Over-boosts in Acourate

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acourate2020
Posts: 26
Joined: 30 May 2020 03:59

Over-boosts in Acourate

Post by acourate2020 » 01 Jun 2020 13:10

Hi Uli

I read your post about differences between Dirac and Acourate where you mentioned "The Acourate calculation avoids over-boosts by principle"

Does this mean Acourate limits all boosting? Or there is a default max boost number?

6dB max default boost? 12dB max default boost?
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UliBru
Posts: 433
Joined: 19 Oct 2019 13:58

Re: Over-boosts in Acourate

Post by UliBru » 01 Jun 2020 13:33

It makes sense to distinguish between filter boost and filter gain.

Filter attenuation and boost:
The filter corrects for local peaks and dips in the frequency response. Correcting peaks is pretty simple. Whereas correcting dips can lead to over-boosts. A simple example: for some reason the frequency response shows some wave cancellation. A sinewave plus a sinewave shifted by 180 degree add perfectly to zero. You can apply very much gain here but it does not help.
At the end the boost has to be limited. Acourate is doing this in a quite sophisticated way. Other programs like Dirac need to apply an averaging of multiple measurents to avoid this.

Filter gain:
Acourate limits the filter gain to 0 dB by default. The filter frequency response does not exceed 0 dB equivalent to 1:1 gain behaviour at that frequency. But you can override the filter gain easily by setting another value in room macro4.
Stay well tuned
Uli

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acourate2020
Posts: 26
Joined: 30 May 2020 03:59

Re: Over-boosts in Acourate

Post by acourate2020 » 01 Jun 2020 14:19

UliBru wrote:
01 Jun 2020 13:33
It makes sense to distinguish between filter boost and filter gain.

Filter attenuation and boost:
The filter corrects for local peaks and dips in the frequency response. Correcting peaks is pretty simple. Whereas correcting dips can lead to over-boosts. A simple example: for some reason the frequency response shows some wave cancellation. A sinewave plus a sinewave shifted by 180 degree add perfectly to zero. You can apply very much gain here but it does not help.
At the end the boost has to be limited. Acourate is doing this in a quite sophisticated way. Other programs like Dirac need to apply an averaging of multiple measurents to avoid this.

Filter gain:
Acourate limits the filter gain to 0 dB by default. The filter frequency response does not exceed 0 dB equivalent to 1:1 gain behaviour at that frequency. But you can override the filter gain easily by setting another value in room macro4.
Thanks Uli !
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