-- Robert Morein. rho@netreach.net prolog@comcast.com prolog@comcast.net south@netreach.net north@netreach.net prolog@netreach.net prologue@netreach.net
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
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.