Recommend a 2 or 3 way project for 80hz and up

[BJosephs]

At a minimum I would use 4 horizontal braces plus 1 vertically. As it stands your top and bottom panels are unbraced and so is your back removable panel. And your side panels have what look like about 8" x 10.5" sections that are unbraced.

I can work more in. I was mostly just matching Troels' bracing approach as a starting point.

For that back panel, continue your braces right to the back and then screw the panel right into the braces. I often prefer to use metal/machine screws and threaded inserts for removable panels instead of wood screws. Glue on extra small pieces of wood to the braces where/if necessary to ensure the inserts are strongly secured.

It turns out the crossover is about half the size I thought so can definitely extend the lower brace and make the removable cover smaller.

Let me say as well though that this topic is rife with personal opinions so others may use a different strategy. Perhaps sift through them and decide what you think is the best for you.

Indeed, but I do agree that some of those larger sections are a risk for resonance. I'm trying to not fill the thing with so much bracing that I can't add adequate absorption. Also the front baffle really doesn't have much surface area left but I can certainly couple the sides and back together more.

 

[jReave]

Just my personal philosophy of course, but if the drivers are of high quality I want the cabinet to be the same too. So if 3rd order distortion is down about 60dB in my drivers, I want the sound transmission through all cabinet walls attenuated about the same. If cone resonances are dead in less than 5msec, I want the same from the cabinet walls too and I don't want reflections from inside the cabinet coming back out through the cone to mess it up either.

So for me this is one of the advantages of DIY - if you want to you can go to extreme lengths to design and build the best cabinet you are able to if the drivers deserve it. That's something lower end speaker manufacturers just can't really do - it would cost them an arm and a leg especially in transportation costs as the weight can start to increase considerably.

Anyways, just my $.02 - I like to over-build when it's warranted.

 

[BJosephs]

Here's a version with a few more horizontal braces and a single dowel running top to bottom. I may not have enough room for a crossover panel but a double check reveals the enclosure is a bit too short for tweeter-at-ear-height so I may just add compartment underneath after all.

 

[jReave]

I definitely like that better. Dowels are certainly effective if you can't get a whole brace in there. Remember though, that if a panel or a brace for that matter are going to flex, the weakest point is in the middle. I do still think that you can make a full brace work vertically however.

Maybe 1 more thing I would consider for your build is to double up your front baffle thickness. Also, don't forget that you can break up your xo into multiple smaller assemblies to make them fit into smaller spaces.