Sound engine is pretty crappy though as well aside from just volume in my experience. I rely a lot on sound and it could be my perception of the sound, but I notice huge differences in volume between different occasions. I also think the sound engine does not take into account vertical distances. Horses on a higher level sound like they are next to you.
Still, I think a slight increase would be a good thing. Cav has been nerfed a lot to make up for the lack of awareness of people. Now you can tell people to 'get cav awareness' but I think the ugly truth is that after 4 years the level of cav awareness isn't gonna get any higher anymore. Increasing the sound level will directly influence the ease of being aware of cav, which could lead to a reduction in their backstabbing potential, perhaps even allowing them be made stronger against aware opponents.
Edit: Here, http://www.mediafire.com/download/4bs70uhob769gk3/Heavy+Hooves.rar
Don't touch this. I was hoping the stated increase of 10 dB was just due to a misunderstanding of how dB works, but I tried it and I could hear every single horse on the map simultaneously, so it might actually have been 10 dB. Surprisingly hearing 20 horses at the same time does not help with your cav awareness. 10 dB is an increase of sound intensity by a factor of 10, so you don't wanna increase it by that much.