Re: Question for Robert Morein...

[OFFICIAL RAM BLUEBOOK VALUATION]

On 25/8/03 6:20, in article ,
"Eric James Niemi" > wrote:

> Would have tried e-mailing you but I didn't have your e-mail
> address...



--
Robert Morein.

[Robert Morein]

"Eric James Niemi" > wrote in message
m...
> Robert,
>
> Would have tried e-mailing you but I didn't have your e-mail
> address...
>
> In your opinion would the following modification work?
>
>
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&selm=3CB4DFE9.8ED24524%40znet.com
>
> I am trying to get the best sound I can with essentially "no budget"
> but don't want to wreck a mic in the process if it doesn't work.
>
> Hope you can give some info on this mod.
> Sincerely,
> Eric

The pros and conds:
Some evidence that the modification would flatten frequency response is
provided by the performance of Panasonic electret mic capsules, which are
frequently used -- though I can't rule out the possibility that Sony made
their own.

Even though the capsules have a window on one surface, they are essentially
omnidirectional except at high frequencies. Omnidirectional microphones have
flatter, more extended response than microphones mounted in such a way as to
give polar response. These capsules, which cost only a few dollars, have
extremely flat response up to, and in some cases, past 20 kHz. This is
partly a property of the capsule, and partly of omindirectional microphones
in general.

The MS-907 is a cardiod mic. Exposing the capsule would remove the polar
pattern, and result in an essentially omnidirectional microphone. Although
this would extend the frequency response, omni mics are useless for location
sound recording, except as lapel mics, because of the excessive intrusion of
ambient sound.

In a very quiet studio, with controlled reflectivity, omnidirectional mics
can be golden, because of their flat, extended response. Such is not the
case here.

The reason Sony was not able to accomplish the frequency response you want
is because small electret capsules have high self-noise. This is the noise
generated by individual air molecules hitting the diaphram, as well as noise
generated within the FET preamp that is also contained in the mic capsule.

Expensive microphones have flatter response because they have lower self
noise, which allows the designers more freedom in the design of the polar
pattern enclosure. This is the reason that despite improvements in recent
years, electret mics have never been able to equal the performance of either
DC condenser mics, or the AC condenser proprietary to Sennheiser.

[Eric James Niemi]

"Robert Morein" > wrote in message >...
> The pros and conds:
> Some evidence that the modification would flatten frequency response is
> provided by the performance of Panasonic electret mic capsules, which are
> frequently used -- though I can't rule out the possibility that Sony made
> their own.
>
> Even though the capsules have a window on one surface, they are essentially
> omnidirectional except at high frequencies. Omnidirectional microphones have
> flatter, more extended response than microphones mounted in such a way as to
> give polar response. These capsules, which cost only a few dollars, have
> extremely flat response up to, and in some cases, past 20 kHz. This is
> partly a property of the capsule, and partly of omindirectional microphones
> in general.
>
> The MS-907 is a cardiod mic. Exposing the capsule would remove the polar
> pattern, and result in an essentially omnidirectional microphone. Although
> this would extend the frequency response, omni mics are useless for location
> sound recording, except as lapel mics, because of the excessive intrusion of
> ambient sound.
>
> In a very quiet studio, with controlled reflectivity, omnidirectional mics
> can be golden, because of their flat, extended response. Such is not the
> case here.
>
> The reason Sony was not able to accomplish the frequency response you want
> is because small electret capsules have high self-noise. This is the noise
> generated by individual air molecules hitting the diaphram, as well as noise
> generated within the FET preamp that is also contained in the mic capsule.
>
> Expensive microphones have flatter response because they have lower self
> noise, which allows the designers more freedom in the design of the polar
> pattern enclosure. This is the reason that despite improvements in recent
> years, electret mics have never been able to equal the performance of either
> DC condenser mics, or the AC condenser proprietary to Sennheiser.


Wow! Great info... Thanks for the quick response. Yes, if it becomes
an omni mic it wouldn't help me at all even if the freq. response got
better. Using it for film/video application where I would need some
directional control.

You saved me from possibly ruining a good mic, thanks again Robert.
Sincerely,
Eric