DIY Cabinet Making

Caper · January 29th, 2005, 02:35 PM

I'm thinking about building an ext. cabinet with a JBL K120 for my SFPR, anyone have any DIY sites bookmarked?

skip62 · January 30th, 2005, 12:30 AM

Celestion
Go to Dr Decibel's Secret's and select "Guitar cabinet design"

Not much, but helpful. I built 2 cabinets, it was a lot more work than I thought and I still have some sanding and covering to do.

Good luck.

Rob DiStefano · January 30th, 2005, 08:09 AM

At the least, a somewhat subjective stuff.

IMO, the recipe for a good cab involves either 3/4" solid pine (for a lightweight and resonant box) or 3/4" birch ply (for a heavy and rugged cab that's definitely less resonant). I prefer cabs that are uncovered, just stained and clear coated - again, to maximize wood resonance. The actual box dimensions aren't that important, IMO - I prefer using 12" wide (11-1/4" actual) 3/4" pine boards, and the finished cab width and height are at best arbitrary. A "floating" baffle is a good way to hang the speaker(s), using a pair of 3/4" hardwood baffle cleats - I like stout 1/2" birch ply baffles, some folks like more flexible 3/8" ply baffles. I add a front 1/4" baffle ply frame and a full grille (cloth is nice but wicker cane is wicked good!). You can seal off the cab, but I much prefer an airy open back, YMMV.

Now to the cab sides joints - for simplicity, you can lap 'em and use square corner cleats with screws and glue ... or a glued box joint and triangle cleats ... or borrow/buy a dovetail jig and create a super strong box sans corner cleats.

IMO, bottom line, ya don't need to get hung up on 'design theory' for speaker or combo cab building - it ain't rocket science, that's for sure. What makes a 'good cab' is mostly in the speaker and a decent solid box, IMO.

If you wish a detailed cost/schedule Excel spreadheet outlining my dovetail cab building process, just shoot me an email or PM.

Caper · January 30th, 2005, 08:19 AM

Thanks skip got it bookmarked, a lot of helpful hints there.

Caper · January 30th, 2005, 08:37 AM

Rob, thanks for the tips. I am thinking open back design. I'll be going with the dovetail joints, probably just take the material to a cabinet shop and have them make and glue the joints. I was looking around Home Depot last night, checking prices on birch plywood, $48 for 3/4" 4'x8' sheet or you can buy it by 1/2 or 1/4 sheet. They also sell small sheets of MDF as well. The cabinet will be the same size as the PR, I was wondering is it recommended to use pine in cabinet design if the amp will be sitting on top of it? Thanks.

Rob DiStefano · January 30th, 2005, 09:09 AM

Quote:

Originally Posted by Caper

Rob, thanks for the tips. I am thinking open back design. I'll be going with the dovetail joints, probably just take the material to a cabinet shop and have them make and glue the joints. I was looking around Home Depot last night, checking prices on birch plywood, $48 for 3/4" 4'x8' sheet or you can buy it by 1/2 or 1/4 sheet. They also sell small sheets of MDF as well. The cabinet will be the same size as the PR, I was wondering is it recommended to use pine in cabinet design if the amp will be sitting on top of it? Thanks.

Make sure the 1/2" birch ply is at least 5 lam, 7 lam is better yet.

If you are dovetailing (half blind dovetail) the cab sides, don't use plywood, use solid 3/4" pine board. IMO, 3/4" solid pine cabs are best for lightness & resonance - a dovetailed box is Extremely Strong, even without gluing.

You must use FLAT, uncupped 3/4" pine boards. Knots are optional - unknotted cabinet-grade pine will cost lots more. Knots can be stabilized by soaking in a good quality thin CYA glue.

tjalla · January 30th, 2005, 09:26 AM

I dunno if there'd be a market for it, but I've always been curious as to whether cab builders (who have the necessary tools) would sell "pre-cut", mass produced, dovetail planks/baffles/grillcloth that potential DIYers could assemble themselves using screws and glue.

Kinda like the many 5E3 amp kits around, this would be "cab-kits" with lower shipping and labor costs would making such a worthwhile venue all around, perhaps.

Or maybe I'm just wrong.

Rob, any thoughts?

