Microphone Feedback - Revision history

ST: I have merged all the content from this page into Feedback / Microphone - please make any new edits on that live page - thanks

2009-01-07T20:12:30Z

I have merged all the content from this page into Feedback / Microphone - please make any new edits on that live page - thanks

← Older revision		Revision as of 20:12, 7 January 2009
Line 1:		Line 1:
			#REDIRECT [[Feedback / Microphone]]



	<!--		<!--

Line 6:		Line 10:

	and see comments in the discussion page for your temporary page for rationale [[Talk:Ken's Main Page (temporary)]]		and see comments in the discussion page for your temporary page for rationale [[Talk:Ken's Main Page (temporary)]]
			-->

	Thanks ST		Thanks ST
	~~-->~~

	Please see comments in [[Talk:{{PAGENAME}}\|discussion for this article]] [[User:ST\|ST]] 12:24, 4 January 2009 (EST)		Please see comments in [[Talk:{{PAGENAME}}\|discussion for this article]] [[User:ST\|ST]] 12:24, 4 January 2009 (EST)

Kjacob: Added link to new article on using the T1 para eq to notch offending frequency

2009-01-04T17:42:59Z

Added link to new article on using the T1 para eq to notch offending frequency

← Older revision		Revision as of 17:42, 4 January 2009
Line 41:		Line 41:
	=== Techniques specific to the {{L1 family}} ===		=== Techniques specific to the {{L1 family}} ===
	* All players should be playing / singing through the {{L1}} closest to them.		* All players should be playing / singing through the {{L1}} closest to them.
	* If you are using a {{T1}} it is often possible to use the parametric EQ section to notch the frequency that is causing feedback.		* If you are using a {{T1}} it is often possible to use the parametric EQ section to notch the frequency that is causing feedback. You can find details in the article: [[Using the T1® to Control Microphone Feedback]]

ST: Please see comments in discussion for this article ~~~~

2009-01-04T17:24:20Z

Please see comments in [[Talk:{{PAGENAME}}|discussion for this article]] ~~~~

← Older revision		Revision as of 17:24, 4 January 2009
Line 10:		Line 10:
	-->		-->

			Please see comments in [[Talk:{{PAGENAME}}\|discussion for this article]] [[User:ST\|ST]] 12:24, 4 January 2009 (EST)

ST at 17:22, 4 January 2009

2009-01-04T17:22:51Z

← Older revision		Revision as of 17:22, 4 January 2009
Line 5:		Line 5:
	Please make edits to the original article [[Feedback / Microphone]]		Please make edits to the original article [[Feedback / Microphone]]

	and see comments in the discussion page for your temporary page for rationale		and see comments in the discussion page for your temporary page for rationale [[Talk:Ken's Main Page (temporary)]]

	Thanks ST		Thanks ST

ST: note to Ken

2009-01-04T17:21:35Z

note to Ken

← Older revision		Revision as of 17:21, 4 January 2009
Line 1:		Line 1:
			<!--

			Ken,

			Please make edits to the original article [[Feedback / Microphone]]

			and see comments in the discussion page for your temporary page for rationale

			Thanks ST
			-->




	== Gain Staging ==		== Gain Staging ==
	Take two minutes to watch this video by clicking on the picture below.		Take two minutes to watch this video by clicking on the picture below.

Kjacob: cleaning up

2009-01-04T16:45:52Z

cleaning up

← Older revision		Revision as of 16:45, 4 January 2009
Line 1:		Line 1:
	~~Proper Gain Staging is essential to avoiding feedback. Please take 2 minutes to review this short video. Although this is based on the Classic and Model I, the principles are generally applicable.~~



	== Gain Staging ==		== Gain Staging ==
	Take two minutes to watch this video by clicking on the picture.		Take two minutes to watch this video by clicking on the picture below.

