Did anyone make 0.53x plans with the score and fold method? Tried to crawl through the posts. I have drawn the 0.53x CAD plans as provided by Tb46 (http://www.diyaudio.com/forums/atta...l-tc9fds-karlsonator_.53x_dual_vifa_tc9fd.pdf). However, it seems this is not conducive to score and fold. Also this requires cutting the driver mounts (1, 2, and 3) in half, which is not ideal. Given simplicity and cleanliness of score and fold, I'd prefer to do that.
All apologies if this has already been asked/answered.
All apologies if this has already been asked/answered.
The easiest way to do score and fold is to cut long strips of the middle panels to the correct internal width (say 8in or whatever the CAD plan that Tb46 has). For a FC 0.53x, you may be better off going with my hand sketch on post 1. and then section by section set them against the plan drawn on the side panel and mark off where to score and then use a stiff ruler to fold against. Test a few pieces with a score and fold to find out by trial and error where the score needs to go relative to an actual corner. there is a small offset. Basically, if you want a corner to go somewhere, you need to score a little past that location otherwise it will be too short.
I did a quick re-scaling of my cut and fold model. Unfortunately, the larger scaling means I had to remove one segment. I also tried to include the segment I left off onto the outer two segment piece, but the three segments is also too long. The attached PDF shows how I scaled it and the cut lengths for the inner cut and fold segments.
I didn't check it, but my understanding is XRK's version is not a strict scaling like what I've done. So like he said, it may work better for you.
Thanks for that Mudjester. Note that the dual TC9FD in 0.53x requires two cutout holes. For the PA130-8, just one hole but the dia is bigger.
Thanks guys. I have partially built the first speaker. Now that I understand how it comes together, I see how the inner portion could be built out of a single piece. I also suspect the top, sides, and back (even front) could be built from a single piece as well (if large enough), with score and fold. Though this may exceed the dimensions of a single foam core piece. If feasible, that would require only gluing two pieces, inner and outer box (less then inner bracing).
In post 1 there is a link to a laser cut score and fold cardboard speaker that is indeed made from one large folded sheet. It's more feasible with the smaller 0.40x.
Karlsonator 0.53x Score and Fold Plans (32" x 40" sheet)
For the 0.53x, keeping the dimensions as provided, you could assemble the box and the inner folded portion utilizing the score and fold method. It would require two 32" x 40" sheets. Due to losses in folds, the dimensions may need to be upsized slightly. See attached. There is plenty of paper remaining for the k-aperture, braces, and other pieces.
For the 0.53x, keeping the dimensions as provided, you could assemble the box and the inner folded portion utilizing the score and fold method. It would require two 32" x 40" sheets. Due to losses in folds, the dimensions may need to be upsized slightly. See attached. There is plenty of paper remaining for the k-aperture, braces, and other pieces.
Is that a standard size for sheets of corrugated cardboard? Foam core comes in standard 20x30in sheets. One thing to try is that foam core sheets can be easily butt joined with hot melt glue to make larger sheets like 40 x 30in or 40x60in with 4 sheets. It is quite strong and joints are hardly visible.
At Dollar Store and Hobby Lobby, yes 20x30 is common. Elmers and other manufacturers sell foam core in various sizes, including 32x40 (Elmers - Foam Board - Acidfree - 1/8 - 32x40 - White, Elmer's Foamboard - BLICK art materials, etc.). I would argue that gluing two sheets together for a score and fold method is far easier than cutting and assembling the individual parts.
There's also a line of foam board from Uline. I was pretty excited when I saw it just recently at work for a presentation. 4 foot by 8 foot sheets: Foamboard - 48 x 96", White S-11755 - Uline
Yes, I have seen this too - they come in thicker panels (0.5in and 0.75in I think are options) as well but the cost is a bit high and you need to get minimum 5 sheets and shipping etc - ends up $100+... May actually work better than plywood as it has self damping qualities and is quite stiff as the cardboard is thicker.
It's all in post number 1.
http://www.diyaudio.com/forums/full...sonator-0-53x-dual-tc9fds-56.html#post3880182
First Build - 0.53x Karlsonator
Well I built a pair of the 0.53x Karlsonators. I am reserving final judgment until the Vifas break in (25 hours on the left channel, 1 hour on right), as I've heard this can truly be significant for any speaker fresh out of the box. But I do want to give some initial impressions.
I will say the midrange sounds very nice. Voices and the midrange of guitars sounds quite clear and convincing. Sparse folky tunes of Andrew Bird, Iron & Wine, Ray LaMontagne (etc.) sound great. The sound staging/dispersion is a neat illusion; they do that remarkably well. Based on my ears and my eyes, I would not think the sound is coming from the speakers but sort of around them.
