I just received my fully loaded 12" Q with high qts option. Was wondering if anyone has been trying or testing sealed enclosures and has some recommendations/tips? I love lows. Had an 18" Q tuned to 28hz for a while but the box is just far too large and heavy for me. Im thinking of building it 1.5-1.75cuft while empty and putting some poly fill against the inner walls... not sure how the box size is affecting the woofer's output exactly.

no need for poly fill.  The enclosure won't be too big anyway.  Look at enclosure recommendations on Fi's technical forum and build the box they provide in cut sheets.

Oh thanks for the heads up, I havent looked at those before. I'll adjust those dimensions a bit and see how it goes!

What about 45 degree pieces in the corners?

If you are running sealed that is not really a necessity either.

Build the box solid, no need for internal 45-degree corners with a sealed box...

Okay, I've built a lot of ported boxes. Making this wayyy too complicated I guess lol

just build the template that Fi gives you and I'm sure it will be good.

Well it sounds great and I couldn't ask more for SQ. I was very surprised at how loud it can play the low notes in the sealed box. I was just trying to achieve some weight reduction from a ported 18" Q to a sealed 12" but the loss of dBs isnt worth it. The 18 was flexing my sound deadened panels and making me say holy shit everytime I listened to it, the 12 in a sealed just feels like a waste of the system. I will forever love ported enclosures and laugh at sealed.... gunna make a ported box for the 12 and see how it goes. I built the sealed enclosure to the cut sheet dimensions plus 3/4" all around (used 1" mdf and added 1" to the dimensions). sealed it all up with silicone ect, there are no leaks

Don't stick it in a ported enclosure if you have the high qts option

Well it sounds great and I couldn't ask more for SQ. I was very surprised at how loud it can play the low notes in the sealed box. I was just trying to achieve some weight reduction from a ported 18" Q to a sealed 12" but the loss of dBs isnt worth it. The 18 was flexing my sound deadened panels and making me say holy shit everytime I listened to it, the 12 in a sealed just feels like a waste of the system. I will forever love ported enclosures and laugh at sealed.... gunna make a ported box for the 12 and see how it goes. I built the sealed enclosure to the cut sheet dimensions plus 3/4" all around (used 1" mdf and added 1" to the dimensions). sealed it all up with silicone ect, there are no leaks

Good luck finding 1" mdf at most stores.

 

Well it sounds great and I couldn't ask more for SQ. I was very surprised at how loud it can play the low notes in the sealed box. I was just trying to achieve some weight reduction from a ported 18" Q to a sealed 12" but the loss of dBs isnt worth it. The 18 was flexing my sound deadened panels and making me say holy shit everytime I listened to it, the 12 in a sealed just feels like a waste of the system. I will forever love ported enclosures and laugh at sealed.... gunna make a ported box for the 12 and see how it goes. I built the sealed enclosure to the cut sheet dimensions plus 3/4" all around (used 1" mdf and added 1" to the dimensions). sealed it all up with silicone ect, there are no leaks

Good luck finding 1" mdf at most stores.

 

Really informative, thank you. If you read what I said, you'd realize that I've used past-tense and that the box has already been built. What do you suggest I do with the woofer then? put it in bandpass?

Technically you can run it in a ported enclosure but make sure to model it to your liking using the High QTS numbers not the standard ones.

I wouldn't run a driver with a Qts that high in a ported enclosure.  They don't have the ability to self dampen enough to get flat response.  If you must go ported, I would sell it and get another driver.

okay thanks for the response, I think my best bet is building a lighter box for my 18 and sell the 12 as it is. Ive tried selling the 18 before and everyone seemed scared of it

okay thanks for the response, I think my best bet is building a lighter box for my 18 and sell the 12 as it is. Ive tried selling the 18 before and everyone seemed scared of it

That's how I got my BTL for dirt cheap, my friend couldn't convince anyone of how awesome it actually was. Lol