	If you are using an {{Classic}} or {{Model I}} follow the instructions exactly as ~~Steve says~~. ~~For other L1 models~~, the principles are ~~still applicable~~.		* If you are using an {{Classic}} or {{Model I}} follow the instructions exactly as shown in the video.
			* If you are using the {{T1}}, the principles are the same as shown on the video: simply substitute the trim on the T1 for the trim on the Classic or Model I. {{T1 icon}}

	{{Get Plugged In Microphone}}		{{Get Plugged In Microphone}}
Line 30:		Line 27:
	=== Techniques specific to the {{L1 family}} ===		=== Techniques specific to the {{L1 family}} ===
	* All players should be playing / singing through the {{L1}} closest to them.		* All players should be playing / singing through the {{L1}} closest to them.
			* If you are using a {{T1}} it is often possible to use the parametric EQ section to notch the frequency that is causing feedback.


Line 37:		Line 35:

	----		----
	~~<references/>~~

	[[category:Feedback]]		[[category:Feedback]]
	[[category:Performance]]		[[category:Performance]]
	[[category:Reference]]		[[category:Reference]]

Kjacob: cleaning up

2009-01-04T16:31:47Z

cleaning up

← Older revision		Revision as of 16:31, 4 January 2009
Line 12:		Line 12:
	* If you are using vocal effects like reverb, chorus or delay, turn them off until you can get sufficient [[Gain Before Feedback\|gain before feedback]] to get performance level volume. Then add the effects back into the signal chain (one at a time) so you can be aware of the individual impacts that each effect is having on feedback.		* If you are using vocal effects like reverb, chorus or delay, turn them off until you can get sufficient [[Gain Before Feedback\|gain before feedback]] to get performance level volume. Then add the effects back into the signal chain (one at a time) so you can be aware of the individual impacts that each effect is having on feedback.

	* Get close to the microphone. No other technique has a big an impact on feedback. Each halving of distance is approximately another 6 dB of [[gain before feedback]]. This means that the difference between working a microphone at 2 inches, and 1/4 inch is 18 dB, which is more than twice as loud.		* '''Get close to the microphone''' when you want to be loud. No other technique has a big an impact on feedback. Each halving of distance is approximately another 6 dB of [[Gain Before Feedback\|gain before feedback]]. This relationship in physics is known as the [[Inverse Square Law]]. This means that the difference between working a microphone at 2 inches, and 1/4 inch is 18 dB, which is more than twice as loud. While good mic technique often involves "working" the microphone at different distances, singers must be mindful of the fact that small changes in distance from the mouth result in very dramatic changes in sound level.

	[[Image:Ferrin_eat_mic.jpg\|Charlie Ferrin at Bose: Nov. 9, 2007]]		[[Image:Ferrin_eat_mic.jpg\|Charlie Ferrin at Bose: Nov. 9, 2007]]
Line 26:		Line 26:
	* Use the high-frequency tone control for the microphone channel carefully. Feedback could occur when this is set too high.		* Use the high-frequency tone control for the microphone channel carefully. Feedback could occur when this is set too high.

	[~~stopped editing here~~]		* Wherever possible, acoustic instruments should use pickups instead of microphones. Pickup systems provide much higher [[Gain Before Feedback\|gain before feedback]] than microphones.

	* ~~Upgrade your power stand~~ to ~~newer software that offer a high gain preset. see: Software Upgrading (This covers firmware update and Version 2~~.~~0 [[Presets/Model I and Classic\|Presets]])~~		=== Techniques specific to the {{L1 family}} ===
			* All players should be playing / singing through the {{L1}} closest to them.

