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Custom DIY 2x15 cab build

#601
Speaking of construction details, how did you go about gluing the baffle in place? It seems like all the others would be relatively easy to fit together and then brad/screw in place because they're square and flush to the other pieces, but the baffle is recessed and you don't have access to the back. How did you keep it square with the rest of the box? And do you lay a bead of PL on the edge, then push it into the box, then fillet an additional bead on the back side through the speaker holes?

Sorry, I'm an utter newb at woodworking.
 
#602
Balog said:
Speaking of construction details, how did you go about gluing the baffle in place? It seems like all the others would be relatively easy to fit together and then brad/screw in place because they're square and flush to the other pieces, but the baffle is recessed and you don't have access to the back. How did you keep it square with the rest of the box? And do you lay a bead of PL on the edge, then push it into the box, then fillet an additional bead on the back side through the speaker holes?

Sorry, I'm an utter newb at woodworking.
Click to expand...

I obviously can't speak for the others who have built this design, but here's how I did it: due to the limited amount of pipe clamps I have, I glued the baffle and back to the top and bottom first (with the sides held in place with strap clamps) then went back and glued in the sides after the top and bottom dried. And actually, even if I had had more clamps I still may have done it this way. It was pretty easy.
 
#603
lucyfur said:
I obviously can't speak for the others who have built this design, but here's how I did it: due to the limited amount of pipe clamps I have, I glued the baffle and back to the top and bottom first (with the sides held in place with strap clamps) then went back and glued in the sides after the top and bottom dried. And actually, even if I had had more clamps I still may have done it this way. It was pretty easy.
Click to expand...

I didn't build the same design, but used a similar series of steps for assembly. Dependant mainly upon how the joints layout between the sections.
For bracing, there are a few different ways of approaching. On a pre designed type of build, where the bracing scheme has already been figured out for You (ala, DIY-fEARful). You can pre attatch the bracing ribs to the top, bottom, back, and side panels, prior to the enclosure assembly. Whereas, If you were doing a complete scratch build, You would have to get the assembly most of the way there, to see where and how much bracing would need to be added.

This is a video, that Speakerhardware put together for helping the buyers of Their flat-pack kits. Not the same design, but will give You an idea of a pretty easy step by step method to assembley.
http://www.youtube.com/watch?feature=player_embedded&v=4wkxJSj_qf8#!

Hope that helps!
 
#604
johnk_10 said:
the cab's actual internal volume is 5.652 cu ft, less the volume of the bracing, the speakers, and the port tubes comes out to 4.588 cu ft, so i went with the port tube length of 3.9" (the way that they come from reliable hardware) which tunes it to 46.3Hz, and it seems to work great tuned at that freq.
Click to expand...

I've started building one of these, mostly due to the great sounds of your recordings johnk_10, as well as the size and weight reduction when compared to an Ampeg 810. As I model this in WinISD, though, I have some confusion about some information you posted way back on page 9 of this thread. In it, you say your internal volume is 5.652, and the volume minus all the extras is 4.588.

First, your starting volume of 5.652 ft^3 I assume comes from a calculation of 23.5x35x11.87 in^3. Is this correct? If so, then for a 14" box, you'd have 11.8" of internal depth, 0.5" back panel, 0.75" baffle, leaving about 0.875 (7/8") from the front of the baffle to the front edge of the cabinet. Is that all the room you left from the front of the cabinet to the front of the baffle?

Second, most all calculations I've seen for computing the internal volume of speakers, port tubes, and bracing is that it should be about 10% of the overall volume of the cabinet. Using this rule of thumb, there should be about 0.56 ft^3 of bracing / etc. for this cab, which would give a net internal volume of 5.1 ft ^3 or so. Where did the 4.588 ft^3 come from? My rough calculations from what I see in your design doesn't seem to add up to over 1 ft^3 of bracing / speakers / ports. What volume did you use for the 3015's?

Sorry for all the questions. I'm just trying to model something with the same sound you're getting, and I don't know whether to use the 4.588 ft^3 approximation, or the 5.1 ft^3 estimate that I get using a back of the envelope calculation.... Thanks!
 
#606
SeismicAssault said:
I've started building one of these, mostly due to the great sounds of your recordings johnk_10, as well as the size and weight reduction when compared to an Ampeg 810. As I model this in WinISD, though, I have some confusion about some information you posted way back on page 9 of this thread. In it, you say your internal volume is 5.652, and the volume minus all the extras is 4.588.

