The cabinet is needed to extend bass response. The resonance freq peak will tell you about how low you can go with a proper enclosure. I would be more worried about the high freq roll off above 5k or 10k when off axis. You may want to consider a 4 inch class driver if you want true fullrange as the 225's tend to need helper super tweeters to sound good.
You may be right, that is a big driver for computer desk work. I just read throught eh thread on the Faital Pro 4FE32. That might be a fun one to try.
http://www.diyaudio.com/forums/full-range/246340-anyone-try-faital-pro-4fe32-3fe22.html
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http://www.diyaudio.com/forums/full-range/246340-anyone-try-faital-pro-4fe32-3fe22.html
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Yes, my idea was to use the 4FE32 in a very compact Karlsonator scaled to 12 in tall x 6 in wide - still small enough for desktop use. Similar to this but smaller and single driver.
http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-21.html#post3560234
http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-21.html#post3560234
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When I look at the Karlson cab, I always think the highs will be impeeded by the slot. Is that so???
Do you have plans for that small Kcab?
Do you have plans for that small Kcab?
I don't know about full size Karlson cabinets but that is not a problem with the ones I have built - the highs sound very good. The driver is situated behind the widest opening of the aperture so much of the highs from the cone make it out. The aperture actually helps the mid range have a more uniform directivity and wider dispersion - so in fact what I hear is better than a bare exposed cone.
You can listen for yourself with sound clips at bottom of the first post.
http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds.html
Plans for 0.53x scale are at above link. Although you can take the original plan by GregB and scale that to whatever you like. If you go with the 4FE32 a 0.4x scale works well for single driver and the 0.53x scale works for the dual driver version. You can get 94dB efficiency with the dual driver version - very sensitive.
You can listen for yourself with sound clips at bottom of the first post.
http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds.html
Plans for 0.53x scale are at above link. Although you can take the original plan by GregB and scale that to whatever you like. If you go with the 4FE32 a 0.4x scale works well for single driver and the 0.53x scale works for the dual driver version. You can get 94dB efficiency with the dual driver version - very sensitive.
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Hey djn,
That FF225WK response is likely in an infinite IEC baffle or similar, so lows will roll-off as early as they can. I'm using the FF225WK in 1cu.f cabs tuned to 39Hz and bass is very-well damped and super-tight once baffle-step is corrected for. Many folks might prefer tuning to 45-50Hz IMO.
The Karlson does "impede" the HF, but it's part of what makes it a simple solution for strong-motor FR drivers: it has lots of gain in the midbass and reduces the HF with greater dispersion, so you can basically stick a Lowther in there and it'd sound balanced, moreso than any sealed/reflex enclosure and somewhat like a much larger BLH would.
FF225WK might indeed be a bit large for desktop duty, depending on what you consider large in your situation. The FF165WK should work in ~15L tuned to 50-55Hz and will likely have better HF, FF225WK really does need a super-tweeter. FF125K could be good in 6-8L.
If you plan to use a subwoofer (do ya?), I don't see a reason to go for too larger a driver anyway, especially for nearfield work. I'm really liking the Tang Band W4-1320SIF bamboo 4" in double-chambered reflex (DCR) enclosures.
IG
That FF225WK response is likely in an infinite IEC baffle or similar, so lows will roll-off as early as they can. I'm using the FF225WK in 1cu.f cabs tuned to 39Hz and bass is very-well damped and super-tight once baffle-step is corrected for. Many folks might prefer tuning to 45-50Hz IMO.
The Karlson does "impede" the HF, but it's part of what makes it a simple solution for strong-motor FR drivers: it has lots of gain in the midbass and reduces the HF with greater dispersion, so you can basically stick a Lowther in there and it'd sound balanced, moreso than any sealed/reflex enclosure and somewhat like a much larger BLH would.
FF225WK might indeed be a bit large for desktop duty, depending on what you consider large in your situation. The FF165WK should work in ~15L tuned to 50-55Hz and will likely have better HF, FF225WK really does need a super-tweeter. FF125K could be good in 6-8L.
If you plan to use a subwoofer (do ya?), I don't see a reason to go for too larger a driver anyway, especially for nearfield work. I'm really liking the Tang Band W4-1320SIF bamboo 4" in double-chambered reflex (DCR) enclosures.
IG
Thanks X. I don't know how to scale, but this looks like a good project for a flee tube amp on my desktop.
Thanks IG. I agree that the FF225 might be too big for what I need. I am now looking at the Faital Pro 4FE32 in either an OB or Karlson cab. I'll probably start with the OB just because it is so easy to do.
Just take a hand calculator and multiply every dimension on GregB's plans by the scaling factor. So for a 0.4x scale Karlsonator, everything is 40% the size/dimension on the drawing.
The Vifa is in fact used as the tweeter/mid on the very popular Manzanita OB project - you can find that in the Multiway forum:
http://www.diyaudio.com/forums/multi-way/110583-fast-fun-inexpensive-ob-project.html
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Thanks sounds easy enough. So I would multiply the full dimention by .4 right? I just did the outside dimentions and that would be a cute little bugger at 6.7" W x 7.1" D x 12.4" T
My 4wpc compactrom amp will do nicely for up close and personal listening.
