Free Speaker Plans

Frequency: From 40 Hz up to 110 Hz

Enclosure Type: Hybrid

Size: 62x62x62cm

Recommended Driver: icon Kappalite-3015lf (668.37 kB)icon Kappapro-15lf-2 (534.42 kB) and icon kappa-15lf (566.56 kB), drivers with EBP of 100 or higher; Fs (27-50 Hz), Qts (0.21 - 0.41), Vas (150 - 300 L) / (7.4 - 11.1 ft^3). Where EBP = Fs / Qts (strictly speaking it's Fs / Qes)


Cubo 15": Cubo is a multi purpose, stand alone bass bin that will equal or out run a single 18" BR*, of similar size, from ~ 40 Hz and up in terms of sensitivity. Utilising a non-expensive driver such as the Eminence 3015LF, Kappa 15LF and Kappa 15LF Pro** and a cut list from a single 18 mm*** sheet (244 x 122 cm) / (8' x 4') with a single angled cut, Cubo 15" realises a cost effective, small and light weight enclosure following the KISS-principle.

Development: In 2007 the first prototype was build and tested. Cubo 15" is the 4th prototype in a line of hybrides aiming at the achievements as stated above.  The measurement below shows the gain over the stated basreflex (see * for details).

Footnotes:* 18Sound 18LW1400 in a 175 liter basreflex tuned to 37 Hz. (6,6 ft^3) vs. Cubo 15 ; Eminence Kappa 15LF.          ** Apart from these drivers Cubo will work with a wide variëty of 15" drivers preferably with an EBP of 100 or higher; Fs (27-50 Hz), Qts (0.21 - 0.41), Vas (150 - 300 L) / (5.5 - 11.1 ft^3). Where EBP = Fs / Qts.  If you're uncertain if a driver is suited, PM or mail me at This email address is being protected from spambots. You need JavaScript enabled to view it.          *** If you want to use 15 mm material use 11-ply Baltic birch, nothing less. Plans available on request.

Cubo 15 plans are also available in an Imperial version, plan available on request.

Designer: Cubo15 [view profile]alt

 

Plan:

Cutsheet (clearly visible after download):

 

 


Posted: 2 weeks 5 days ago by Cubo15 #21939
Cubo15's Avatar
@Mini-Mad: Kick is covered by 80 - 300 Hz, so a Cubo 15 covers only a small fraction of the kick, hence you might be looking at the wrong place. That being said, strong output @ 118 - 125 Hz will emphasize kick to the chest, which in most cases would mean EQ your tops 3 - 5 dB or so. A high EBP, low Qts driver, with medium Vas driver would also emphasize the lower kick frequencies.

@Cees: It's a good driver and all T/S-parameters are fine, except Xmax (which is tiny) and would limit power handling to 200 - 300 W. It would be a great candidate however for a kick-bin or a top cabinet.

@Johan: I've got good experiences with the Kappa 15LF, however the Fane looks to be (a fraction of) a fraction better.

Best regards

Cubo
Posted: 3 weeks 5 days ago by johangastorp #21917
johangastorp's Avatar
Kappa 15lf or fane sovereign PRO 15-600lf for the extended Box? Same price on the driveris.

Best regards Johan
Posted: 4 weeks 5 hours ago by cvbaudio #21902
cvbaudio's Avatar
Dear Cubo

I'm new at the forum

I have 4 P-AUDIO SN15MB

MID BASS WOOFER
Size (in.) 15.0
Power RMS (Watts) 300
Fs (Hz) 47.0
Xmax (mm) 3.5
Sensitivity 1w/1m (dB) 100
Qts 0.26
Vas (lt) 176.75

I would like to use them in the cubo 15
Is this good choice ?
Posted: 4 weeks 1 day ago by mini-mad #21900
mini-mad's Avatar
Thank you dear sir. And thank you again for such a great design!

Quick question.... is there a way to EQ a little kick into this box?
Posted: 4 weeks 2 days ago by Cubo15 #21872
Cubo15's Avatar
As it's quite an efficient driver it wouldn't be a waste. Just make sure you either use it in Cubo 15 Extended, with the magnet inside the chamber (not in the horn) or in Cubo 15 Extra Extended (e-mail me at questionsaboutcubo(at)gmail.com for the plan).

@t.geessounds and mini-mad: Well done, those look like textbook examples.

