top end than dual cap condensers.
121' pg18
http://www.royerlabs.com/pdf/manuals/R-121manual.pdf

I have a print out for the RCA Varacoustic' (a low ball general purpose' mic for it's time) that isn't well behaived on the back side but very broad up front, Cascade does 500, 1k, 5k, looks good for what's shown.. Don't have the KSM44, but this seems fairly the norm' for dual-caps from what I've seen ..hell for a lot of LDC cards' for that mater.
http://shure.com/stellent/groups/pu...documents/web_resource/us_pro_ksm44_en_ug.pdf

I've been aware of the general consistent patterns of ribbons but it never struck me before to the possible extent of it.
I was just wondering if this a rather very general trend?

Hi Mixsit,

Excellent observation!
The explanation is very simple--the polar pattern depends on the diaphragm physical size. Since the ribbons are quite narrow, their pattern is uniform up to very high frequencies. However, if we look at their vertical polar response then we discover it is quite poor. On the other hand, since condensers (most often) have a circular shape their polar response is uniform in different planes, but (esp. for the LDC) much more frequency dependant due to larger diaphragm size.

Best, M

 

[mixsit]

Hey that's fantastic. And logical!
It also indicates something I wouldn't have thought to look for in if I were say micing mando/guitar/vocal combinations (and I am ) it would behoove me to mount the mic horizontally. Very cool. Thank you.
Now I want to get in and play with the vertical' and see how far that bit of attenuation effect goes.