Fun build!
I finished a pair of Mini Ks!
No real idea what I was doing, but they sound great! Paired with a mini BT amp, they are a gift for my newly graduated daughter starting her first job.
If you see any big mistakes, let me know!
I got more sheets of foam for me......
Thanks x!
I finished a pair of Mini Ks!
- Are they perfect? Not by a longshot.
- Are they cheap? You betcha! Thirtyish bux
- Are they fun? 2 nights of amusement! More to come.....
No real idea what I was doing, but they sound great! Paired with a mini BT amp, they are a gift for my newly graduated daughter starting her first job.
If you see any big mistakes, let me know!
I got more sheets of foam for me......
Thanks x!
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
Dressed them up a bit for the office
My daughter thought white foam core was a bit stark for the office, so we dressed them up a bit. Grey primer undercoat and Stone texture paint to hide the um....flaws... Turned out rather nice I think!
The paint seems to toughen up the surface just a tad, too. If it ruined the sound quality, my ears could not tell.
My daughter loves them!
My daughter thought white foam core was a bit stark for the office, so we dressed them up a bit. Grey primer undercoat and Stone texture paint to hide the um....flaws... Turned out rather nice I think!
The paint seems to toughen up the surface just a tad, too. If it ruined the sound quality, my ears could not tell.
My daughter loves them!
Nice work Gecko! Very clean and neat. Glad you like the sound!
I am surprised the volatile vapor/fumes from the paint did not delaminate the paper from the foam or melt the foam. I had that happen once, which is why only water based paints can be used on foamcore, in general. Maybe the primer was water based and that protected the paper/foam? It looks real nice though what you did.
Paint
I did several tests on scrap board and a many of the paints did delaminate the foam core. The grey primer in light coats was kind to the paper and and foam. I used foam core from Office Depot.
The under coat primer was Rust-oleum Painter's Touch 2X Ultra Cover Flat Gray Primer. Pretty sure the marketing dept got paid by the word for that!
The winning formula was 2 light coats of the gray primer allowed to dry, then the stone paint on top to taste. Pretty quick and easy
Folded MTL for the Vifas are next for the back porch! Cutting starts after work.
I did several tests on scrap board and a many of the paints did delaminate the foam core. The grey primer in light coats was kind to the paper and and foam. I used foam core from Office Depot.
The under coat primer was Rust-oleum Painter's Touch 2X Ultra Cover Flat Gray Primer. Pretty sure the marketing dept got paid by the word for that!
The winning formula was 2 light coats of the gray primer allowed to dry, then the stone paint on top to taste. Pretty quick and easy
Folded MTL for the Vifas are next for the back porch! Cutting starts after work.
During this sad period where we all stayed at home, I took the opportunity to make what was a long plan, a big Karlsonator with the Lii F15 driver.
It is a big beast driven with a First Watt F5.
There is no damping at all, no joins, and it sound just like I hoped it would, big sound a very low level with all the details the recording provides. Moreover, there is no particular "sweet spot", you can sit anywhere or place the baffles a bit like you can if the configuration of your room isn't ideal.
It is a big beast driven with a First Watt F5.
There is no damping at all, no joins, and it sound just like I hoped it would, big sound a very low level with all the details the recording provides. Moreover, there is no particular "sweet spot", you can sit anywhere or place the baffles a bit like you can if the configuration of your room isn't ideal.
Attachments
Thanks Freddy, It sounds great altogether.....of course, I made it, how could I say otherwise
The most impressive is Glen Gould's piano, man how great pianist he was ! He is in your room and you can appreciate his touch, that wasn't that obvious on my previous system.
Something is sure, if the recording isn't the best you know it straight away.
BTW, you know I have a copy of the old Karlson site, I made it just before it closed down, in case you would like it.
With this Lii F15 I should be around 93db sensivity which is great with the FW F5. I repeat again, I believe OSB is a very interesting material for building enclosures because it heterogeneous, avoiding internal reflexions but a pain to work.
Toopy, wow! That’s got to be the biggest Karlsonator I have ever seen!
Nice work!
Thanks, it wasn't easy to do on my kitchen table
.....but I had time....and I took it. I
Hi Tooppy
what are the enclosure's external dimensions?
OSB should (?) have much better internal damping than plywood or MDF.
Did you cut it by handsaw ? - if by power saw, what type and teeth blade would you suggest to minimize fraying? How are the panels joined/glued?
