Way cool! Karlson tech is the number 1 way to go - (I learned that some years ago but am not in good enough shape to build)
its more elegant and petite than my scrap K5
XRK971 Karlsonator 4
freddy rough K5
its more elegant and petite than my scrap K5
XRK971 Karlsonator 4
freddy rough K5
An externally hosted image should be here but it was not working when we last tested it.
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Bob,
Yes, the rear and front chamber are connected by a port or channel per the drawings. I just don't have my k aperture slot go all the way to the top. For a couple of reasons: it gives the foam core front sheet more structural integrity, and it effectively increases the path to extend the bass a little bit.
X
Yes, the rear and front chamber are connected by a port or channel per the drawings. I just don't have my k aperture slot go all the way to the top. For a couple of reasons: it gives the foam core front sheet more structural integrity, and it effectively increases the path to extend the bass a little bit.
X
Thanks, though small - wasn't sure how that would effect the output. I don't have a strong science/design background, but I've learned very small changes in port size and placement can effect the output in unexpected ways. Looks like a great spot to apply the economy and flexibility of a foamcore build for experimentation. Looking forward to my shot at the build.
Hi X,
Thanks for another fun build, I am ready to build the .53X Karlsonator and will build it then saw the .4X version. I have a question please, is that a divider right above the Vifa driver? If so does it go all the away across to seperate the top of the slot from the bottom?
Thanks,
Webber
Thanks for another fun build, I am ready to build the .53X Karlsonator and will build it then saw the .4X version. I have a question please, is that a divider right above the Vifa driver? If so does it go all the away across to seperate the top of the slot from the bottom?
Thanks,
Webber
Webber,
That is just a small .75 in tall strip of scrap foam that is glued across the back of the wing to give it more stiffness at the point where the front chamber is deepest. It may act as a "divider" but that was not the intention. If you use a double layer of foam core on the front wing you won't need this - or if you are using plywood or mdf you won't need this either. It extends almost the width of the front chamber but can be smaller. I tried using a Wong panel without it and there is excessive vibration and flapping of the wings without it. I should take a picture of the inside of one for all to see. In the 0.4x build I was lazy and in a hurry so the front wing panel is glued on - so I can't remove it without damaging it. Getting the driver out may require a few surgically placed screw driver access holes in the front wing panel and careful manipulation of the driver out through the front aperture. Oh well...
That is just a small .75 in tall strip of scrap foam that is glued across the back of the wing to give it more stiffness at the point where the front chamber is deepest. It may act as a "divider" but that was not the intention. If you use a double layer of foam core on the front wing you won't need this - or if you are using plywood or mdf you won't need this either. It extends almost the width of the front chamber but can be smaller. I tried using a Wong panel without it and there is excessive vibration and flapping of the wings without it. I should take a picture of the inside of one for all to see. In the 0.4x build I was lazy and in a hurry so the front wing panel is glued on - so I can't remove it without damaging it. Getting the driver out may require a few surgically placed screw driver access holes in the front wing panel and careful manipulation of the driver out through the front aperture. Oh well...
I just confirmed that the Vifa driver can be safely removed without cutting any holes in the front wing panel. There is just enough room to get a screwdriver onto the screw and to tilt the driver to the side a little to pull it out. I adjusted the stuffing a bit (removed some to see if bass output was improved - yes it helps.) So plan on adjusting to taste. Also, I added some stuffing behind the wing panel hidden (not visible from front) and this seemed to tame the excessive sibilance that I noticed. Lots of room for adjusting to your own taste. Overall though, I am very happy with how this speaker sounds. I think I will bring these to my office at work.
0.4x Scale Karlsonator with single Vifa - Build 4 - Detail of Wing Brace
Here is a detail of the brace that I use to stiffen the K-aperture wing. Also, you can see how the screws are accessible through the front slot. It was all very serendipitous but I like how I am able to glue the front wing on - it makes for a very quick and easy build as the screw holders for the 0.54x scale one were time consuming to make and glue.
Here is a detail of the brace that I use to stiffen the K-aperture wing. Also, you can see how the screws are accessible through the front slot. It was all very serendipitous but I like how I am able to glue the front wing on - it makes for a very quick and easy build as the screw holders for the 0.54x scale one were time consuming to make and glue.
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Freddi,
What 5 in driver are you using there and is that just a scaled down multi chamber K15 type enclosure? How does it sound as a 5 in box?