Best regards

Cubo
Posted: 4 weeks 2 days ago by xqzme #21870
xqzme's Avatar
Hello Cubo

I love your design, and I really hope that I soon get my own made, but theres a problme!

I bought some badass units (i think at least!), because I got a offer I could not refuse.
At first glance I thought they looked perfect for the Cubo, but then I saw that the Vas is too low.... and I can't really assess what it effects, and which impact it will make, now that the rest of the specifications fit ...

Would it be a waste, to make 2 x cubo15 out these drivers?

RCF L15P540:
8 Ω
Program Power:1000 W AES
Power handling capacity:500 W AES
Sensitivity:98 dB
Frequency Range:40 Hz ÷ 2000 Hz
Effective Piston Diameter:330 / 13 mm/inch
Max Excursion Before Damage (peak to peak):36 / 1.4 mm/inch
Minimum Impedance:6.8 Ω
Voice Coil Diameter:76 / 3 mm/inch
Resonance frequency:50 Hz
DC resistance:5.6Ω
Mechanical factor:9.7
Electrical factor:0.41
Total factor:0.39
BL Factor:21.4 T · m
Effective Moving Mass:106 g
Equivalent Cas air load:100 liters
Effettive piston area:0.085 m²
Max. linear excursion (mathematical):6.5 mm
Voice - coil inductance @ 1kHz:1.5 mH
Half-space efficiency:2.94%

Full specs in the attachment
Posted: 1 month 1 week ago by mini-mad #21865
mini-mad's Avatar
Here are 2 of my 4 boxes... kappa LF loaded. I had them built for my daughters 18th and i ha e to say they sounded brilliant, even just two of them!!

Thanks again Mr Cubo!!
Posted: 1 month 1 week ago by t.geessounds #21864
t.geessounds's Avatar
just finish 2
thanks
Cubo
Posted: 1 month 1 week ago by mini-mad #21862
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Thank you again.... i always look forward to reading your posts on here as your a very helpful man and have a vast knowlegde wen it comes to your boxes and driver. Again, i cant thank you enough!

I'll get a set of 15XS's as my matrix amp does 4x 1200 @4ohm... so maybe i'll get the 4ohm versions (not bothered about resale prices)
Posted: 1 month 1 week ago by Cubo15 #21861
Cubo15's Avatar
How much power do you have available? If you can give this driver 1000 - 1500 W and high pass it lowish, yes, this is the driver for you. It would be more subby.
This is what I tell you based upon my personal experience.
Seriously I'm looking in the pdf's just like you could ;)
This is what I tell you in a response to:
the reason i ask you is that you prob have the baskests knocking around to know the answer to this.... i know you said the stud pattern was the same for the kappa LFpro as with the fane 15XB.... would the 15XS also be the same

Best regards
Posted: 1 month 1 week ago by mini-mad #21860
mini-mad's Avatar
I understand the paper work but im asking what your EARs tell you as i have paper work that says my car can do 127mph... but it never will...
So im asking your judgement and im very happy to hear the verdict. Thank you
Posted: 1 month 1 week ago by Cubo15 #21859
Cubo15's Avatar
How much power do you have available? If you can give this driver 1000 - 1500 W and high pass it lowish, yes, this is the driver for you. It would be more subby. Seriously I'm looking in the pdf's just like you could ;)

Best regards

Cubo
Posted: 1 month 1 week ago by mini-mad #21848
mini-mad's Avatar
Mr Cubo... 1st of all thank yoooooooooooooooooooooooooooou!

i have 4 of these bad boys and do like their sound. i know i already asked a similar question and the reason i ask you is that you prob have the baskests knocking around to know the answer to this.... i know you said the stud pattern was the same for the kappa LFpro as with the fane 15XB.... would the 15XS also be the same and would this be a good driver and more "subby" then the LFpro's? the kappas do a good job but i want to cut down from 4 boxes down to 2 and load with a pair of kick ass drivers without having to build two more boxes for new drivers (while selling my 4x kappa loaded boxes.

thanks in advance if you do know the answer to any of my questions.
Posted: 1 month 2 weeks ago by Eiser #21842
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Interesting!

I guess I'll take the Kappa 15LFA then :)

Thanks a lot for your help!
Posted: 1 month 2 weeks ago by Cubo15 #21840
Cubo15's Avatar
If you look at all the T/S-parameters, the difference in Xmax is kind of a mystery, as these drivers should be the same. My preliminary conclusion is that the Kappa 15LF and the KappaLite have the same gap depth and voice coil winding height, it's just that Xmax at 10% THD is likely measured for the 3015LF and the Kappa 15LF Xmax was probably measured less favourable, or mathematically derived, while they're likely still the exact same.

