# Feature request: Frequency Response test & A-weighting

**URL:** <https://forum.quantasylum.com/t/feature-request-frequency-response-test-a-weighting/1981>\
**Category:** QA40x\
**Created:** [July 28, 2025, 3:18pm UTC](https://forum.quantasylum.com/t/feature-request-frequency-response-test-a-weighting/1981 "2025-07-28T15:18:20Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Simmatth](https://avatars.discourse-cdn.com/v4/letter/s/bcef8e/32.png) [@Simmatth](https://forum.quantasylum.com/u/Simmatth)\
**Post date:** [July 28, 2025, 3:18pm UTC](https://forum.quantasylum.com/t/feature-request-frequency-response-test-a-weighting/1981/1 "2025-07-28T15:18:20Z")

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Hello

I was doing a frequency response test after having measured A-weighted noise. The result was really bad so I thought my circuit was at fault.

After investigating, it became clear the A-weighting was influencing the results. After turning it off I was left with a perfectly linear frequency response.

Could the A-weighting be turned off during frequency response testing? Or at least a warning should appear when the weighting is turned on and a test is performed.

This could save a lot of time and grey hairs!

Thank you.

Kind regards  
Simone

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**Author:** ![matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@matt](https://forum.quantasylum.com/u/matt)\
**Post date:** [August 4, 2025, 4:31pm UTC](https://forum.quantasylum.com/t/feature-request-frequency-response-test-a-weighting/1981/2 "2025-08-04T16:31:53Z")

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Hi @Simmath, thanks for the observation!

It’s very useful to be able to measure the spectrum with weightings applied. At a minimum, it allows you to put the analyzer into loopback and inspect the weighting visually. And in he case of a phono preamp, it’s very useful to apply the the an anti-weighting and linearize the response.

Also, there is a very clear annunciator telling you weighting is active. Anytime you see an annunciator in the upper left, the message is telling the user something very important related to the measurement

 ![image](https://canada1.discourse-cdn.com/flex032/uploads/quantasylum/original/2X/b/b13bf4708900cf5326c1c925a47a3980d8abc5cd.png)