Is 60v too much for 4ohm drivers?

[Votandrums]

Ok so im finally done building my two t48's amp rack and all cables. I have a gig on the 31st and it'll be my first outing as a soundman and using bfm gear. My question ia this. I have 3015lf drivers in my t48s that are 4ohm. I know 8ohm is desireable but they were priced at half price and 2 is all I see us needing anyway.
In doing calculations im getting 42v should be my limiter setting but the plans say 60v for the 3015lf without mention of impedance. Should i use the 60v or my calculated 42v? Also what frequency test tone should i use to set my limiter. I searched and could not find the thread on how to set a limiter. Maybe im doing something wrong there but i didn't want to ask without searching first.
Off topic but when i did my leak testing i couldnt help it but i ran a 40hz test tone and turned it up pretty good. It sounded like a freight train was running through the house. That was just one cab. I cant wait to see what these things are gonna do live and at full volume.

[Bill Fitzmaurice]

60v will toast a 4 ohm 3015LF. 42v is correct.

[Seth]

50 or 60hz sinewave seems to be the common frequency to set sub limiters, speakers disconnected.

[Votandrums]

Awesome thanks for the replies. Ill do the setup tomorrow afternoon. I love this forum. Now to finish my OT12's and get rid of thr muddy jbl 2x15 mains.

[Grant Bunter]

What are you using for your limiter?
We can collectively help out in no time (I now have both a DCX and a PA2+, so know either...)