First, your starting volume of 5.652 ft^3 I assume comes from a calculation of 23.5x35x11.87 in^3. Is this correct? If so, then for a 14" box, you'd have 11.8" of internal depth, 0.5" back panel, 0.75" baffle, leaving about 0.875 (7/8") from the front of the baffle to the front edge of the cabinet. Is that all the room you left from the front of the cabinet to the front of the baffle?

Second, most all calculations I've seen for computing the internal volume of speakers, port tubes, and bracing is that it should be about 10% of the overall volume of the cabinet. Using this rule of thumb, there should be about 0.56 ft^3 of bracing / etc. for this cab, which would give a net internal volume of 5.1 ft ^3 or so. Where did the 4.588 ft^3 come from? My rough calculations from what I see in your design doesn't seem to add up to over 1 ft^3 of bracing / speakers / ports. What volume did you use for the 3015's?

Sorry for all the questions. I'm just trying to model something with the same sound you're getting, and I don't know whether to use the 4.588 ft^3 approximation, or the 5.1 ft^3 estimate that I get using a back of the envelope calculation.... Thanks!
Click to expand...

i just estimated the areas of the bracing, speakers and port tubes. if you built a cab using the same outer dimensions as mine out of 1/2 ply, use a 3/4" thick baffle and inset it 1 1/8" (to allow for the grill panel). and the two port tubes are 4" flared ones that are 3.90" deep.
 
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#607
Codger said:
Hopefully not too OT. Has someone built a dual 12" version of this thing?
Click to expand...

The 15PR400 and 3015 are a special breed. Not really counterparts in 12" off the top of my head. You'd think 12PR300 and 3012HO, but they're pretty different. I think maybe Deltalite 2512 II or S2012's might be the closest. John even has done some cool cabs with the Deltalites. :cool: There may be others in terms of tone, but not tone and output capability of those 15's.
 
#612
kraigo said:
One more thing to worry about is that it's void free. Cabinet grade and marine grade plywoods are your best bet. Once the cab is glued and screwed, warpage isn't much of a concern.

KO
Click to expand...

Right, I'm interested in a piece being unattended for a period, if pieces are waiting to be assembled. Laying flat with weights will discourage warping, but I don't know which woods might be best in this regard. Just interested...
 
#614
Freddels said:
John said that he just got his at the local Home Depot. I think once you brace it, there shouldn't be any warping issues. I wouldn't buy it just to sit around for a long period. Buy it when you're ready to do the build.
Click to expand...

Well I was asking for more than one reason, tell you the truth... I don't deal with plywood beyond framing, etc for construction most of the time, and I know it's a hot-topic around here... so I tapped the conversation!

I am going to be doing something bass-cab-wise though, so I'm not entirely trolling... thanks Fred! :cool:
 
#616
Count Bassie said:
They resist warpage fairly well?
Click to expand...

The short answer is yes...

But I haven't had any speaker cabinet panels warp, once the cab is glued and screwed, regardless of what type of plywood...

My understanding is that "real" Baltic Birch is 9 plies for 1/2", and 13 plies for 3/4", which are necessarily "thinner" than standard (regular) Birch plies, and resists warping better because of the increased plies of alternating grain, and also has fewer, if any voids in the various layers.
 
#617
ScottTunes said:
The short answer is yes...

But I haven't had any speaker cabinet panels warp, once the cab is glued and screwed, regardless of what type of plywood...

My understanding is that "real" Baltic Birch is 9 plies for 1/2", and 13 plies for 3/4", which are necessarily "thinner" than standard (regular) Birch plies, and resists warping better because of the increased plies of alternating grain, and also has fewer, if any voids in the various layers.
Click to expand...

Cool. Thanks for the replies on this guys. I dig this 215 cab as well, John did a snap job on it... I'm considering, when I can get time, bread and space together, either this same idea or the Omni 15TB I've still got sitting in my machine here.
 
#619
gimp said:
Two questions - feel free to PM an answer if you prefer.

1. What was your build cost (with or without drivers), and
2. Have you considered building for others?
Click to expand...


answer to # 1, see post #158 in this thread on page 8. ;)
answer to # 2- I have, but I just don't have the time with all of my custom bass builds and restorations.
 

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