The speaker is completed. Here is a photo of it with a CD case for size reference. It is very small and compact at 12 in tall x 6 in wide x 6.5 in deep. This size is perfect for a bookshelf or a desk.
How does it sound? In a word - amazing! It sounds very very good. The highs are clearer than the dual driver 0.54x scale version . I think it may be that the direct radiator cone area is better matched to the Karlson aperture size in this format - or the mid-bass is cleaner? The bass extension is quite nice - not as deep of course as the 0.54x version - but very satisfying. I played "Sermon on the Mount" by Dave Brubeck and his sons - there is a beautiful Cello and it comes through very natural and smooth. I played some Robert Cray and that sounded great. If you pair this with a sub crossed at 80 Hz and below it will really shine - but it sounds great as is. For a desktop computer speaker, it will easily beat a $100+ pair that is out there. The wide angle directivity is very nice and apparent when you step back and walk around the room - it sounds very uniform.
Anyhow, I don't have any reservations about recommending this build. You will not be disappointed. For the cost of a $10 Vifa, 1 sheet of foam core, some pillow stuffing, and a $0.85 terminal cup - this speaker is awesome!
I am very happy with it.
Cheers,
X
Dang X, that was fast. I've not hear Ks before but always assumed that off axis just a little bit would kill the highs because the wings block them. Is that true? Like I said, just an assumption.
Great job on these. I am really looking forward to building mine.
Thanks. Just the opposite is true with Karlsons in off axis listening. They are better than a bare cone radiator. My measurements and sims prove it - look in the kicks butt thread.
The total time to build was 30 min to cut pieces. 1 hr to glue initial pieces. 15 min to glue side panel and 6 hrs for PVA to dry. Another 20 min for front panel.
X, I did a look back for plans. Can't find them. You (and your clips) got me fired up so I went to the store for some board. They were out of stock - but I do have plenty of 1/4" plywood in the shed.
There is a link to GregB's plans in post 1 scale it by 0.4x. I took the liberty of adjusting the 6.1 in width to 6.0 and the depth to exactly 6.5 to keep it simple. You will need to account for thickness of plywood if that is what you are using. Although thai design is pretty forgiving of a small change in dimensions.
The foam makes it go real fast and keep the project light weight.
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Awesome.
One of these days x is going to surprise everyone and make a speaker out of plywood.
Yes, that will be the day.
Hi X,
Once again another fine build, well I started this morning building the .4X and just finished the first one. It took 4.5 hours from drawing to listening, The use of the foam safe instant glue works for me but is expensive, well they sound fantastic. It puts out plenty of bass and the clarity is amazing. Those Vifa drivers are such a deal. I am driving the speaker with a TPA3116 2 channel amp with an 18 volt 3 amp computer brick power supply, the only thing is with the amp it doesn't seem to go as loud as my Lepai 2020+ with a 5 amp brick power supply. Here are some pics
Thanks,
Webber
Once again another fine build, well I started this morning building the .4X and just finished the first one. It took 4.5 hours from drawing to listening, The use of the foam safe instant glue works for me but is expensive, well they sound fantastic. It puts out plenty of bass and the clarity is amazing. Those Vifa drivers are such a deal. I am driving the speaker with a TPA3116 2 channel amp with an 18 volt 3 amp computer brick power supply, the only thing is with the amp it doesn't seem to go as loud as my Lepai 2020+ with a 5 amp brick power supply. Here are some pics
Thanks,
Webber
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Webber,
That looks fantastic! Nice job - it's great to see someone else build it on the same day! I am glad you like the sound.
Regarding the volume of the 3116d2 amp: it should be as loud if not louder than the ta2020 - it might just be the input sensitivity of the front end. What are you driving the amp with? An iPod may not have enough oomph to get max volume. Try the headphone outputs of a real CD player or drive with a preamp put from a stereo receiver.
Excellent work!
That looks fantastic! Nice job - it's great to see someone else build it on the same day! I am glad you like the sound.
Regarding the volume of the 3116d2 amp: it should be as loud if not louder than the ta2020 - it might just be the input sensitivity of the front end. What are you driving the amp with? An iPod may not have enough oomph to get max volume. Try the headphone outputs of a real CD player or drive with a preamp put from a stereo receiver.
Excellent work!