Just got my Hella Twin Supertone Horns from Safe Drives today and installed them (118 dB) They were $60.99 and only took 2 days to ship to my house.
Here is a better view of what they look like right out of the box
You can find these horns, as well as others from Safe Drives in this link below:
Installation requires removal of the front bumper. Once everything was off, I removed the negative terminal to my battery. The two oem horns are located down in the driver side corner. This is what your oem horns look like
You only have to remove 2 nuts to get them out, and this is what it looks like after they're off
Next you'll have to chop off the harnesses and crimp on some female connectors. Other horns may be different!
The yellow/black wire is positive, and the brown wire is negative. I guess you could mount these however you want... I wasn't sure how they were supposed to sit, so I pointed them down. Here is the bottom one mounted and wired
Then both mounted and wired
Then a few more beautiful shots to get a better idea
Installation was very simple, but I needed to buy the female connectors along with nuts/bolts to mount the horns since Hella doesn't include any hardware. These are 300Hz and 500Hz. They sound pretty euro to me but are a little higher pitched than I thought. I still like em though They are fairly loud, but I really haven't gotten the chance to just lay on the horn and compare to the oem ones. There are 2 sound clips floating around the vortex somewhere, but I don't know where they are and haven't made my own yet.