That looks about right IMO.
I personally have never used BSC on any Karlson. If configured in the manner I deem to be proper - mind you not everyone has to share this view - the mid and upper bass gain in addition to the aperture diffraction at higher frequencies mostly balances things fairly well, sometimes a little bit too well. I used Fostex FF125K with its rising response and Philips AD9710/M8 with its 100dB/W/m plateau above 2kHz with fairly balanced results and no need for BSC. It is ultimately a personal preference and ultimately best determined in-situ. I've been wanting to see for a long time someone stick a Lowther in a Karlson.
I personally have never used BSC on any Karlson. If configured in the manner I deem to be proper - mind you not everyone has to share this view - the mid and upper bass gain in addition to the aperture diffraction at higher frequencies mostly balances things fairly well, sometimes a little bit too well. I used Fostex FF125K with its rising response and Philips AD9710/M8 with its 100dB/W/m plateau above 2kHz with fairly balanced results and no need for BSC. It is ultimately a personal preference and ultimately best determined in-situ. I've been wanting to see for a long time someone stick a Lowther in a Karlson.
It turned out beaultiful on that finish.
Are the mesurments better than the foamcore version?
How low is it getting on your room?
I'm really going for it, and make the vent corners all rounded. Maybe today ordering the drivers, and when it arrives, will get the cut plans to the local shop to do it on plywood 15mm.
@xrk971,
How do you characterized sound of this to the .53x? Which one is better for watching TV, mostly movie?
The W5-2143 XKi has real bass down to 50Hz for sure. The wooden version needs foam installed in the inside of the outer chamber to sound right. There is a detailed photo of how to do that in this thread.
@hammercha The W5-2143 XKi probably has better bass than 0.53x Karlsonator but I would say mids clarity of dual 3FE25-16 is better for TV.
And what do you think about the XKi calculated for an Alpair 11MS, compared to the W5 2143?
Sensibility is less, but it's bigger SD may compensate, don't you think? I was originally thinking about an Alpair 11MS on a simple bass reflex or mini oken, but as my tube amp is a 3.5W, I still can't decide.
XRK, I have the W5-2143 on the way, meanwhile I'm going page by page of this topic. I'm getting half through it, and also doing my homework on the karlson theory.
One thing that captured my attention here is about the K aperture. As per the Karlson papers I'm reading, the exponencial aperture is the key for getting a flat response. I saw that the aperture recommended on the XKi has a different size and something like an open format to draw the curved line, and that is the point of my questions here:
1. I believe the 2" top offset for starting the aperture has something to do with blocking the back wave coming from the duct, correct?
2. The end format is different from the K Aperture of the original Karson design, as the recommendation for the XKi is the curved line goes down until reach the base of the speaker 1" away from the side wall, while the Karlson design has the exponential aperture finishing on the side wall, almost 1 inch (20mm) above the base of the speaker. Is there a reason for it?
3. I'm thinking about making a prototype first, using foam core, so I can make 2 different apertures and play with than, but I don't have anything but a cellphone to take any measurements... Would this be useful?
4. On my final cabinet, I'm planning to use 12mm ply, or maybe 18mm hardwood. Is there any benefit of cutting the aperture with 45 degrees angle? I don't know if the thickness of the aperture plays any role on the diffraction / distortion / resonant forms here. But definitely a 5mm cardboard or ply aperture will sound different from a 18mm thick aperture.
How high the aperture begins and its width will affect the tuning of the front chamber. Higher and wider will both raise that frequency.
The end (bottom) of the aperture isn't critical or even much important in itself IMO. How tight or open the profile is in front of the driver will have a greater effect, which might then determine what the end of the aperture is like. Tighter/narrower will be more colored and will give broader MF/HF dispersion, effectively producing a BSC-like effect. I would recommend a fairly open aperture with the driver you intend to use.
The end (bottom) of the aperture isn't critical or even much important in itself IMO. How tight or open the profile is in front of the driver will have a greater effect, which might then determine what the end of the aperture is like. Tighter/narrower will be more colored and will give broader MF/HF dispersion, effectively producing a BSC-like effect. I would recommend a fairly open aperture with the driver you intend to use.
Hi IG81
lets say I want to make a "K of sorts" for Eminence's Delta 10A. Which if any A/B/or C ways of connecting the vent to the chamber would you choose ?
