My horn has 2 parts to it. Do i need to replace it with a similar horn?

[Paddy_g46]

Basically it halfords they sell a single horn and a double horn like the 1 on my valver, the single is quite a bit cheaper. Whats the difference?!

 

[MT AUDIO]

double will be louder and a combined higher and lower tone,just get the single

 

[dajones]

sounds better as a single ive disconnected one of mine