My Statement Monitors Project

[Ironman129]

Will 3/4" cabinet grade plywood work just as good as MDF? It's $28 for a 4'x8' sheet at HD.

[Dave W]

Will 3/4" cabinet grade plywood work just as good as MDF? It's $28 for a 4'x8' sheet at HD.

I would avoid any plywood from HD or Lowes. There are several reasons, but mainly it's just not up to quality required for a loudspeaker (voids, low ply count, thin face veneers, etc.). You'll also likely run into some serious tear-out problems if you are going down the kerf-cutting path for bending the sides.

[JonMarsh]

If you go with plywood, you want high density baltic birch ply or equivalents. Imported stuff is good, and a good US made product is ApplePly.

A couple of places to get premium ply in small quantities is Rockler and Woodcraft, if you have one of their stores within driving distance. I've bot both within 25 miles.

[Ironman129]

Ok, so I'm almost done with all the cutting, Dado, and sanding to get ready to start gluing. I decided to try kerf cutting the MDF and I have to admit I don't see why people don't like it. It took me about 5 mins per piece and do be honest was a lot easier for me than doing any of the other cutting. Anyway, I'll start posting more pics as I start getting them assembled.

[Ironman129]

I'm planning on letting it dry over night filling the kerf cuts with titebond II. Any advantage to mixing it with the saw dust from all the cutting? I believe I have enough to use it by itself, but if it will fill better being mixed I'll do that. It's nice to see it starting to take shape!
:B

[Sylvan]

Looking good!

[Ironman129]

Rookie mistake #187

DO NOT use wood glue for filling kerf cuts! It will promptly run out of the cuts and on to your work bench and everything else. :M I found that mixing it with saw dust to thicken it will help keep it in place. Now the question is how long do i let it dry? I'm going to let it dry over night, but do you think it will more than 12 hours?

I need to get working on my XOs!

[Hdale85]

Yeah, kerf cuts kind of suck. If I ever do a curved cabinet again I'll design it to be multiple layers of 1/8-1/4" ply from the start. Don't have to worry about filling kerfs and what not and can do a bigger radius.

[Ironman129]

I was getting ready to glue the side braces and back together and there are gaps almost 1/8" in some parts, and doesn't seem to fit well with the braces. I'm probably going to get some more MDf and recut it. I could use bondo to fill everything, but if you look closely enough, you can tell it;s not a nice smooth curve.

Next dilemma. Paint or veneer? I know this question is asked alot. I found what looks like a nice HVLP Kit on amazon. But if I paint, I won't have the wood grain look to it. Any suggestions from those more experienced?

[Ironman129]

So I have the cabinets glued together. As I mentioned before, when I did the initial curve with the kerf cuts it didn't seem t keep it's shape as there as some huge gaps in the top and bottom. Next time I won't glue until I am ready to just glue the sides to the cabinet. Now I know I still have a lot of sanding to do but I figured I could either fill it with bondo (I have a few mistakes that can use that) or cover it with 1/8" hardboard top and bottom. Any recommendations?

I know in the original design It calls for a 3/4" roundover. I purchased the bit, but I was planning on continuing the curve through the baffle. Should I still do the roundover if it's not a straight edge on the sides of the baffle?

Forgive the amateurish nature of the build. This if my first DIY and the tools I had at my disposal was a handheld rotary tool and a table saw. The experience of doing this build makes me want to do it again, only better. I'm half tempted to scrap it and start over. Most of the mistakes are covered and no one will notice them, but I know they're there. I am planning to use a veneer and that should make it look nice, but It's probably the OCD of just knowing the mistakes that are there! :M

[yzracer14]

With gaps that big, I don't think bondo is the best choice. Some sort of epoxy would better fill those gaps. After that, I would laminate with tempered hardboard.

[Ironman129]

With gaps that big, I don't think bondo is the best choice. Some sort of epoxy would better fill those gaps. After that, I would laminate with tempered hardboard.

