- this got me curious so here at 1/24 octave and way up (~40" up) from the floor are a 0.4 scale foam core Karlsonator with Vifa TC9FD vs a somewhat larger volume vented paper mache "head" loaded with MCM's 5 inch monitor speaker.
FWIW, the little Karlsonator extends to about 55Hz - not a lot of power but has a nice LF characteristic. MCM's cousin to PA130 rolls off after ~13K and has a nice midrange overall. They are good for $10.
the vented head is weak on the bottom and too weak there to maintain the rolloff slope
FWIW, the little Karlsonator extends to about 55Hz - not a lot of power but has a nice LF characteristic. MCM's cousin to PA130 rolls off after ~13K and has a nice midrange overall. They are good for $10.
the vented head is weak on the bottom and too weak there to maintain the rolloff slope
Thanks for all the info. Since I have the Vifa drivers I may attempt to build another one. I will need more hot glue though. If I do, I will attempt to brace it. I will say though, I had a lot of trouble getting everything to fit together tight. Seems like everything was off by a 1/4" or more. Well enough for an air leakage. I also found the bracing detail to be very confusing. (Hence why I skipped it. Also the precut shapes did not match the angle of my folded horn. Perhaps I should have laid it all out and sketched on the side piece beforehand...)
Here's another question. Just how densely does the stub need to be damped? In purely subjective terms. I would say mine is moderately stuffed, versus loosely stuffed or heavily stuffed.
Here's another question. Just how densely does the stub need to be damped? In purely subjective terms. I would say mine is moderately stuffed, versus loosely stuffed or heavily stuffed.
Hi,
I just stumbled upon this thread, and it looks like a ton of fun!
I have a full case of Dayton ND90-8 (60 pcs!!) laying around originally intended for a line array project that was never realized.
I just threw a few in a small cab to have a quick listen.
They sound smooth enough, and can play impressivly loud due to some serious excursion capabilities.
It would be a fun little project to try them out in a Karlsonator cab. Does anybody know if a pair would work in a 0.53 versjon?
I just stumbled upon this thread, and it looks like a ton of fun!
I have a full case of Dayton ND90-8 (60 pcs!!) laying around originally intended for a line array project that was never realized.
I just threw a few in a small cab to have a quick listen.
They sound smooth enough, and can play impressivly loud due to some serious excursion capabilities.
It would be a fun little project to try them out in a Karlsonator cab. Does anybody know if a pair would work in a 0.53 versjon?
I used TS params from here:
Dayton Audio ND90-8 3-1/2" Aluminum Cone Full-Range Driver 8 Ohm
Those are great drivers and when in parallel, you will have an 89dB sensitive speaker that reaches about 51Hz (-3dB). Scale the GregB Karlsonator pdf plan by 0.53x in height and depth, but scale by 0.47x in width in order to match the Qts and Vas correctly for an optimal flat response. Should be very nice.
Important to have the K-aperture terminate in a sharp cusp and not a slot on this one - to get the smoothest and deepest response. Stop 3in from the top.
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Is polyfill directly behind the drivers an issue? I didn't stuff this area but I noticed some loose fill there when I took mine apart in attempt to reseal them. I'm assuming this fell due to gravity/vibration as I didn't glue in the polyfill, it was merely stuffed in.
Just so I understand the physics correctly. The folded horn portion of the enclosure is to allow for the bass to...exist(?) in its long wavelength and be ported/forced through the front enclosure. Hence why this needs to be airtight. Any leakage and this wave will collapse. The stub behind the drivers is an artifact of the folded horn enclosure. Filling/damping this is to prevent unwanted resonances from that geometric shape. Mids and highs are produced directly via the driver. That is, the folded enclosure doesn't do much to amplify the mids/highs. And finally, the K-portion is for dispersion(?).
Is any of this right?
I also realized that the binding posts I purchased and forced through the back of the enclosure are dubious at best. This may be one of the primary sources of leakage. Did you guys just run a loose wires out of the enclosure and seal it up?
Just so I understand the physics correctly. The folded horn portion of the enclosure is to allow for the bass to...exist(?) in its long wavelength and be ported/forced through the front enclosure. Hence why this needs to be airtight. Any leakage and this wave will collapse. The stub behind the drivers is an artifact of the folded horn enclosure. Filling/damping this is to prevent unwanted resonances from that geometric shape. Mids and highs are produced directly via the driver. That is, the folded enclosure doesn't do much to amplify the mids/highs. And finally, the K-portion is for dispersion(?).
Is any of this right?
I also realized that the binding posts I purchased and forced through the back of the enclosure are dubious at best. This may be one of the primary sources of leakage. Did you guys just run a loose wires out of the enclosure and seal it up?
You have it all correct except that the stub is needed to provide bass amplification as it is the length of the TL that is important. I have polyfill all the way down behind the drivers - that is fine. I have it moderately stuffed in the stub. I have used cheap $1 spring clip terminal cups sealed with hot melt. Most of time I run loose wires thru a hole sealed with hot melt. Yes, K-aperture is for dispersion and it increases bass extension.
Thanks a lot X!
I will try this one out for sure!
John Murphy at Trueaudio.com tested and used this driver for his corner line array project.
He measured this driver with slightly different specs, FS 84,1 Hz, VAS 0,0043 qi andre QTS 0,757.
I dont know if this makes any difference thow....
