Hello everyone, I searched around to see if someone has built this cabs on a 3/4" plywood but with no luck I have found any. I am getting ready to built this cab for knowledge and testing (with Dayton Audio PA385S-8) but I am planing on using a 3/4" Plywood from my local Lowes store (just for testing and learning purpose, I don't want to invest on a $80 sheet right now and maybe screw something up) and wondering if the change in thickness of the panels and braces, have a major change in the cab performance? It's a .75" is about 1.05mm bigger than the suggested 18mm panel thickness.
NOTE: I was thinking of enlarging the sides (panel 6), the upper front (panel 9), the lower front (panel 10) and the top/bottom (panel 7), to compensate a bit.
Questions:
1st - Using a 3/4" Plywood from my local Lowes store and wondering if the change in thickness of the panels and braces, have a major change in the cab performance?
2nd - Should I just go with the original external measurements and don't worry about the internal volume?
3rd - Should I enlarge outer panels to compensate a bit and leave the internal panels and braces alone or should I do something to the inside panels as well?
4th - Is the Baltic Birch plywood actually 18mm or a bit smaller?
Panels to enlarge:
#6 - 646.10 x 552.10
#7 - 253 x 464
#9 - 295.05 x 464
#10 - 95.55 x 464
Thanks in advance for the help?
NOTE: I was thinking of enlarging the sides (panel 6), the upper front (panel 9), the lower front (panel 10) and the top/bottom (panel 7), to compensate a bit.
Questions:
1st - Using a 3/4" Plywood from my local Lowes store and wondering if the change in thickness of the panels and braces, have a major change in the cab performance?
2nd - Should I just go with the original external measurements and don't worry about the internal volume?
3rd - Should I enlarge outer panels to compensate a bit and leave the internal panels and braces alone or should I do something to the inside panels as well?
4th - Is the Baltic Birch plywood actually 18mm or a bit smaller?
Panels to enlarge:
#6 - 646.10 x 552.10
#7 - 253 x 464
#9 - 295.05 x 464
#10 - 95.55 x 464
Thanks in advance for the help?
Last edited:
Hi Fresh101,
Is your plywood really 3/4"/.750"? It usually ends up being 23/32"/.719" nowadays. Looking at it from prior experience w/ Hornresp simulations of this enclosure:
To question 1: No.
To question 2: I would. The driver makes much more of a difference than this minor wall thickness change.
To question 3: See #2.
To question 4: Yes, 18mm or 0.709" (haven't measured any in a while).
Regards,
Is your plywood really 3/4"/.750"? It usually ends up being 23/32"/.719" nowadays. Looking at it from prior experience w/ Hornresp simulations of this enclosure:
To question 1: No.
To question 2: I would. The driver makes much more of a difference than this minor wall thickness change.
To question 3: See #2.
To question 4: Yes, 18mm or 0.709" (haven't measured any in a while).
Regards,
Hi Fresh101,
Is your plywood really 3/4"/.750"?
Regards,
Hello TB46 and thank you for your response. I just checked on Lowes site and the plywood I was planing on using it actual thickness is .71" = 18.034mm which is really close. Thanks
Weight it. Lay the opposite side panel across everything (don't glue), and stack a bunch of 45 pound barbell plates on it for 24 hours. Evenly, of course. When that cures, flip it over, glue the last panel, and weight the other side. Use a few brads or screws to keep the corners in alignment, if necessary. If it isn't CNC-cut, it will usually be a little "twisted". A 16th of an inch or so is no big deal.
I'd suggest the accuracy of your cuts is going to be a bigger issue than the thickness of ply
What do you mean by this, I am extremely a*al about preciseness on cuts. I like to double and triple check on markings and cutting and then recheck after cutting of the exact measurement, I always aim to cut slight bigger (1/16") and start shaving to the exact size . So I don't think the accuracy will be a problem.
Last edited:
What do you mean by this, I am extremely a*al about preciseness on cuts. I like to double and triple check on markings and cutting and then recheck after cutting of the exact measurement, I always aim to cut slight bigger (1/16") and start shaving to the exact size . So I don't think the accuracy will be a problem.
Size isn't the biggest issue with horn sub assembly. Squareness is a lot harder to verify and maintain. Angled cuts will tend to magnify those errors. And if the bracing isn't exact (and I mean exact in size, placement, and squareness) it can warp a cabinet a good 1/8 of an inch. And you wouldn't know it till you try to put on that last side panel and see that two of the corners don't quite line up.
Size isn't the biggest issue with horn sub assembly. Squareness is a lot harder to verify and maintain. Angled cuts will tend to magnify those errors. And if the bracing isn't exact (and I mean exact in size, placement, and squareness) it can warp a cabinet a good 1/8 of an inch. And you wouldn't know it till you try to put on that last side panel and see that two of the corners don't quite line up.
Ok now that makes sense. I am planing on using 90 degree angle square to help square things up, as well as using jigs and guides to help keep panels dewarped and in place while glue cures. Thanks for all the heads up.
Yep, didn't mean to insult your capabilities - moreso point that that "nominal" measurements of timber may vary +/- 0.5mm, but it's easy enough to get a cut 0.5mm off square
The acumulative error of the latter is much worse than the former!
Understandable, thanks
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
- Home
- Loudspeakers
- Subwoofers
- Building THAM15 in 3/4" Plywood