It is fairly easy. You will need to edit a text file in the folder /system/etc. I'm not sure you can access that if you aren't rooted. The file to edit is default_gain.conf. Use a text editor and VERY carefully edit just the speaker section changing the numbers to match the example below on the screen shot. It may distort a little at max volume but drop the level one notch or use a level of 60 where I used 62.
Depending on your device, the file to edit may have a slightly different name. It end with. CONF and the contents will look like the screenshot. I have done this on a Note2 and a Tab3. You have to reboot after the edit.
Samsung Galaxy Note2
Dr. Ketan 4.4.2 ND3