Crackling sound when pausing or playing or seeking in a video or audio track

I have an audio problem. When i pause or play a video or audio, or go forward or backwards through the track, i get an annoying crackling sound. This began happening after i changed from CCCP to k-lite codec pack.
Anyone have any idea what i could to fix this?

Here are some things to try that can help solve audio issues:

[1] Windows Control Panel > Sound > Speakers > Properties > Advanced > disable the two "Exclusive mode" options
[2] Windows Control Panel > Sound > Speakers > Properties > Enhancements > Disable all sound effects
[3] Disable fast startup in Windows 10: Windows Control Panel > Power Options > "Choose what the power buttons do" > uncheck "Turn on fast startup"
[4] On laptops: Windows Control Panel > Power Options > select "High performance"  power plan. If this works, then increasing the value of "Minimum processor state" in the other power plans may also solve it.
[5] Use Latency Monitor (https://www.resplendence.com/latencymon) to check if you have any driver installed that cause high DPC latency. Such drivers should be replaced with a newer (or older) version.

To be clear, this began happening after i changed from CCCP to k-lite codec pack, so i highly doubt that any of your suggestions have anything to do with it.
I did try your first suggestion and it didn't do anything.
Suggestion 2 was not an option, and suggestion 3 and 4 are not relevant as i'm on a desktop using windows 7.

Does it also happen if you lower the volume?

You can try with different audio renderer:
MPC-HC options > Playback > Output

Setting it to "Default DirectSound Device" does seem to solve this issue (this is the default in CCCP).

There have been many improvements to MPC-HC compared to the version that was used by old CCCP.

The internal audio renderer has several benefits compared to the default Directsound renderer. But of course this crackling issue is not good. It is not a common issue, so I need some more information to perhaps be able to fix it, so renderer does not need to be changed.

Could you test if the crackling goes away if you lower the volume a little bit to 80 or 90%?
Does the problem occur with all videos, or just with specific audio formats or speaker configurations?
You mentioned it happens when pausing/seeking. Is the sound quality normal during uninterrupted playback?
Which audio hardware does your computer use? (Codec Tweak Tool > Generate Log)

I'm not a native english speaker, so i'm not sure i'm using the exactly correct words to describe this.
It happens with internal audio renderer enabled.
It happens when you pause/play, or jump forwards or backwards in the video or audio file. Basically, interrupting the playback in any way.
It is not dependent on audio level, and is noticeable even at say 10%.
It is most noticeable at relatively low audio levels (i'm talking about the level within the file itself, not what you have set at in computer settings).
It does not happen when pressing pause/play in a place in the file where there is no audio being played. It does however happen if you jump from a place in the file where there is some audio being played to a place where none is being played.
It seems to occur with all videos.
Changing from my headset to my TV's speakers, i did not notice it with the TV speakers (these are the only two audio sources i have). However, this could simply be because it's harder to notice somewhat subtle sounds with speakers rather than a headset.
I did try to connect my headset to my laptop, and i did not notice the issue there (i have k-lite codec pack installed on my laptop as well).
So, there might be some kind of issue with how my headset interacts with my desktop.
I normally use a wireless headset for audio.

The Log (i used the default settings for log):
Codec Tweak Tool | Log file | Generated at 2020-08-27 15:53:52

##### System Information #####

OS: Windows 7 Professional (6.01.7601) (x64)
CPU name: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
CPU details: 4008 MHz | 8 core(s) | Family 6 Model 94 Stepping 3
Memory: 16352 MB
Screen size: 3840x2160 (32bits) (60Hz) (150%)
GPU: NVIDIA GeForce GTX 1080
VendorID: 10de, DeviceID: 1b80
GPU memory: 8192 MB
GPU driver: nvd3dumx.dll (Version 26.21.14.4614) (5-15-2020) (NV 446.14)
Audio device: Realtek High Definition Audio
VendorID: 10ec, DeviceID: 0900, SubSys: 10438691
Audio driver: RTKVHD64.sys (Version 6.0.1.7629) (10-6-2015)

##### K-Lite Codec Pack #####

KLCP version: 15.7.0
KLCP type: standard

Speaker conf: as is

MPC renderer: madVR
MPC subs: VSFilter
MPC audio: Internal Audio Renderer

##### Decoder Settings #####

LAV Video:
H264=DXVA2CB HEVC=DXVA2CB VP9=DXVA2CB VC1=0 MPEG2=1 MPEG4=1 WMV3=0

LAV Audio:
MP3=1 AC3=1 DTS=1 DTSHD=1 EAC3=1 TRUEHD=1 AAC=1 Vorbis=1 LPCM=1 WMA=0

##### DirectShow Filters (32-bit) #####

Description: File Source (Soft-Denchi.)
File name: c:\program files (x86)\softdenchi\sdmedia.ax
CLSID: {18832FDB-D9D2-40C8-9051-6400E0053F4C}
Merit: 00400000 = MERIT_UNLIKELY

(A total of 77 filters, 1 shown, 76 hidden)

##### DirectShow Filters (64-bit) #####

(A total of 81 filters, 0 shown, 81 hidden)

##### ICM Class Manager (32-bit) #####

(A total of 2 filters, 0 shown, 2 hidden)

##### ICM Class Manager (64-bit) #####

(A total of 2 filters, 0 shown, 2 hidden)

##### Default source filters (32-bit) #####

.sdmedia{18832FDB-D9D2-40C8-9051-6400E0053F4C} File Source (Soft-denchi.)

(A total of 57 default source filters, 1 shown, 56 hidden)

##### Default source filters (64-bit) #####

(A total of 55 default source filters, 0 shown, 55 hidden)

##### ACM and VFW Codecs (32-bit) #####

(A total of 14 codecs, 0 shown, 14 hidden)

##### ACM and VFW Codecs (64-bit) #####

(A total of 13 codecs, 0 shown, 13 hidden)

Installing Logitech G HUB on my laptop made the issue appear when using my headset (which is a logitech headset) on my laptop. So it's probably an issue with how Logitech's software interacts with MPC.

Wireless bluetooth headsets are very sensitive for audio issues. That is a common problem with many applications. Even bugs in Windows and drivers have caused problems several times. If you search the Internet you find many people with problems.

It may get improved with buffer configuration options in the internal audio renderer in the future. Until then just use DirectShow if that works good for you.