Audiophile speakers that get loud

I have Dynaudio C1s and while I like their sound, I can’t turn them up as loud in my small room as I would like to sometimes without the woofers maxing excursion. I have a JL audio sub but the C1s are not high passed. Any attempts I’ve tried to do this have lost the sound I like at lower levels. Any ideas on what I should try?

I’m trying the plugged port idea. It definitely changes the sound and the driver excursion. I think my ultimate answer though is a 3-way speaker that has a more prominent mid-range. Any suggestions?  I’m trying to stay under $6-7k. 
Get Dynaudio contour 60s. You will not need subs. These speakers are incredible for loud dynamic playback with bass that is palpable, super deep and highly impactful; 
I test drove a pair of Usher Be-718 Tiny Dancers and I was able to push them to crazy-loud levels and they never skipped a beat. They have the added bonus of an easy WAF appearance. 
I had a pair of dynaudio audience 80’s for a week. I wanted to replace my kef R105/3’s with them and the bass lines coming from the A 80’s was impressive! Actually they were really musical,and they were the entry level at the time. If you like the Dynaudio sound(who doesn’t) go up the ladder some. 
I would recommend Usher if the op wasn't already happy with the Dyn's
Well, ATC speakers thrive on playing loud and also sound fantastic.  Music Direct sells the SCM40 v.2 for $7k I believe with a 60-day trial period.  They are floorstanders, but they’re a sealed design and only go down to 48Hz so should work fine in your room.  

If you have to have monitors there’s a pair of Joseph Audio Pulsars at US AudioMart for $3650 (List $7700) that should play plenty loud, sound amazing, and you’ll save a good bit of coin.  Best of luck.