Would you attempt to further squash the 16" height? I would use a K-tube on top.
At the other extreme, what height, etc. do you think might work well for a K10, including option (if useful to SQ) of curved or approximated curved reflector ?
A retake of a K12 might make more sense but I'm stuck on seeing what might be done with 10 inch drivers.
A smoothing stub could be employed. I'd like to retain some "hit".
Eminence's first B102 was a great driver for Ks. When they dropped magnet strength, they lost midrange output and HF extension -that said, I think the current B102 is workable for Karlson type.
A test box with variable baffle angle - removable reflector, vent panel, etc. sure would help sort matters - 'maybe " --]there's so much which could be adjusted via aperture - vent location - vent type (distributed vs single /dual) -shelf vent may benefit with a V notch per Nexo's vent patent, lowpass gap too.
lets say I want to make a "K of sorts" for Eminence's Delta 10A. Which if any A/B/or C ways of connecting the vent to the chamber would you choose ?
Would you attempt to further squash the 16" height? I would use a K-tube on top.
At the other extreme, what height, etc. do you think might work well for a K10, including option (if useful to SQ) of curved or approximated curved reflector ?
A retake of a K12 might make more sense but I'm stuck on seeing what might be done with 10 inch drivers.
A smoothing stub could be employed. I'd like to retain some "hit".
Eminence's first B102 was a great driver for Ks. When they dropped magnet strength, they lost midrange output and HF extension -that said, I think the current B102 is workable for Karlson type.
A test box with variable baffle angle - removable reflector, vent panel, etc. sure would help sort matters - 'maybe " --]there's so much which could be adjusted via aperture - vent location - vent type (distributed vs single /dual) -shelf vent may benefit with a V notch per Nexo's vent patent, lowpass gap too.
Attachments
Ok. Found something that explain part of my doubts here. I'm still thinking about how a proporcional exponencial adapted design from original Karlson's would affect the dips of the total spectrum, as per the theory of the K-tube and the exponencial design.
Hard to say, I'm not sure how each would behave, though B and C are fairly similar. Honestly, the SK8 is already pretty much a K10 and should work well, perhaps with Vb and Fb accommodations for a given driver. It measured fairly well and was well-behaved in its gain-BW.
My thinking as of late - as far as using a Karlson into the midrange and treble regions - is more focused on just making it worthwhile despite the response anomalies and subjective coloration. That means tuning for actual mid/upper-bass gain over the same driver as a direct radiator, usually in the 80Hz-300Hz region or so. This will often be tuning the rear higher so as to blend the response to the upper chamber gain, which is often more of a peak by itself, think sealed back response. Low bass will have to be traded-off naturally. Front chamber design should be about making this peak of lower Q, somehow. The aperture should take the driver's response into account, in which a rising response is IMO better - not that this is news to you.
I've put the TK6 aside for now, but may come back to it in the spring/summer. I might try another 8" PA FR for fun. The holey-vent seemed to tame the super-high Qt. I've been busy adding bracing and better absorption to my 5cu.ft TD15M boxes, as well as re-doing its DSP XO.
I've just bought a pair of Fane Studio 5FRK, these have a strong motor and could do a good XKi type. Mass-corner is ~420Hz on them. I have other plans for these, but if the mood strikes me, I might pop one into my XKi, its present tuning should not be wildly inappropriate.
XRK, The drivers will arrive on next week. Good ply is expensive here, so I will experiment something: 4mm ply + 5mm cardboard foam. Will try to make 3 internal bracing (one in each axis), cut the foam to fit just right and glue it all together, putting the recommended foam inside and inside the front pannel, besides the ply +FC. Another experiment for your list, let's check the results in a month or so, with documented construction.
@X
Looking to build some XKi for RS100-8 based on your sketches at hte beginning of the thread
Was planning to build four of them for 7.1 surrounds, what do you think of that application?
The only downside I can see: power handling might be limited, so my alternate plan would be two RS-100-4 in series in a ported box (https://www.werner007.de/lautsprecher-2/kompaktboxen/twinsurro)
Looking to build some XKi for RS100-8 based on your sketches at hte beginning of the thread
Was planning to build four of them for 7.1 surrounds, what do you think of that application?
The only downside I can see: power handling might be limited, so my alternate plan would be two RS-100-4 in series in a ported box (https://www.werner007.de/lautsprecher-2/kompaktboxen/twinsurro)