{"@context":"http://iiif.io/api/presentation/3/context.json","id":"https://arsc.aviaryplatform.com/iiif/n00zp3xm5m/manifest","type":"Manifest","label":{"en":["Phase Equalization and Its Importance in the Playback of Disc Records"]},"logo":"https://d9jk7wjtjpu5g.cloudfront.net/organizations/logo_images/000/000/019/original/ARSC_Full_Logo_RGB_K.jpg?1605438091","metadata":[{"label":{"en":["Agent"]},"value":{"en":["Gary A. Galo (Presenter)"]}},{"label":{"en":["Date"]},"value":{"en":["2009-05-29 (Created)"]}},{"label":{"en":["Format"]},"value":{"en":["Audio"]}},{"label":{"en":["Description"]},"value":{"en":["\u003cp\u003eThe subject of phase equalization in the playback of disc records is generally neglected. A recording curve is normally described as a plot of velocity or amplitude from the lowest to the highest recorded frequencies. However, all analog filters produce frequency dependent phase shifts. The phase response of a disc record, though not as widely understood as its velocity and amplitude response, is nonetheless an important part of the disc’s recording characteristic. In order to achieve the most accurate playback, it is essential to compensate for both the frequency response of the record as well as its phase response. With analog filters, such as those found in any analog phono preamplifier, phase correction happens automatically as a result of the playback equalization curve – proper phase response “comes along for the ride” with analog filters, so transfer and restoration engineers need not concern themselves with it. The era of digital signal processing has made it possible to apply disc playback equalization in the digital domain. One of the advantages of digital filters is that they can be designed to affect only amplitude, and can be free of the phase shift problems inherent in analog filters. This is certainly beneficial in single-ended equalization applications, including the reduction of various noises on analog sources, as well as altering the tonal balance of an imperfect recording. However, it is not desirable when applying playback equalization to phonograph records, which must complement the recording characteristic. All phonograph records have an inherent phase response which “came along for the ride” when the recording characteristic was applied. When applying complementary playback equalization in the digital domain, it is essential that digital filters be designed to mimic both the amplitude and phase response of the recording. This presentation begins with a tutorial on the nature of phase and phase shifts, how analog filters produce phase shifts, and how complementary recording and playback characteristics result in a playback that is both flat in terms of frequency response, and phase-neutral. The phase characteristics of several common recording and playback curves for 78-rpm and LP records are examined. Though technical by its very nature, the concepts will be presented in a way that is both useful to audio engineers and understandable to those with minimal technical background.\u003c/p\u003e"]}},{"label":{"en":["Language"]},"value":{"en":["English"]}},{"label":{"en":["Publisher"]},"value":{"en":["Association for Recorded Sound Collections"]}},{"label":{"en":["Rights Statement"]},"value":{"en":["\u003cp\u003eCopyright Association for Recorded Sound Collections\u003c/p\u003e"]}}],"summary":{"en":["\u003cp\u003eThe subject of phase equalization in the playback of disc records is generally neglected. A recording curve is normally described as a plot of velocity or amplitude from the lowest to the highest recorded frequencies. However, all analog filters produce frequency dependent phase shifts. The phase response of a disc record, though not as widely understood as its velocity and amplitude response, is nonetheless an important part of the disc\u0026rsquo;s recording characteristic. In order to achieve the most accurate playback, it is essential to compensate for both the frequency response of the record as well as its phase response. With analog filters, such as those found in any analog phono preamplifier, phase correction happens automatically as a result of the playback equalization curve \u0026ndash; proper phase response \u0026ldquo;comes along for the ride\u0026rdquo; with analog filters, so transfer and restoration engineers need not concern themselves with it. The era of digital signal processing has made it possible to apply disc playback equalization in the digital domain. One of the advantages of digital filters is that they can be designed to affect only amplitude, and can be free of the phase shift problems inherent in analog filters. This is certainly beneficial in single-ended equalization applications, including the reduction of various noises on analog sources, as well as altering the tonal balance of an imperfect recording. However, it is not desirable when applying playback equalization to phonograph records, which must complement the recording characteristic. All phonograph records have an inherent phase response which \u0026ldquo;came along for the ride\u0026rdquo; when the recording characteristic was applied. When applying complementary playback equalization in the digital domain, it is essential that digital filters be designed to mimic both the amplitude and phase response of the recording. This presentation begins with a tutorial on the nature of phase and phase shifts, how analog filters produce phase shifts, and how complementary recording and playback characteristics result in a playback that is both flat in terms of frequency response, and phase-neutral. The phase characteristics of several common recording and playback curves for 78-rpm and LP records are examined. Though technical by its very nature, the concepts will be presented in a way that is both useful to audio engineers and understandable to those with minimal technical background.\u003c/p\u003e"]},"requiredStatement":{"label":{"en":["Attribution"]},"value":{"en":["\u003cp\u003eCopyright Association for Recorded Sound Collections\u003c/p\u003e"]}},"provider":[{"id":"https://arsc.aviaryplatform.com/aboutus","type":"Agent","label":{"en":["Association for Recorded Sound Collections"]},"homepage":[{"id":"https://arsc.aviaryplatform.com/","type":"Text","label":{"en":["Association for Recorded Sound Collections"]},"format":"text/html"}],"logo":[{"id":"https://d9jk7wjtjpu5g.cloudfront.net/organizations/logo_images/000/000/019/original/ARSC_Full_Logo_RGB_K.jpg?1605438091","type":"Image"}]}],"thumbnail":[{"id":"https://d9jk7wjtjpu5g.cloudfront.net/public/images/audio-default.png","type":"Image","format":"image/png"}],"items":[{"id":"https://arsc.aviaryplatform.com/collections/2671/collection_resources/128441/file/240038","type":"Canvas","label":{"en":["Media File 1 of 1 - ARSC_conf_2009_Galo_audio.mp3"]},"duration":724.5575,"width":640,"height":360,"thumbnail":[{"id":"https://d9jk7wjtjpu5g.cloudfront.net/public/images/audio-default.png","type":"Image","format":"image/png"}],"items":[{"id":"https://arsc.aviaryplatform.com/collections/2671/collection_resources/128441/file/240038/content/1","type":"AnnotationPage","items":[{"id":"https://arsc.aviaryplatform.com/collections/2671/collection_resources/128441/file/240038/content/1/annotation/1","type":"Annotation","motivation":"painting","body":{"id":"https://aviary-p-arsc.s3.wasabisys.com/collection_resource_files/resource_files/000/240/038/original/ARSC_conf_2009_Galo_audio.mp3?1714691324","type":"Audio","format":"audio/mpeg","duration":724.5575,"width":640,"height":360},"target":"https://arsc.aviaryplatform.com/collections/2671/collection_resources/128441/file/240038","metadata":[]}]}],"annotations":[]}]}