Cheers,
Trev

Rob DiStefano · January 30th, 2005, 09:40 AM

Quote:

Originally Posted by tjalla

I dunno if there'd be a market for it, but I've always been curious as to whether cab builders (who have the necessary tools) would sell "pre-cut", mass produced, dovetail planks/baffles/grillcloth that potential DIYers could assemble themselves using screws and glue.

Kinda like the many 5E3 amp kits around, this would be "cab-kits" with lower shipping and labor costs would making such a worthwhile venue all around, perhaps.

Or maybe I'm just wrong.

Rob, any thoughts?

Cheers,
Trev

Yep, I've sold more than a few DIY dovetailed cab sides, which just need to get press-fit together. Not everyone has a half blind dovetail jig, nor an understanding of the somewhat complicated dovetailing process. So, the builder gets "the box" and can add the baffle board, grille, cleats, rear panels, etc., which are much easier to accomplish with simple tools. Plus, shipping of the knocked-down cab sides is lots easier/cheaper!

telel6s · January 30th, 2005, 09:47 AM

Rob,

I'm planning out a cabinet for my Mission Deluxe and a 15" speaker. Reading a bunch of your previous posts and your website have been a big help. Thanks.

Question for you on the cane grill. There's a post on TDPRI about how you do that when the cane is behind the baffle board, and then use a "tone ring" to mount the speaker behind that. What I'd prefer is the look of the full baffle being covered by the cane (like in the picture of your first post in this thread).

Do you use any spacer on the front side of the baffle for that or is the cane laying directly against the baffle? Also, is the speaker then mounted directly to the baffle or do you still us the tone ring?

And while I have your attention, is the 1/2" birch ply still thick enough to hold the 15" speaker or should I go to 5/8 or 3/4 due to the bigger hole in the board?

Thanks much.

Joe

Rob DiStefano · January 30th, 2005, 10:10 AM

Quote:

Originally Posted by telel6s

...

Question for you on the cane grill. There's a post on TDPRI about how you do that when the cane is behind the baffle board, and then use a "tone ring" to mount the speaker behind that.

Yes, a "speaker spacer" - to add distance between the cone and the grille."

What I'd prefer is the look of the full baffle being covered by the cane (like in the picture of your first post in this thread).

That's the way I do it, these dayze - no more behind-the baffle "retro radio look".

Do you use any spacer on the front side of the baffle for that or is the cane laying directly against the baffle?

There's a frame of 1/4" x 1" birch ply that's glued and stapled around the front perimeter of the baffle board, to add distance between the cone and the grille ...

Also, is the speaker then mounted directly to the baffle or do you still us the tone ring?

Directly to the baffle - no speaker spacer needed or wanted.

And while I have your attention, is the 1/2" birch ply still thick enough to hold the 15" speaker or should I go to 5/8 or 3/4 due to the bigger hole in the board?

A 1/2" birch ply baffle will hold any speaker sizes, with ease - even a pair of massive 15" bass speakers for a 2x15 cab.

Thanks much.

Joe

Yer welcome!

tjalla · January 30th, 2005, 10:35 PM

And I wonder how much it would cost to ship 4 planks over to Australia - it seems to cost an arm and a leg to have someone do this in pine over here.

Might drop you a line sometime Rob. I've got this lovely Weber 15A150 that has no home at the moment.

Cheers,
Trevor

Doc · January 31st, 2005, 09:06 PM

The trick with cane is soaking it for 30 minutes or so in water. It softens and expands. As it dries it tightens. I like to use 3/4 pine for the cabs as well.

Dale

Led Hed · January 31st, 2005, 09:20 PM

I asked this same question about cab kits just a few days ago, and pretty much received no response. In case you decide not to build your own, I found a couple places that build nice looking cabs that you can order unloaded and put in the speaker of your choice.

http://www.avatarspeakers.com/

http://www.jdesigncabs.com/

Doc · January 31st, 2005, 09:38 PM

Sorry about the no response! I guess I missed it. Old age here I guess.

David Barnett · January 31st, 2005, 09:41 PM

www.mojotone.com also has empty cabinets in a variety of styles.

Rob DiStefano · February 1st, 2005, 06:28 AM

Quote:

Originally Posted by Doc

The trick with cane is soaking it for 30 minutes or so in water. It softens and expands. As it dries it tightens. I like to use 3/4 pine for the cabs as well.