I place the small triangular bracing at 1/3 the width, though 1/4 would also do.

Best regards

Cubo
Posted: 1 month 2 weeks ago by Eiser #21837
Eiser's Avatar
Cubo15 wrote:
If you look at the T/S-parameters and such data of the 3015LF and the Kappa 15LF, you will notice that they're pretty much the same, which means they're pretty much the same, except the aluminum chassis and the neo magnet.

Interesting. This favours the Kappa 15LF, since it's much cheaper.

One parameter i stumbled upon though, was the xmax - doesn't it make a difference that the Kappa 15LF has 5,5mm vs 9,6mm on the Kappalite?
Or will it require that you use an amplifier that exceeds the physical limit of the Kappa 15LF before the extra xmax becomes beneficial?

You can leave that bracing out in the Extended version but please put some bracing against that front panel (two pieces, with the same distance between them as the small triangular bracings).

Will do that! I guess the 41x6cm panel can be cut up and used as these 2 braces :) While we're on it, where should I mount the small triangular braces? Something like 1/4 inside, measured from the side towards the middle? Hope it makes sense :)

And thanks a lot for your help.

Can't wait to hear how this awesome design sounds!
Posted: 1 month 2 weeks ago by Cubo15 #21835
Cubo15's Avatar
If you look at the T/S-parameters and such data of the 3015LF and the Kappa 15LF, you will notice that they're pretty much the same, which means they're pretty much the same, except the aluminum chassis and the neo magnet.

You can leave that bracing out in the Extended version but please put some bracing against that front panel (two pieces, with the same distance between them as the small triangular bracings).

Best regards

Cubo
Posted: 1 month 2 weeks ago by Eiser #21833
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Question is just if the Kappalite is noticeably better...
Posted: 1 month 2 weeks ago by COZY PILLOW #21832
COZY PILLOW's Avatar
The Kappa 15LFA works very well in this cab but if you can afford it use a better driver?
Posted: 1 month 2 weeks ago by Eiser #21830
Eiser's Avatar
About to start building my first Cubo15, and I'm really excited about it!

Still not sure which driver to use - standing between the Kappa 15LFA and Kappalite 3015LF

Will the Kappalite 3015LF, besides being a lot lighter, perform significantly better than the cheaper Kappa 15LFA?

Also, will the extended version be the best for the 3015LF?

Have looked through most of the thread, but can't seem to find a clear answer on this one, so sorry if it's already been answered!

Thanks a lot :)

EDIT: Yet another question: Is the part marked with blue (bracing under the top plate) necessary in the extended version? Of the builds I've seen here, it seems like a lot of people have left it out....

[File Attachment: Cubo15ExtSk.png]
Posted: 1 month 2 weeks ago by Cubo15 #21826
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Does that mean the 15xb IS the better driver?

Yes, no, depends. If you made the Cubo 15 out of paper mache or some low grade ply, you might not even bother. Same goes if you don't have the extra amplifier power available and whether you've decent processing or not. It's definately an upgrade tho.

According to the pdf's they both have the bolts at 14.56"

Best regards

Cubo
Posted: 1 month 3 weeks ago by mini-mad #21824
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Anyone.... i ask as i have a party in two weeks and if the stud pattern is the same and its a heavy'er bass i'll buy a pair....
Posted: 1 month 3 weeks ago by mini-mad #21823
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Does that mean the 15xb IS the better driver? I have the 15LFs and looked unto upgrades.... do they have the same stud pattern?
Posted: 1 month 3 weeks ago by t.geessounds #21821
t.geessounds's Avatar
thanks for the reply sir
but i dont think i have ever seen the plan for the extra extended..magnet inside the chamber is like your profile pic right??
thanks
Posted: 1 month 3 weeks ago by Cubo15 #21820
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In general or between the 15LF and the 15XB? If in general, there isn't a best driver out there, if there was I would keep it a secret and sneaky sell completed Cubo 15's with that driver, I would probably call my secret alter-ego KidCreole or something.

If specific: The 15XB has an aluminum chassis, a 4" instead of a 3" voice coil, better excursion parameters, higher motor strenght, etc. This will also give you more options if you ever decide to build something else.

Best regards

Cubo