Good speakers for Parasound Halo JC1

@mikempls , I am very familiar with the JC1. It is arguably one of the finest amps on the planet. If you factor in the price, it is the finest amp on the planet. It will drive ANYTHING. It is one of the best amps to drive Magneplanars and Sound Labs ESLs. Of these speakers the Magnepan 3.7i is the best value. The 20.7 is a better speaker but twice the money. If you are a heavy metal person they are not the right speaker for you. ESLs are a whole other bag of worms but the Sound Labs 645s are the sweet spot in terms of value. If you are a classical person they can not be beat. If you are a rocker you will need a subwoofer system.  For dynamic speakers IMHO Magico makes the best but a value they are not. For bookshelf speakers on stands you can not beat Harbeths. For value Golden Ear Tritons. For beautiful woodwork Sonus Faber. If you are a heavy metal person Klipsch Cornwalls will rip your head off.  

What size is your room?

@bubba12 , you can listen to anything on Maggies but they are volume limited and they do not do low bass well. Subwoofers can take care of that problem but the other problem is if you have one of the speakers that has Maggies wonderful ribbon tweeter (best tweeter in the world) you risk blowing it if you push too hard. Magneplanar has a tweeter replacement program. They sent you a new one and you send the old core back which they re-manufacture. 

I have set up lord knows how many Maggies over the years. I owned Tympany 3s for two years. They are not a speaker I would recommend to a hard rocker.