XKi - X's ab initio Karlson 6th Order Bandpass

[freddi]

There's Karlson activity in Thailand

PA Speaker designs by THA

what does Rodden's arrangement really do? ("It slices - it dices" ??) - There's some real builds of "this"

usually the apertures are done as such

but i see one has turned them around in this suggestion

Metro's cabinet is easier to grasp and xrk971's "XKi" model would make something similar

 

[iowajosh]

Betsy-k, suitable or not?

 

[xrk971]

Hi Freddi,
Thanks for pointing this out - that sure looks just like an XKi with a double aperture.

An externally hosted image should be here but it was not working when we last tested it.

But the one with the aperture turned around would be better and I have in fact, built this. I put two PA-130's on an angled V and had a flat diamond K aperture on the face.

 

[xrk971]

Kappa 15c, sorry
Apart from that , I also have a pair of crites cast woofers in a pair of Klipsch belle clones

An idea I've been toying with is replace the belle bass bin with something of equivalent bulk but which can go lower than a stock Klipsch bin (which rolls off below 100 Hz) and higher (about 600-800 Hz)
The easy option would be a reflex bin - like an altec 19
I've tried K15 in the past but they start to sound "different" above 400 Hz. I wonder if your designs can do any better . What I was thinking is a karlson variant lying on it's side . As we know karlsons have awesome hit but the stock k15 rolls off a bit early below 60 Hz.if we could get another 0.75 to 1 octave below that , I can run true 2 way without needing a sub

I'm not too constructed by bulk but ideally, the cab would match the dimensions of my bass bin .

https://www.diyaudio.com/forums/mul...ates-variation-belle-klipsch.html#post4207025

Hope that explains my use case .

CW1526C cast frame.

FS is 26.3, Re is 3.36, VAS is 506.3 Liters, BL is 12.49, QM is 9.93, QE is 0.27, QT is 0.26. Sensitivity is 97 db. Coil is 1 mH.

Pmax is 150 watts. Xmax is 7.15 mm, MMS is 75.5 grams, Cms is 0.486 mm/N/CODE][/QUOTE]

I will need the Sd in cm^2 for the Crites woofer.

 

[xrk971]

Ok, so let’s shoot for circa -6dB at ~30Hz and -3dB at ~40Hz ok? Having no real limitation on bulk is a nice advantage when it comes to modeling a solution. There will be some the usual Karlson “W” dips in the 200Hz to 500Hz range, but generally not audible. Some drivers are perfect for this alignment, others not so much - we will have to see how it works in the sim.

For K15c XKi:

So what I have so far is a 250 liter box, about 19.5in wide x 22.5in deep x 34.5in high (all internal dimension). Assuming you will use 3/4in ply that will give 21in wide x 24in deep x 36in tall cabinet. The vent is 19.5in wide x 2.5in tall x 16in long. The front chamber is 1/3rd the total volume.

This will give 95.3dB sensitivity at 2.83v and 1m. -3dB at 34Hz and -6dB at 30Hz.

I can't predict how high it will go, but that is mostly limited by bandwidth of the driver - which seems to have a nasty peak at 1.8kHz. So some attenuation there by the aperture might be a good thing.

 

[xrk971]

Here was the XKi with dual PA130-8 with a small AMT super-tweeter in the middle. The K aperture has been removed here for clarity. This one was tuned as a mid-bass and above so goes down to about 90Hz. Sounds pretty good.

 

[freddi]

reA130 x2 XKi ooh - that looks good. I'd like to have one which would subjectively give a good midbass horn a run - maybe work also with a large AMT,

Here's Raymond Rodden's patent from 1982

https://patentimages.storage.googleapis.com/15/c5/c3/475b9c64e0ffde/US4313521.pdf

 

[zobsky]

I will need the Sd in cm^2 for the Crites woofer.

Should be equivalent to the Klipsch k33 woofer,from which it was reverse engineered i.e. 890 cm2 . I'll see if I can find a defacto spec value

 

[freddi]

"889.60" is what I have for the Eminence version of K33

 

[freddi]

X - is there a "high" spl 15" driver spec which will work to make a Karlsonator (or XKi) roughly the same bulk (or less) as K15 yet go a 1/3 octave or so lower? A tapped pipe with K aperture might work - may sound different.

