Yes, planning on using it more for mids/highs, crossing between 150-750 hz. (So no 40hz high pass needed) Helper woofer looking like 2x 15" per side, so they will hopefully provide the lower end punch I'm looking for. Being able to cross lower to play around with xo freq might not be a bad thing though. Max spl around 117 db from first go-round is likely enough volume.. though having more headroom never hurts. 
What wattage corellates with 28v rms? I'm running these off a receiver with 80w per channel rms.
What wattage corellates with 28v rms? I'm running these off a receiver with 80w per channel rms.
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28.3v over an 8 ohm load is ~100 watts - ~80 watts over 8 ohm load is 25.3v. A 16 liter front chamber is pretty close to a K12's front chamber in volume. Maybe X will sketch out dimension details. This would be something I might like built.
a rough kludge in hornresp with the 115bk fudge model says
https://i.imgur.com/T7f6QQW.jpg
I had 250TC in a stock slit vent K12 with slits damped and there was no bass nor boom so assume the rear chamber was larger than needed. Sound quality was excellent for a 12" FR with no apparent artifacts. Another good driver was Eminence's Cannabis Rex guitar speaker but that would require a crossover and tweeter.
2 strong 15 per side in a reflex will get some dynamics (and clear mids) - probably moreso than a horn of equivalent bulk and cutoff. Many years ago, JBL had a "tent sale" where they sold their 2 x 15 cabinet loaded for $200 each - including shipping to anywhere in the US (!) A lot of people bought the cabinets, then sold the drivers on Ebay for profit.
a rough kludge in hornresp with the 115bk fudge model says
https://i.imgur.com/T7f6QQW.jpg
I had 250TC in a stock slit vent K12 with slits damped and there was no bass nor boom so assume the rear chamber was larger than needed. Sound quality was excellent for a 12" FR with no apparent artifacts. Another good driver was Eminence's Cannabis Rex guitar speaker but that would require a crossover and tweeter.
2 strong 15 per side in a reflex will get some dynamics (and clear mids) - probably moreso than a horn of equivalent bulk and cutoff. Many years ago, JBL had a "tent sale" where they sold their 2 x 15 cabinet loaded for $200 each - including shipping to anywhere in the US (!) A lot of people bought the cabinets, then sold the drivers on Ebay for profit.
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80L = 4882 in^3
rear vol: .80 x 4882 = 3905.6 in^3
front vol: .20 x 4882 = 976.4 in^3
Assume internal width of 18";
rear csa: 3905.6/18 = 217 in^2
front csa: 976.4/18 = 54 in^2
too big.
Assume internal width of 16";
rear csa: 3905.6/16 = 244 in^2
front csa: 976.4/16 = 61 in^2
too big.
Assume internal width of 14";
rear csa: 3905.6/14 = 279 in^2
front csa: 976.4/14 = 70 in^2
Looks reasonable, see sketch.
Volumes are approximately right, if including ducting volume, and I did not subtract the driver displaced volume. Volumes (areas actually x width) taken in front of and behind the temporary blocking extrusion above the driver at the corner of the duct... not sure if that's exactly how/where you calculated them?
Note that I've tipped it forward so that the sound comes out horizontally - for pedestal mount or stacking on top of other drivers as in my case.
Thanks
Attachments
Yep Freddi's got it. Was just a crude sketch to get the volumes close, ran out of time to add the driver and finish the model. Wanted to flesh out how I'd make the driver vertical instead of angled. I'll finish it tomorrow and add some iso views of it in 3d.
Do i also have the duct length wrong? I just saw Freddi erased part of it.
Do i also have the duct length wrong? I just saw Freddi erased part of it.
Duct only needs to be 10.5in long and if the top wall is 19in, you probably don't need to wrap it. I calculate 93L (not subtracting duct or divider wall volume). I think you only need to make it 17.5in deep.
That's interesting to make it a parallelogram, probably helps reduce resonances.
17.5in x 14in x 20in = 4900in3
x (2.54cm/in)^3 = 80.3L
Btw, I just tested a new small XKi I made with dual PA130-8's and dual vents driven by a small Pass ACA 5w SE Class A amp. Sounds great and proves that the ACA can drive 4ohm loads. I don't have the aperture yet, but sounds pretty nice at this stage even though tuned pretty high at 80Hz.
Sound clip:
http://www.diyaudio.com/forums/attachment.php?attachmentid=634329&d=1504837285
That's interesting to make it a parallelogram, probably helps reduce resonances.
17.5in x 14in x 20in = 4900in3
x (2.54cm/in)^3 = 80.3L
Btw, I just tested a new small XKi I made with dual PA130-8's and dual vents driven by a small Pass ACA 5w SE Class A amp. Sounds great and proves that the ACA can drive 4ohm loads. I don't have the aperture yet, but sounds pretty nice at this stage even though tuned pretty high at 80Hz.
Sound clip:
http://www.diyaudio.com/forums/attachment.php?attachmentid=634329&d=1504837285
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Ok, thanks! Do you not count the duct volume then for either front nor back chamber volumes? If so, my rear chamber volume is a bit small. I'll play with it more tomorrow on lunch at work. My volumes are calculated stragiht from the surface area minus the dividers, so it ought to be pretty close, just need to subtract duct volume and driver volume from the back chamber, so it may get a hair deeper.