If I put a 1/8" Hardboard on top and bottom would that work? Then veneer over that? The inside of the cabinets are sealed. I went over all the internal joints with wood glue to make sure.

I also seemed to have forgot to order the .25 mH 20 gauge inductor for the crossover, so I am stuck a little there too :M . I am trying to find a store here in Charlotte that would have it.

[yzracer14]

I honestly don't know. To me, it looks like the cab may not be structurally sound due to the gaps in your pics. Which is why I suggested epoxy. Epoxy is intended for larger gaps like that and it will give you back some strength as well as seal any leaks that you may not be able to see.

That's what I would do, but if you're sure it's sealed up well enough, then simply laminating hardboard should work just fine.

[Coconutout]

Hi Ironman I hope i mentioned this before but have you thought about cabinet volume displacement from those motor caps? they'll probably take up more than 10% of the volume which would change the cabinet tuning. I don't know the details of it though. ;p

[Ironman129]

XO help

Coconut,

Your inbox is full. I did add to the volume since the motor run caps are BIG! also I was wondering if anyone could answer a couple of questions for me. With the motor run caps can they be placed on their sides on the cross overs or do they need to be upright? Can the XO boards be placed on the foam, or should they be screwed or Velcro'd to the cabinet? Also I am planning the XOs for the 2RCC as well and wanted to get the same types of caps for the mids and woofers. If I run them in parallel do I need to have the same values? I need 56uf and was wondering if I could to a 50uf and a 6uf. Again I appreciate the help.

Scott

[meb46]

Ironman - the gaps in the top to side panels are pretty significant and I would question if these are doing to be strong enough. Filling these with bond will not increase the strength obviously and the added 1/8 MDF will also provide minimum added strength. I would be inclined to remove the sides and try them again. You need to be careful when you put the ratchet straps on curved sides as they can close up and pull the sides in strange directions. On my last curved sides project I did, I used pre-pressed 25mm ply. Even these didn't fit onto cabinets correctly and even with about 10 ratchet straps they eventually pulled away. I think the most robust way to do the curved sides is as suggested early, will multiple thin layers of MDF and let each layer dry over night before moving onto the next layer etc. I'm not a fan of kerf cutting as I think it provides a weaker side panel and you can't really stack up layers as they would then create voids. Curved sides are a challenge in themselves... I learnt the hard way!

[Ironman129]

I'm actually redoing the whole cabinet. I'll finish these just for the experience but there are too many mistakes for me to live with. The next round I'll do together with the 2RCC I can still use the XOs in the new cabinets plus it will give me a chance to test the drivers.

[Coconutout]

hi ironman. you can mount those motor run caps anyway you like along with the rest of the crossover components be it on a piece of mdf, pegboard whatever. but as for simply laying them on the foam, not recommended unless you plan to never move the speakers from the moment you place in the crossover. those motor run caps are exactly as the name advertises- caps meant for motors- in vehicles, air conditioners ect. as such, they're meant to withstand serious punishments and mounting them upside down or whatever wouldn't even constitute as a problem.

i've been checking regularly on your thread to check your progress since yours now share the exact components as mine. i can't wait to hear your impressions of them!


how much did the cabinets cost you btw? if i had an extra cabinet i'd build another pair of statmenets in a heartbeat. cabinets are always the most time consuming part.

[Ironman129]

The XOs will be on peg board, but I didn't know if I could just set the peg board on the foam or if I should secure it to the cabinet somehow. I will need to split them up in to at least 2 boards, maybe three. I definitely won't be able to pull them through the woofer cut out so I don't know if I should make it a removable baffle.

[Coconutout]

if you could somehow divide the crossovers into two or three sections, and dexterous enough to reconnect them from inside, i think it's quite possible to fit them through the woofer hole. or yes, removable baffle.

you would wanna secure the pegboard to the enclosure with screws otherwise they'll shift around and eventually break connections.