Here is an email directly from ProBox. I asked them how their product would stand up to 2 JL Audio 10W3's in a custom enclosure. Here is their reply...
"Greetings, I already know what hits the hardest because we have done the test. Go to www.proboxloaded.com and check out the "Loaded" section of the site. Look for Part number NT110L-500...this is the best as far as fit and efficient bass load due to port location. The New ProBox sub has been optimized to play very aggressive at our tuned port frequency. It has a 2.5 inch voice coil, power handling 600 watts rms, special suspension for vented enclosures.
We have notice that most enclosures are making contact with the seat cushions or the carpet on most downfire models. Since we know the mounting depth of our sub we have recessed it a bit to allow a custom CNC machined grill to keep the seat cushion away when seat in the down mode. Plus we got an extra db of gain from the recess due to a "Horn Load" effect on the front side of the cone. I know for a fact there is not a dual 10" sealed enclosure on the market that can compete with this....This was the whole reason behind the complete build.....max performance without the worry of will it work. You gotta hear it to believe it, it sounds like 2 -12" subs....I can give you more detailed info of how it works if you like....my contact....972-571-5330."
"Greetings, I already know what hits the hardest because we have done the test. Go to www.proboxloaded.com and check out the "Loaded" section of the site. Look for Part number NT110L-500...this is the best as far as fit and efficient bass load due to port location. The New ProBox sub has been optimized to play very aggressive at our tuned port frequency. It has a 2.5 inch voice coil, power handling 600 watts rms, special suspension for vented enclosures.
We have notice that most enclosures are making contact with the seat cushions or the carpet on most downfire models. Since we know the mounting depth of our sub we have recessed it a bit to allow a custom CNC machined grill to keep the seat cushion away when seat in the down mode. Plus we got an extra db of gain from the recess due to a "Horn Load" effect on the front side of the cone. I know for a fact there is not a dual 10" sealed enclosure on the market that can compete with this....This was the whole reason behind the complete build.....max performance without the worry of will it work. You gotta hear it to believe it, it sounds like 2 -12" subs....I can give you more detailed info of how it works if you like....my contact....972-571-5330."