How to Enable Harman / Kardon Enhancements on your HTC One M8 (Video)

Sprint recently introduced the Harman and Kardon special edition of the HTC One M8 and all I could think was, “Poor Sprint”. You see, all of the changes are simply software tweaks and, because of that, it isn’t that hard for a crafty developer to get a hold of those changes and tweak them to work on other versions of the same device. Such is the case here. XDA Developer baadnewz created a flashable zip file that anyone with root access and a custom recovery can flash to gain the benefits of the Harman and Kardon tweaks. Check below for how to enable it. And no, this wont make the Harman/Kardon headphones appear next to your device when done…

I. Before You Begin

1. This is supposed to work on all US variants of the HTC One M8. Please let me know in the comments if it does or doesn’t work for you (please list what version you have in the comment).

2. You need to have fastboot disabled. Go to Settings > Battery Manager > Turn OFF Fastboot.

II. Root Your HTC One M8

1. You must be rooted, have an unlocked bootloader, and custom recovery. If you don’t, head to my How to Root the HTC M8 (All-in-One Toolkit Method) video, complete that. and come back here to continue.

III. Gain S-Off on your HTC One M8

1. You must have S-Off on your HTC One M8 as well (which the above procedure doesn’t do for you). If you don’t, head to our How to Gain S-Off on the HTC One M8 video, finish it, and return here to continue.

IV. Flash the Harman/Kardon Enabler

1. On your HTC One M8’s internet browser, type in the following into the URL bar and hit enter: (link shortener used to simply make it easier to type in)

2. Once on that page, download the enable_hk_and_adsp_update zip file and save it to your phone.

3. Turn off the phone.

4. Turn in back on by holding down Volume Down and Power at the same time to get to Hboot mode.

5. Push Volume Down then Power to select Recovery mode.

5. Tap Backup then swipe to backup (to make a backup of your device just in case).

6. Tap Back.

7. Tap Install then go to Downloads and select the enable_hk_and_adsp_update zip file and swipe to flash it.

8. Tap reboot.


47 thoughts on “How to Enable Harman / Kardon Enhancements on your HTC One M8 (Video)”

    1. @pasquale_tedesco:disqus
      Over on the developer’s original thread, yes. You just need this if you have an issue:

      ISSUE 3 I did everything and it still doesn’t show up on my Verizon M8

      Reason: Happens Because Verizon uses a different settings.apk.
      Solution:Grab and flash from recovery

      Now, as far as rooting is concerned, the Toolkit DID work for Verizon, but not sure if it still does… If you find out let me know!

        1. I like to do this to my verizon htc (m8) like you did. how can do i Grab and flash from recovery?

          1. Are you rooted already? If so just follow this procedure and if it works your good to go. If not, then head to the developer’s page linked above and download that Verizon HK fix file and flash it the same way you flashed the enable HK file.

          2. Can confirm this works after performing the above on Verizon HTC One M8. SuperSU via TWRP, after WeakSauce.

          3. Wait can you clarify something? You were NOT rooted when you did the Firewater procedure? It gave you TWRP? Then you flashed SuperSU from there and then followed this?


          4. It’s like this. WeakSauce for temp root, install SuperSU, then Firewater to get S-Off AND unlock the Bootloader. Then, removed WS and SuperSU (had to remove root) . After that, just a matter of installing Recovery (TWRP in my case) and flashing SuperSU to gain perm root. Then, yes, flashed h/K zip via TWRP. Didn’t see it in settings until I also flashed the VRZ settings zip. Hope this helps. 🙂

            Thank you.

          5. Hi David, I hoping you can help me or send me where I can follow a guide. Current state for my phone is unlocked used firewater, weak sauce etc. s-off. I have downloaded the files to enable Harman and also verizon on phone. Looking at your video when I follow your video / instruction up to step 4 and 5 when I set my phone to recovery as instructed it goes to a triangle with exclamation point. It does not goto the program you show that execute the backup and installs the enabler. Can you help. Please.

