here you go 
Needed Files:
*Xvid4Psp 5.0+ XviD4PSP Download - Softpedia Download R25 UNOFFICIAL (Thanks to eazynow82 telling me)
*AviSynth 2.5.8 Free-Codecs.com :: Download AviSynth 2.6.0 : AviSynth is a very very powerful tool for video post-production.(If XvidPsp didn't install it already for you)
*ColdBoot Installer(PS3 PKG File) FileSwap.com : Coldboot_Installer_1.0.rar download free(1s For Geohotz CFW if you still have it and the other 1 is for the rest of CFW)
Backup AC3 files:
FileSwap.com : Original_Coldboot.rar download free
Download Videos from Youtube:
http://keepvid.com/
Computer:
1.Once done downloading & installing the files needed download a music file or can be a video file.
2.Open XvidPsp and press the open button search for the video or music file you downloaded( if doesn't show up change the file to all movie files or all audio files).
3. Make sure the Format:Audio,Filtering: Disabled,& Audio Encoding:AC3 640k
4.Press Play button and when you want a part of your song just press set start and set end, it must be 8 secs ,apply trim if not sure it will play once applied stay on that screen if its correct if not than remove trim and reset end trim.
5. Press the Configure button everything should be set except for source stereo this should be Convert to 2ch Stereo press apply and than OK once done.
6.Go to the Encode button and save to where ever you like named coldboot_stereo (i place mine on my desktop) were still not done with XvidPsp tho we need to go back and go into Configure settings to change source stereo to Convert to 5.1 channels (multisonic) apply,OK and encode again but name this save coldboot_multi
7.Plug in your USB to your computer and make a new folder called coldboot. place the ac3 files we created into their, place the coldboot_installer.pkg onto your usb while were still on the computer
PS3
1.Now go to your PS3 plug your USB into the far right most port (closest to your blu ray drive) install the the coldboot pkg file and open it once downloaded back up your current coldboot files by holding for a sec select.
2.On top should should say it was successful, now press and hold for a sec circle and should say it copied ac3 files just exit the app out by pressing ps button and restart your ps3 to check your new boot up sound.
credits to shiro wherever he got it from
and btw i don't have any virus scans for these files but i can confirm that they don't contain virus. but if you don't trust me or the files then just don't download them.
enjoy
edit: you can use http://www.computerhope.com/issues/ch001002.htm that page to download any youtube video by putting the video's URL in the URL text field on step number 2

Needed Files:
*Xvid4Psp 5.0+ XviD4PSP Download - Softpedia Download R25 UNOFFICIAL (Thanks to eazynow82 telling me)
*AviSynth 2.5.8 Free-Codecs.com :: Download AviSynth 2.6.0 : AviSynth is a very very powerful tool for video post-production.(If XvidPsp didn't install it already for you)
*ColdBoot Installer(PS3 PKG File) FileSwap.com : Coldboot_Installer_1.0.rar download free(1s For Geohotz CFW if you still have it and the other 1 is for the rest of CFW)
Backup AC3 files:
FileSwap.com : Original_Coldboot.rar download free
Download Videos from Youtube:
http://keepvid.com/
Computer:
1.Once done downloading & installing the files needed download a music file or can be a video file.
2.Open XvidPsp and press the open button search for the video or music file you downloaded( if doesn't show up change the file to all movie files or all audio files).
3. Make sure the Format:Audio,Filtering: Disabled,& Audio Encoding:AC3 640k
4.Press Play button and when you want a part of your song just press set start and set end, it must be 8 secs ,apply trim if not sure it will play once applied stay on that screen if its correct if not than remove trim and reset end trim.
5. Press the Configure button everything should be set except for source stereo this should be Convert to 2ch Stereo press apply and than OK once done.
6.Go to the Encode button and save to where ever you like named coldboot_stereo (i place mine on my desktop) were still not done with XvidPsp tho we need to go back and go into Configure settings to change source stereo to Convert to 5.1 channels (multisonic) apply,OK and encode again but name this save coldboot_multi
7.Plug in your USB to your computer and make a new folder called coldboot. place the ac3 files we created into their, place the coldboot_installer.pkg onto your usb while were still on the computer
PS3
1.Now go to your PS3 plug your USB into the far right most port (closest to your blu ray drive) install the the coldboot pkg file and open it once downloaded back up your current coldboot files by holding for a sec select.
2.On top should should say it was successful, now press and hold for a sec circle and should say it copied ac3 files just exit the app out by pressing ps button and restart your ps3 to check your new boot up sound.
credits to shiro wherever he got it from

and btw i don't have any virus scans for these files but i can confirm that they don't contain virus. but if you don't trust me or the files then just don't download them.
enjoy

edit: you can use http://www.computerhope.com/issues/ch001002.htm that page to download any youtube video by putting the video's URL in the URL text field on step number 2