A couple of points.  The Waves MaxxAudio Pro is what does the Plug-in notifications.  It is controlled in the Advanced settings.

I don't remember having a sound distortion situation on any of my systems.  

There is also an equalizer you can use to adjust the sound on each device you have, then save that setting so it is loaded when that device is being used.

Have you tried sound using devices other than the built-in speakers?

Oh , the one thing I haven't done is : get everything maxxaudio/waves cleaned out of the registry. But this is a very very risky way to go and may not even solve it.

They say here that it is solved :

Solved: XPS 15 9560, Doing away with Waves MaxxAudio, Fixed - Page 4 - Dell Community

 ... maybe for some.

A lot of maxxaudio problems here on the forum and elsewhere. Seems Dell doesn't care. I'll bet you it is in the new 9730 too.

Because I'm in the same situation , I 'll post here. Not really giving you a solution     Gillesvp (opening poster). Sorry.

I've been dealing with this audio problem for days (weeks) now.
This is an  expensive premium laptop for content creators and Dell can't get the audio right ? (Dell XPS17 9720).

I get that Dell wants to "enhance" the little speakers' sound . I get that they want to give you an immersive game or movie experience , but it should be possible to completely bypass it , or even to uninstall it. And you can't . Certainly not in the maxxaudio pro software window. In fact if you turn maxxaudio off , the volume goes up and down , and when you pause and start again , the vol is lower and then goes " normal" , of course other effects are not gone either.
Another thing that I notice and seen by others is a small delay to hear system sounds . Could be a w11 thing or again these : "enhancements" .
This is a bad workaround: https://www.dell.com/community/XPS/XPS-15-9520-Windows-notification-sounds-are-delayed/m-p/8338237#M106446

Processing audio at that level is going to create distortions and arctifacs . And it does.
I want my audio straight like a lot of other people . No enhancements , at least not at the HP output or USB audio output !
My old XPS with sigmatel chips and drivers were great and clean , straight sound, these Realtek (more like UNrealtek) are bad. It starts with : they can only go 24 bit/48khz ??
What ? A premium , expensive creators' laptop in 2023 and it can't make use of 96/192k audio ?  So I have these big 24b-96k files for nothing ?

Realtek website is what ? Sh_t. Nothing to look for there.
Some trouble with SD card reader too , what do you know : Realtek too !
I wish I could return this laptop , but I have it now for 6 weeks...
Last Dell for me. This and awful w11 , so Apple next ?

I've tried everything on YT video's , Dell forum , reddit and others.
Mostly the same : run trouble shooter , reinstall/disable/update drivers . Stop some services, get some to not start. Tried it all ...

Some of those wave/maxxaudio you can disable even uninstall but there is still some kind of audio manipulation left.

So it must be in the 300 MB+ Realtek driver ?

So while you can disable and uninstall some : you loose external mic . Headphone is ok and you can still select it in W11 via settings.

The time between a knock on the (bild in) microfoons and hearing it through the speakers is also an unacceptable 0,5 sec or more. (yeah , yeah , update your driver as if i didn't already do that). Of what I tested of the microphones , it's not a great sound without some help from .... maxxaudio ?

Now the audio problem here:

In device manager : software components : Realtek Audio Effects component and Realtek Audio Universal service is now disabled.
Software devices : Waves Audio effects component , also disabled

In : Sound , video and game controllers , I have 4 times the Realtek Soundwire HW audio codec device driver. 1 seems to be for the speakers , 1 for the HP out , 1 for microfoon , and another , I don't know. When disabling them or uninstall , there is no output and input device detected. You restart and the bad Realtek drivers are back again. Looking for the other drivers (at show compatible hardware) and select the one of 2 microsoft HD drivers , it won't install those drivers or still says output device not detected. Trying some other HD drivers on that list , you get a blue screen ... great !

So I'm stuck . Yes there is sound , but there is still some sort of compression or loudness (normalisation) for volume or trebble/bass and more spacial .

Now I know in windows : settings> sound> speakers (or HP) , there are buttons for spacial (off of course) , but still the : Audio enhancements CANNOT be switched off , If you do : device default effects off , on the speakers tab and/or on the HP tab , YT stops playing , WMP , or " media player " stop, can't find codec or something.
This was also in the days when the computer was spanking new and nothing was altered or disabled. It was the first thing I did when hearing the awful "enhanced" sound.

Then:
Control panel > hardware and sound>manage audio devices , you get the Sound window . Never did I have the enhancement tab like it should be in w11 at properties: right click for speakers properties > advanced tab : again switching off : Enable audio enhancements , same as doing it in settings : no audio ! ( same here in HP properties.)

