Size: 62x62x62cm

Frequency: From 40 Hz up to 110 Hz

Enclosure Type: Hybrid

Recommended DriverKappalite-3015lfKappapro-15lf-2kappa-15lf or  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" realizes 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 hybrids aiming at the achievements as stated above.  The measurement below shows the gain over the stated bass reflex (see * for details). Cubo 15 plans are also available in an Imperial version, plan available on request.

Versions: As a rule of thumb:

Qts x Vas > 120, Cubo Standard
Qts x Vas = 100 - 120, Cubo Extended or Standard
Qts x Vas < 100, Cubo Extended
Qts x Vas < 50; Cubo 15 Extra Extended

Footnotes:* 18Sound 18LW1400 in a 175 liter bass reflex 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.

Designer: Cubo15 [view profile]alt

 

Cubo 15 Standard Plan:

Cutsheet (clearly visible after download):

Cubo 15 Extended Plan:

Cubo 15 Extra Extended Plan:

Only the 2 inner horn panels are different from Cubo 15 Extended, all else equal.

 

 



biggins's Avatar
biggins replied the topic: #24467 5 days 22 hours ago
Hi Cubo, 

I have a quick question. Is it OK to mix the extended versions of the Cubo 15 with the original, non-extended version. 

My assumption is that it is not OK to mix designs as the extra horn length will cause issues with the phase alignment but just wanted to check.

Ps: thank you for your kick and sub designs. We have been using them South Australia and they have been sounding great  <3  For a picture of your designs in-situ, check the banner on my stalkbook page.

https://www.facebook.com/2ndClassSleeper/
Cubo15's Avatar
Cubo15 replied the topic: #24466 6 days 3 hours ago
Well, you can always build Cubo 15 Extra Extended if you feel like it ;)
yanng22's Avatar
yanng22 replied the topic: #24465 6 days 4 hours ago
Hi Cubo
My Kappa is an old version , the Qts x Vas =52.6 , ( the LF2 as 59.6).
That's why I hesitate , 52.6 is near the limit between the extra extended and extended plan.

Best regards
Cubo15's Avatar
Cubo15 replied the topic: #24457 3 weeks 5 days ago
@Yanng22: I've calculated Qts x Vas as 59.6 for the Kappa Pro 15LF so I would advise to build Cubo 15 Extended and not Extra Extended.

@ Steve k: If the angles between panels are not shown in the plan you can assume they have a 90 degree difference. The angle between the first horn panel and the baffle is 87 degrees, although if you use an expanding or filling glue type (like polyurethane or epoxy), you can get away with a 90 degree angle as the difference is less than one millimeter.

Best regards Cubo
Steve k's Avatar
Steve k replied the topic: #24456 3 weeks 5 days ago
Hi Cubo. Just embarking on a extended build. What angle is the extra piece set at in relation to the panel that mounts the driver? Many thanks Steve K
yanng22's Avatar
yanng22 replied the topic: #24455 3 weeks 6 days ago
Hi cuboFor a Kappa pro 15LF QTS x VAS = 52.3I hesitate between the extended and the extra extended.Best regards
Cubo15's Avatar
Cubo15 replied the topic: #24408 3 months 3 weeks ago
Hi Geritas,

The JBL 2226H is a good driver both for Cubo 15 Extended and Cubo Kick 15.

Best regards Cubo
geritas's Avatar
geritas replied the topic: #24407 3 months 3 weeks ago
Hi Cubo15 ,  is the JBL 2226H a good driver for the cubo15, cubo15 Extended,  cubo kick or with one for this driver?
Thanks in advance.
Cubo15's Avatar
Cubo15 replied the topic: #24375 7 months 2 days ago
A 909 kicksound peaks at 63 Hz and is -10 dB at 180 Hz and 30 Hz, so Cubo Kick 15 looks to be the best choice here.

Best regards Cubo
redtag's Avatar
redtag replied the topic: #24371 7 months 1 week ago
Actually I use them mostly home and for some raggae/dub parties and pure techno. But if I listen on psy.. I want more 909 kicksound. 
Cubo15's Avatar
Cubo15 replied the topic: #24370 7 months 1 week ago
It really depends on your needs, one Cubo Kick 15 on one Cubo 15 is usable for Live music where there isn't much sub content to cover. For DJ's two Cubo 15 for every Cubo Kick 15 often balances out. Cubo Kick 12 by the way reaches the same sensitivity eventually, it just steps in from a higher frequency, missing the lowest bit of the kick, in exchange it reaches higher.