A piece of 8.5" x 11" paper is 93.5 sq in. This speaker's face would be 83.08 sq in. Perfect for sitting on either side of my monitor.
As I looked at the Karlon Plans, I realized it is a tapped horn!
My 4wpc compactrom amp will do nicely for up close and personal listening.
A piece of 8.5" x 11" paper is 93.5 sq in. This speaker's face would be 83.08 sq in. Perfect for sitting on either side of my monitor.
As I looked at the Karlon Plans, I realized it is a tapped horn!
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A Karlson is a whole bunch of stuff and 'tapped horn' certainly is one way to look at it on certain variations. Unless the opening/venting between chambers becomes close in dimension to the CSA, it behaves more as a bandpass enlcosure with the slot providing an "escape route" for direct-radiated HF.
IG
I've never heard one, but I've read many places that the K cab has great midbass punch. I always assumed that is because the mix of the front and back wave as well as the slot acting as a horn bumping up the lower end.
The "official story" as I understand it:
As an antenna guy, John Karlson tried to apply microwave principles to his enclosure and have it be a quarterwave stub impedance matcher. The high-impedance speaker diaphragm is poor at transmitting power into the low-impedance air, so the restricted volume of air contained within the front chamber provides a higher impedance for the cone to work upon. In turn, this excited volume of air radiates with greater area and lower impedance via the K-slot. In a way, it's kind of a one-step horn instead of a gradual flare.
I don't know how well this holds under scientific scrutiny, but a working combination of strong-motor driver and suitable Karlson enclosure does have good sensitivity and can work over nearly 3 octaves. Getting a smooth response and minimizing the nulls above the passband is key if it is to be used fullrange. The larger Karlsons do have a lot of midbass punch. A K15 loaded with a GPA 515-8GHP might put giant horns to shame for 50Hz-200Hz performance.
IG
Note that the larger the driver, the narrower its polar response, so for this type of app a more 'focused' presentation is desirable same as horn/WG loading in a large room.
The trade-off being potentially less mids/HF 'detail' and of course a larger cab unless a dipole or ~aperiodic loading is used.
GM
Thanks Bob, that is good to know. I assume that is why the graph shows a certin rolloff but the Fs is much lower.
Thanks GM. I agree with the larger driver issues. I've now decided on a 4" driver in a small Karlson cab. I am going with the Kcab just because I've always wanted to try them.
Change in plans. I will start out with the $10 Vifa TC9FD-18-08 3-1/2" Full Range Paper Cone Woofer in the Karlson cabs. It has a Qts of .89...........will that work in the Kcabs?
http://www.parts-express.com/pedocs/specs/264-1062-vifa-tc9fd-18-08-specifications.pdf
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http://www.parts-express.com/pedocs/specs/264-1062-vifa-tc9fd-18-08-specifications.pdf
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Single Vifa TC9FD and 0.4x Karlsonator
I think you need to distinguish between the Karlson cabinet (coupled chamber bandpass cabinet) and the Karlsonator. The Karlson only works well in full size as it does NOT scale well below 12/15 or 0.8X. If you like a Karlson in a smaller size - you want to build the Karlsonator, which does scale well for smaller drivers. The Karlsonator is indeed closer to a tapped horn but I look at it more as a back loaded horn with mild (tapped horn-like) coupling between the rear and front through the front chamber and Karlson aperture.
If you want to go with the Vifa, use the dual driver approach at 0.53x scale (15 in tall). My scaled down 0,53x scale plans are here:
Original Karlsonator plans for GregB's design is here:
If you want to go with a cute single Vifa Karlsonator at 0.4x scale (12 in tall x 6.1 in wide), it can work, albeit with only 85 dB efficiency and bass extension is down to about 80 Hz which is not bad for a desktop computer speaker.
Here are the predicted (walls far away) Freq Response, Impedance, Cone Displacement, and Impusle for a single Vifa in a 0.4X Karlsonator. Looks pretty good actually.
Good luck and please post your build as a follow-up to the 0.53X mini Karlsonator thread. http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds.html
Regards,
X
I think you need to distinguish between the Karlson cabinet (coupled chamber bandpass cabinet) and the Karlsonator. The Karlson only works well in full size as it does NOT scale well below 12/15 or 0.8X. If you like a Karlson in a smaller size - you want to build the Karlsonator, which does scale well for smaller drivers. The Karlsonator is indeed closer to a tapped horn but I look at it more as a back loaded horn with mild (tapped horn-like) coupling between the rear and front through the front chamber and Karlson aperture.
If you want to go with the Vifa, use the dual driver approach at 0.53x scale (15 in tall). My scaled down 0,53x scale plans are here:
Original Karlsonator plans for GregB's design is here:
If you want to go with a cute single Vifa Karlsonator at 0.4x scale (12 in tall x 6.1 in wide), it can work, albeit with only 85 dB efficiency and bass extension is down to about 80 Hz which is not bad for a desktop computer speaker.
Here are the predicted (walls far away) Freq Response, Impedance, Cone Displacement, and Impusle for a single Vifa in a 0.4X Karlsonator. Looks pretty good actually.
Good luck and please post your build as a follow-up to the 0.53X mini Karlsonator thread. http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds.html
Regards,
X
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