# PB4 Lowpass Filter Issue?

**URL:** https://forum.audiomodern.com/t/pb4-lowpass-filter-issue/2543
**Category:** Uncategorized
**Created:** [March 17, 2025, 10:24pm UTC](https://forum.audiomodern.com/t/pb4-lowpass-filter-issue/2543 "2025-03-17T22:24:19Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Birbhope](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.audiomodern.com/birbhope/32/868_2.png) [@Birbhope](https://forum.audiomodern.com/u/Birbhope)
#### Post date: [March 17, 2025, 10:24pm UTC](https://forum.audiomodern.com/t/pb4-lowpass-filter-issue/2543/1 "2025-03-17T22:24:19Z")

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Hi,  
Not a massive deal but when I use the LPF on sound like a kick (or even a hat) a popping or clicking transient sound seems to get through most of the time.  
Anyone else experience this? It seems more pronounced in iOS but I’ve heard it on the desktop as well…

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### Author: ![Studiodbfx](https://avatars.discourse-cdn.com/v4/letter/s/bbe5ce/32.png) [@Studiodbfx](https://forum.audiomodern.com/u/Studiodbfx)
#### Post date: [March 17, 2025, 10:37pm UTC](https://forum.audiomodern.com/t/pb4-lowpass-filter-issue/2543/2 "2025-03-17T22:37:42Z")

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It might be a phase issue?

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### Author: ![Audiomodern](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.audiomodern.com/audiomodern/32/3_2.png) [@Audiomodern](https://forum.audiomodern.com/u/Audiomodern)
#### Post date: [March 18, 2025, 7:46am UTC](https://forum.audiomodern.com/t/pb4-lowpass-filter-issue/2543/3 "2025-03-18T07:46:40Z")

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Thanks for your input! We’re looking into it.