Postponement of 6dB Boost Removal

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The PRSS has decided to postpone the removal of the 6 decibel (dB) boost that was originally scheduled for February 26, 2015. The removal of the 6dB boost is a necessary action to take, but we have examined our upstream operations closely and determined our role in this process would benefit from additional time and preparation. We’ve also seen on the listservs, and in individual communications, that there remains some confusion among station representatives over what they are supposed to do at their sites.

I want to express my appreciation for the time, effort and resources that our station partners have put into readying themselves, and I sincerely apologize to those station folks that undertook great efforts to be ready. That said, we are firmly committed to ensuring that we, on our end, and all members of the station community are fully prepared and not adversely affected by the removal of the audio boost.

One important point I want to make is that this action is not directly connected to the PRSS loudness initiative, which is specifically focused on improving consistency of content submitted by program producers prior to distribution. The removal of the boost may provide benefits for producers and producing stations striving to meet the new PRSS standard, and the two initiatives share similar timelines, but they are not connected and should not be perceived as such. The fact that some are seeing these two initiatives as the same means we need to do a better job at communicating.

The PRSS added the 6dB boost in April 2013 when we moved into our new Washington, D.C., headquarters. At that time, we added the boost as a short-term fix to a problem that arose during our move from the old facility to the new one. We made this adjustment to keep consistent the audio levels coming out of the receivers, but this was not intended as a long-term solution.

We’ve known that to achieve a proper end-to-end system alignment, we would eventually have to remove this boost. By adding 6dB of gain before transmission, the overall headroom of the system decreased. That lack of headroom can create moments of full scale digital distortion even when programs are compliant with the PRSS audio submission standards. Removing the boost will rectify this problem and allow a true unity gain transmission path.

Moving forward, our plan is to do the following:
1.            PRSS - Determine where exactly we are not achieving unity gain between producer facilities and PRSS, and where we would need to make adjustments on the day we remove the boost.
2.            PRSS - Craft and publish a schedule for steps 4 through 7 once we have identified these upstream audio points.
3.            PRSS - Institute a new version of the test signal for stations calibrated at -24 LUFS.
4.            PRSS - Coordinate level adjustments with producers of live streams to compensate for the removal of the 6dB boost.
5.            PRSS - Eliminate the 6dB boost.
6.            Stations - Compensate for the audio shift at their locations.
7.            PRSS - Adjust levels to achieve unity gain for all other producers not covered in step 4.

Please note that steps 4-6 will occur simultaneously, so the PRSS will be involved in helping stations through this process. Step 7 will take place at some point in time between when the PRSS has removed the 6dB boost and when a producer’s show will first air. In addition, we expect that executing steps 1 and 2 will take several months, so steps 4-6 are not likely to occur until late spring or early summer.

Stations will need to include in their planning how to be sure that any local content stored meets the new audio loudness standard to ensure consistency between local content and PRSS-delivered content.

As always, the PRSS Help Desk is available to help with and track your questions or comments at prsshelp@npr.org or call 800.971.7677.

 

 

Posted: February 25, 2015