Enclosure bracing for 8 cu. ft. boxes questions?

[VolvoHeretic]

I have replaced the 1x3/4 inch particle board screw flanges for the removable front and back panels to my particle board 8 cubic foot base reflex enclosures with 2x2 bracing. They only had pieced together flanges with at least 8 inches of gaps and with no bracing along the corners, front to back of the boxes, only the side to side horizontal 2x4 brace. They also had about 2 inch fiberglass insulation on the bottom, back, and one side of the box.

I would like to glue the front or back panel on, preferably the front, and if so, I would add a removable section at the horn so I could remove the horn and driver without having to break them apart.

I wonder if I should add diagonal 2x2's on every panel to add more dampening bracing; 4 around the woofer and 2 each on each of the other panels? I haven't calculated the new net volume minus the drivers, but the gross volume is 8.0x cubic feet.

What do you all think?

Edit: Also, if I flipped the horn upside down, and raised the woofer up along the baffle, I could place the acoustical centers of the drivers closer together, and separate the woofer from the port more.

Edit 2: I just realized that the woofer is screwed down on the weak point on the driver and not along the cast motor structure flanges. I have just rotated the woofer 180 degrees after 35 years, can I just rotate them another 45 degrees or should I add 4 more threaded screw inserts and use all 8 screw holes?

[Alien_Shore]

I would like to glue the front or back panel on, preferably the front, and if so, I would add a removable section at the horn so I could remove the horn and driver without having to break them apart.

I would think that with some weather stripping and good screws, you wouldn't need to glue the baffle to the cabinet, it should hold air just fine if you use sufficient screws.

[Altec Best]

Volvo I think they are all good ideas..You can never go wrong with more bracing..The diagonal pieces on the side panels should be enough. I would personally glue the baffle on and leave the back with screws like Alien Shore said.. I would also make sure that you seal it real tight..You will be surprise how small a leak that can make a huge difference.. Remember you cabinet will be pressurized once the woofer gets cranking..If there are any leaks they will be found by your woofs..I think the insulation was fine the way or the amount that you had in it.As far as moving the woofer closer to the horn not a bad idea IMO especially if you sit close to the speakers.But not necessary I think..If you are 10 feet away they should be fine..What are your impressions of them ? Can you tell the sound is coming from 2 different locations ?

[VolvoHeretic]

Thanks for the replies Alien and AB, with this tin ear, I can't hear anything. For now, I am going to just add the mentioned diagonal 2x2 bracing and leave the baffle and rear panel removable with 1/2x3/16 inch foam seal and also seal all of the other bracing seams with PL400 sub-floor adhesive. I haven't listened to the stereo for a month and a half and don't want to waste more time building a new front baffle just yet.

[VolvoHeretic]

Ok, I added 0.682 cubic feet of 2x2 bracing to the 8.0729 cu. ft. boxes for a 7.391 cu. ft. gross. So, what is the cu. ft. of the 16" woofer? I will figure out the horn by myself. I re-stapled in the original 2" fiberglass insulation and sprayed it with Rustolium rubberized spay coating to try and seal the fiberglass (since I can't understand why fiberglass isn't banned like asbestos), like as seen on TV where the guy sprays a duck boat with a storm door cut into the bottom. I am also going to spray the 418's chrome dome with it also to dampen it, shouldn't I also cut a vent hole into it and add a cooling vent for it?

Pictures to follow.

[Phil-G]

don't worry about the small bits of floating glass you inhale. it should work it's way out thru your skin,,,, eventually

[Alien_Shore]

Ok, I added 0.682 cubic feet of 2x2 bracing to the 8.0729 cu. ft. boxes for a 7.391 cu. ft. gross. So, what is the cu. ft. of the 16" woofer?

The 15" 515 occupies 0.30 cubic feet. So you could estimate 0.35 cubic feet for your 16" woofer.
Although since you are already calculating to the 10,000th of accuracy, you may not want to estimate

[VolvoHeretic]

Lol, too funny guys, I just spit-out a shot of rum onto the computer. Sorry, but I am a structural engineering drafter and naturally carry all of my decimal points out... I am going to import and scale 2d pictures of the 32B horn and 802 driver and draw them in 3D and will also have their displacement carried out the the .0000th foot.