WRX V2

I have just bought a Blitz DD Blow Off Valve for my subaru impreza wrx 1995 but for me to get that whooooosh sound i have to take the rev's to about 45000 rev to get the sound but i want the sound to click in at about 2000 revs some 1 told me that you can adjust these to how loud you want it so can some please tell me how to adjust the dump valve so it clicks in at about 2000 revs and get a loud noise it will be a great help from you lads

Thanks Lads.