World Library  
Flag as Inappropriate
Email this Article

Presence (amplification)

Article Id: WHEBN0020967664
Reproduction Date:

Title: Presence (amplification)  
Author: World Heritage Encyclopedia
Language: English
Subject: Presence
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Presence (amplification)

In an amplifier, a presence control controls "presence". A presence control boosts the upper mid-range frequencies. Thus by increasing the presence with the presence control, the sounds of voices and such instruments seem more "present".[1]

On television production studio's sound desk, there can be several presence controls, for several different, switchable, frequencies.[2] There is a limit to the flexibility of such controls, and they are sometimes insufficient. If the degree of mis-match between microphones is great, simply increasing presence is not enough, and instead a sound engineer will use a graphic equalizer, sometimes several, each connected to an individual sound channel.[3]

Presence controls can also be found on electric guitar amplifiers. The first presence control on a Fender amplifier, for example, appeared in 1954 on the Twin. In 1955 it appeared on the 1/15 Pro-Amp, the 3/10 Bandmaster, and the 2/10 Super.[4] The original Fender presence control acted upon the amplifier's negative-feedback loop. As the level of "presence" was increased, so more and more of the higher frequencies in the negative-feedback loop were dumped to ground, leaving the low and mid-range frequencies. Increasing the presence resulted in there being less and less negative feedback on high frequencies. The effect varied according to amplitude.[5]

Later Fender amplifiers used a different presence control. The presence control on the 1975 Super Twin did not modify the negative feedback loop, but was an active equalization circuit, controlling the 3.9kHz frequency range. It had the ability to both amplify (boost) and attenuate (cut), unlike the earlier presence control.[5]

In a 3-way loudspeaker system, with tweeter, woofer, and mid-range speaker, a presence control is simply a volume control for the mid-range speaker.[6]

References



This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.