Dale

I use Country Seat superfine prewoven wicker cane. It takes a good hour of soaking in water that starts off really HOT to loosen up the fibers. Drip out as much water as possible, then staple one side to the BACK (not the edge!) of the baffle board, and *stretch* it as much as possible to the opposite side/back of the baffle board and staple (yes, you do want to have pre-finished the baffle board with something that repels water - it's also nice to spray paint the front of the baffle in flat black). It'll feel like the cane won't stretch, but it does just a little and that's crucial to getting a drum-tight cane grille. Stretch and staple the other sides Trim off any excess cane, and neatly fold and staple the corners (hint: you MUST round off ALL the edges and *corners* of the baffle board when cane grilling!). Trim the corner folds. Allow a few hours for the cane to dry drum tight. The next day, you can mist on a few light coats of clear to seal the cane (both sides). I also wick in some thin CYA to the corner folds to ensure they won't ever unfold - probably overkill, though.

4mal · February 3rd, 2005, 08:13 PM

and do you like it ? I have a jointech fence for for my table saw / router tables which is cool for detail stuff but I'm thinking that a dedicated jig might be a better bet. Thanks, Mal

Rob DiStefano · February 3rd, 2005, 08:55 PM

Quote:

Originally Posted by 4mal

and do you like it ? I have a jointech fence for for my table saw / router tables which is cool for detail stuff but I'm thinking that a dedicated jig might be a better bet. Thanks, Mal

Porter-Cable dovetail jig, the older model. It works just fine for me, though I did make a modification to the front board clamping system to improve the boad-to-board consistency. My jig is setup to only work with 3/4" thick board stock (1" yard lumber), and I'd never mess with that setting.

More important than the jig is to have a dedicated router that's set up to work with yer jig - once you dial in the router bit height, you don't wanna ever take that bit out ... trust me on that one!

And, you've got to understand the dovetail process - how to label the boards for grain follow-through and how they're oriented for each step of the process. It ain't all that easy to understand - I eventually wrote it all up in a spreadsheet, printed it out, and keep it taped to the shop wall. Now I can dovetail a box in about 15 minutes, and it's perfect.

Lastly, all bets are off if yer board stock is cupped more than 3/32" for a 12" wide board!

I love a nicely dovetailed box as much as I love the smell of pine dust in the morning.

For a picture tutorial of my dovetail cab building, visit this page - www.frettech.com/rfc/cab/

dean · February 3rd, 2005, 09:55 PM

Definitely check out the "Enclosures" board on the Weber site:

http://www.webervst.com/vstbbs/bbs.html

There is always some decent ongoing discussions, and there are some good links at the top of the board to help you out with some of the nitty-gritty.

And, of course, Rob's stuff - he makes it look so easy!

Dean

4mal · February 4th, 2005, 12:50 PM

Thanks Rob. That must be the 12 " model of the Porter Cable. I was at Woodcrafters a couple of days ago and saw their 24 ". At 400 bucks it is a bit pricey but it is beautiful fixture. I know what you mean about getting your router dialed in. I use a thing called the 'bladeguage' to help on the height. It is kind of a stairsteppy looking thing with a large magnet base, a ground wire, battery and led. You bring the bit up to touch and when it does the led glows. You get a very accurat, 'rough' setting. I still scrap some wood to be sure that I'm dialed though ...

Rob DiStefano · February 4th, 2005, 12:57 PM

Quote:

Originally Posted by 4mal

Thanks Rob. That must be the 12 " model of the Porter Cable.

Yep - I've no need for wider board widths.

I was at Woodcrafters a couple of days ago and saw their 24 ". At 400 bucks it is a bit pricey but it is beautiful fixture. I know what you mean about getting your router dialed in. I use a thing called the 'bladeguage' to help on the height. It is kind of a stairsteppy looking thing with a large magnet base, a ground wire, battery and led. You bring the bit up to touch and when it does the led glows. You get a very accurat, 'rough' setting. I still scrap some wood to be sure that I'm dialed though ...

I use a similar "rough in" gauge - but the final setting might take as many as 3 or 4 tries to nail the bit height perfectly. Oh yeah, GOT to be a carbide bit, too!

