Mini Karlsonator (0.53X) with Dual TC9FDs

[von Ah]

Nice! I’ll take two of each!

 

[xrk971]

Mine are also upside down up high above the kitchen cabinets near the soffit.

 

[davetest]

I love my 0.53x's with Dual TC9FD's and would love to do something similar using vertical lengths of 8" or 10" plastic drain pipe for the main body with the K mouth cut into the pipe itself. What do you think? ...especially hopeful from any welcome input from X ?

 

[xrk971]

I think someone has done that. Bit more as a pipe TL with K aperture exit.

You could get large PVC sewer pipe. Circa 8in to 12in dia. Make Karlsonator with it by placing an angled baffle inside. You would have to cut the baffle in a long ellipse to fit the pipe. It would look cool.

That sewer pipe isn’t cheap. Best to find scraps from a contractor laying sewer systems for a new subdivision.

Cardboard Sonotube for concrete fence post foundations is another option.

 

[davetest]

...off to scrounge some offcuts of tube now. Back soon if it works

 

[5lowDown]

I am thinking of building a pair of these with my son (our first audio project) using foamboard. I have searched and cannot find a range of Thiele small parameters that would work well with this design. I’m sorry if I’ve missed it. What should I be looking for in terms of Tsp’s, especially what to avoid.

Thanks in advance.

 

[xrk971]

Just pick the drivers that have already been simulated in this thread (there are at least 50). 3 of those are under $20 that I can remember off the top of my head and sound great.

2x TC9FD, 2x 3FE25-16, 1x PA130-8 all in 0.53x scale. Or single 3FE25-4 or 3FE25-8 or TC9FD in 0.40x scale. Probably PS90-8 works well too.

If you have a particular driver in mind, look for moderate Qts (0.5 to 0.8) and Vas approx equal to box volume. Fs around 60 to 80Hz. Many drivers work as it’s a forgiving design.

 

[soundaddict]

What if I use one 3fe25-16 for a 0.4x mini Karlsonator? 0.53x seems overkill as I have a small listening space. I have already bought the 16ohm model.

 

[hammercha]

I have 3FE25-16 on 0.4x. This is my desktop speaker for music and audio for skype and zoom call. I could not be more happier. Thanks to X for this design.

 

[soundaddict]

@ hammercha Glad to hear it, thank you. I see it has a Qts of 0.82, it should work. I am torn between 0.4X and 0.53x, I do not want to lose that image provided by the bigger speaker, but my space is limited.

 

[hammercha]

I wanted to get better sound from 0.53x, but I need speaker for my desk. So I choose 0.4x. Not only it fits on the space, it sounds really good for my application.

 

[xrk971]

Thanks for sharing hammercha! Glad the high impedance 16ohm driver works for you. That might be good for some tube amps. The 8ohm variant is excellent too.

I find that imaging with 0.40x Karlsonators is superb. I remember the soundstage is wider than the speakers.

 

[jimk04]

What are the critical aspects of the design.? I have some nice Wharfedale boxes i would like to repurpose. The rear panel and baffle are removable so I can access the inside. They are 350x195x235 internal if I ignore the lips to fix the baffle and rear cover.
I assume the 'vent' from the rear chamber is key and is related to the driver sd? I saw a comment about aiming for VAS to be similar to box volume and also Qts to be 0.5 to 0.8 or so and with an fs 50Hz or so. And the length of the line (TL ?) i assume is important too.

Sorry to ask this, I know it must be annoying when people ask 'can I substitute this driver'.....or 'can I make it this size instead! It just seems these are quite close!

 

[xrk971]

Hi Jim,
It needs to be simulated. Will need TS parameters from your drivers. I have been doing sims for various drivers for people since this thread started. I am a lot busier nowadays so takes me a few days or a week to get to it. I don’t know how you can repurpose an existing box because you need the sides to come apart in order to glue the new channels. It’s a folded mass loaded TL with the output feedback onto the driver via a K aperture.

If you want to repurpose a box, the XKi is easier. Just take 2/3rds total volume for rear chamber and 1/3rd for front. Calculate the bass reflex box vent size using rear volume and make a slot vent on the top equal to area and length calculated. Add K aperture.

Sort of like this (for W5-2143):

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

 

[jimk04]

Thanks X.
I have a couple different pairs of Mark Audio drivers dat doing nothing and didn't know if one may be suitable. (Thinking of just using one pair)
Please don't expend any time unless you do have to fire up the software.

The boxes look like this at the moment and so its possible to create the folded channel.

Or i have these Seas MCA15. I dont expect you to sim all 3 X but if casting your eyes over the TS parameters tells you one is better than the other please just go for that one. And again only when you have the software open, don't make a special effort. Thanks

 

[xrk971]

Hi Jimk04,
I made a nice design for CHN-70 that probably would work well for any MA CCX-70. Also works for Radio Shack 40-1197.

Improving the CHN-70

 

[dBel84]

Hey X - do you have the construction measurements for this design - I have a CHN-70 that I would like to try this in. tia..dB

 

[xrk971]

Hi dBel,
It’s in the title of that post.

CHN-70 in a 0.44x (0.55x W) Karlsonator

0.44x scale in height and depth and 0.55x scale in width. So the proportions are a bit more wider than usual. It’s important to add melamine foam on the walls of the inside and outside chamber.

 

[dBel84]

Thanks, I had done some digging last night and found the now defunct link in the first post

Plans for 0.44x tall x 0.44x deep x 0.55x wide K'nator for FE103SOL or FE103/RS 40-1197: https //plus.google.com/photos/10054...49816297868412

I think I have it figured out and will pick up some foam board to try it out before building in wood.

 

[xrk971]

I wonder if the plans for the Pluvia 7 could work?

https://www.diyaudio.com/forums/att...or-0-53x-dual-tc9fds-karlsonator-pluvia-7-pdf