Baffle Material And Type Question

Discussion in 'Cabinets & Speakers' started by KraftyBob, Jul 9, 2018.

  1. KraftyBob

    KraftyBob Well-Known Member

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    I'm going to start the rebuild project on my speaker cab pretty soon. I'm converting a headless MG250DFX 2x12 into a 1x12 cab for my DSL40C so I need to make a new baffle. I was going to use 3/4" Birch ply and reached out to a friend of mine who has a nice home shop to see if he can help me with the speaker cut out. He said he has Maple I can have and that it's characteristics are somewhat similar to Birch. He thinks he might have both solid and ply.

    I did some checking and from what I can find Maple has a similar high end resonance of pine and the low end thump of birch ply. The only drawback was weight but for my project it's just the baffle so I'm not concerned about that.

    Pretty much everything I read defaults to birch for the baffle and there isn't much else on maple. Also, a lot seem to suggest ply vs solid. I don't know if it's a cost thing, or functional, or both?

    Part of me is wondering if I'm over thinking it because the rest of the cab is MDF. I'm just trying to avoid having to redo it if maple is not a good option.

    What say you Marshall forum?
     
  2. GIBSON67

    GIBSON67 Well-Known Member

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    Maple should be good enough! But in what thickness? Half inch would be a minimum, I would think.

    I think the solid vs ply thing would be because most solid wood planks only come in 12 in wide boards, so ply could be anything wider, basically.
     
  3. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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    build a whole new cab w/ maple... :)...

    The reason for ply vs solid, is warpage. Plywood has less tendency to warp, once assembled & if it does, it won't disfigure the cab, or leak air. If the baffle warps it will either leak air, of disfigure the speaker.

    Birch & maple are both used for drums, as a standard.

    Look at @Geeze 's cab's he's built. Sell the MG for $50 empty (if you can get it) to pay for the wood. You'll be much more happy, than cutting down an MDF cab...
     
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  4. KraftyBob

    KraftyBob Well-Known Member

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    I'm using 3/4". The baffle will be about 17 1/2" x 26" so it needs to be strong. Dogs of Doom echoed what I've been finding online about solid woods while researching this afternoon - warping. 26" is probably to large a span for a solid wood - even if it's several pieces - because if it warps due to humidity/temp changes, and it pulls on the speaker frame it could cause the voice coil to rub.

    @Dogs of Doom - I originally thought about building a cab because there aren't many 1x12 options wide enough for the DSL40's 24" width. The problem is I'm very limited on time for the foreseeable future so that could easily take 6, maybe 9 months to complete. When I came across the headless MG online I grabbed it because it would save months on this project. Heck, I bought the MG over a month ago and am now just getting to the planning stage. Time building the cab means less time playing guitar so I'll take playing over building right now.

    BTW, if you're thinking that I can enlist my friend who has the shop to help build the cab - he's also my jamming buddy and we've had little time for that lately. Maybe some point in the future when I have more down time.

    So to answer my questions: If my friend has Maple ply I'll use that. If not, I'll buy the birch ply.

    Thanks for your responses.
     
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  5. Geeze

    Geeze Well-Known Member

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    If your buddy has maple ply - it will work fine. Solid - if you are 5/8" to 3/4" you'll probably be fine unless you're in an area with large humidity swings. I'd cut the solid maple into planks that cover at least a 1/3 of the height and reverse the center section and glue with a Titebond II or III type glue. I only edge glue after experimenting with dados, biscuits and dowels - not found it necessary with Titebond. Just need to rip the edges square and straight.

    I've done some very crazy shit with solid wood strips, chunks and planks for guitar cabinets and not had anything warp or delaminate.

    Russ
     
  6. KraftyBob

    KraftyBob Well-Known Member

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    I’m back... Just heard from my friend. After a quick look at his stock the 3/4” Maple ply he has is only 15” wide. I need 17 1/2”. He said he could biscuit join two pieces. He does have 1/2” & 1/4” maple ply that would fit and he could glue them together for a 3/4” piece.

    He also has 3/4” Red Oak that would fit but I know very little about this. I did read that Red Oak has no acoustic properties - but some say that’s good because you don’t want the wood to color the sound. Someone also said that if red oak is not properly sealed it gives off a gas that corrodes. Said it ruined a friends speakers. Sounds like BS to me but who knows - stranger things have happened.

    Thinking I’ll just go back to my original plan and get a sheet of birch ply.

    Thoughts?
     
  7. KraftyBob

    KraftyBob Well-Known Member

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  8. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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    ½" would work for a 1x12. It's an open back MDF cab, right?

    TBH, you're not going to get a lot of anything special tonally. The cab is already tuned a certain way. You might get a little brightness from the baffle being a harder wood (than MDF), but, the cab will deaden out vibrations on the top/bottom/sides & the open back will let the pressure escape out the back.
     