I got all four done. I must say, I'm somewhat disappointed in the sound. Perhaps I'm spoiled. Others are impressed by them.
IMO they sound tubby. The bass is surprising, if not too exaggerated. Percussion and bass guitar are surprising from such small speakers, They sound much bigger than they are. They sound better when played loud.
Vocals are another matter. Male singers sound like they're in a well.
I recall some suggestions regarding stuffing. They currently have some acoustic stuffing in the stub cavity above and behind the driver, with some more loosely behind the driver. I'll add more in the path leading to the slot and more densely stuff the area directly behind the driver. I recall reading that adding stuffing reduced the bass output but made the bass tighter. I'll report back.
IMO they sound tubby. The bass is surprising, if not too exaggerated. Percussion and bass guitar are surprising from such small speakers, They sound much bigger than they are. They sound better when played loud.
Vocals are another matter. Male singers sound like they're in a well.
I recall some suggestions regarding stuffing. They currently have some acoustic stuffing in the stub cavity above and behind the driver, with some more loosely behind the driver. I'll add more in the path leading to the slot and more densely stuff the area directly behind the driver. I recall reading that adding stuffing reduced the bass output but made the bass tighter. I'll report back.
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In the words of Gilda Radner's SNL character, "Never Mind."
After adding stuffing to the boxes (and a Royal Oak Brewing Mean Streets Amber Ale to me) the sound is very much improved.
Full disclosure: the enclosures are 1/4" baltic ply. The motorboard and front K-slot boards are 1/2" baltic ply. The interior panels are dampened with 1/8" closed cell foam. The front of the baffle boards and the back of the K-slot boards are covered with the textured closed cell foam shown in the attached photos.
Rather than binding posts, I use Neutrik Speakon connectors. I always want a product of Lichtenstein in all my speaker build.
The enclosure are glued together with Loctite PL supplemented by brads from a Paslode finish nailer and liberal clamping. There are no air leaks.
After the added stuffing, and the beer, the sound is very much improved. The tight percussion is even better. The drum solo on Brubeck's Take Five is amazing. The cymbals are now readily apparent.
Vocals, male and female, are improved. The "down a well" effect is gone. They are amazing little speakers. I'm eager to see how the mate up to some DIY subs.
After adding stuffing to the boxes (and a Royal Oak Brewing Mean Streets Amber Ale to me) the sound is very much improved.
Full disclosure: the enclosures are 1/4" baltic ply. The motorboard and front K-slot boards are 1/2" baltic ply. The interior panels are dampened with 1/8" closed cell foam. The front of the baffle boards and the back of the K-slot boards are covered with the textured closed cell foam shown in the attached photos.
Rather than binding posts, I use Neutrik Speakon connectors. I always want a product of Lichtenstein in all my speaker build.
The enclosure are glued together with Loctite PL supplemented by brads from a Paslode finish nailer and liberal clamping. There are no air leaks.
After the added stuffing, and the beer, the sound is very much improved. The tight percussion is even better. The drum solo on Brubeck's Take Five is amazing. The cymbals are now readily apparent.
Vocals, male and female, are improved. The "down a well" effect is gone. They are amazing little speakers. I'm eager to see how the mate up to some DIY subs.
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DizRotus:
Those look fabntastic! Like mini PA boxes with Speakons and black Duratex paint. I have never heard one made of half in BB ply - that is some stiff stuff. Glad you like the sound and Take 5 is one of my favorites. Try listening to Paul Desmond's Glad to be Unhappy (I think he played sax for Brubeck in Take Five) sometime - the wide sound stage on these will go beyond their placement width.
Congratulations!
Another happy build of the mini K'nator!
I like the thing about product of Lichtenstein in all my builds - LOL! Didn't know Speakons came from there.
Those look fabntastic! Like mini PA boxes with Speakons and black Duratex paint. I have never heard one made of half in BB ply - that is some stiff stuff. Glad you like the sound and Take 5 is one of my favorites. Try listening to Paul Desmond's Glad to be Unhappy (I think he played sax for Brubeck in Take Five) sometime - the wide sound stage on these will go beyond their placement width.
Congratulations!
Another happy build of the mini K'nator!
I like the thing about product of Lichtenstein in all my builds - LOL! Didn't know Speakons came from there.
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It's tricky. Make sure you take photos in landscape format with your phone or camera. I have tried rotating it before in a program but sometimes it still uploads sideways or worse, upside down.
What's the logic behind such a small editing window on this forum? Now it's too late to go back to rotate the two middle pictures attached to post #1454, even if I knew how.
On another note, one of my TC9FDs seems to be defective. Sounds like the voice coil is rubbing. It badly distorted right out of the box. At first I suspected a problem with the hot rodded TDA7297 that I was using, but quickly changing channels (love those Speakons) caused the problem to follow the speaker, thus acquitting the amp. Gently touching the surround makes the problem disappear. Has anyone else had a dud TC9FD?
A replacement is on the way from PE.
On another note, one of my TC9FDs seems to be defective. Sounds like the voice coil is rubbing. It badly distorted right out of the box. At first I suspected a problem with the hot rodded TDA7297 that I was using, but quickly changing channels (love those Speakons) caused the problem to follow the speaker, thus acquitting the amp. Gently touching the surround makes the problem disappear. Has anyone else had a dud TC9FD?
A replacement is on the way from PE.