Jesse
Resonances, be gone!
Did not find displacement info for Fane, so used 12lta - ought to be close-ish...
.071 ft3
122.69 in3
80L = 4882 in^3
rear vol: .80 x 4882 = 3905.6 in^3+122.69 (driver) = 4028.3 in^3
front vol: .20 x 4882 = 976.4 in^3
Assume internal width of 14";
rear csa: 4028.3/14 = 288 in^2
front csa: 976.4/14 = 70 in^2
Front curtains are just fudged, I'm not sure what the standard amount of coverage is, or standard radius etc, so I'll just show what I did for comments... so the 2nd picture is showing the curtains face-on, ie. the view is normal to that angled face.
.071 ft3
122.69 in3
80L = 4882 in^3
rear vol: .80 x 4882 = 3905.6 in^3+122.69 (driver) = 4028.3 in^3
front vol: .20 x 4882 = 976.4 in^3
Assume internal width of 14";
rear csa: 4028.3/14 = 288 in^2
front csa: 976.4/14 = 70 in^2
Front curtains are just fudged, I'm not sure what the standard amount of coverage is, or standard radius etc, so I'll just show what I did for comments... so the 2nd picture is showing the curtains face-on, ie. the view is normal to that angled face.
Attachments
you've got fine drafting skills ! - on a little 8-inch 70Hz tuned K, used a fairly fast aperture suggested by a friend played well. I'd like another stab at this one with less cavity peak/prettier graph. Its got a lot of hit for a tiny cabinet with an 8. A 10" sounds in an old K12 sounds more like a real drum kit.
YouTube
YouTube
thanks Freddi, but I better be at least okay at it given that it's what I do for a living
Just keep in mind that the aperture is faked... not sure how much its actually supposed to cover the speaker cone area. Also not sure about how high up that slot should go, curtain radius, etc.. does Akabak model this sort of thing?
Also, does the angle of the driver relative to the curtain matter much? I drew it at a 65 deg angle from horizontal, so a 25 deg angle from the driver.
Just keep in mind that the aperture is faked... not sure how much its actually supposed to cover the speaker cone area. Also not sure about how high up that slot should go, curtain radius, etc.. does Akabak model this sort of thing?
Also, does the angle of the driver relative to the curtain matter much? I drew it at a 65 deg angle from horizontal, so a 25 deg angle from the driver.
You might want a radius round-over on that knife edge on the port to reduce turbulent chuffing and even whistling sound when that sharp. The speaker looks like a large PE coach's ball whistle. Don't forget to add felt around back chamber near driver, and line the inside of the front chamber, aperture and all with felt. It really improves the sound definition and reduces echo sound.
Don't forget to add felt around back chamber near driver, and line the inside of the front chamber, aperture and all with felt. It really improves the sound definition and reduces echo sound.Good idea, may as well round over the edge on the inside of the port as well...
It looks... interesting. Not felt line the entire rear chamber? Just adjacent to driver.. or opposite driver on back of chamber?
It does look bigger than the measurements might suggest when I throw it in a corner with some other enclosure models. Something to do with the sharp angles maybe.
Any rules of thumb for the aperture? Area, length of slot, vertical justification of curtain radius centers relative to driver center, angle of aperture boards relative to driver baffle?
best,
Jesse
Edit:
Also, that rear chamber is ~2.33 ft^3, so it would also suffice for a plain sealed enclosure if you removed the "curtains" to compare the difference. I was thinking even with the curtains on it would then be a sealed enclosure with potentially better dispersion... though I don't have any idea how the front chamber behind the curtain/above the driver would affect things.
It looks... interesting.
Not felt line the entire rear chamber? Just adjacent to driver.. or opposite driver on back of chamber?It does look bigger than the measurements might suggest when I throw it in a corner with some other enclosure models. Something to do with the sharp angles maybe.
Any rules of thumb for the aperture? Area, length of slot, vertical justification of curtain radius centers relative to driver center, angle of aperture boards relative to driver baffle?
best,
Jesse
Edit:
Also, that rear chamber is ~2.33 ft^3, so it would also suffice for a plain sealed enclosure if you removed the "curtains" to compare the difference. I was thinking even with the curtains on it would then be a sealed enclosure with potentially better dispersion... though I don't have any idea how the front chamber behind the curtain/above the driver would affect things.
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There is a non-dimensional curve fit of the K aperture that is scalable here:
http://www.diyaudio.com/forums/full-range/213594-karlson-10.html#post3528706
http://www.diyaudio.com/forums/full-range/213594-karlson-10.html#post3528706
Xrk,
If you had a pair of Fostex Fe206 drivers, and you wanted to build a Karlson style boxes, which way would you go?
-"Classic"- Karlson 12
-Karslonator
-Xki
Assume that your goal is to use it without sub, so you may want to make it go as low as possible, even if it means somewhat less efficiency...
If you had a pair of Fostex Fe206 drivers, and you wanted to build a Karlson style boxes, which way would you go?
-"Classic"- Karlson 12
-Karslonator
-Xki
Assume that your goal is to use it without sub, so you may want to make it go as low as possible, even if it means somewhat less efficiency...