Do you think the max volume on your Samsung Vibrant is too low? If the answer to this question is yes, there is an easy way to make your Samsung Vibrant speaker louder. XDA forum member bchalk has posted the steps required to make it easier to hear the speakerphone on your Samsung Vibrant. It is pretty easy and definitely worth a try if you are having issues.
To make this work, you will have to punch a code into your dialer and then select the volume type that you want to change and then set the volume level. The default level appears to be 88 but you can max this out at 100.
bchalk has posted a warning that 100 is almost intolerable. It is extremely loud so beware!
For more information including full directions, click here or on the source link! Good luck!