A member asked me to see if the 300TC could work in a Karlsonator. Yes, indeed it does! More info in this thread:
Mini Karlsonator (0.53X) with Dual TC9FD's
But short story is that you can scale the base 12in Karlsonator plans by 1.38x high and deep x 1.25x wide for a cabinet for a cabinet with the following response:
One nice thing about placing a 15in fullrange behind an acoustic lens like the K-aperture is that it reduces beaming, making for a much wider angle and more uniform polar pattern.
Mini Karlsonator (0.53X) with Dual TC9FD's
But short story is that you can scale the base 12in Karlsonator plans by 1.38x high and deep x 1.25x wide for a cabinet for a cabinet with the following response:
One nice thing about placing a 15in fullrange behind an acoustic lens like the K-aperture is that it reduces beaming, making for a much wider angle and more uniform polar pattern.
LingWendil should get credit for that.
I just pushed a bit:
Which immediately triggered:
Shortly after that, I had: "The Dream"
If I can source a pair of either the 12 or 15 in the US without prohibitively expensive shipping I think I want to build a pair this year for sure, the graphs look gorgeous
I suppose once you find out how to get bootleg 18mm Baltic birch ply from the black market, you would have to cross the border to Canada and smuggle these back.
SOV.12-250TC - Solen Electronique Inc.
$146CAN is a fair price for such an extreme driver.
A Karlsonator may be the ideal cabinet because the K-aperture provides two benefits: wide dispersion to combat the beaming from a 12in full range, and the K-aperture applies a high pass shelf that might tame the rising top end that many people feel a need for electronic EQ. We won’t know until we build though. This is a good candidate for XPS foam pathfinder - add the baffle board with 3/16in plywood to anchor the driver. Make the K aperture out of 3/16in ply bonded to 1/2in XPS with non hardening industrial or construction adhesive - latex caulking works. That will dampen vibrations. Interior of cabinet should be lined with eggcrate foam. Exterior front chamber should be lined with melamine sponges.
XPS and ply works very well as a speaker if you have followed Vunce’s 10F/RS225 FAST TL build. It sounds great and no rattles or problems.
10F/8424 & RS225-8 FAST / WAW Ref Monitor
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I suppose once you find out how to get bootleg 18mm Baltic birch ply from the black market, you would have to cross the border to Canada and smuggle these back.
SOV.12-250TC - Solen Electronique Inc.
$146CAN is a fair price for such an extreme driver.
And the 15" isn't that much more expensive at 179$ CAD per.
Fane, 39cm Paper Cone Pro Fullrange, with 51mm Voice Coil.
The 12" is great, but the 15" is greater!
Fane speaker cabinet.
Plywood 18mm.
66cm high×39.5cm width×30.5cm depth. Indernal dimensions.
*Bracing left-right end, 28cm from the bottom.
Bracing front-rear 30.5x39.5 cm 8 holes 60mm each.
Bracing right left 17x39.5 cm 8 holes 60mm each.
Speaker center position 22.5cm from the top.
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My sims for a Fane 12-250TC in a sealed box with critical damping of 0.71 seems to get only about -3dB at 97Hz with floor and back wall reinforcement. If placed on ground, there is a big floor bounce cancellation that will have a dip at about 400Hz.
Here is frequency response with effects of room bounce for cabinet sitting on floor next to a back wall:
If we place cabinet on a tall stand away from surfaces, you only get -3dB of 97Hz:
Max SPL is at about 32Vrms and 114dB.
Attachments
A member asked me to see if the 300TC could work in a Karlsonator. Yes, indeed it does! More info in this thread:
Mini Karlsonator (0.53X) with Dual TC9FD's
But short story is that you can scale the base 12in Karlsonator plans by 1.38x high and deep x 1.25x wide for a cabinet for a cabinet with the following response:
One nice thing about placing a 15in fullrange behind an acoustic lens like the K-aperture is that it reduces beaming, making for a much wider angle and more uniform polar pattern.
Can you use foam for such a large cabinet?
Thanks X.My sims for a Fane 12-250TC in a sealed box with critical damping of 0.71 seems to get only about -3dB at 97Hz with floor and back wall reinforcement. If placed on ground, there is a big floor bounce cancellation that will have a dip at about 400Hz.
Here is frequency response with effects of room bounce for cabinet sitting on floor next to a back wall:
If we place cabinet on a tall stand away from surfaces, you only get -3dB of 97Hz:
Max SPL is at about 32Vrms and 114dB.
Sorry,i'm not a speaker expert, can you explain what do you mean damping of 0.71 ?
I think that is something to do with damping materials but ...
Finally what you think,is it something that need improvements?
I have tried to add sheep's hair as damping material.
Nothing special,just two sleeping pillows,about 4kg. and only at the right and left upper sides.
I feel that i hear a better and more deep bass.
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There is a point of “just right” or critical damping (stuffing amount) that doesn’t have overshoot and doesn’t attenuator bass more than needed. Mathematically it is called critical damping factor equal to sqrt2/2. I personally like mildly overdamped about 0.6. You can read about it on internet search.
But ultimately, adjust stuffing to your liking. It’s not a big deal - it will sound quite nice with a lot of stuffing. I like removing rather than adding.
Stuffing increases the virtual volume and makes deeper bass at expense of lower SPL. Try removing the pillow covers. It allows free air to move through.
Fiberglass insulation is great. Line the walls with eggcrate foam (mattress cover liner) then add stuffing.
But ultimately, adjust stuffing to your liking. It’s not a big deal - it will sound quite nice with a lot of stuffing. I like removing rather than adding.
Stuffing increases the virtual volume and makes deeper bass at expense of lower SPL. Try removing the pillow covers. It allows free air to move through.
Fiberglass insulation is great. Line the walls with eggcrate foam (mattress cover liner) then add stuffing.