So what now ? Dell's Proprietary software , wave/maxxaudio , the Realtek drivers are blocking straight audio even if some don't start and/or are disabled ? That is just ... well some words I can't use here.

So how can I still hear these " enhancements" . First it sounds too spacial and the distortions it brings to some tracks, then when a song has a fade out at the end , you hear the bass is stronger , trebbles are faded , like they want to filter out end noise.

When you put any audio player's volume on max and the computer's volume lower , it seems normal BUT , you put systems vol on max and any audio player ( WMPlegacy, media player, movies & tv, KMPlayer) you turn the volume down you get that same effect . So what does it do at different levels of both volume levels? Enhance ? HAHA ...

I haven't got and USB audio device , so I don't know if I can get some real straight audio out of that , or if some driver ( it seems Intel driver USB audio) is messing this up too ?

So again in a pemium laptop , with only 4 flimsy USB-C ports , where one is used for the power, ( which I don't like ) , one for the mouse ( because most mice are still USB-A , or have a USB-A dongle for wireless) , and a LAN dongle , the 4 th is taken by a USB audio device , that may have it's own issues ?

Yes I now about dockingstations and hubs, and what do you know , if anything is not right with devices (like ext drives or audio ) connected to USB , first thing that is adviced , is to not put it in hubs but straight into the USB port of the computer.

A computer like this XPS should not need a external audio device. If I wanted this cr_p , I would have bought a 500 $ Acer , not a 3000 $+ Dell XPS.

So what now ? What, the dreaded full reset ? It is not going to change anything , just all the maxx audio cr_p will be back and you have to ajust a couple of hundred settings in win11 and other software !

Linux ? Is there a distribution that can handle new hardware ? No , same as here , Realtek driver for audio in linux , you must be joking. Why oh why Dell , can't we install ubuntu that comes with an XPS 13 , on an other XPS ?

There are some other issues too with my XPS 17 , I should open a forum post for it too, but just for information :
Dell says in its xps-17-9720-set up pdf pg 8 , that there are 5 devices ontop of your screen , 1 rgb/IR camera , 2 IR LED's , a camera status light and ambient light sensor. So why if you shine with a flash light , do I find 2 more holes left of those 5 ? (not the 2 microphones really on top of the lid)  NSA peek cams ?

Not a peep in Dell pdf's why and how to use the ambient light sensor.
Why are movement (of people or driving cars) in video's so less smooth on a 4 k screen ? More or less so in different mediaplayers ? Can't Intel Xe convert lower res to 4k ?
SSD prices are coming down and one of the reasons why I bought this XPS was a 2nd bay for an extra SSD. There was no choice to order this XPS with a 2nd SSD , but reading the posts here about it , you need to buy a copper heatspeader that costs maybe 1 $ to make , and buy it at amazon at 30 bucks ? I have not opened mine , so I can't see whether there is a heatspreader already inside.

But the main problem still is the audio.  Thank for reading !

Well , I could look up all the specs of the sigmatel chips from my old computer.

Not so for Realtek ! Mine and I suppose all the 17 , 15 inch XPS's use Realtek ALC711-CG and Realtek ALC1319D, but no information about them , not from Realtek (I emailed them) or sites like Mouser.com , or just a search.

While these audio problems are probably only software related , these mediocre Realtek chips could/should be replaced in something worthy of a Dell XPS.

Look at the service manual pg 32 (of the XPS 17 9720) : the audio board is removable  >> can we get a better one in the future ( not Realtek) , Dell ?

Even like a payed upgrade .

Some reads about the audio problem to try :

https://www.reddit.com/r/Dell/comments/jcmt8x/maxxaudio_pro_how_do_you_uninstall_it_in_2020/

https://www.reddit.com/r/Dell/comments/6cumny/how_do_i_remove_this_maxxaudio_garbage/

And the one I already gave :

Solved: XPS 15 9560, Doing away with Waves MaxxAudio, Fixed - Dell Community

So I 've been tinkering some more. Changed the 4 Realtek drivers with Microsoft Trusted Audio drivers from the list (the MS HD drivers won't install) , then deleted the 311 MB Realtek driver in control panel >uninstall programs , because that's where the MaxxAudio Pro by Waves – Speaker and Microphone Audio Control and Nx 3D Sound links to in start menu, when you want it uninstalled. That app goes to : C:\Windows\System32\DriverStore\FileRepository\wavesapo11de.inf_amd64_1e5a06dcbe1d259a where you find WaveSvc64 and 31 other files , but the system doesn't let you delete any of it.
There are ways to try but kind of elaborate.

After a restart , yes the Realtek drivers are again installed, BUT in device manager > Software components , the Realtek Audio Effects component and Realtek Audio Universal service and Waves Audio effects component are gone. In settings (and control panel >sound> speaker properties ) , the device default effects button is gone , but no Windows 11 enhancement tab in properties.

