HOME » BROADCASTERS

• LICENSING
• ITUNES® TAGGING
• STATION RESOURCE GUIDE
• QUALITY IMPLEMENTATION
• Proper Time and Level Alignment
• Quality Audio Processing
• AES Audio Phase
• Station Information Services (SIS) & Program Service Data (PSD)
• Multicasting
• Broadcast Equipment Partners
• What are Data Services?
• What is IBOC Technology?
• IBOC White Papers
• US REGULATORY
• SPECIAL RADIO OFFER FOR BROADCASTERS

• 
  WHAT IS HD RADIO?
• 
  HOW DOES IT WORK?
• 
  MULTICASTING
• 
  THE HD DIGITAL RADIO ALLIANCE
• 
  THE BUZZ ABOUT HD RADIO
• 
  FIND A STATION
• 
  BUY A RADIO
• 
  EXPERIENCE IT
• 
  WWW.HDRADIO.COM

AES Audio Phase

After setting up the HD Radio audio levels and processing, there may be a slight dip or null when listening to a receiver blend from analog to digital and back again.  This is usually caused by the analog AES and the HD Radio AES being 180º out of phase.  There are three separate solutions to correct this problem:

• Recent exciter software versions feature a checkbox on the Analog Audio Diversity delay screen that can be selected to invert the digital audio phase. This should improve the audio levels when blending between FM and HD Radio.
• If an Omnia 6 series processor is being used, go to the INPUT MENU and then the INPUT MODE and check the INVERT BOX.  This will invert the phase of the AES audio input. If you are using the box to process both the analog and the HD Radio audio, this method will not be effective. The procedure changes the phase on both the analog AND the digital, which means the AES will still be in the same relationship and still cause a null during the blend. The INVERT switch may be moved further down stream in future revisions so only one of the processing streams would be affected. Please contact the manufacturer for these possible updates.
• If you are using the Orban 8500, there is a software upgrade available on their website that will provide a solution to phase reversal.

There may be additional manufacturers that provide similar capabilities. For a list of some of the broadcast equipment manufacturers that might be helpful, click here.