That plexiglass aperture should ameliorate some of the fears folks have about Karlson type speakers
Are you listening to Gould's later "Goldberg" performance? How does your big Karlsonator sound with harpsichord ? (those seem tough to record and some modern recordings far worse than those a half century ago)
I'd love to have a copy of the old Karlson forum but wonder if anyone would be interested at this point in time (?) Something like DropBox might distribute it.
what are the enclosure's external dimensions?
OSB should (?) have much better internal damping than plywood or MDF.
Did you cut it by handsaw ? - if by power saw, what type and teeth blade would you suggest to minimize fraying? How are the panels joined/glued?
That plexiglass aperture should ameliorate some of the fears folks have about Karlson type speakers
Are you listening to Gould's later "Goldberg" performance? How does your big Karlsonator sound with harpsichord ? (those seem tough to record and some modern recordings far worse than those a half century ago)
I'd love to have a copy of the old Karlson forum but wonder if anyone would be interested at this point in time (?) Something like DropBox might distribute it.
I use osb for testing cabinets and cheap builds, some people really liked it varnished. I've found big differrences between OSB brands, check before buy. OSB3 and OSB4 grades use to looks better.
I cut osb with a circular saw with finishing blade, carbide tipped 160mm x 40 teeth. No big chipping problems in good panels. For finer cuts, try lifting the blade and move slowly.
Edge cut is always rough, I finish it with a roundover router pass.
Osb glues very well. Nothing special, just good carpenter glue D2 type (Pattex Express).
Hope this helps,
Víctor
Freddi
I drew every parts on paper to fit to the best the size of the sheets of OBS3 sold, and give it to the shop to cut.
OSB3 is water resistant and used for floor renovation.
I then get home with all the pieces cut.
But you know the storage is often lousy in these shops and the planks are swayed. So you always need to adjust afterwards.
All is handsawed , any power saw makes too much vibrations for a straight cut ; don't forget it is all made on my kitchen table.
The only power tool I used was a dremmel to cut the main circular hole for the driver and of course a drill. But I had to modify it to get the right radius and made the cut in two operations. As it would cut just half the thickness of the plank, I need to flip the plank over and repeat the cut on the other side. Again due to vibrations, I had to do it slowly, it took me about 3/4 of an hour to make one cut then flip over another 3/4H.
When you live in a flat and have no dedicated space, you can't have the right tools to work.
The big deal was also the chamfers, all made with wood grater, but the OSB chipped easily with this tool, so I first needed to cut the surface with a cutter to get something clean.
All is cleated, glued, screwed and small gaps are pasted or even injected with glue.
All the outside edges are protected with a coat of glue then a coat of paste.
The sides are tinted with two different colours then varnished with one coating only, the top and inside have one coat of pre and two coats of paint.
Gould's recordings are probably the later ones, in the seventies, CBS and Sony.
For the Karlson site see your PM here on this site.
I drew every parts on paper to fit to the best the size of the sheets of OBS3 sold, and give it to the shop to cut.
OSB3 is water resistant and used for floor renovation.
I then get home with all the pieces cut.
But you know the storage is often lousy in these shops and the planks are swayed. So you always need to adjust afterwards.
All is handsawed , any power saw makes too much vibrations for a straight cut ; don't forget it is all made on my kitchen table.
The only power tool I used was a dremmel to cut the main circular hole for the driver and of course a drill. But I had to modify it to get the right radius and made the cut in two operations. As it would cut just half the thickness of the plank, I need to flip the plank over and repeat the cut on the other side. Again due to vibrations, I had to do it slowly, it took me about 3/4 of an hour to make one cut then flip over another 3/4H.
When you live in a flat and have no dedicated space, you can't have the right tools to work.
The big deal was also the chamfers, all made with wood grater, but the OSB chipped easily with this tool, so I first needed to cut the surface with a cutter to get something clean.
All is cleated, glued, screwed and small gaps are pasted or even injected with glue.
All the outside edges are protected with a coat of glue then a coat of paste.
The sides are tinted with two different colours then varnished with one coating only, the top and inside have one coat of pre and two coats of paint.
Gould's recordings are probably the later ones, in the seventies, CBS and Sony.
For the Karlson site see your PM here on this site.
Attachments
@vitorio - thank you very much for those details.
@tooppy - that's an amazing build using hand saws and rasps. Does your enclosure have an offset "stub" feature? (part shown in green below)
I sent you a link to my drawings in your PM box.