On the negative side, I have to say there is no bass whatsoever, like not even a hint. I put on a bit of a torture test for the little guys, MGMT - Electric Feel (Justice Remix). Now let me tell you, if you haven't heard this song, it bumps. Crank it up and feel the baseline boogie. While the Karlsonators did the sparse, whisper sweetness well, they fell flat on their faces with the MGMT. I don't mean to say that the bass could be a little fuller or that I expect a 3" speaker to rumble the floor. It is as if someone put a high pass filter on the speakers. It's simply not there. I put on some Cassadega from my boys Bright Eyes. Nice full band music (vocals, acoustic guitars, electric guitars, bass guitar, fiddles, cellos, lap steel, organs, backing vocals, and pianos). Voices, strings, and piano sound nice. However, with the kick drums, toms, snare, there is no thump or snap. Bass guitar is essentially inaudible. To a much lesser degree, the treble seems to be rolled off a bit. Cymbals and sibilance are quieter than I am used to.
My construction methods weren't perfect but I don't think it's too far off the plan. If being airtight is important, I am far from perfect there. I tried to get the seams as best I could. Where I couldn't, the hot glue is at least covering the air gap.
I did verify polarity on the speakers (positive voltage "push" test), so that is not a problem.
I had the opportunity to compare these to a bluetooth speaker I purchased a number of years ago as a kitchen/bathroom system. Logitech UE Mobile Boombox (apparently not for sale anymore, but a nice sounding little speaker, retailed for $95 or less). I would say the midrange of the Karlsonator sounds more hifi but otherwise the Logitech wins. The Logitech doesn't excel in its realism but it has a nice coherence; all portions of the audio spectrum as represented well, from bass through treble. These 2" (approx) drivers put out a shocking bit of thump in their tiny enclosure (barely larger than a soda can). This is why I'm so shocked at the complete void of bass in my Karlsonators, especially considering the rave reviews it's received. Logitech seems to be able to handle volume better too; sounds nice at all levels. The Karlsonators begin to shout very quickly with heavy volume. (Again, this could be due to break-in.)
I'm curious to hear what other builders might have to say. Have other builders been satisfied with the bass/thump out of these guys? I would think in a very small room these might do well, where the reflections might keep the bass from losing energy as quickly. My room, however, is rather large and these are a good 6 feet off the front wall, so they are not going to benefit from any wall-loading.
Well I built a pair of the 0.53x Karlsonators. I am reserving final judgment until the Vifas break in (25 hours on the left channel, 1 hour on right), as I've heard this can truly be significant for any speaker fresh out of the box. But I do want to give some initial impressions.
I will say the midrange sounds very nice. Voices and the midrange of guitars sounds quite clear and convincing. Sparse folky tunes of Andrew Bird, Iron & Wine, Ray LaMontagne (etc.) sound great. The sound staging/dispersion is a neat illusion; they do that remarkably well. Based on my ears and my eyes, I would not think the sound is coming from the speakers but sort of around them.
On the negative side, I have to say there is no bass whatsoever, like not even a hint. I put on a bit of a torture test for the little guys, MGMT - Electric Feel (Justice Remix). Now let me tell you, if you haven't heard this song, it bumps. Crank it up and feel the baseline boogie. While the Karlsonators did the sparse, whisper sweetness well, they fell flat on their faces with the MGMT. I don't mean to say that the bass could be a little fuller or that I expect a 3" speaker to rumble the floor. It is as if someone put a high pass filter on the speakers. It's simply not there. I put on some Cassadega from my boys Bright Eyes. Nice full band music (vocals, acoustic guitars, electric guitars, bass guitar, fiddles, cellos, lap steel, organs, backing vocals, and pianos). Voices, strings, and piano sound nice. However, with the kick drums, toms, snare, there is no thump or snap. Bass guitar is essentially inaudible. To a much lesser degree, the treble seems to be rolled off a bit. Cymbals and sibilance are quieter than I am used to.
My construction methods weren't perfect but I don't think it's too far off the plan. If being airtight is important, I am far from perfect there. I tried to get the seams as best I could. Where I couldn't, the hot glue is at least covering the air gap.
I did verify polarity on the speakers (positive voltage "push" test), so that is not a problem.
I had the opportunity to compare these to a bluetooth speaker I purchased a number of years ago as a kitchen/bathroom system. Logitech UE Mobile Boombox (apparently not for sale anymore, but a nice sounding little speaker, retailed for $95 or less). I would say the midrange of the Karlsonator sounds more hifi but otherwise the Logitech wins. The Logitech doesn't excel in its realism but it has a nice coherence; all portions of the audio spectrum as represented well, from bass through treble. These 2" (approx) drivers put out a shocking bit of thump in their tiny enclosure (barely larger than a soda can). This is why I'm so shocked at the complete void of bass in my Karlsonators, especially considering the rave reviews it's received. Logitech seems to be able to handle volume better too; sounds nice at all levels. The Karlsonators begin to shout very quickly with heavy volume. (Again, this could be due to break-in.)