	~~From the Official Product FAQs <ref>[http://www.bose.com/controller?event=VIEW_STATIC_PAGE_EVENT&url=/musicians/support/product_faqs.jsp&ck=0#question40 Official Product FAQs]</ref>.~~

	~~Techniques that control feedback with a conventional system help with the Personalized Amplification System™ approach also.~~		== Other Resources ==

	~~== Other general notes ==~~		* [http://www.shure.com/stellent/groups/public/@gms_gmi_web_ug/documents/web_resource/us_pro_mics_for_music_sound_ea.pdf Shure® article on mic technique] Shure Educational Publication 2006 39 pages - pdf format

	* All players should be playing / singing through the L1™ System closest to them
	* Wherever possible "acoustic" instruments should use pickups instead of microphones. This is important because many players find it a struggle to keep a consistent and close distance between the microphone and their instrument. Also, an instrument can be a source of feedback as it resonates with the amplified sound.
	* Another (low priority) design guide-line could be to keep open microphones as far apart as possible. Neighboring systems with open microphones can mutually decrease gain-before-feedback



	~~=== Handling the Microphone ===~~
	~~shure.com notes <ref>[http://www.shure.com/shurenotes/how_june2004/default.asp Miking Live Vocals - from shure.com]</ref>~~


	Seems like a pretty natural thing, doesn't it? But how your vocalists handle the microphone has a major effect on the resulting sound. It may look great, but your tech team won't get the sound they want when your soloist holds a microphone an arm's length from her mouth.

	~~=== Why? ===~~

	The first reason is the inverse square law. If you hold your mic a half-inch from your lips it receives a given amount of sound energy from your voice. Move it twice as far-one inch-and it receives one-fourth as much energy. That extra half -inch takes away three-quarters of the efficiency of your sound system. While good mic technique involves "working" the microphone, singers that fully extend their arms when reaching for that climax, are usually doing it for dramatic effect. Small changes in distance from the mouth can result in very dramatic changes in sound level.

	Second: When you move the microphone away from your lips, you must turn up the microphone level at the mixer to be heard, and more unwanted sound enters the mic. When sound from a monitor speaker enters the microphone , it instantly becomes the earsplitting screech we know as feedback. Keeping the microphone close to your mouth minimizes feedback.


	~~See the whole article: [http://www.shure.com/shurenotes/how_june2004/default.asp Miking Live Vocals]~~

	~~== Other References ==~~
	* [http://www.shure.com/stellent/groups/public/@gms_gmi_web_ug/documents/web_resource/us_pro_mics_for_music_sound_ea.pdf Microphone Techniques for Live Sound Reinforcement] Shure Educational Publication 2006 39 pages - pdf format
	~~- [http://bose.infopop.cc/eve/forums/a/ga/ul/5711082304/us_pro_mics_for_music_sound_ea.pdf alternate source for above]~~

	~~[[User:ST\|ST]] 15:46, 22 August 2006 (GMT-7)~~
	----		----
	<references/>		<references/>

Kjacob: continuing to edit...

2009-01-04T14:00:53Z

continuing to edit...

← Older revision		Revision as of 14:00, 4 January 2009
Line 1:		Line 1:
	Proper Gain Staging is essential to avoiding feedback. Please take 2 minutes to review this short video. Although this is based on the Classic and Model I, the principles are generally applicable.		Proper Gain Staging is essential to avoiding feedback. Please take 2 minutes to review this short video. Although this is based on the Classic and Model I, the principles are generally applicable.



	== Gain Staging ==		== Gain Staging ==
Line 10:		Line 12:
	* If you are using vocal effects like reverb, chorus or delay, turn them off until you can get sufficient [[Gain Before Feedback\|gain before feedback]] to get performance level volume. Then add the effects back into the signal chain (one at a time) so you can be aware of the individual impacts that each effect is having on feedback.		* If you are using vocal effects like reverb, chorus or delay, turn them off until you can get sufficient [[Gain Before Feedback\|gain before feedback]] to get performance level volume. Then add the effects back into the signal chain (one at a time) so you can be aware of the individual impacts that each effect is having on feedback.

