Meant Visaton B100 of course. All fingers and thumbs on the phone.
Spent today trying to put together the foamcore 0.53x Karlsonator for W5-2143.
Think I may have bitten off a bit more than I can chew.
Didnt help running out of hot melt at a critical time.
Yes, I had a heap more sticks, no they did not fit the gun they sold me.
And with NZ in lockdown again, getting more glue might be a bit harder.
Anyhow, I should have read XRK's build instructions a bit more carefully because I hadn't offset the hardboard backing where I intend to attach the driver; thought wood would be better as this driver is quite weighty.
And using 1cm foamcore may not have been a great idea either; Im guessing that most of you use 0.5cm foamcore?
Because of the panic moment when I ran out of glue I had to use gorilla expanding foam which looks pretty rubbish on white foamcore.
But it is all a learning curve.
For a while there I was getting quicker!
I dont think I need 13 pieces of foamcore fillets for reinforcing really as this thing feels pretty robust as is. But once I get more hot melt glue sticks that fit my gun, I will be sure to add reinforcement where it seems necessary.
Im wondering how people even up edges that might not be entirely true? Do you use a sander or a gentle plane? I seem to be fixing edges to make them either fit better or eliminate obvious places where there will be air gaps. Or is it easier just to add a bit of hot melt glue?
Spent today trying to put together the foamcore 0.53x Karlsonator for W5-2143.
Think I may have bitten off a bit more than I can chew.
Didnt help running out of hot melt at a critical time.
Yes, I had a heap more sticks, no they did not fit the gun they sold me.
And with NZ in lockdown again, getting more glue might be a bit harder.
Anyhow, I should have read XRK's build instructions a bit more carefully because I hadn't offset the hardboard backing where I intend to attach the driver; thought wood would be better as this driver is quite weighty.
And using 1cm foamcore may not have been a great idea either; Im guessing that most of you use 0.5cm foamcore?
Because of the panic moment when I ran out of glue I had to use gorilla expanding foam which looks pretty rubbish on white foamcore.
But it is all a learning curve.
For a while there I was getting quicker!
I dont think I need 13 pieces of foamcore fillets for reinforcing really as this thing feels pretty robust as is. But once I get more hot melt glue sticks that fit my gun, I will be sure to add reinforcement where it seems necessary.
Im wondering how people even up edges that might not be entirely true? Do you use a sander or a gentle plane? I seem to be fixing edges to make them either fit better or eliminate obvious places where there will be air gaps. Or is it easier just to add a bit of hot melt glue?
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Nice work Luigi. Running out of hot melt. We have all been there! But to have the wrong size refills is a bummer. Maybe get the different hot melt gun that fits the incorrect glue?
Cutting the raw stock to precise width strips using a metal straight edge and utility knife if a learned skill and guy get better at it with practice. That makes the joints tight and relatively gap free. Hot melt or caulking can fix big gaps. Structurally though it is better that you have solid contact with no gaps.
Good luck!
Cutting the raw stock to precise width strips using a metal straight edge and utility knife if a learned skill and guy get better at it with practice. That makes the joints tight and relatively gap free. Hot melt or caulking can fix big gaps. Structurally though it is better that you have solid contact with no gaps.
Good luck!
All gd advice thx X.
I have Ados and Gorilla glue so can press on with that during the lockdown.
I take it you mainly use thin foam board 0.5cm?
The 1cm stuff is firmer but more expensive here. Harder to cut nice edges.
I have some black 0.5cm foam board that I guess is easier to cut and score.
Will use that for a Faital 4FE32 project.
I have Ados and Gorilla glue so can press on with that during the lockdown.
I take it you mainly use thin foam board 0.5cm?
The 1cm stuff is firmer but more expensive here. Harder to cut nice edges.
I have some black 0.5cm foam board that I guess is easier to cut and score.
Will use that for a Faital 4FE32 project.
The stuff I use is sold as 30in x 20in sheets 3/16in thick (4.8mm or circa 5mm thick). They come in different grades. The $1 from Dollar store are very light and soft and “crispy”. Fine for quick inexpensive builds. The $4/sheet “Elmers” brand is much thicker cardboard facing (still 3/16in thick overall) and has a tough coating on it. Harder to cut but makes durable nicer speakers. Good for more long term projects. Be careful of the ones with gloss coating - hot melt will not stick to that surface. The matte satin finish board is fine.
Just a random question here X.
With the slightly bigger 0.53x build, and using the 1cm foamboard, do I need to place/stick anything like felt (or perhaps a piece of EVA foam) on rear surface of the enclosure (with the terminal cup) that the back of the driver faces?
I have a whole lot of dacron that I will fill the first part of the line with.
Perhaps this is sufficient??
With the slightly bigger 0.53x build, and using the 1cm foamboard, do I need to place/stick anything like felt (or perhaps a piece of EVA foam) on rear surface of the enclosure (with the terminal cup) that the back of the driver faces?
I have a whole lot of dacron that I will fill the first part of the line with.
Perhaps this is sufficient??
Because of the lockdown here, which seems to be working, thankfully, have not been able to get more gluesticks so using Ados and Gorilla glue instead.
the terminals are now installed, that worked just gluing them on.
And am nearing the end; has taken forever, seemingly. Might stick to 5mm stock next time, if there is a next time!
the terminals are now installed, that worked just gluing them on.
And am nearing the end; has taken forever, seemingly. Might stick to 5mm stock next time, if there is a next time!
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I will be perfectly honest with you and state that I have made some fairly basic errors that are quite hard to undo after applying hot melt glue. That's why there are no close-ups!