  9. KraftyBob

    KraftyBob Well-Known Member

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    Actually it’s a closed back cab. I’m making the new baffle taller so it covers the slot where the head used to be. But the speaker area is fully enclosed.

    I have the G12M-65 Creamback in my DSL and bought a used G12T-75 for the cab. From what I’ve read the T-75’s like closed back cabs and I thought it would pair up nicely with the Creamback. I tested it when I bought and like what I hear so far.

    So you think a 1/2” maple ply baffle will be ok if it’s 17 1/2” H x 26” W?
     
  10. ampmadscientist

    ampmadscientist Well-Known Member

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    Maple is just a waste of money.

    Birch plywood ("gap-less birch") aircraft grade birch, marine grade birch plywood has no air pockets.
     
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  11. KraftyBob

    KraftyBob Well-Known Member

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    The reason for Maple is my friend has extra stock laying around his shop and said I could take what I need so there is no cost. He doesn’t have birch so maple or red oak are my only “free” options.

    If those don’t work I’ll buy a piece of birch.
     
  12. KraftyBob

    KraftyBob Well-Known Member

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    While I have you guys... in a 1x12 closed back cab is it bad to center the speaker? I ran across some threads that said you should offset the speaker by 3/4” - 1” so frequencies don’t get messed up/cancel inside the cab. But looking at a lot of 1x12 cabs online (good name brands) it appears that the speakers are centered.

    On the other hand, the speaker on the DSL40C is mounted off center to the right when looking at the front of the amp. Which puts it directly under one of the power tubes and closer to the power transformer (I think that's what it is?). If it was centered there would still be plenty of clearance for the OT which is on the other side of the chassis. Being a partial open back I would think that frequency cancellation wouldn't be an issue?
     
    Last edited: Jul 10, 2018
  13. Geeze

    Geeze Well-Known Member

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    If you're a pounder a 1/2" baffle in a closed back cab wouldn't be my first choice due to baffle flexure. Home Creepo has multi ply 24x48" 11/16" unknown wood that works as well as birch. Don't buy into the tone wood debate - on an acoustic guitar, OK. On a cab [built 22 to date] I've yet to see / hear anything that leads me down the deep dark hole of tone wood. I pick 'em for pretty.

    I don't have a definite answer on the centered / not question - but, there is too much application of HiFi sound reproduction engineering and practices that don't apply well to the LoFi of guitar amp sound creation. Do what appeals to you.

    BTW - the Wood Database is a great source for wood strength, work-ability and hazards [if any].

    http://www.wood-database.com/red-oak/

    Russ
     
  14. KraftyBob

    KraftyBob Well-Known Member

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    Thanks again, Russ - I greatly appreciate. I think I’ll give the Oak ply a shot then. Worse case I yank it, get some HD Ply and redo the baffle.

    I’ll update at a later date when I’m done and let you guys know the results.
     
  15. FutureProf88

    FutureProf88 Well-Known Member

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    I built a birch baffle for a repaired/repurposed/homebuilt 212 once. It is is an MDF cabinet and the whole thing turned out fairly well. PM me if you have any questions.
     
  16. KraftyBob

    KraftyBob Well-Known Member

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    Thanks for the offer. I’ll keep that in mind as I’m doing this.
     
  17. pedecamp

    pedecamp Well-Known Member

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    Being the cab has MDF sides I'd go with ply for the front and back. I find mixing the two create good sound out of a cab. I always build ply cabs with MDF front and back for best sound, all ply sounds boxy to me.
     
  18. tschrama

    tschrama Well-Known Member

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    In my experience the front baffle is best kept non resonant.. very thick ply.... or mdf.
     
  19. KraftyBob

    KraftyBob Well-Known Member

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    I'm going with the 3/4" Oak ply. Worse case I don't like it and build a new baffle out of Birch. I'm not gluing the grill cloth so every thing I'm doing is fixable/reversible.
     
  20. gearhead

    gearhead Member

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    3/4" ply will work good. I've built a 1x12 and a 2x12 with marine grade plywood from Home Depot.(Also, MDF is freakin HARD *SS wood. But can damage easily from moisture.)
    Minimum I would use on the baffle would be 5/8". You don't want it to flex much. As far as void free etc, in my opinion, and just my opinion & experience, unless you are really cranking the power up, you aren't gonna notice much difference in sound. You WILL notice a difference between a plywood cab vs an MDF cab. I made a 1x12 cab from an old baffle (5/8") that came from a set of old 60's speakers from who knows what. I used 1/2" BS plywood and sealed it. Has internal bracing in all the corners and everything is glued & screwed together. I can crank my 50 watt Marshall to 10 and no issues. Just sayin.
     

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