Category: SPL

Understanding SPL metric “dB C Minus A”

Understanding SPL metric “dB C Minus A”

When measuring SPL, indicating the frequency weighting curve used for the measurement is critical. Below we see the A (orange) and C (red) weighting curves, the two choices you are likely to encounter on a typical SPL meter, thanks to IEC 61672. Although these weighting curves owe their creation to a failed attempt at emulating …

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All About SPL: Rational Acoustics Webinar

All About SPL: Rational Acoustics Webinar

As part of the ongoing Smaart Operator Fundamentals Online webinar series, Rational instructor Chris Tsanjoures and I gave a webinar covering an overview of SPL principles and practices as well as the SPL featureset in Smaart v8 and Smaart SPL. Enjoy:  

A hidden consideration when choosing a mic and interface for SPL monitoring rigs

A hidden consideration when choosing a mic and interface for SPL monitoring rigs

One thing that doesn’t usually come into play for general measurement work, but is mission critical for SPL measurements, is headroom. This is a two-part concern. Max SPL To perform properly at concert levels, the measurement mic should be able to withstand levels of up to 140 dB SPL. Many measurement mics hit severe distortion / …

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Smaart SPL

Smaart SPL

For the last six months or so I’ve been working on Smaart SPL, a standalone SPL measurement and logging tool from Rational Acoustics. I’ve learned a lot along the way and I’m very proud of what we’ve got now that it’s finally out in the wild. One of the cool aspects of this project has …

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SPL and Exposure data from nine shows I worked recently – here’s what I’ve learned from that.

SPL and Exposure data from nine shows I worked recently – here’s what I’ve learned from that.

This chart shows NIOSH exposure dose data for nine live music events I worked on in the last few months, sorted by performance duration (longer performances on the right). The data is stated in percent dose, with 100% representing the full recommended exposure limit for the day. Green bars indicate shows that I mixed (I had …

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Just How Enforceable Are Noise Ordinance Laws?

Just How Enforceable Are Noise Ordinance Laws?

In a previous post I outlined the problems with stating an SPL limit in terms of a signal number. To review, a dB SPL value is technically meaningless without information about the time-domain (integration time) and frequency-domain (weighting curve) details of the metric. There is a world of a difference between 100 dB Peak C …

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