Mini Karlsonator (0.53X) with Dual TC9FDs

[perceval]

Hello X,

I forgot if I asked you before, but I'm looking to downsize my beach speaker setup (now using the TABAQs) to a dual 0.53x pair. I still have a bunch of those AHE drivers I sent you... do you think they would work into the dual 0.53x?

I now have access to 2cm boards of rigid blue foam, so I'll be making a lightweight version for carrying to the beach! So happy I finally found that material here... will be so easy to demo prototypes!

 

[perceval]

Well, nothing like hands on experiments...

I built a one dual K with two AHE drivers I had laying around.

Build was fine, took a few hours only, as I was using rigid blue foam and hot glue.

But...

My TABAQs are not ready for retirement yet.
The frequency response of the dual AHE K is far from perfect. There's a lot of phase wraps (comb filtering?) around 5kHz, causing the big drop there.

I may revisit this with other drivers later, but as it stands now, this is not enjoyable listening.

 

[xrk971]

Let me run a sim for you. It may be size wrong at 0.53x - it should sound balanced and with deep bass. It will never be hifi with smooth frequency response and flat phase. Its advantage is wide soundstage and no need for BSC.

 

[perceval]

Thanks, X.

Yeah, it is not balanced at all... didn't even bother bringing it to a friend who wanted to hear it.

 

[freddi]

one of these days I may be interested in a dual driver Karlsonator. My Karlsonator12 with 12LTA (and helper tweeter) and ferrite Nirvana Super10 is very good as is the Karlsonator6 with FE164 and L.Cao F6 TheJessMan's Karlsonator8 measured even better than the 12 when both were loaded with a Visaton BG20. (I don't think Jesse had the stub filled on the Karlsonator12 for its test at his place)

Beta10cx in the Karlsonator 12 went below 40Hz solid and with little cone excursion - but I didn't like its relatively weak/laid-back midrange. It needs another pound of magnet slug. Maybe I'll mount one of my prized cast frame Eminence 12cx with 80oz motor in the Karlsonator12 for evaluation - those are close to 100dB at 1 watt. Also, Beyma's 12cx has a much better (stronger) midrange than Beta10cx and more extended woofer top end than Beta12cx.

I need one more stab at a "K10" - Karlson's original K12 can be great with the right speaker - they're a little bit large for a strong motor 10.

 

[xrk971]

Thanks, X.

Yeah, it is not balanced at all... didn't even bother bringing it to a friend who wanted to hear it.

I should have run sims for you before telling you it would work at 0.53x scale. This driver is peculiar and has a real mid-bass hump and 60Hz peaky bass overshoot if used as dual drivers in a 0.53x W x 0.53x H&D. No wonder it doesn't sound right.

Try making the cabinet 0.42x wide (you can take current cabinet and slice off one side then re-center the baffle board. You should get something better behaved like this, but still mod-bass heavy at 300Hz - best if used near a back wall or corner to boost the bass:

But best performance is actually single driver in a very compact 0.37x (all dimensions) and you get something fairly balanced with 65Hz F3 - you will be surprised by how balanced it sounds - very easy to make:

One more thing - important to make the Karlson aperture go to a sharp cusp - not a slot. That changes the bass roll-off slope quite a bit.

 

[Buehgemeiste]

But best performance is actually single driver in a very compact 0.37x (all dimensions) and you get something fairly balanced with 65Hz F3 - you will be surprised by how balanced it sounds - very easy to make

That looks great and the cab size nice for an outdoor boombox.
Which driver is it?

 

[xrk971]

Perceval had access to these as made in Taiwan.

AHE8P00A tested in subjective blind thread no 3.

http://www.diyaudio.com/forums/full...ind-comparison-3in-5in-drivers-round-2-a.html

?????AHE 8P00A???3??????????????????~Fostex TB ?????(21206258966085)?????|??NO.1 ????

 

[perceval]

Thanks a bunch, X.

I think I will keep it simple and go for the single 0.37x.
Are there any dimensions already done with plans out there (I found nothing in this thread) or do I have the figure it out myself?

New to Ks but willing to learn.

 

[perceval]

Ok, I really don't know how to scale down to 0.37x... any pointers?

 

[Buehgemeiste]

...AHE8P00A...

A google search has only one result....this thread.

 

[perceval]

It's a driver made in Taiwan, and to my knowledge, only sold here.

Here is the link of the auction page they have around here, kinda like eBay...

http://goods.ruten.com.tw/item/show?21206258966085

 

[xrk971]

A google search has only one result....this thread.

I gave the link in my post.

 

[perceval]

And I will gladly share the real measurements as soon as I find out how to scale the thing to 0.37x.

I tried to scale a few ways, looking at the 0.53x, and the 0,40x, and trying some math, but couldn't find it.

 

[freddi]

i believe it would be a 0.37 scaling of the Karlsonator(12) - - ?

there's a large picture available at GregB's Stupidhifitricks gallery but this should be big enough to read. I have a pair of this Karlsonator

https://lh6.googleusercontent.com/-.../AAAAAAAABik/txissf4J4PI/s800/Karlsonator.png

 

[perceval]

Soooo...

I just paste the picture in some CAD or Vector drawing design, shrink to 37% of the original size and measure the resulting image?

 

[perceval]

Well, I just did it with that picture.

But, resizing down to 53%, or 40%, do not match the dimensions posted in this thread for those sizings....

 

[freddi]

I guess X will have to clarify - I assumed he was working from GregB's Karlsonator12 dimensions for scaling

at 0.37 scale from the original Karlsonator ("12"):

I get roughly 11.47" (29.13 cm) tall x 6.2" 17.74mm) wide x 6.57" deep (16.68mm) deep for external dimensions at 0.37 scale.

here's the ~ 1/4 scale image for easier reading of the original dimensions
http://i.imgur.com/9YhM6or.png

 

[xrk971]

The plans and the scaled drawings of the original Karlsonator are all on the first post. It might be easier to take the plans for 0.4x and scale by 0.93x. Don't do it with a photocopier - take critical dimension and multiply and redraw. Height, width, depth, baffle board setback, internal divider position etc.

 

[perceval]

I do the scaling in Pixelmator, a program like Adobe Photoshop. Using rulers and guidelines. But trying to scale the original file, I couldn't get the same dimensions as with the ones posted for 0.53x and 0.40x.

Anyway, thanks freddi and X. I'll try it again and see how close I get get to freddi's dimensions for the 0.37x.

Off to bed now, and something to try tomorrow! Cool!