Help - Pumps too loud

[Jaws]

I currently have two Mag 36 pumps one running my return and one running my closed loop. It sounds like a lawnmower in my living room to be honest. I've almost positive there's a problem with the pumps because there's no way they should be that loud. There's a couple things I'm curious about though:

On the return, the pump is plumbed with 1" pvc to a tee. After the tee, each side of the tee goes to a 3/4" SCWD. Each SCWD has two 1" returns, that alternate current as a result of the SCWD. Is the Mag 36 too much pump for the SCWD's? Could I get the same flow from a Mag 24 or something that size?

Both of the Mag 36's are plumbed with 1" pvc. Some have told me that changing it from 1" to 1.5" will make a difference in noise level. I can see it making a bit of a difference but does it really make as big of a difference as I would need it too (lawnmower to microwave)?

Lastly, if I determine that I need to go with different pumps, which would you say is quieter - Dolphin Ampmaster 3000 (3600gph) or a Reef Flo Dart or Barracuda (3500/4500gph)?

If anyone who can offer some help with these issues, I would really appreciate it. I have about two weeks to get all this sorted out so the sooner I can make a decision to stay with my old pumps or go with new ones, the sooner I can start listening to my tv on 20 volume again instead of 60 like I am now.