That said, building foamcore speakers seems to involve a bit of a learning curve. And things that might at first seem insurmountable you can seemingly cut around and get back on track again. At least, that's my initial experience.
I haven't the foggiest how I'm going to lay out the Karlson slot though; might be a bit a by-guess-and-by-golly job that one. Unless you have a few hints and tips as to how to go about it.....
That said, building foamcore speakers seems to involve a bit of a learning curve. And things that might at first seem insurmountable you can seemingly cut around and get back on track again. At least, that's my initial experience.
I haven't the foggiest how I'm going to lay out the Karlson slot though; might be a bit a by-guess-and-by-golly job that one. Unless you have a few hints and tips as to how to go about it.....
On a piece of paper with the outline of the baffle, draw the correct position for the vertex of the Karlson. Take a pencil and move your forearm about your elbow as the pivot, and quickly and smoothly on one stroke, draw an arc tangent to the vertical slot and intersecting the bottom corner. Now fold the paper at the centerline. Use scissors to cut the outline of the aperture and you have a perfect mirror image copy. The scissors smooth out any rough errors your hand made drawing the arc. You now have a template to cut the K aperture.
Look at my latest foam core speaker here - a simple prismatic box but lots of details on how to make baffle support the driver screws, Noico damping sheets, bracing, foam padding etc.
Foam Core Board Speaker Enclosures?
Look at my latest foam core speaker here - a simple prismatic box but lots of details on how to make baffle support the driver screws, Noico damping sheets, bracing, foam padding etc.
Foam Core Board Speaker Enclosures?
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So today we decided to try to finish these 0.53x Karlsonators.
The final panel didn't really fit all that well on either so I had to do a bit of fudging with sandpaper and hot melt.
And decided to use expanding foam glue because hot melt would have bonded by the time I tried to fit the panel. My glue gun is rubbish.
I know that gorilla glue eats away at the foam but it does seem to fill in the gaps nicely and the glue adheres okay to the paper bits of foamboard.
So now we just wait and see how many air gaps there are.
Using lots of weight to pin the side panel in place. Hope they don't collapse!
The final panel didn't really fit all that well on either so I had to do a bit of fudging with sandpaper and hot melt.
And decided to use expanding foam glue because hot melt would have bonded by the time I tried to fit the panel. My glue gun is rubbish.
I know that gorilla glue eats away at the foam but it does seem to fill in the gaps nicely and the glue adheres okay to the paper bits of foamboard.
So now we just wait and see how many air gaps there are.
Using lots of weight to pin the side panel in place. Hope they don't collapse!
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PA 130-8s are on sale for $14.78 at PE so I made the plunge today. Several years back I added ducts to a couple of .42 scaled K-12s with horizontal port and shelf but lost my wife and just kinda stalled out. The little K boxes are stacked in a corner looking at me and I am going to give them a chance with my little aliexpress.com amp.
I also have a full sized K-12 with a guitar speaker. It was built from measurements taken from an early K-12 kit assembled by my brother and driven with a University 312. I later built a pair driven by Lafayette Electronics re-labeled 312s or knock-offs. I let them get away due to size replacing them with BIC Venturi book shelf speakers. I now use a BIC America 10" sub with small 2-way side speakers for my TV and stereo system.
I also have a full sized K-12 with a guitar speaker. It was built from measurements taken from an early K-12 kit assembled by my brother and driven with a University 312. I later built a pair driven by Lafayette Electronics re-labeled 312s or knock-offs. I let them get away due to size replacing them with BIC Venturi book shelf speakers. I now use a BIC America 10" sub with small 2-way side speakers for my TV and stereo system.
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FWIW I like K12 a lot - its best with say something like Kappa12a's parameters. It has more dynamics on a Rudy Rosa synth track than my Klipschorn and a K-tube will work pretty well. The way the K12 GRABS those heavy string sounds on Rudy is amazing. 312 and Diffusicone12 are pleasant but delicate/weak speakers. For guitar I had a Cannabis Rex12 inK12 and thought that was pretty nice. Also, had a Commonwealth12 w. K12 - but only ran on music.
Its time to create a sticky thread for Karlson heritage speakers with their plans. I need someone to draw the following in readable form:
Karlson's first "EIGHT, Karlson's X15 and the X15 spinoff, Acoustic Control 115BK. plus can't locate GregB's K5 plan scaled from 1960's K8 - that one might be considered a cute toy (or perhaps a midrange box).
Its time to create a sticky thread for Karlson heritage speakers with their plans. I need someone to draw the following in readable form:
Karlson's first "EIGHT, Karlson's X15 and the X15 spinoff, Acoustic Control 115BK. plus can't locate GregB's K5 plan scaled from 1960's K8 - that one might be considered a cute toy (or perhaps a midrange box).
regarding XKi alignments, that made me think of a little K8 copy where I hacked a slot port at the top. A refined version of that would make a cool little speaker for use with woofer/subwoofer. IIRC there was no duct on the port - just the top side's boundary - so tuned pretty high.
W8-1772 seemed pretty good in smaller K's - I did not like it in the old Karlsonette (1954 K12 --- FE206EN was really fun in K12.)
A smoothing stub added above the vent might make a flat response. Note XRK's little Karlsonator's low end response
W8-1772 seemed pretty good in smaller K's - I did not like it in the old Karlsonette (1954 K12 --- FE206EN was really fun in K12.)
A smoothing stub added above the vent might make a flat response. Note XRK's little Karlsonator's low end response
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