	* Get close to the microphone. No other technique has a big an impact on feedback. Each halving of distance is approximately another 6 dB of gain before feedback. This means that the difference between working a microphone at 2 inches, and 1/4 inch is ~~18dB!~~		* Get close to the microphone. No other technique has a big an impact on feedback. Each halving of distance is approximately another 6 dB of [[gain before feedback]]. This means that the difference between working a microphone at 2 inches, and 1/4 inch is 18 dB, which is more than twice as loud.

	[[Image:Ferrin_eat_mic.jpg]]		[[Image:Ferrin_eat_mic.jpg\|Charlie Ferrin at Bose: Nov. 9, 2007]]

	* Use a directional microphone. Hypercardioid is better than cardioid, which is ~~way~~ better than omnidirectional. All sound waves impinging on the microphone from a direction other than the intended signal is "noise" and will lower the threshold of feedback.		* Use a directional microphone. Hypercardioid is better than cardioid, which is better than omnidirectional. All sound waves impinging on the microphone from a direction other than the intended signal is "noise" and will lower the threshold of feedback.

	* Use as few open microphones as possible. When a microphone is not in use, turn it off.		* Use as few open microphones as possible. When a microphone is not in use, if possible, turn it off.

	* When stand mounting a directional microphone, tilt the microphone up ten or twenty degrees off the horizon so that it is less sensitive to direct sound from the speakers.		* When stand mounting a directional microphone, tilt the microphone up ten or twenty degrees off the horizon so that it is less sensitive to direct sound from the speakers.
Line 26:		Line 28:
	[stopped editing here]		[stopped editing here]

	~~== Notes from {{Bose}} ==~~
	~~=== My vocal microphone keeps encountering feedback. Is there anything I can do to stop it? ===~~
	From the Official Product Troubleshooting Page <!-- TODO fix this link --><ref>[http://www.bose.com/controller?event=VIEW_STATIC_PAGE_EVENT&url=/musicians/support/troubleshooting.jsp&ck=0#feedback Official Product Troubleshooting Pages]</ref>.

	* Orient the microphone so that it is not pointing directly at your Cylindrical Radiator™ loudspeaker. It’s best when your system is not directly behind you- give greater than 5 feet distance between you and your system.
	* Try using a “close-miking” technique to increase the gain at the microphone and to reduce unwanted stage sound.
	* Use the HIGH tone control knob for the microphone channel carefully. Feedback could occur when this is set too high.
	* Upgrade your power stand to newer software that offer a high gain preset. see: Software Upgrading (This covers firmware update and Version 2.0 [[Presets/Model I and Classic\|Presets]])		* Upgrade your power stand to newer software that offer a high gain preset. see: Software Upgrading (This covers firmware update and Version 2.0 [[Presets/Model I and Classic\|Presets]])
	* If using a vocal effects processor, make sure that it is not contributing to the feedback problem.
	* If stand -mounting a directional microphone, tilt the microphone up ten or twenty degrees off the horizon so that it is less sensitive to direct sound from the speakers.
	* Try a different microphone such as a directional mic. Hypercardioid microphones work well with the system.

	~~=== How do I control feedback that I may get when using microphones? ===~~
	From the Official Product FAQs <ref>[http://www.bose.com/controller?event=VIEW_STATIC_PAGE_EVENT&url=/musicians/support/product_faqs.jsp&ck=0#question40 Official Product FAQs]</ref>.		From the Official Product FAQs <ref>[http://www.bose.com/controller?event=VIEW_STATIC_PAGE_EVENT&url=/musicians/support/product_faqs.jsp&ck=0#question40 Official Product FAQs]</ref>.

	Techniques that control feedback with a conventional system help with the Personalized Amplification System™ approach also.		Techniques that control feedback with a conventional system help with the Personalized Amplification System™ approach also.

