will they go louder

I had 1.6 Maggies with an Innersound ESL amp (a special one with an extra big power supply) so it had about 1000 watts and they played insanely loud.

I have heard the 3.5 tweeter is a bit more sensitive than the QR but I do wonder if you have enough power myself...

Thank you for your responses. I think my amps are powerful enough - they are the Magtech amps with a lot of power into four ohms. They sound very good with the Maggie speakers. I don't usually plan to play speakers so loud - I think I could damage my hearing. But on the right occasion (such as when relatives come and want to blast out the room) it would be nice to be able to do this without blowing out a fuse. But I'd rather blow the fuse than the tweeters so I'll stick with the proper fuses.

Sounds like you might own the wrong speakers for your son to enjoy. Magnepans look like they should play at ear bleeding levels, but my experience is they wont in large rooms, or if you sit past 8ft from them. For reference I am speaking 98-100 db's or more.

Do you have 1W/1M spec of your speakers? Then calculate the theoretical max SPL of your system at 1 meter with the amps you have (it will be less due to room absorption). Then starting at 1 Meter, calculate -6dB less for each doubling of distance to your listening position; this is the theoretical max SPL of the system at your listening spot.

Maggies are not point source speakers -they are dipoles- so the rules are a bit different. At least this can help you get a rough idea of what's happening.

Can you lower the amp gain controls so your son cannot drive it to full output (the fuse popping point) using preamp gain?
Brad