 

[xrk971]

This doesn't have much above 1khz, but it seems to have some impressive numbers below. In a very compact XKi of 17in wide x 12in deep x 24in tall (internal 80 Liter) with a 17in wide x 1.5in high x 13.5in long vent, I simulate a 94dB sensitivity at 2.83v and -3dB of 48Hz and -6dB of 43Hz. It can handle 1500w power.

LaVoce WAN15400:
https://www.parts-express.com/pedocs/specs/293-726--lavoce-wan154.00-specifications.pdf

Def_Driver "WAN15400" | LaVoce 15 95dB 1500w inch Xmax 12.5mm
Sd=830cm2
Fs=40Hz
Mms=200g
Qms=8.50
Qes=0.42
Re=5.3ohm
BL=25.0Tm
Vas=105L

An externally hosted image should be here but it was not working when we last tested it.

 

[zobsky]

For K15c XKi:

So what I have so far is a 250 liter box, about 19.5in wide x 22.5in deep x 34.5in high (all internal dimension). Assuming you will use 3/4in ply that will give 21in wide x 24in deep x 36in tall cabinet. The vent is 19.5in wide x 2.5in tall x 16in long. The front chamber is 1/3rd the total volume.

This will give 95.3dB sensitivity at 2.83v and 1m. -3dB at 34Hz and -6dB at 30Hz.

I can't predict how high it will go, but that is mostly limited by bandwidth of the driver - which seems to have a nasty peak at 1.8kHz. So some attenuation there by the aperture might be a good thing.

Let me draft this up in SketchUp and start planning the build
Thx

Is the crites woofer more suitable ?

 

[freddi]

hey X - is there a good XKi for Dayton's 12" PA310 woofer? - despite having very flat response up high, its too dull in a traditional K12. Perhaps an XKi with shallower front chamber would balance better. A solid 50Hz or rock solid 60Hz would terrific. It might have to be used 3 way. Maybe I better stick with Kappa12a. I had one of my Kappa12a sitting on a large book and it slid down with book's corner putting a 2 1/2" crease in the cone - no tear but can't seem to fully get the crease reversed.

Def_Driver "PA310-8" | DAYTON 96.1dB 450 watts Xmax 5mm
Sd=530.9cm2
Fs=39Hz
Mms=72.8g
Qms=8.85
Qes=0.30
Re=5.5ohm
BL=18.0Tm
Vas=91.8L

 

[xrk971]

The PA-310 should work fine tuned to 50Hz. How big of a box are you looking for.

 

[freddi]

size wise - something which one who has multiple hernia issues can lift w/o immediate death - I'd give up a bit of that 50Hz low end - if can be picked up reasonably easily.

 

[xrk971]

W5-2143 XKi in BB ply is being laid out now. Hopefully will be done in a few weeks. 9in W x 11in D x 13 H (external). Fairly compact.

 

[perceval]

Very compact!

Compared to the size it needs in a TABAQ. Cool.
Nice little shelf unit. It'd be perfect for a small room study.

Will keep an eye on the future build.

 

[xrk971]

I am really considering of adding an optional (by-passable) internal Class D Bluetooth amp. In which case the binding posts could be used to tie left and right speakers to the amp located in one cabinet. Alternatively, could use small TDA7298 Class AB amp and BT module. The bypass toggle switch would have to switch the binding post input from external amp to a channel 2 out. I think I can do it with DPDT?

 

[freddi]

W5-2143 should be great in an XKi assuming favorable front cavity resonances. X - do you have a recommended passive crossover for your Beta 8cx/PRV 280 XKi?

 

[xrk971]

do you have a recommended passive crossover for your Beta 8cx/PRV 280 XKi?

I only ever ran that as an active with DSP, but seem to recall that I used a 24dB/oct XO at 2kHz. I applied a mild shelf to the tweeter for flattening. So I guess that is a 3rd order XO, but a lower order one might have worked too.

XKi - X's ab initio Karlson 6th Order Bandpass

Revisiting stuff I did years ago, this speaker sounds quite good!

Here is a slap bass clip:
https://www.diyaudio.com/forums/att...h-bandpass-xki-beta-8cx-slap-bass-09-vent-zip