Because onboard audio sucks. Anyone who says their onboard audio is good clearly haven't tried any Creative sound card before

I've started from Sound Blaster Live! Plus, then X-Fi Fatal1ty PCI-e, then Recon3D PCI-e then this card

I tried testing a few onboard audio, all of them sucks
Except for those motherboards that comes together with onboard Creative chip built-in like my previous Gigabyte GA-Z97X-Gaming G1

I just finished removing the Recon3D card replacing it with the AE-5 then doing a clean install of my Windows 10
Hot damn, it's 10 times better than the Recon3D. Can immediately hear the differences especially when watching movies & listening to music

Regret I didn't upgrade sooner. Where did you buy your card bro? I bought directly from Creative store, much cheaper than buying from Shopee / Lazada
Also, what speaker are you using with your card? I'm using Edifier S730

God damn, that's a very expensive machinery you got there
Not really into headphones, that's why I spend more on speakers

You can definitely tell the difference of the onboard and AE-9 with that headphone. For people with budget gaming headset, better upgrade their cans first before getting a DAC, because I find those on board Realtek ALC1220 quite good already.

ALC1220 is a good chip. It can even produce better dynamic range and THD than some external DAC with low quality chip.

Sometimes people find their on board sound not good is actually because of noise and interference due to grounding or other hardware.

Maybe software or hardware issue but since you already use other hardware for it no point to check the cause.

Lucky me my 300 ohm headphone no difference whether listen from external DAC or mobo DAC or even from my handphone.

Your mobo on board sound card is the DAC bro

ACL1200 is the DAC chip.
DAC = Digital-to-Analog Converter

all equipment that convert digital input (pc,cd etc) to speaker called DAC.. just got a different level of DAC

personally was using SB back when on-board audio sucks big time ; but nowadays still using the on-board..  and when needed just use straight the Sony WH-1000XM3 .. coz not really using PC for listening music..

ACL is a codec same thing as those old school VIA codecs. it still needs a DAC to work.

each mobo audio consists of a codec, a dac and an adc. generally they suckballs unless for example gigabyte x570 that uses an ess sabre. However the realtek ACL still makes the output sucksballs even with a sabre mainly blaming on the software side.

External dac also need to have usb codecs to run.. However youre not entirely wrong either about certain ALC chips because their lower end will have an integrated dac but they are usually terrible.

Theyre generaly the controllers that prepare the digital signal from the source to be processed by the DAC chips.
It can actually be quite confusing from even back in the days with alot of debates because some codecs comes with a simple dac while some doesnt. Some comes as a pcb with multiple components while some is fully integrated. Some even have an integrated amp which most ALC does.

So yeah.... i rather just call them a controller/processor instead. For example the soundblaster you using has something called the Xfi processor chip that acts the same way as the realtek.

not all ALC has integrated DAC and probably using a separate one could be better. And hiding the chip info has always been common practice. Even on rams they sometimes remove the IC’s code so need typhoon burner to find out what it is.

Sabre dac is just a dac it cant communicate with windows, so that’s what the ALC is used for, thus the ALC is more like a controller as i’ve mentioned... The DAC the Realtek ALC are all different chips that makes up a circuit.

maybe ALC is easier to implement on the mobo as theyve been doing it for so long. So just pass the DAC task to the sabre for “better” sound.

That’s technically what most audiophiles look at.. the controller, the dac, the amp to be all discrete and somewhat soldered isolated from each other.

they are very clearly separated on the pcb. you can see each of the chips. Audio circuits are very simple. If you wanna make the effort, you can even make your own DAC like someone did and sold in this forum. pretty affordable sabre equiped usb thumbdrive DACs

That’s technically what most audiophiles look at.. the controller, the dac, the amp to be all discrete and somewhat soldered isolated from each other.
my latest purchase. no good DAC on this so i disabled the audio in the bios entirely.

But the cover is meant for EMI shielding 

Just wondering, the mobo I'm planning to use is Asus TUF B550M PLUS WIFI and this mobo only has one 3 pin ARGB Header.

Are you using some kind of 3 pin ARGB splitter to connect all the ARGB case fans, AIO and the GPU support bracket?