I am putting together a box for a single 12" xcon. It will net 2.7 ft^3 and be tuned to 30hz. My question is: how much difference will lining the inside of the box with resin make? Is it worth the extra time and money? This is a daily setup, I do not compete. Will my ears b  able to tell the difference?

Nope.

No

No Sir, It will not be necessary ... Please sand all of your surfaces clean and smooth and you should be just fine ...

That is what I have always done and been just fine. The last box I made I coated with resin and it was not only a pain but still stunk a week later! I Didn't want to go through that again if it wasn't completely necessary. Thanks

What about 45's in the corners?

That is what I have always done and been just fine. The last box I made I coated with resin and it was not only a pain but still stunk a week later! I Didn't want to go through that again if it wasn't completely necessary. Thanks

Yea, it takes a while for that sstuuf to actuall cure ...

 

What about 45's in the corners?

I do not have them in mine ... Alot of people run them, and alot of people do not ...

I would assume that the larger the enclosure that is built, the more sence it would make to use them ...

 

then again Sir ... just my suggestion here

I have 45s in mine, but i don't know if it really makes a big difference. I'm sure its not audible.

Nope not a difference

After testing with and without 45's and resin recently i've discovered a few things. Just forget everything you've heard about either of them. Really! It doesn't make sense anymore. On lower power the 45's made a few tenths, but the moment you crank out past a few thousand watts the 45s were non existent.

 

As for the resin, It's not that easy to sand. It's a quick way of sealing and trying to get smooth quickly. I would recommend some enamel paint and working your way through different grit sandpaper to smooth it out and just lay it on smooth. 

 

So i'd use 45's for lower power and resin for bigger enclosures that you don't wanna spend weeks on getting perfect. A smaller box would benefit from TLC of sanding and painting over resin any day in my opinion.

The resin is more of a quick fix for any gaps in the box material. MDF by nature is porous and that coat of resin can be used to mitigate that effect for those who are...anal retentive. Really, it won't matter much so long as you seal all your gaps well. It's completely unnecessary when using materials like multi-ply birch and solid woods, though.

 

As for the 45s, it depends on where they're placed. The intent should be maximum laminar flow (aka not turbulent) as that's when it starts to impact you on the meter. I've seen some box designs that have a small strip of material that is 45ed on each side that caused the enclosure to lose 2dB on the meter due to introducing turbulent flow.

 

Now if someone designed a software to simulate "wind tunnel" response for enclosure building, nobody would be safe in the lanes.