And after running the troubleshooter , the HP output gets clear, straight audio! All the artifacts are gone . You can still select HP or speakers BUT and here it comes: the speakers don't work anymore! You can hear a system sound like clicking on the volume once and then it stops. None of the media players work with the speakers , no matter what you select as renderer in the KMPlayer list.
With the 4 drivers , in events it says Device not started (RTKSdWHwCodec) , but the HP output works ! I don't get it.

The Intel Smart Sound Technology for Mipi soundwire audio , bluetooth and USB , device working properly but in events , it says not started, IntcSDW. In Device manager >Audio inputs and outputs the devices started and are working.

So I've got the output working without any "enhancements" . A lower volume, and it was already lower than my computer with bridged sigmatel audio. The Realtek ALC1319D seems to be a class D amp, not the best but it is efficient for more battery time. Nearly all power efficient devices use class D these days. I also noticed that the delay when you click play in Audacity is gone. Media players are faster too, like play / pause and clicking on timeline. System sounds don't have that delay anymore BUT still the first time you click it , it still has that little click/pop sound.

I think the ultimate is a clean Windows 11 install but NOT the Dell OEM version. So getting all the junk out and a cleaner register too. Dell edits their version of Windows 11 , like blocking the Windows 11 native sound enhancements to give exclusive priority to this maxxaudiowaves.

Not only am I hesitant to reinstall, especially with a version with which you have to install all the drivers in the right order, and to get a clean version from Microsoft ( I don't have a activation key) download the ISO and install it on a USB stick , also lose McAfee 10 month earlier than expected, get the office DL again with activation , and of course all the programs and their many, many settings.

Even then I need to keep Dell out with their automatic updates or they install the maxxaudio/waves again. And how do I know a windows update isn't going to mess things up again? Does windows update manufacturers drivers? I think only their generic ones?

I see a new Realtek High Definition Audio Driver 10.0.212.1, A47 373 MB 13 mar 2023.
Makes you wonder why so big. So the generic microsoft and others in the list of drivers are around that size too? What a waste of space.

https://www.dell.com/support/home/en-th/drivers/driversdetails?driverid=rrm1n&oscode=w2021&productcode=xps-17-9720-laptop

Like always nonspecific info: " Dell Technologies recommends applying this update during your next scheduled update cycle. The update contains changes to maintain overall system health. It ensures that the system software remains current and compatible with other system modules (firmware, BIOS, drivers, and software) and may include other new features."
And :
- This audio driver requires the Waves MaxxAudio Pro or Dell Optimizer application to be installed to have full functionality. What functionality?

This with maxxaudio/waves has been going on since at least 2018. Dell doesn't care so I have no expectations that this is going to solve the maxxaudio problem or revive my speakers.

And what functionality?

The only email reply from realtek stated that the driver itself doesn't do audio enhancements. Then why is it so big? With 7zip you can look in the driver and the only thing I can find that could point to maxxaudio/waves is WweConfigurationDll.dll. But from the little to find about it, it doesn't seem to be related.
Again hesitant to install it, what if it messes up my HP output? But I like to get the speakers going again.

So this is FAR from "solved". But I can play music like it is intended, not like some at maxxaudio/waves and Dell want me to hear. Now more silent parts in movies don't sound like there is an aircon running in the background. Since the output volume is not very high, I need to use my HP amp but you do anyway with higher impedance HP's.

Maybe another way to go is using drivers for realtek audio from others like the business version of the xps is Precision 5770, but it uses the same realtek driver, but with Dell optimizer. The business variant of maxxaudio but with some other functions too , same problems I guess. OR go non Dell. Maybe drivers for other computers (HP, Lenovo,....) that use the realtek chips.

Thanks for reading. Any suggestions?

if it's so annoying, you can physically disconnect the audio board cable. the sound on the built-in speakers will work through HDR, but the jack and card reader will not work

I don't know what HDR is?, But losing the card reader and HP jack is not an option. Besides if I only wanted to use the speakers, then I would keep maxx audio. You don't expect great or straight sound from the little speakers.

Now that the HP out is the way it should , and the speakers don't work and video stutters without a HP plugged in.... no choice , have to try the new realtek driver :

The peek into the driver with 7zip did not show everything, but you can unpack the driver (in the install window) and then you see the Waves garbage in 2 folders.

The undeletable : WavesSvc64 is there too and
C:\Windows\System32\DriverStore\FileRepository\wavesapo11de.inf_amd64_1e5a06dcbe1d259a, gets updated.
If you don't restart the first time , you see all but nVidia audio is gone in devicemanger. Audio in and outputs too.