          6. You need to flash a custom recovery first (the rooting procedure I have you do does that for you but I’m not sure if it’ll work for Verizon). I’ll be doing a post on rooting the Verizon M8 and how to install recovery this week, but if you can’t wait for that then just Google “TWRP for Verizon HTC One M8” and you should find a how to for flashing it (no need to do anything in the procedure for rooting, just flash recovery).

  1. But aren’t you just getting half the story here? The M8 HK has hardware enhancements in the speakers and the DAC. You can’t root phones and flash zip drives all Frankenstein scotch tape style for that.

    1. As far as I know (and the code seems to suggest) there isn’t any hardware changes between the HTC One M8 and HK edition… Besides the wired headphones that they provide which help but you benefit from the software enhancements regardless of the headphones (any nice pair of headphones will help further of course).

  2. Hi David, I hoping you can help me or send me where I can follow a guide. Current state for my phone is unlocked used firewater, weak sauce etc. s-off. I have downloaded the files to enable Harman and also verizon on phone. Looking at your video when I follow your video / instruction up to step 4 and 5 when I set my phone to recovery as instructed it goes to a triangle with exclamation point. It does not goto the program you show that execute the backup and installs the enabler. Can you help. Please.

  3. John Conatser

    not showing up on my tmobile m8, they talk of changing a script, how do i even find that and then change it?

    1. Download a file explorer from the play store. Es file explorer will work. Then navigate to where he says in his solution open the file and edit it like he says then save it.
      Before you do make sure you have a back up on recovery just in case.

      1. Hey David, is the T-Mobile M8 able to receive this update? What’s the final word on that? I see 2 people here now who say they can’t get it to work. Have you actually seen it work on a T-Mobile M8 yet? Please let me know. Thanks.

  4. i have the Htc m8 for tmobile and i did everthing step by step and i didnt get the harman/karden and my boom surround had also poof. i did everything down to a tea and still nothing idk if iam doing something wrong or it is just for sprint

    1. Confirm you have s-off by turning off the phone and turning it back on by holding down volume down and power. You should see s-off at the top of that screen.
      If so then try some of the developer’s solutions listed in his post whet you downloaded the zip from.

      1. yes the s-off and i try changing the script using es file explorer and it refuse to save the script. iam using viper so my build is 1.6x

        1. Tony,

          See my most recent post (August) above. I have ViperOne M8 too! You need the more recent version of HK for it to work on ViperOne. Make sure you flash version 4.1 first, and then if and when you update to 4.4.3, you will need to flash the 4.4.3 fix AFTER flashing 4.1 (whether regular or VZW version). Then it should work. I have T-Mobile and for me at least it did just fine. You MAY wanna try the Verizon (VZW) one too since you’re Sprint (CDMA). Not really sure, but after you read my post, you’ll see that it might work for you if the regular one doesn’t.

          Good luck!


  5. Doesn’t work for me, unfortunately. Here’s my setup:

    International HTC One M8
    Build 1.54.401.5
    Bootloader unlocked, Root, TWRP, S-OFF
    Flashed in Recovery
    harman/kardon audio Setting not visible in Settings, BoomSound is still there (Also in the status bar when listening to music.)

    Troubleshooting solutions in original post and searching the XDA thread, as well as the web, didn’t help.
    I checked /system/customize/ACC/default.xml. The harman line is there and set to true. (boomsound_effect is set to false btw.)

    Seems like two other people over at XDA had the same problem. One guy from the Netherlands ended up flashing a custom ROM, something I’d like to avoid. Another guy from Italy never posted again after a few posts. (Pages 53-55) I unfortunately can’t post in the XDA Developers thread, because I don’t have enough posts. :-/

    Any help would be greatly appreciated!

    1. I just played around a little bit and here’s the kicker:
      With HK enabled (harman set to to true and boomsound set to false) there’s no difference in sound over headphones when flipping the BoomSound switch on and off.
      I flashed the HK disable zip (checked default.xml, harman is set to false, boomsound to true) and now when I flip the BoomSound switch there’s a noticeable difference in sound.

