Lumber choice for cab build.

Discussion in 'Cabinets & Speakers' started by RJW, Dec 6, 2021.

  1. RJW

    RJW Member

    Joined:
    Nov 29, 2021
    Messages:
    39
    Likes Received:
    90
    I’ve started building cabs For my first build I’ve started a 112 (20x16x9”) with 1/2”MDF. I think next time I need AT LEAST 5/8” but probably thicker. I’m finding that the 1/2” is a small width to glue against or to drill into.

    What lumber do you prefer in your build? I’m mainly focused on the thickness and type from a builders standpoint. And maybe what types of joints you prefer. I don’t have a router table yet But maybe in the near future.

    Any other tips I may not have considered yet are welcome. I’m sure I’ll have plenty more cab build questions along the way.

    Edit: I’m starting with the 112 to figure out the process. I’ll eventually go bigger to a 212 and 412.
     
    Last edited: Dec 6, 2021
    GIBSON67 and fitz288 like this.
  2. Gutch220

    Gutch220 Well-Known Member

    Joined:
    Feb 19, 2018
    Messages:
    1,380
    Likes Received:
    1,372
    Location:
    NJ
    in general, the standard is 3/4" (13-ply) Baltic Birch plywood. you could get away with 5/8" baltic birch though.

    glued box joints are best

    you can use thinner MDF for the front baffle and back, just be sure to use T-nuts to hold the speakers, not screws into MDF.

    If you want a bare wood cabinet, stained, then go with solid hardwood. since you're not a business, price doesn't really matter
     
    Last edited: Dec 6, 2021
    tschrama, fitz288 and ibmorjamn like this.
  3. South Park

    South Park Well-Known Member

    Joined:
    Sep 14, 2019
    Messages:
    3,842
    Likes Received:
    3,586
    You can us 1/2 wood just put a strip of wood in the corners on the inside the 5/8 wood is to heavy . You can look at how kitchen cabinets are put together on the corners
     
    tschrama and fitz288 like this.
  4. fitz288

    fitz288 Well-Known Yinzer Gold Supporting Member

    Joined:
    Apr 7, 2020
    Messages:
    4,161
    Likes Received:
    10,682
    Location:
    the Burgh
    I am by no means a professional musician, my stuff never leaves the house, and I have no requirements for road worthiness.
    For my cab builds, I've used 5/8" ply on a 212 and 1/2" on some 112's & 110's.
    I've never used MDF, so I have no tips for construction techniques with that material.
    I do my corners with an interior cleat and a 1/4 round on the outside that's the thickness of the ply.
    This is easy to do with glue, screws, and a power sander.
    For cabs with a face frame, I used 1-1/2 poplar milled to size (router required for 3/4" round-over).
    Here's some threads with pics.
    DONE: Cabs Build for my Class5H | MarshallForum.com
    NAD? MG15 Micro Stack Cabs Build | MarshallForum.com
    Origin 212A Cab Build: Done | MarshallForum.com
     
    GIBSON67 likes this.
  5. pedecamp

    pedecamp Well-Known Member

    Joined:
    Dec 7, 2009
    Messages:
    18,383
    Likes Received:
    19,063
    I use 3/4" birch ply that has at least 9-13 layers, the more layers the better. And use 1/2" MDF for the front and back of the cab to absorb some of the sound waves so the cab doesnt sound boxy. Just glue it and screw it! :yesway:
     
    fitz288 likes this.
  6. Dogs of Doom

    Dogs of Doom >>> Moderator <<< Staff Member

    Joined:
    Aug 2, 2012
    Messages:
    26,420
    Likes Received:
    35,153
    Location:
    Los Angeles
    If you want a woodgrain cab like @Geeze builds, then 3/4" is best thickness. The type of wood is only limited to what's available & your woodworking skills, & tools...

    9" seems like a shallow cab. Many woods come in 12" strips, by certain foot lengths x's 3/4".

    The front baffle should be plywood. You could use MDF, or other fiberboard, but you want it to be durable. The back can be either ply or fiber as well.

    If you are skilled w/ wood & have tools/clamps, etc., you can cobble wood together to make baffles, rather than using sheet board. You'll need to have a decent shop for that.

    Easy, is to get some 12" board & make the sides, top & bottom, then use plywood for front/back. You just don't want a board that will develop a rattle, which is why people suggest a voidless wood like baltic birch. Ply's w/ voids, use fillers & the fillers shrink, dry up & rattle loose inside the plys...

    Look through a few of Geeze's threads & see what he does.
     
    Sapient, tschrama and fitz288 like this.
  7. Geeze

    Geeze Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,973
    Likes Received:
    4,186
    Location:
    Floating around TN in Marshall Heaven
    I second the question that @Dogs of Doom asked on the 9" depth. Are you building a closed or open back cab? Marshall did 9" on the early 1936 [closed back] 2x12's and moved to 12" soon after. I've heard two possibilities - stability with a 60 to 70lb amp on top or they sounded like crap. I suspect it was both.

    Where are you located?

    If you plan to tolex / cover them #2 pine, poplar or BB. If you run thinner than 3/4" you may need to run bracing across the sides to avoid unwanted [think POS car with earthquake level stereo vibrating to bits] resonance. The poplar can be sourced at Lowes - the long sides will need to be ripped square.