I'm curious to hear what other builders might have to say. Have other builders been satisfied with the bass/thump out of these guys? I would think in a very small room these might do well, where the reflections might keep the bass from losing energy as quickly. My room, however, is rather large and these are a good 6 feet off the front wall, so they are not going to benefit from any wall-loading.
Attachments
Thanks for sharing and for taking the plunge to build these! I am sorry it is not making bass for you, but I assure you these make great bass if you make it right. I am afraid you have an air leak - it has nothing to do with breaking the drivers in - they should work out of the box. The bass is particularly good on these speakers - better than any other speaker for the same size. I noticed your K-aperture goes all the way to the top and is a rather wide slot. Let it go 3 in from the top and end in a narrower 3/16in wide slot. That may pull the bass down 2 to 5Hz, but that doesn't sound like what you are suffering from. This is a TL speaker, and operates kind of like a flute, recorder, or other woodwind instrument. If you have ever played one, you know you can't hit the lowest note if one of your finger pads has even a slight leak. The leak collapses that 1/4 wave air column. It is important that the panels that make up the middle are all uniform in width by +/- 1mm so that the glue has a chance to seal. The capping operation should be resting on edges that are more or less very level and uniform. With a mistake like this it may be hard to trace the leak, especially if it is one of the internal walls. You can use a razor and cut little windows in the walls to check the internals and repair by adding more glue and the glue the window you cut out back on with hot melt. PVA is great sealer glue. Gorilla expanding glue works well to seal leaks too.
This speaker should hit 55Hz no problem and you will hear and feel bass as a jet of air passing through the narrow portion of the K slot on kick drums. It is enough to put a candle out.
Bcmbob was one of the first to make these in foam core and he was very happy with the bass. Look at his build and comments here:
http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds-31.html#post3734859
Bcmbob did some frequency sweeps and was getting 60Hz clearly and some at 50Hz. Check it out here:
http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds-35.html#post3738404
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Thanks for posting, and for trying these. 
As far as the MIA bass, bass is what these things do best. I suspect that there is a wiring issue. Sounds like the speaker may be out of phase with each other. Flipping the phase of one speaker will give the symptoms you describe. I'd double check that. Did you wire the two drivers in each speaker in parallel?
Break in shouldn't make a huge difference WRT amount of bass, so I don't think it is that.
Another thing it could be is the source. What are you using as an amp? Could it have a built in highpass? Not uncommon for amps intended to be used with a sub.
Most consumer PC speakers have the midbass bumped up rather absurdly, to make up subjectively for their small size. It's possible you are accustomed to this. However, you should still be able to hear the basslines clearly, so I don't thing that is it either.
Also, FWIW they will have a lot more bass when on the floor. On mine it is too much.
Lastly, try to patch up any air leaks. Use duct tape if you have to.
As far as the MIA bass, bass is what these things do best. I suspect that there is a wiring issue. Sounds like the speaker may be out of phase with each other. Flipping the phase of one speaker will give the symptoms you describe. I'd double check that. Did you wire the two drivers in each speaker in parallel?
Break in shouldn't make a huge difference WRT amount of bass, so I don't think it is that.
Another thing it could be is the source. What are you using as an amp? Could it have a built in highpass? Not uncommon for amps intended to be used with a sub.
Most consumer PC speakers have the midbass bumped up rather absurdly, to make up subjectively for their small size. It's possible you are accustomed to this. However, you should still be able to hear the basslines clearly, so I don't thing that is it either.
Also, FWIW they will have a lot more bass when on the floor. On mine it is too much.
Lastly, try to patch up any air leaks. Use duct tape if you have to.
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Good point GregB about flipped polarity of one speaker relative to other. That will kill the bass for sure. Don't know what amp you are using but several of my cheap Chinese amps have the speaker output polarity mislabeled on one speaker. That is, if you connect it according to the silkscreen markings, you will be in flipped polarity and there will be no bass. You may also sense a weird phasiness sound when this happens.
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I tore apart one of the speakers in attempts to seal it up. The bass may have improved slightly but certainly not blowing out any candles. I do have stuffing in the stub and felt on backside of speaker aperture. One thing I will admit I did not do is put all of the bracing in. Mostly because my cuts did not fit and I did not think bracing would have any positive effect on sound.
I did wire in parallel. Used the same lead from the two speakers to tie back to the common wire. My amp is a fairly reputable brand so I don't think my amp has incorrectly labeled leads.
I will also admit that my geometry was not perfect. I do think however that the quarter wave port is fairly well sealed, at least with hot glue. So no air should be able to leak through.
I did wire in parallel. Used the same lead from the two speakers to tie back to the common wire. My amp is a fairly reputable brand so I don't think my amp has incorrectly labeled leads.
I will also admit that my geometry was not perfect. I do think however that the quarter wave port is fairly well sealed, at least with hot glue. So no air should be able to leak through.