the stock horn is dinky and can barely be heard over the exhaust..

so what do you do about it? replace it with come Hella brand supertone dual horn car horns.

I mounted mine lower on the bike to encourage the sound to be heard by others around and not just me. The wiring is simple and requires only some 2 male and 4 female spade crimp on connectors, 4 feet of 18ga black wire and 4 feet of 18 ga red wire.

it was easy to mount the horns to the subframe that supports the lower fairings - and run a red and black wire each with a female spade on the bottom end. both reds are combined onto a single male spade connector and the same is done for the blacks.

once you disconnect the stock horn plug the red and black spades into the horn wires.

all done. and now you have a 135db horn setup that is compact, light weight, and gets attention.

 

I mounted one Fiamm (round style with circular air passage snorkle; not air horn,available at most Pep Boys or large chain stores) on the bracket just above the air duct covers on my old 9. Didn't have to run a relay with only one horn. Loud as hell, too. I agree with those stock things being crap; nobody can hear 'em. When I hit the horn, I wanna be heard; not laughed at...
Did you run a relay? Do your lights dim when you hit the button? If so, you're drawing too much amperage. I had tried using 2, but had too much current draw. FWIW.

 

atleast on the 95zx6r (i checked the wiring diagram) the wiring supporting the horn goes straight from the battery to the fuse (10amp) through the switch then the horn and back to the battery. as long as the fuse is high enough amperage and the wires are the propper gauge to handle the power then there is no need for a relay.
a slight dimm is normal for a heavy power draw or even a low power output from the alternator at idle.

but when its only used momentarily and does not need to be supported for long periods of time like a coolant fan would then it is fine.