Best regards Cubo
redtag's Avatar
redtag replied the topic: #24367 7 months 2 weeks ago
Ok :p I want more kick for my setup as showen before. What should I build? 2 cubo 12 kick? Any suggestions? And what driver? Cubo 15 would be to much for single Cubo 15 extended? 
Cubo15's Avatar
Cubo15 replied the topic: #24329 1 year 1 week ago
On paper the Snake Pro ESX155 looks better than the RCF 15P540, however the Xmax looks questionable to me, efficiency is also a bit lower at 2.2%. If the specs are indeed true, the ESX155 would be the better choice. However, considering the tops you're using both will work and I expect you'll have output to spare (on the Cubo 15's).

I've updated the plans page, to include an easy calculation to what version suits what driver best:

Qts x Vas > 120, Cubo Standard
Qts x Vas = 100 - 120, Cubo Extended or Standard
Qts x Vas < 100, Cubo Extended
Qts x Vas < 50; Cubo 15 Extra Extended

Best regards Cubo
caczank's Avatar
caczank replied the topic: #24327 1 year 2 weeks ago
I'm look the plans for the cubo 15 and cubo 12, then, I decide to buid cubo 15 because is more suitable for my needs.

What I need: A pair of small bass cabinets to play live with my small band (4 components: drums, keyboards, acoustic guitar, vocals. The bass line is played from the keyboard). Other important point is there this bass cabinets need to be easy to be moved from one place to another. For me the cubo desing is the best compromise between space and SPL.

The way whic I will use 2 cubos is runing it by a DBX drive rack PA2, for use the crossovers, compression and limiter, and power it by an NUKE 3000 amp (~2000 W RMS @ 4 ohms bridged).

The drivers which are possible at Brazil are:

Snake Pro ESX155 - Cost 609 BRL
Cms - NA mm/N
FS 35 Hz
Qms 7,123
Qes -0.362
Qts - 0.345
Le - 0,92 mH
Vas - 193 L
Power (RMS) - 600 Watt
Re - - Ω
Coil - 100 mm
Impedance (Ohm) - 8 ohm
Mms - 107g
Sens. - 97dB
Xmax - 9,5mm
EBP 101
QtsxVas 66,6
Eff 2,6%

RCF 15P540 - Cost 839 BRL
Cms - NA mm/N
FS 50 Hz
Qms 9,7
Qes -0,41
Qts - 0,39
Le - 1,5 mH
Vas - 100 L
Power (RMS) - 500 Watt
Re 5,6 Ω
Coil - 76 mm
Impedance (Ohm) - 8 ohm
Mms - 106g
Sens. - 98 dB
Xmax - 7 mm
EBP 128
QtsxVas 39
Eff 2,94%

The tops which I use are 2 full range 200 W RMS, 12 pol woofer and driver, crossed, and use it in stereo mode. I will cross the cubos, to run in mono, at HP @ 40 Hz and LPF @ 100 ~110Hz. The system is for live sound in open and close spaces, but not at so high loud levels.

The questions:

1. What are the cost benifit choice between the 2 drivers?

2. What is the correct choice: cubo 15 standart or extended?

Thanks in advance for the support and attention. All information in this forum is very hellpfull. I'm read the full topic for cubo 12 and now i'm reading the topic for cubo 15 (at page 44).
Cubo15's Avatar
Cubo15 replied the topic: #24325 1 year 3 weeks ago
Hi,

You can use the Ciare NDC 15-4S in Cubo 15 Extra Extended (send me an e-mail at questionsaboutcubo at gmail dot com) or in Cubo Sub. In Cubo 15 it will have about 100 dB/W/m sensitivity, so about 130 dB continuously (not factoring power compression). In Cubo Sub it's about 3 - 5 dB lower, so 125 - 127 dB continuously but what you miss in SPL you'll get back in air movement if playing 30 - 40 Hz.

Best regards Cubo.
Slotcar55's Avatar
Slotcar55 replied the topic: #24321 1 year 4 weeks ago
hello everyone, I would have a question about the Cube extended.It would be my intention to use a CIARE NDC 15-4S NEO, in an extended cube box. these are the parameters: Thiele-Small
Qms 2,59
Qes 0,28
Qts 0,25
Fs 31,20 Hz
Re 5,96 Ohm
Mms 160,97 g
Cms 0,16 mm / N
Bl 26,09 T * m
Sd 830,00 cm2
Vas 156,24 litri
u 1,66%
XMax 11,5 mm
Le 1,07 mH
Rms 12,18 Kg / s
Larghezza di banda di efficienza 112,92


could it be a good choice?I have a couple of them at home and I would like to use them to build a couple of compact divers for a small PA. what could be about the pressure in spl max achievable?
tonskulus's Avatar
tonskulus replied the topic: #24313 1 year 1 month ago

Cubo15 wrote: n0 is the driver efficiency (in %), some manufacturers give it in the PDF. It's also used to calculate the drivers sensitivity (although most manufacturers use sensitivity figures from a rampant marketing department). n0 (a.k.a. Eta Zero a.k.a Reference Efficiency) is calculated from the Fs, Qes and Vas as follows:

Fs^3 x Vas / Qes x 9.6E--8

Half space sensitivity: 112 + 10 x log (n0/100)

So for the L15P540

50^3 x 100 / 0.41 x 9.6E-8 = 2.93%

112 + 10 x log (0.0293) = 96.7 dB/W/m

As most 4" VC drivers have a lower Fs,you would have to raise Vas and lower Qes a bit to compensate.