One restart to get the old ones out , the second to install the new one.
Waves Audio effects & Realtek Audio effects component And Realtek Audio universal service , are back in Software components. New driver is back in : control panel > programs uninstall .

Audio through speakers is back BUT so are system sound delays and harder clicking .
Enable audio enhancements is back in speaker properties and in settings, and again if I switch them off , no sound ! Also in Level tab , speaker and main volume are connected again , that was different before the new driver install. This also for HP out but system sounds are not delayed here. Audacity play delay is back but less.

The weird compression/ loudness with tracks fading out , seems to be gone , as is the effect of very low volume of the media player with high system volume.

Some realtek and waves services I stopped were running again. AutoRuns show that the 3 I unchecked are running again , 2 of them have double entries that are unchecked.
This is all without the actual Maxxaudio app installed , or at least the user interface uninstalled.
Only the new Realtek driver is in : Setings> apps> installed apps , no maxxaudio or waves.

Microphone sounds better , suppresses all background noises/pops but the delay is still too big.
How is it posible that the (bad) webcam picture has a very small delay but sound has a big delay ? It doesn't make sence ! So video recorded with it , is not lipsync.

The same crackling voices with speakers is also back again although volume stays the same .

So what have we learnt from this driver install ?

It restores audio if you switched off and/or deleted/disabled too much .
That this driver (10.0.212.1_A47) seems better than the previous one BUT if you're doing a clean install to get rid of all maxxauduo/waves , you CANNOT or should not install the Dell Realtek audio driver because it includes these programs and it still bypasses w11 audio. This means switching off Dell automatic updates and hope windows updates doesn't install this.

I don't see another solution than a clean install of windows (from microsoft site) without any audio drivers from Dell/Realtek for audio.

The registry has so many entries for maxxaudio and waves (like HKEY_LOCAL_MACHINE\SOFTWARE\Waves Audio) , and while it is better with the new driver , it is still not how it should be. Especially with HP on , it seems there is still a little audio manipulation going on , far less than before , but more than when I got only the HP out working (but the speakers stopped) . The fact that in settings or control panel the enhancements cannot be turned off is not how it should be , nor is the W11 enhancement tab.

I'm certainly not looking forward to this forced clean install , with the risk that the generic windows drivers for audio are not good or won't install or work , or don't recognize the HPout , although there are 3rd party programs that could .

Contacted Dell support , so far not much help there. They are good if you have a hardware problem , and then replacing it , but software/drivers not so much. And why is that definitely in this case ?
I did a run down of all recent models on the US site , and what do you know , XPS, Inspiron , some Vostro's , Latitude , Precision ALL use maxxaudioPro !! (or Dell optimizer). With Realtek chips and of course Realtek drivers, some even >800 MB (just the download , not unpacked)!!

The one XPS uses is less than 400 MB , some around 250 MB , but also have the wavesdrivers incl. 

nVidia & Intel Xe graphic drivers are also >800 MB , so it seems excessive for just audio.

Vostro 15 has Cirrus-Logic-High-Definition-Audio-Driver ,
Some Alienware and G series have different chips or Realtek too but not the XPS chips ALC711 & ALC1319.

Why are Realtek audio drivers in microsoft update catalog only 11-12 MB ??
https://www.catalog.update.microsoft.com/Search.aspx?q=realtek%20high%20definition%20audio%202022

If nearly all Dell computers of the last generations have Realtek & Maxxaudio , why do some (like me ) have trouble with it ? Why do millions of other Dell customers don't complain about the audio ? Do they like listening to their music distorted by ridiculous spacial effects , and loudness , bass & trebble manipulation ?

Well Dell support already quit . After some sfc /scannow  and DISM.exe /Online /Cleanup-image /Restorehealth , and trying in clean boot , which reverted it back to the bad state before deleting the driver , they say to do a re-install . 

I tried a Realtek HD driver for an Intel nuc , but 2 BCOD's ! Another one I found that could have worked , but it didn't want to install.

Yes I will do a clean re-install , but that is going to take some time.
When I do a clean re-install it is the chance to tryout software like "risky" software
and old software , and games because nothing to loose. Maybe mess around in registry , try the hard way to delete files that the system won't let me delete.

Then try to delete everything maxxaudio/wave from the driverpackage and try to install it. 

The thing is that after going to all that trouble of a clean re-install, and somehow I get the bad drivers back through windows update , it will be for nothing.

Or after the waranty runs out , try some linux distro's .

Wow if I had known this was this bad , I would not have bought it , or any other Dell , because nearly all have this maxxaudio/enhancement/realtek garbage.

If I'm successful of getting rid of this with a clean install , and keep it clean even after W11 updates , I will let you know. 

Suggestions always welcome .