[Ray Thomas[_2_]]

A few SD 1/2" condensor mics have interchangeable omni and cardioid capsules
depending on ones need, such as Behringer and Rode...not to mention even
even Schoeps and Sennheiser (eg MKH 8020 8040) if your budget goes that
high. Would a cheap and nasty conversion from cardioid to omni not be
possible by simply wrapping some insulation tape (or large size heatshrink)
around the side vent holes of a cardioid capsule ? I remember that was the
main reason stage performers are told not to grasp the upper end of an SM
57/58 too high near the basket area, thus killing off it's directional
capabilities and turning it into an omni. Or are there other more subtle
design principles at work which would prevent such a low cost 'conversion' ?
Ray

[Anahata]

On Wed, 23 Jul 2008 04:12:04 +0000, Ray Thomas wrote:

Would a cheap and nasty conversion from cardioid
to omni not be possible by simply wrapping some insulation tape (or
large size heatshrink) around the side vent holes of a cardioid capsule

Yes, but it wouldn't be a very good omni. The vent holes are the visible
difference but they are not the only difference.

A similar question appeared here a couple of weeks ago. The answer was
that, though the vents make an important contribution to the mic's
pattern, the capsule's interior design also has to be tweaked to the get
the best response.

--
Anahata
==//== 01638 720444
http://www.treewind.co.uk ==//== http://www.myspace.com/maryanahata

[Scott Dorsey]

Ray Thomas wrote:
A few SD 1/2" condensor mics have interchangeable omni and cardioid capsules
depending on ones need, such as Behringer and Rode...not to mention even
even Schoeps and Sennheiser (eg MKH 8020 8040) if your budget goes that
high. Would a cheap and nasty conversion from cardioid to omni not be
possible by simply wrapping some insulation tape (or large size heatshrink)
around the side vent holes of a cardioid capsule ? I remember that was the
main reason stage performers are told not to grasp the upper end of an SM
57/58 too high near the basket area, thus killing off it's directional
capabilities and turning it into an omni. Or are there other more subtle
design principles at work which would prevent such a low cost 'conversion' ?

If you do this, it will become an omni, but the frequency response will be
very bizarre because the volume of the chamber behind the diaphragm won't
be optimal for an omni.

However, the bizarre frequency response can be fun sometimes... it used to
be fairly common to block the vents on an SM-57 in order to turn it into
a weird-sounding omni guitar amp mike.

Do not use "insulation tape" or other crap that leaves residue. Keep a
roll or two of real gaffer's tape around the studio. Cheap tape will mess
up your cables.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Richard Crowley]

"Scott Dorsey" wrote ...
Do not use "insulation tape" or other crap that leaves residue. Keep a
roll or two of real gaffer's tape around the studio. Cheap tape will mess
up your cables.

Even real gaffer's tape will gum up genuine rubber cables when
left in contact for a long time in elevated temperatures. Beware.

[Scott Dorsey]

Richard Crowley wrote:
"Scott Dorsey" wrote ...
Do not use "insulation tape" or other crap that leaves residue. Keep a
roll or two of real gaffer's tape around the studio. Cheap tape will mess
up your cables.

Even real gaffer's tape will gum up genuine rubber cables when
left in contact for a long time in elevated temperatures. Beware.

Oh, absolutely. And a month in your car's trunk in the summer definitely
counts.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."