4mal · February 4th, 2005, 02:03 PM

I need to think through the length issue. I might want to do a chest someday - shame you can't rent the darned thing! I've been having good luck with the bits I got at Jointech. Their stuff is pretty good. They seem to be about the same grade as the individual Porter Cable bit's I bought and were a heck of a lot cheaper. I would not do their floating tables thing again though. I bought the phenolic replacement tops and they are a pain in the butt. I figured that living out here in rain land those tops would weather in my garage better than most. The probably will, now having them stay in alignment is another story ... That would be my particular 'woodworking crss to bear' ...

The Fence is friggin' amazing though. It's accuracy is limited more by my ability than it's ...

Rob DiStefano · February 9th, 2005, 10:07 AM

If you're using my cab building Excel spreadsheet, please be aware that the dovetail board labeling arrangement is incorrect.

The process will still produce a perfectly dovetailed cab, but the order of front and back and grain follow-through will be incorrect. This is a minor issue, but one that needs correcting.

Please email me for an updated cab spreadsheet or see below ...

Sorry,
Rob.

Jerry J · February 10th, 2005, 02:22 PM

Rob,

I like colors and after reading your post about wood finishes resonating better than covered cabinets, I think I might stain the bare wood for two projects I'm FINALLY starting - an 18 Watt 2x12 combo and a replacement cabinet for my SFVC (big enough to fit a 12" speaker and a little deeper).

Have you tried colors stains on your wood cabinets? I like the colors Marshall uses on their amps and would like to get close to one of those.

As for the clear coat, do you use lacquer or a polyureathane for greater durability?

Finally, a bit of advice about HD or Lowes plywood. I have found really nice select pine for my cabinets at HD and Lowes but found that their birch plywood was not voidfree. I ended up getting a "Void-Free" piece of birch plywood from a high quality lumber yard in Alexandria (Smoots - which has been in business for close to 200 years). I got a 5'x5' piece for $25 and its definitely void-free. The piece of plywood from Lowes will go back.

January 29th, 2005, 02:35 PM	#1 (permalink)
Caper Friend of Leo's Join Date: Mar 2003 Posts: 2,169 7 Photos	DIY Cabinet Making I'm thinking about building an ext. cabinet with a JBL K120 for my SFPR, anyone have any DIY sites bookmarked?

January 30th, 2005, 09:26 AM	#7 (permalink)
tjalla Tele-Afflicted Join Date: Mar 2003 Location: Perth, Western Australia Posts: 1,947 7 Photos	IKEA-ised cabinet building? I dunno if there'd be a market for it, but I've always been curious as to whether cab builders (who have the necessary tools) would sell "pre-cut", mass produced, dovetail planks/baffles/grillcloth that potential DIYers could assemble themselves using screws and glue. Kinda like the many 5E3 amp kits around, this would be "cab-kits" with lower shipping and labor costs would making such a worthwhile venue all around, perhaps. Or maybe I'm just wrong. Rob, any thoughts? Cheers, Trev

January 30th, 2005, 09:47 AM	#9 (permalink)
telel6s Tele-Afflicted Join Date: Jun 2003 Location: Northern Virginia Posts: 1,180 80 Photos	Cane Grill question for Rob Rob, I'm planning out a cabinet for my Mission Deluxe and a 15" speaker. Reading a bunch of your previous posts and your website have been a big help. Thanks. Question for you on the cane grill. There's a post on TDPRI about how you do that when the cane is behind the baffle board, and then use a "tone ring" to mount the speaker behind that. What I'd prefer is the look of the full baffle being covered by the cane (like in the picture of your first post in this thread). Do you use any spacer on the front side of the baffle for that or is the cane laying directly against the baffle? Also, is the speaker then mounted directly to the baffle or do you still us the tone ring? And while I have your attention, is the 1/2" birch ply still thick enough to hold the 15" speaker or should I go to 5/8 or 3/4 due to the bigger hole in the board? Thanks much. Joe __________________ Mama always said, "A little tone is good for the soul."

