Reply To: Mastering Without A Limiter?

February 17, 2023 at 6:54 am #4937
Bob Katz

    The very few situations JJ mentioned about the highest peak do have to be “carefully contrived” as JJ mentioned. For example, I recorded my talk/demonstration for the SF section of the AES. And at the end asked for a figurative round of applause for one of the attendees. And I applauded three inches in front of a Shoeps hypercardioid condensor mike. Later, while sweetening the pcm recording for later re-streaming I examined the level of the 45 minute recording (made without a limiter and including music demonstrations and speech) and found that somewhere in it there was a +11 dBTP! What what what? Where where where?

    Sequoia’s algorithm for finding the highest sample peak in the recording totally failed to find the spot. I figured there must be some failure in the true peak algorithm. I mean really “+ 11 dBTP”!!!  I divided the search through the recording in half and in half again and again until I isolated the highest sample peak to be —— aha!!!!! That pesky applause.

    The applause was so transient and its peak level so instantaneous that inserting  my trusty DMG Limitless did nothing practically. It was too fast for the true peak detection limiter to even react or show. Pushing the threshold radically did get it to react of course in the most hilariously sick sounding way you can imagine. And clearly this section of the recording was anything but essential. Using Sequoia’s object-based processing I cut the object with the crazy applause and applied the digital limiter only in that section just for shits and giggles and maybe some concerns that it might cause a lossy codec to turn over and die 🙂

    But seriously, this is what JJ meant by a contrived situation. In most cases a 4X oversampling true peak measurement or detection algorithm will find what you want and you can either manually attenuate if necessary to arrive at -1 dBTP max, which is usually satisfactory for any reasonably speedy lossy bitrate. Or peak limit if it’s a good sounding invisible limiter. Or let it clip the codec if it’s a mild clip and not a sonically very important part of the work, like this close miked applause.

    So I concur with you working without a limiter for 99% of the music you’ll encounter in the wild. If the TP doesn’t exceed -1 dBTP for 99% of that typical material.

    I can confirm that -1 dBTP is a good number to not exceed for You Tube’s Opus 128 Kbps codec with high quality music. I performed a test with some “audiophile quality” music and it really went down hill if I let it get to 0 dBTP max. And -1 was acceptable.

    And considering Spotify is a little more forgiving and Apple’s lossy now can do 48 kHz at 256 Kbps VBR I would say you are probably fine for most music without a limiter up to -1 dBTP.