High Dynamic Range (HDR) is a term that commonly refers to display screens. Displays with HDR will offer a greater contrast ratio (blacks and whites) and color range (all other colors) than a standards HD display. However, according to Pro Audio Technology in a recent blog for TD sister site CE Pro, high dynamic range can apply to audio as well:
Knowing that it could be confusing to use the term high dynamic range to describe audio performance, Hales says that it is nevertheless worthwhile.
Hales says the phrase ‘high dynamic range’ when applied to audio equates to the differences between the highest ‘level’ a system can reproduce, which is loudness in the case of audio, and the lowest ‘level’ a system can reproduce without disappearing into the system or room noise floor. For comparison purposes he says, think of it as the highest levels of brightness and the deepest black levels in video.
The article goes on to give the science behind audio high dynamic range:
“You can determine if a loudspeaker will be able to reproduce the full dynamic content of movie soundtracks. You just need to know the loudspeaker ‘sensitivity’ [how loud the speaker will play at one meter from the speaker with one watt of input power], a loudspeaker’s maximum power handling, and the distance the speaker must ‘throw’ the sound to reach the listener,” he explains.
Maximum output at one meter can be calculated using this formula:
SPLmax, 1m = SPLo+10* LOG (max input power), where SPLo is the sensitivity specification of the speaker.
Hales points out there are some caveats when determining loudspeaker dynamics indicating that some speaker sensitivity specifications are calculated with the figure of 2.83 volts input and not one watt. Hales comments that with speakers rated at impedance levels lower than 8 ohms 2.83 volts represents more than one watt.
The article continues:
Once the maximum SPL at one meter is determined Hales says the maximum SPL at a given distance can be determined with this formula:
SPLdistance = SPLmax, 1m-20*log (distance in meters)
The goal, Hales continues, is to identify speakers that can reach the 105dB target at the listening distance with headroom. Defining headroom, Hales says there should be 3dB of headroom, which means the speaker should actually produce 108dB at the listening distance.
Learn more about audio high dynamic range at CE Pro.
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