	~~== Microphone on a Stand ==~~
	~~Here's a sketch of setting up a microphone on stand.~~



	== Other general notes ==		== Other general notes ==

	* All players should be playing / singing through the L1™ System closest to them		* All players should be playing / singing through the L1™ System closest to them
	* Every doubling of distance between the microphone and the singer reduces gain-before-feedback by a factor of 4. The difference between 1/2 inch and an inch can be significant.
	* Wherever possible "acoustic" instruments should use pickups instead of microphones. This is important because many players find it a struggle to keep a consistent and close distance between the microphone and their instrument. Also, an instrument can be a source of feedback as it resonates with the amplified sound.		* Wherever possible "acoustic" instruments should use pickups instead of microphones. This is important because many players find it a struggle to keep a consistent and close distance between the microphone and their instrument. Also, an instrument can be a source of feedback as it resonates with the amplified sound.
	* Another (low priority) design guide-line could be to keep open microphones as far apart as possible. Neighboring systems with open microphones can mutually decrease gain-before-feedback		* Another (low priority) design guide-line could be to keep open microphones as far apart as possible. Neighboring systems with open microphones can mutually decrease gain-before-feedback

Kjacob: add ferrin photo

2009-01-04T13:47:20Z

add ferrin photo

← Older revision		Revision as of 13:47, 4 January 2009
Line 12:		Line 12:
	* Get close to the microphone. No other technique has a big an impact on feedback. Each halving of distance is approximately another 6 dB of gain before feedback. This means that the difference between working a microphone at 2 inches, and 1/4 inch is 18dB!		* Get close to the microphone. No other technique has a big an impact on feedback. Each halving of distance is approximately another 6 dB of gain before feedback. This means that the difference between working a microphone at 2 inches, and 1/4 inch is 18dB!

	[~~add an eat the microphone image~~]		[[Image:Ferrin_eat_mic.jpg]]

	* Use a directional microphone. Hypercardioid is better than cardioid, which is way better than omnidirectional. All sound waves impinging on the microphone from a direction other than the intended signal is "noise" and will lower the threshold of feedback.		* Use a directional microphone. Hypercardioid is better than cardioid, which is way better than omnidirectional. All sound waves impinging on the microphone from a direction other than the intended signal is "noise" and will lower the threshold of feedback.

Kjacob: First Edition

2009-01-03T22:30:15Z

First Edition

New page

Proper Gain Staging is essential to avoiding feedback. Please take 2 minutes to review this short video. Although this is based on the Classic and Model I, the principles are generally applicable.

== Gain Staging ==
Take two minutes to watch this video by clicking on the picture.

If you are using an {{Classic}} or {{Model I}} follow the instructions exactly as Steve says. For other L1 models, the principles are still applicable.

{{Get Plugged In Microphone}}
== Techniques For Reducing Feedback ==
* If you are using vocal effects like reverb, chorus or delay, turn them off until you can get sufficient [[Gain Before Feedback|gain before feedback]] to get performance level volume. Then add the effects back into the signal chain (one at a time) so you can be aware of the individual impacts that each effect is having on feedback.

* Get close to the microphone. No other technique has a big an impact on feedback. Each halving of distance is approximately another 6 dB of gain before feedback. This means that the difference between working a microphone at 2 inches, and 1/4 inch is 18dB!

[add an eat the microphone image]

* Use a directional microphone. Hypercardioid is better than cardioid, which is way better than omnidirectional. All sound waves impinging on the microphone from a direction other than the intended signal is "noise" and will lower the threshold of feedback.

* Use as few open microphones as possible. When a microphone is not in use, turn it off.

* When stand mounting a directional microphone, tilt the microphone up ten or twenty degrees off the horizon so that it is less sensitive to direct sound from the speakers.

[[Image:MicGoodBad.gif]]

* Use the high-frequency tone control for the microphone channel carefully. Feedback could occur when this is set too high.

[stopped editing here]

== Notes from {{Bose}} ==
=== My vocal microphone keeps encountering feedback. Is there anything I can do to stop it? ===
From the Official Product Troubleshooting Page <ref>[http://www.bose.com/controller?event=VIEW_STATIC_PAGE_EVENT&url=/musicians/support/troubleshooting.jsp&ck=0#feedback Official Product Troubleshooting Pages]</ref>.