January 30th, 2005, 10:35 PM	#11 (permalink)
tjalla Tele-Afflicted Join Date: Mar 2003 Location: Perth, Western Australia Posts: 1,947 7 Photos	Hmmm... And I wonder how much it would cost to ship 4 planks over to Australia - it seems to cost an arm and a leg to have someone do this in pine over here. Might drop you a line sometime Rob. I've got this lovely Weber 15A150 that has no home at the moment. Cheers, Trevor

January 31st, 2005, 09:06 PM	#12 (permalink)
Doc Tele-Holic Join Date: Aug 2003 Location: South Dakota Posts: 981	The trick with cane is soaking it for 30 minutes or so in water. It softens and expands. As it dries it tightens. I like to use 3/4 pine for the cabs as well. Dale __________________ Guitars: Teles, LP, others. Amps: El Diablo, Richter 5E3, 5E3 Head, Traynor Bass Master II, Epi Jr Head, Gretsch/Supro, 60's Univox and others. Current Board-Guitar>Tuner>Java Boost> Huckleberry>Fuzz Head>Top Fuel>SFX-03> Keeley Comp>Clone Chorus>FL3> Amp

January 30th, 2005, 12:30 AM	#2 (permalink)
skip62 Tele-Meister Join Date: Aug 2003 Location: Dallas, TX Posts: 337	Celestion Go to Dr Decibel's Secret's and select "Guitar cabinet design" Not much, but helpful. I built 2 cabinets, it was a lot more work than I thought and I still have some sanding and covering to do. Good luck.

January 30th, 2005, 08:09 AM	#3 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 63 Posts: 4,915	At the least, a somewhat subjective stuff. IMO, the recipe for a good cab involves either 3/4" solid pine (for a lightweight and resonant box) or 3/4" birch ply (for a heavy and rugged cab that's definitely less resonant). I prefer cabs that are uncovered, just stained and clear coated - again, to maximize wood resonance. The actual box dimensions aren't that important, IMO - I prefer using 12" wide (11-1/4" actual) 3/4" pine boards, and the finished cab width and height are at best arbitrary. A "floating" baffle is a good way to hang the speaker(s), using a pair of 3/4" hardwood baffle cleats - I like stout 1/2" birch ply baffles, some folks like more flexible 3/8" ply baffles. I add a front 1/4" baffle ply frame and a full grille (cloth is nice but wicker cane is wicked good!). You can seal off the cab, but I much prefer an airy open back, YMMV. Now to the cab sides joints - for simplicity, you can lap 'em and use square corner cleats with screws and glue ... or a glued box joint and triangle cleats ... or borrow/buy a dovetail jig and create a super strong box sans corner cleats. IMO, bottom line, ya don't need to get hung up on 'design theory' for speaker or combo cab building - it ain't rocket science, that's for sure. What makes a 'good cab' is mostly in the speaker and a decent solid box, IMO. If you wish a detailed cost/schedule Excel spreadheet outlining my dovetail cab building process, just shoot me an email or PM.

January 30th, 2005, 08:19 AM	#4 (permalink)
Caper Friend of Leo's Join Date: Mar 2003 Posts: 2,169 7 Photos	Thanks skip got it bookmarked, a lot of helpful hints there.

January 30th, 2005, 08:37 AM	#5 (permalink)
Caper Friend of Leo's Join Date: Mar 2003 Posts: 2,169 7 Photos	Rob, thanks for the tips. I am thinking open back design. I'll be going with the dovetail joints, probably just take the material to a cabinet shop and have them make and glue the joints. I was looking around Home Depot last night, checking prices on birch plywood, $48 for 3/4" 4'x8' sheet or you can buy it by 1/2 or 1/4 sheet. They also sell small sheets of MDF as well. The cabinet will be the same size as the PR, I was wondering is it recommended to use pine in cabinet design if the amp will be sitting on top of it? Thanks.

January 31st, 2005, 09:20 PM	#13 (permalink)
Led Hed TDPRI Member Join Date: Mar 2003 Location: Eugene, OR Posts: 31	Extension Cabs I asked this same question about cab kits just a few days ago, and pretty much received no response. In case you decide not to build your own, I found a couple places that build nice looking cabs that you can order unloaded and put in the speaker of your choice. http://www.avatarspeakers.com/ http://www.jdesigncabs.com/

January 31st, 2005, 09:38 PM	#14 (permalink)
Doc Tele-Holic Join Date: Aug 2003 Location: South Dakota Posts: 981	Sorry about the no response! I guess I missed it. Old age here I guess. __________________ Guitars: Teles, LP, others. Amps: El Diablo, Richter 5E3, 5E3 Head, Traynor Bass Master II, Epi Jr Head, Gretsch/Supro, 60's Univox and others. Current Board-Guitar>Tuner>Java Boost> Huckleberry>Fuzz Head>Top Fuel>SFX-03> Keeley Comp>Clone Chorus>FL3> Amp

January 31st, 2005, 09:41 PM	#15 (permalink)
David Barnett Poster Extraordinaire Join Date: Mar 2003 Location: LIttle Rock, AR Age: 52 Posts: 5,494	www.mojotone.com also has empty cabinets in a variety of styles.

