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.

 

 



Cubo15's Avatar
Cubo15 replied the topic: #24408 1 month 16 hours 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 1 month 1 day 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 4 months 1 week 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 4 months 2 weeks 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 4 months 2 weeks 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 4 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 9 months 2 weeks 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 9 months 3 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 9 months 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 10 months 4 days 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 10 months 3 weeks 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 11 months 2 weeks 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 11 months 2 weeks 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 1 day 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 4 days 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 5 days 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 5 days 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 1 week 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 1 week 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
tonskulus's Avatar
tonskulus replied the topic: #24292 1 year 1 week ago
Tested RCF L15P200A (cubo extended, magnet in horn), lows were totally missing, sound was one noted mid bass / no punch.  L15P540 is working much much better, even tho it's mid bass driver there was more 40-50Hz SPL compared to P200A.

P200A specs:
4 inch voice coil
Fs 29Hz
Qts 0.28
Qms 10
Qes 0.3
Xmax 9mm
Bl 17.2
Vas 280litres

Dont know what's wrong with this, specs are not too far off from recommended drivers.. maybe cubo standard would be better?
Cubo15's Avatar
Cubo15 replied the topic: #24283 1 year 1 month ago
Thanks for the review. The L15P540 is definitely most suited for Extra Extended.

As a rule of thumb, if:

Qts x Vas > 120, Cubo Standard
Qts x Vas = 100 - 120, Cubo Extended or Standard
Qts x Vas < 100, Cubo Extended

Only for Cubo 15:

Qts x Vas < 50; Cubo 15 Extra Extended

Best regards Cubo
tonskulus's Avatar
tonskulus replied the topic: #24280 1 year 2 months ago
Ok, just for fun I made single Cubo15 extended because I had 4 x RCF L15P540 drivers laying around and waiting for something. Magnet is in a chamber, as it is much better this way (tested both ways).
Results:
Surprisingly good amount of SPL, 50Hz and up but plays down to 40Hz. Nice and punchy, when crossed at 80-90Hz.
For electronic dance music, psytrance, house etc.. very good design. 4 x similar cubo15's would be enough even for bigger parties!
For live music, well..propably not my first choice.
For comparsion, I do have many different subwoofer designs/boxes like standard reflex, miniscoop, hog scoops, 18" bandpass etc..

Oh, almost forgot to say, single man can lift and move cubo15 easily (18mm ply) which is also nice feature! Lots of fun from such a small design all in all.

Just wondering if I should try extra extended version.. I think L15P540 likes small chambers anyway.
pukis's Avatar
pukis replied the topic: #24279 1 year 2 months ago
Greatings cubo and other members,
My question is: is a fane sovereign pro 15-600lf suited for the cubo 15 enclosure ?
Thanks.
Grymer's Avatar
Grymer replied the topic: #24275 1 year 2 months ago
It's running through an amp that's rated at 600 RMS at 4 ohm, which both cubos are getting power from. So essentially they're at 300w each. The ohm does go lower than 4ohm, so the amp can probably do a bit more.

It's for a 12v speaker. The ones you keep hearing about haha. The way I'll set it up is with a hard-limiter. I'm gonna optimise the speakers for Spotify running on a mobile-phone. Signal from computers and phones using soundcloud is way louder, but since spotify is the main source, I'm gonna tell everybody using something else to lower the volume.

I'll run a sinus-tone and then set the voltage of the amp to around 40-50v (around 300-400w). I'll set the hard-limiter to that point and then put on spotify and crank the master up, so it barely touches the limiter :)

If you have any suggestions for a good setting for my limiter (It's a compressor), then fire ahead :)
Grymer's Avatar
Grymer replied the topic: #24274 1 year 2 months ago
It's running through an amp that's rated at 600 RMS at 4 ohm, which both cubos are getting power from. So essentially they're at 300w each. The ohm does go lower than 4ohm, so the amp can probably do a bit more.

It's for a 12v speaker. The ones you keep hearing about haha. The way I'll set it up is with a hard-limiter. I'm gonna optimise the speakers for Spotify running on a mobile-phone. Signal from computers and phones using soundcloud is way louder, but since spotify is the main source, I'm gonna tell everybody using something else to lower the volume.

I'll run a sinus-tone and then set the voltage of the amp to around 40-50v (around 300-400w). I'll set the hard-limiter to that point and then put on spotify and make sure it just barely touch the limiter :)

If you have any suggestions for a good setting for my limiter (It's a compressor), then fire ahead :)