      This looks to me like the HK enhancements were actually working before. I just can’t see it in the settings, similar to Issue 3 for Verizon users in the thread.

        1. So, I just had some time to work on this again. Disabling and re-flashing didn’t help, even after updating to 1.54.401.10.

          But somebody pointed me to the solution:
          Going Super CID. After doing that and re-flashing, the H/K settings are there, BoomSound is gone, etc. 🙂

          Maybe something to add to your original post?

          1. Hey 123,

            I have the T-Mobile HTC One M8. The last OTA update took me from Build # 1.17 (something like that) to my current one which is 1.57.531.7. I’m guessing yours may be different because it’s an international version? Anyway, glad you finally got it to work! I got it too and I think HK makes a noticeable improvement, even though BoomSound was pretty great too.

      1. Jeff Nmi Ruiz

        Honestly, I don’t know. Shortly afterwards, I added a Custom ROM from Team Viper which over wrote H/K audio.

  6. You don’t need S-OFF. I got HK WITHOUT S-OFF. Just use the S-ON zip file (after doing a backup) and it should work for everyone. Not sure why that was made out to be such a big deal. The rooting is prob necessary though, I guess? But S-OFF is not.

    1. S-Off is necessary for certain varieties and firmwares so its included since we don’t have a good list of what needs it and what doesn’t (plus most devices do need it).

      1. To David (and all),

        The HK link above is to the now discontinued HK page. The developer has a new guy handling the new page, which can be found here: (David please update your link above in the article, but keep the old link too and let ppl know to ONLY use it to obtain the HK disabler ((see below)))

        The old page ended at Version 3, and included both an S-ON and S-OFF version. The new page is already up to (as of the present time) Version 4.1, which includes an update to the sound files (Version 4.0) and a newer update which allows you to install HK even on other ROMs such as ViperOne (which I have, and it’s awesome!). Version 3 will likely not work on ViperOne (it didn’t for me).

        Also, one of the contributers to Version 4.1 (EarlyMon) has told me directly that SOME T-Mobile M8s MAY have to use the Verizon (VZW) version of the HK mod (4.1) in order for it to work. He said they’ve found some success that way for T-Mobile ppl who couldn’t get it to work with the regular mod. The new 4.1 version DOES REQUIRE S-OFF, so unlike Version 3, you must take the extra step to achieve S-OFF on your phone before downloading Version 4.1. And lastly, you can use the Version 3 DISABLER from the old page if needed. I will update David if I find out it’s not ok to use it, but as of this time, I was told it should be just fine. Feel free to test it yourself if you can’t wait. See link above for more info.


  7. hi am a novice at this rooting and s-off tech stuff, but managed to root my htc one m8. but on trying the s-off not so successful. I watched the video and followed it closely on doing an s-off. I get to the part were I have to agree the terms and say yes. But then nothing happens after waiting for sometime still nothing happens. Any ideas would appreciate.. regards. albouet

      1. checked tutorial watched video again , watch it work on your video , but alas not on mine. I tried again..again I get to the disclaimer and say yes and nothing happens..regards..albouet

    1. You won’t get ota updates unless you replace the custom recovery with the stock. And after getting the update, reflash the custom

  8. Daniel Jitbahadoer

    i installed everything a while a go and it worked, however i’m now having problems installing ota updates. I’ve unrooted and went back to stock recovery but at about 30% the process stops and there is a message saying that the default.xml is changed or corrupted.
    I think it has to do with th HK alteration. Any tips on how to remove everything and go back to real stock?

  9. マリカーマリック

    Hi everyone,

    I’m having some issues with my International HTC One M8 after installing the H / K mod: It is stuck on the cyanogenmod boot animation.

    International HTC One M8

    Bootloader unlocked, Root, TWRP, S-OFF
    Flashed hk_enable_and_adsp_update_v3.z.. in Recovery

    I’m getting quite desperate. Any help would be much appreciated-

  10. Taylor Hughes

    i have a Verizon htc one m8 with viper rom 4.0.3 on it….and it installs successfully but when rebooted it stays on starting apps..

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