February 3rd, 2005, 08:13 PM	#17 (permalink)
4mal Friend of Leo's Join Date: Mar 2003 Location: The Gorge Posts: 2,198	Rob - whose Dovetail jig are you using and do you like it ? I have a jointech fence for for my table saw / router tables which is cool for detail stuff but I'm thinking that a dedicated jig might be a better bet. Thanks, Mal

February 3rd, 2005, 09:55 PM	#19 (permalink)
dean Friend of Leo's Join Date: Mar 2003 Location: Twin Cities, Minnesota Age: 60 Posts: 2,042	Check out . . . Definitely check out the "Enclosures" board on the Weber site: http://www.webervst.com/vstbbs/bbs.html There is always some decent ongoing discussions, and there are some good links at the top of the board to help you out with some of the nitty-gritty. And, of course, Rob's stuff - he makes it look so easy! Dean __________________ "I used to be clueless, but I've turned that situation around 360 degrees."

February 4th, 2005, 12:50 PM	#20 (permalink)
4mal Friend of Leo's Join Date: Mar 2003 Location: The Gorge Posts: 2,198	Thanks Rob. That must be the 12 " model of the Porter Cable. I was at Woodcrafters a couple of days ago and saw their 24 ". At 400 bucks it is a bit pricey but it is beautiful fixture. I know what you mean about getting your router dialed in. I use a thing called the 'bladeguage' to help on the height. It is kind of a stairsteppy looking thing with a large magnet base, a ground wire, battery and led. You bring the bit up to touch and when it does the led glows. You get a very accurat, 'rough' setting. I still scrap some wood to be sure that I'm dialed though ...

February 4th, 2005, 02:03 PM	#22 (permalink)
4mal Friend of Leo's Join Date: Mar 2003 Location: The Gorge Posts: 2,198	I need to think through the length issue. I might want to do a chest someday - shame you can't rent the darned thing! I've been having good luck with the bits I got at Jointech. Their stuff is pretty good. They seem to be about the same grade as the individual Porter Cable bit's I bought and were a heck of a lot cheaper. I would not do their floating tables thing again though. I bought the phenolic replacement tops and they are a pain in the butt. I figured that living out here in rain land those tops would weather in my garage better than most. The probably will, now having them stay in alignment is another story ... That would be my particular 'woodworking crss to bear' ... The Fence is friggin' amazing though. It's accuracy is limited more by my ability than it's ...

February 9th, 2005, 10:07 AM	#23 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 63 Posts: 4,915	REVISION ... If you're using my cab building Excel spreadsheet, please be aware that the dovetail board labeling arrangement is incorrect. The process will still produce a perfectly dovetailed cab, but the order of front and back and grain follow-through will be incorrect. This is a minor issue, but one that needs correcting. Please email me for an updated cab spreadsheet or see below ... Sorry, Rob.

February 10th, 2005, 02:22 PM	#24 (permalink)
Jerry J Tele-Holic Join Date: Mar 2003 Location: NoVa Posts: 660	Rob - have you tried color stains?? Rob, I like colors and after reading your post about wood finishes resonating better than covered cabinets, I think I might stain the bare wood for two projects I'm FINALLY starting - an 18 Watt 2x12 combo and a replacement cabinet for my SFVC (big enough to fit a 12" speaker and a little deeper). Have you tried colors stains on your wood cabinets? I like the colors Marshall uses on their amps and would like to get close to one of those. As for the clear coat, do you use lacquer or a polyureathane for greater durability? Finally, a bit of advice about HD or Lowes plywood. I have found really nice select pine for my cabinets at HD and Lowes but found that their birch plywood was not voidfree. I ended up getting a "Void-Free" piece of birch plywood from a high quality lumber yard in Alexandria (Smoots - which has been in business for close to 200 years). I got a 5'x5' piece for $25 and its definitely void-free. The piece of plywood from Lowes will go back.