Cubo 18:
Cubo 18 is a multi purpose, stand alone bass bin that, like Cubo 15, will equal or out run a single 18" BR*, of similar size, from ~ 40 Hz and up in terms of sensitivity. Cubo 18 works with a wide variety of 18” drivers. It has a cut list from just over a single 18 mm*** sheet (244 x 122 cm) / (8' x 4') with a single angled cut. Cubo 18" realizes a cost effective, small and light weight enclosure following the KISS-principle.
Development:
In 2007 the first prototype was build and tested. Cubo 18" is the 5th prototype in a line of hybrids aiming at the achievements as stated above.  Cubo 18 Standard and Cubo 18 Extended will both work with a wide variety of drivers, if uncertain which one will be most suited, build Cubo 18 Extended or mail me at This email address is being protected from spambots. You need JavaScript enabled to view it.
Size: 62x62x65cm (HxWxD)    
Frequency: From 40 Hz up to 110 Hz    
Enclosure Type: Hybrid

3D Model (by K-M-Sound-System):

 
Footnotes: 18” drivers preferably with an EBP of 100 or higher; Fs (22-42 Hz), Qts (0.25 - 0.58), Vas (200 - 450 L) / (7.4 – 16.7 ft^3). Where EBP = Fs / Qts . Measurements will follow.
 
Cubo 18/15 (difference): Cubo 18 is 3 cm (/ 1 1/6th inch) deeper then Cubo 15. Due to phase similarities Cubo 18 and Cubo 15 can be  used together without noticeable issues. Cubo 18 has on average slightly more output for a given input in comparison with Cubo 15 (based upon electro-mechanical relatively similar drivers), especially between Fc high and Fc low,whilst Fc high and Fc low, remain similar (= cut-off frequency).
 
 
 
 Cubo 18: Front view
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Cubo 18: Side view without side panel
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Cubo 18: Driver for comparison
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Cubo 18: Detail magnet and bracing
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Cubo 18: Magnet facing out
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Cubo 18: Magnet in chamber
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Cubo15 replied the topic:
3 weeks 1 day ago
For best low end mount the magnet in the horn, for a warmer tone to the sound and a bit less low frequency, mount the magnet in the chamber.
Josef replied the topic:
3 weeks 6 days ago
Hello I am new here and I am interested in rebuilding the Cub18. I have a question: Does it matter whether the magnet is in the chamber or facing outwards?
Many thanks Josef.
Zambrotta replied the topic:
5 months 3 weeks ago
Another question there is a wave of paraflex subwoofers around everyone going paflex from your expertise mr Cubo how good are they
Zambrotta replied the topic:
5 months 3 weeks ago
Hello Cubo how are you. I have a question is the Cubo 18 suitable for small to medium sized events in a scenario wherby i will use it with a mid high cabinet directly on top of the cubo 18 using a speaker pole.
yNicoDev replied the topic:
1 year 7 months ago
Hello

Would it be a good idea to put the PDN.18BR40 speaker in the cubo18 box? I have two lying around at home...

If so, extended or normal version? I seem to remember that I quickly reached the xmax in BR
Cubo15 replied the topic:
1 year 9 months ago
As the V18-1000 is based on the PD.1850/1, the current PD.1850/3 is probably the closest in weight and performance. The 18DS115 is neodymium and can be seen as a step up in performance but like the 18IPAL, it will need amplifiers in excess of 2000 - 3000 W per driver to really showcase their difference. Up to about 1000 - 1500 W per driver of amplifier power I would consider neodymium drivers like the LF18N401, 18NLW9400 or the 18NW100. Their Qts is a bit higher to be considered true analogs of the V18-1000 but it's still in the right ball park. While they "only" have 4" voice coils, they're of a newer generation and typically weigh less than 10 kg.
DevFelix replied the topic:
1 year 9 months ago
I understand. It was clear to me that such non-neodymium drivers would make transport considerably more difficult. However, I first wanted to weigh what is possible without paying attention to the weight.

Are there drivers that deliver similarly good results, and maybe even be neodymium-loaded in the best case?

Im located in Germany.
Cubo15 replied the topic:
1 year 9 months ago
@oskarociak: If you already have it you might as well use it, it should take similar power as in the reflex but will have more output. It does benefit from a high pass filter around 35 - 40 Hz, due to the limited Xmax.

@DevFelix: Drivers like the V18-1000 are not very common and tend to be expensive as well (large voice coil and low Qts do that to any driver). The V18-1000 was basically a cheaper alternative for the PD.1850. Non- neodymium drivers like that are a b!tch to move though, you need to be in great shape to not mind.

Where are you located?
DevFelix replied the topic:
1 year 9 months ago
Hey Cubo,
great design!

The Gain SPL Diagram clearly shows that the case works very well together with the V18-1000.
Unfortunately, it is only available to a limited extent in my region. Is there a good alternative?