* Orient the microphone so that it is not pointing directly at your Cylindrical Radiator™ loudspeaker. It’s best when your system is not directly behind you- give greater than 5 feet distance between you and your system.
* Try using a “close-miking” technique to increase the gain at the microphone and to reduce unwanted stage sound.
* Use the HIGH tone control knob for the microphone channel carefully. Feedback could occur when this is set too high.
* Upgrade your power stand to newer software that offer a high gain preset. see: Software Upgrading (This covers firmware update and Version 2.0 [[Presets/Model I and Classic|Presets]])
* If using a vocal effects processor, make sure that it is not contributing to the feedback problem.
* If stand -mounting a directional microphone, tilt the microphone up ten or twenty degrees off the horizon so that it is less sensitive to direct sound from the speakers.
* Try a different microphone such as a directional mic. Hypercardioid microphones work well with the system.

=== How do I control feedback that I may get when using microphones? ===
From the Official Product FAQs <ref>[http://www.bose.com/controller?event=VIEW_STATIC_PAGE_EVENT&url=/musicians/support/product_faqs.jsp&ck=0#question40 Official Product FAQs]</ref>.

Techniques that control feedback with a conventional system help with the Personalized Amplification System™ approach also.

== Microphone on a Stand ==
Here's a sketch of setting up a microphone on stand.

== Other general notes ==

* All players should be playing / singing through the L1™ System closest to them
* Every doubling of distance between the microphone and the singer reduces gain-before-feedback by a factor of 4. The difference between 1/2 inch and an inch can be significant.
* Wherever possible "acoustic" instruments should use pickups instead of microphones. This is important because many players find it a struggle to keep a consistent and close distance between the microphone and their instrument. Also, an instrument can be a source of feedback as it resonates with the amplified sound.
* Another (low priority) design guide-line could be to keep open microphones as far apart as possible. Neighboring systems with open microphones can mutually decrease gain-before-feedback

=== Handling the Microphone ===
shure.com notes <ref>[http://www.shure.com/shurenotes/how_june2004/default.asp Miking Live Vocals - from shure.com]</ref>

Seems like a pretty natural thing, doesn't it? But how your vocalists handle the microphone has a major effect on the resulting sound. It may look great, but your tech team won't get the sound they want when your soloist holds a microphone an arm's length from her mouth.

=== Why? ===

The first reason is the inverse square law. If you hold your mic a half-inch from your lips it receives a given amount of sound energy from your voice. Move it twice as far-one inch-and it receives one-fourth as much energy. That extra half -inch takes away three-quarters of the efficiency of your sound system. While good mic technique involves "working" the microphone, singers that fully extend their arms when reaching for that climax, are usually doing it for dramatic effect. Small changes in distance from the mouth can result in very dramatic changes in sound level.

Second: When you move the microphone away from your lips, you must turn up the microphone level at the mixer to be heard, and more unwanted sound enters the mic. When sound from a monitor speaker enters the microphone , it instantly becomes the earsplitting screech we know as feedback. Keeping the microphone close to your mouth minimizes feedback.

See the whole article: [http://www.shure.com/shurenotes/how_june2004/default.asp Miking Live Vocals]

== Other References ==
* [http://www.shure.com/stellent/groups/public/@gms_gmi_web_ug/documents/web_resource/us_pro_mics_for_music_sound_ea.pdf Microphone Techniques for Live Sound Reinforcement] Shure Educational Publication 2006 39 pages - pdf format
- [http://bose.infopop.cc/eve/forums/a/ga/ul/5711082304/us_pro_mics_for_music_sound_ea.pdf alternate source for above]

[[User:ST|ST]] 15:46, 22 August 2006 (GMT-7)
----
<references/>

[[category:Feedback]]
[[category:Performance]]
[[category:Reference]]