    The #2 pine and BB you'll need to source at specialty places. Another light weight reasonably priced is African mahogany which can be had in 12" to 16" widths and is generally a 'happy' wood AKA not prone to warp or cup issues. I've made some 1960B 4x12's out of it and like them a lot at any volume.

    For figured wood the sky is the $$ limit and how much effort you want to put up with. Cherry, sapelle, maple & walnut are easy to work but can be harder to source and can require planer / drum sander to work to the thickness you need.

    Feel free to ask all the questions you need - especially the ones you think are too stupid to ask.

    Russ
     
    Sapient and fitz288 like this.
  8. RJW

    RJW Member

    Joined:
    Nov 29, 2021
    Messages:
    39
    Likes Received:
    90
    I’m finding 9” is very shallow but not too shallow. The speaker is less than 6 inches deep. The plan was actually 10.5 but I had a few perfect 9” wide strips available.
     
    fitz288 likes this.
  9. RJW

    RJW Member

    Joined:
    Nov 29, 2021
    Messages:
    39
    Likes Received:
    90
    The plan on paper was 10.5” deep but I abandoned that bc I had few perfect 9” strips cut already. The plan is also closed back.

    I’m basing most of it off of an old Ibanez combo amp I converted to cab. Except it will be wider rather than taller.

    I had planned on tolex but if it’s problematic w MDF I’ll skip that part and do it next time with better lumber.
     
    fitz288 likes this.
  10. fitz288

    fitz288 Well-Known Yinzer Gold Supporting Member

    Joined:
    Apr 7, 2020
    Messages:
    4,161
    Likes Received:
    10,682
    Location:
    the Burgh
    Cab volume is more of a factor with the depth than the clearance for a speaker to fit.
    Part of the reason combos and smaller cabs are open / semi-open back.
    Since you're building it, you can experiment with what sounds best.
    Tolex on MDF is not a problem, Marshall does it all the time.
     
    RJW and Dogs of Doom like this.
  11. Dogs of Doom

    Dogs of Doom >>> Moderator <<< Staff Member

    Joined:
    Aug 2, 2012
    Messages:
    26,420
    Likes Received:
    35,153
    Location:
    Los Angeles
    MDF is a good candidate for tolex, since MDF is prone to chipping & water damage, the tolex will protect it...
     
    RJW and fitz288 like this.
  12. Matthews Guitars

    Matthews Guitars Well-Known Member

    Joined:
    Aug 17, 2019
    Messages:
    5,309
    Likes Received:
    8,060
    MDF is great for cabinets that will not see road usage or used outside in the rain. It's the affordable material of choice for stereo speakers, even fairly high end ones. It's good if you don't want the cabinet's own sound coloring the total sound.

    For guitar work, I only recommend plywood. Void free Baltic Birch when possible. It's available in metric thicknesses, most often. 13mm, 15mm, and 17mm, or 1/2", 5/8", and 3/4" equivalent.

    Very interestingly, in recent months, at least in the USA, the price of all common types of plywood absolutely soared. But not the price of slow selling stuff that was for special premium projects.

    Because of that, I got premium void free maple plywood for LESS than the cost of the cheapest exterior grade 1/2" plywood you could get!

    How often do you see that the PREMIUM option is also the CHEAPEST option?
     
  13. Tatzmann

    Tatzmann Well-Known Member

    Joined:
    Nov 8, 2021
    Messages:
    567
    Likes Received:
    807
    MDF or similar sawdustcrap has as much
    business in my cabinetworld as plywood
    has in my guitarworld, namely fckn none.
     
    Matthews Guitars likes this.
  14. Geeze

    Geeze Well-Known Member

    Joined:
    Jul 25, 2015
    Messages:
    1,973
    Likes Received:
    4,186
    Location:
    Floating around TN in Marshall Heaven
    One thing that has stuck with me from a HiFi tube & speaker manual on cab size it seems you can build them too small and too large but that there is a wide space in between the two extremes.

    Post your progress!

    Russ
     
    RJW and fitz288 like this.
  15. Matthews Guitars

    Matthews Guitars Well-Known Member

    Joined:
    Aug 17, 2019
    Messages:
    5,309
    Likes Received:
    8,060
    I love cabinets that are 14 inches deep from front to back. Every time I find a cabinet that has the low end punch that makes me grin, it's 14 inches deep. To me that is the sweet spot.
     
  16. RJW

    RJW Member

    Joined:
    Nov 29, 2021
    Messages:
    39
    Likes Received:
    90
    since this is my first attempt, it’s really to see what works best in my shop. I should mention I plan on making a bunch of different cabs since I already bought plenty of parts, tools, hardware, tolex, grill cloth, etc.
    I’ll consider that next build. It would certainly be easier to get a drill or screwdriver inside a deeper cab
     
    fitz288 likes this.
  17. RJW

    RJW Member

    Joined:
    Nov 29, 2021
    Messages:
    39
    Likes Received:
    90
    I’ll add some pics when I have more than a pile of woodpieces. Maybe when in starts to look like a box lol. I had to move everything inside my house due to the weather
     
    Geeze and fitz288 like this.

Share This Page