Greetings
oskarociak replied the topic:
1 year 9 months ago
Thanks
I have speaker in bad reflex (90L)
Cubo15 replied the topic:
1 year 9 months ago
The Sigma Pro-18A-2 is a good speaker for Cubo 18 Standard, the main two drawbacks are the lowish Xmax and the 3" voice coil. Do you use these already or are you planning to buy them?
oskarociak replied the topic:
1 year 9 months ago
Hi
would it be a good idea to put the Eminence Sigma Pro-18A-2 speaker in the cubo18 box?
Cubo15 replied the topic:
2 years 1 week ago
I never reversed polarity with the magnet visible (it sounded fine to me) but it also depends on the tops you're using, so you can always try both ways and have a listen.
dave305 replied the topic:
2 years 1 week ago
good morning when mounting the speaker backwards (magnet out) on the Cubo 18 do I have to revers the wire polarity?
Cubo15 replied the topic:
2 years 6 months ago
The 18 Sound 18NTLW5000 does not fit (under normal circumstances) in Cubo 18, mounted with the magnet in the horn, due to the driver depth. However some changes can be made to make it fit. It does fit mounted with the magnet in the chamber, with some minor changes.

It does work best in Cubo 18 Extended, if you need help with making changes so it fits, send me an e-mail at: questionsaboutcubo at gmail dot com

Cubo
Trizzor replied the topic:
2 years 6 months ago
Hello, have anyone Test the 18 Sound 18NTLW5000 in die Cubo 18? Or can say if the ntlw will work in the Cubo 18?

Thx
dave305 replied the topic:
2 years 11 months ago
Thank you very much, I`ll send you pics and keep you posted
Cubo15 replied the topic:
2 years 11 months ago
@Dave305: From that list I would choose the FTR18-4080FD, it's a good driver for Cubo 18 Extended. I think you also e-mailed me that you wanted 30 Hz performance, in which case you're better off using Cubo Sub. However the FTR18-4080FD might be on the light side for all day 30 Hz performance (couldn't find Xmech though).

@Jack: The 18NLW9400 is the 18Sound equivalent of the B&C 18NW100, both rated at 1200 W AES, it would be my choice with an amplifier of roughly 1200 W or less. The 18TLW3000 is a very high power driver, with the 4 Ohm version looking best (better than the 8 Ohm version), it's a good choice if you have around 1800 W or more to power it with.

Cubo
jack.bergquist23 replied the topic:
2 years 11 months ago
Hi All,

So after faffing around for too long I missed the boat on the 18nw100 availability and they're now on back order for at least 80 days from one of the few places that ship to NZ :-S I'd heard some positive things about the 18TLW3000 en.toutlehautparleur.com/18-sound-18tlw3...r-4-ohm-18-inch.html but it EBP (as you've defined Fs/Qts) is only 91hz. Is this going to make it a non-starter? Very open to other suggestions - am trying to balance getting something that will work well in the Cubo 18's (which I have the wood cut and ready for) and be ported into one of the paraflex designs once the price of timber goes back down in NZ (3 sheets per box at $280nzd a shot is a bit nuts!)
dave305 replied the topic:
2 years 11 months ago
Hello, MR.Cubo
Trying to build the cubo18 not sure which of the two I should build
the drivers in my price range and in stock are

JBL. 18SWS1000

SWLENIUM 18SWS1000

CELESTION FTR18-4080FD

EMINENCE KAPA PRO

CELESTIOR. CF1830E
Maikolmks replied the topic:
3 years 2 weeks ago
thank you very much Mr. CUBO. anyway I was wrong to write. I have the 18NLW9400, so it will work fine inside
Cubo15 replied the topic:
3 years 2 weeks ago

The 18NLW2400 is an 18 inch extended low frequency loudspeaker designed for high SPL subwoofer applications in either a reflex, bandpass or horn loaded configuration. Compared to our industry standard 18LW1400, the 18LW9400 provides higher maximum SPL, increased program power handling and lower power compression. In order to furtherly increase power handling and reduce power compression figure, 18NLW9400 uses the same voice coil ventilation technology developed for our flagship 9000 neodymium transducer series. 

Apparently, they couldn't choose it's final name then. Now it's known as the 18NLW9400 ;)

Both the Ciare Cw455 and the 18NLW9400 will work best in Cubo 18 Extended.

Best regards Cubo

Maikolmks replied the topic:
3 years 3 weeks ago
hello Mr. CUBO, I have recently purchased an 18NLW2400, would it work better in the standard or extended version?
Cubo15 replied the topic:
3 years 1 month ago
Hi Nugget,

Those are looking great! All measurement data is welcome.

Cubo
Nugget replied the topic:
3 years 1 month ago
Hey Cubo after you helped me and everyone else here so much, i thought you might be happy about some building Pics. I built 4 Cubo 18 extended in February and also did some measurements, which i uploaded as pictures too. If you're interested in the measurement data for group delay, distortion, etc. just tell me and i will send them to you.

Here's the link: www.audiofotos.eu/album/cubo-18-extended.mxi