Best regards Cubo


Thanks!  I'll keep my eyes on similar drivers having 4" coil etc..  

L15P540 is still good driver anyway, nothing wrong with that.. tight and punchy. Sometimes these drivers are making loud bangs (input power around 1kW peak) while cone moving around 15-20mm only..sounds like coil hitting back plate. However, specs says Xdamage being as high as 36mm!  
No matter if rising HP up to 45-50Hz, still bottoming or something similar if pushed up to 1kW. 
Cubo15's Avatar
Cubo15 replied the topic: #24304 1 year 2 months ago
n0 is the driver efficiency (in %), some manufacturers give it in the PDF. It's also used to calculate the drivers sensitivity (although most manufacturers use sensitivity figures from a rampant marketing department). n0 (a.k.a. Eta Zero a.k.a Reference Efficiency) is calculated from the Fs, Qes and Vas as follows:

Fs^3 x Vas / Qes x 9.6E--8

Half space sensitivity: 112 + 10 x log (n0/100)

So for the L15P540

50^3 x 100 / 0.41 x 9.6E-8 = 2.93%

112 + 10 x log (0.0293) = 96.7 dB/W/m

As most 4" VC drivers have a lower Fs,you would have to raise Vas and lower Qes a bit to compensate.

Best regards Cubo
tonskulus's Avatar
tonskulus replied the topic: #24302 1 year 2 months ago

Cubo15 wrote: If you want similar performance to the L15P540 but louder, I would look at a driver that has a similar n0 (~3%) with a 4" voice coil and a Xmax between 7 - 9 mm.

Best regards Cubo


That would be ideal.  Sorry, but what is n0? 
Cubo15's Avatar
Cubo15 replied the topic: #24300 1 year 2 months ago
If you want similar performance to the L15P540 but louder, I would look at a driver that has a similar n0 (~3%) with a 4" voice coil and a Xmax between 7 - 9 mm.

Best regards Cubo
tonskulus's Avatar
tonskulus replied the topic: #24299 1 year 2 months ago
Yes, its possible.  I have seen 4ohm versions tho.. Anyway I will put these two drivers to my dual 15" reflex to see how they perform there. 
Need to look for more drivers because I really would like to have two cubo15 enclosures with proper sound.  L15P540 is good when it comes to sound quality, but it lacks Xmax..and therefore cannot be pushed harder.

I'll keep informing about these odd RCF drivers, this thing has to be figured out! 
Cubo15's Avatar
Cubo15 replied the topic: #24298 1 year 3 months ago

Re = 3.1ohms

That indicates a 4 Ohm driver or an internal (semi) shortcut.

Normally it's an 8 Ohm driver, so that's not a good sign for any of the listed T/S-parameter to actually apply to this driver. At this point I would either conclude that the driver is not what it says on the label (even if it was the label is contradicting itself), or it's defective.

Best regards Cubo
tonskulus's Avatar
tonskulus replied the topic: #24296 1 year 3 months ago
Made some more outdoor test w/ P200A but it just wont work as I was hoping.  Lots of uncontrolled cone movement but not enough SPL and overall quite horrible honky/flappy sound quality.  
I think Cubo wants tighter driver having more BL or something to get it right!
tonskulus's Avatar
tonskulus replied the topic: #24294 1 year 3 months ago
Yes there are three variations:  L15P200,  P200A and P200AK but there seems to be different parameters over internet as you said.  My versions are 200A indeed. 
I'll take some basic measurements like Fs out of these, let's see what is going on!

I've got two of these drivers, used but mint condition (looks like new!).

EDIT:  measured FS = 29...30Hz.
Re = 3.1ohms
Cubo15's Avatar
Cubo15 replied the topic: #24293 1 year 3 months ago
I've seen some different versions of the L15P200A on the internet, some of which have a Qes as high as 0.63, which would explain the lack of 40 -50 Hz. The version with a Qes of 0.3, claims a 4" voice coil, a Mms of 77 g, a Xmax of 9 mm and a BL of 17.2 N/A. That combination seems unlikely, if not completely wrong.

If you have the ability to measure the T/S-parameters, that would be a good thing to do, as the T/S-parameters as you posted do not indicate anything like you've reported. Unless it is a new driver (unused), if so that would be a likely cause.

Best regards Cubo