alt

Cubo Sub / Cubo 21

The largest cabinet from the Cubo series stands upon the edge of portabilty; To big to be compact, to compact to be big.

Like it's predecessors Cubo 12, Cubo 15 and Cubo 18 it's a stand-alone bass bin. It will equal or out run an 18" reflex cabinet from 30 Hz and up in terms of sensitivty*. Like all Cubo-designs it excels on the KISS-principle, with a single angled cut and a cut list from 1 and a 1/2 sheets of 244 x 122 cm / 8' x 4'.

Development

Based on Cubo 15 and Cubo 18, Cubo Sub is the 3rd prototype in a series of cabinets aiming at good reproduction down to 30 Hz. Mount the driver with the magnet in the horn for best low frequency reproduction from 30 Hz up to 100 Hz. With the magnet in the chamber for maximum output from 35 Hz up to 110 Hz.

Versions

Cubo Sub is optimized for single 15"/ 18" drivers**, and single 21" drivers, nicknamed Cubo 21. 

All 21" drivers will fit in the standard Cubo Sub but in that case care must be taken when pre-drilling the bolt pattern. Plans for Cubo 21 are available through e-mail (questionsaboutcubo at gmail dot com).

*        Measurement against BR18a tuned to 37 Hz

**      Due to reproducing sub frequencies 18" drivers with an Xmax of 7 mm or more are favoured. On average a 15" needs 1.5 times the excursion capabilities to produce the same output as an 18" driver or 2 times that of a 21" driver.

Acknowledgements

The designer likes to thank Xoc1 for his aid in the development process.

 

 

alt

 

alt

 

alt

 alt

 Download highest quality: Picture below / right click / save as.

alt

alt

  Download highest quality: Picture below / right click / save as.

alt

 

Preliminary measurements can be found here: http://www.freespeakerplans.com/index.php?option=com_jfusion&Itemid=64&jfile=viewtopic.php&p=11555#p11555


Posted: 1 month 3 weeks ago by Cubo15 #22836
Cubo15's Avatar
@T.geessounds: The 18NLW9601 is not the most efficient subwoofer, I would only recommend it if you have at least a solid 1500 W or more to feed it. In a Cubo 18 Extended it's about 2 dB less efficient than a Cubo 15 loaded with the Eminence Kappa 15LF. At full power it can rival with a double Cubo 15 loaded with the Kappa 15LF. If I had a 2000 - 2500 W amplifier it would be one of the few 18"driver choices for Cubo Sub.

@Geritass:

RCF: Cubo Sub: LF18X451 Cubo Sub and Cubo 18 LF18N451, LF18N401
18Sound: Cubo Sub and Cubo 18: 18NLW9601 (see above), 18NLW9000 Cubo 18: 18NLW9400
B&C: Cubo Sub: 18SW115, 18SW100 Cubo Sub and Cubo 18: 18NW100
Faital Pro: Cubo Sub: 18XL1600, Cubo Sub and Cubo 18: 18HP1020

All drivers will have similar low frequency response, maximum SPL will be mostly power related below 80 Hz. Choose the one with the biggest coil, for either Cubo Sub or Cubo 18, with most Xmax for Cubo Sub

Best regards

Cubo
Posted: 1 month 4 weeks ago by geritass #22833
geritass's Avatar
Hi, Cubo. may you recommend me the best subwoofer speaker for the CUBO SUB, and the CUBO 18 than reach the maximum Low frecuencie and maximum SPL (18sound, RCf, B&C, faitalpro)
thanks
Posted: 2 months 3 days ago by t.geessounds #22823
t.geessounds's Avatar
would the 18sound 18nlw9601 work well in the cubo sub??
Posted: 3 months 1 day ago by Cubo15 #22773
Cubo15's Avatar
@Valmiki77: I would use the 18SW3000 in Cubo Sub with the magnet inside the chamber. That way it will start to roll off somewhere around 35 Hz and be usable from 30 Hz and up. With the magnet inside the horn it will go a few Hz lower but at the cost of maximum output.

You could also build Cubo 18 Extended, which will be somewhere inbetween the Yorkie and Cubo Sub.

@t.geessounds: IIRC Valmiki77 already bought the 18SW3000 a few years back.

Best regards

Cubo
Posted: 3 months 4 days ago by t.geessounds #22769
t.geessounds's Avatar
valmiki77 wrote:
Cubo, do you think these prv's will cut it in the cubo sub?
www.parts-express.com/prv-audio-18sw3000...ofer-8-ohm--294-2755
How low do you think I'll get with them? I already have the subs in a Yorkie ls608 enclosure but I need to go lower than 50hz. These subs roll steep below 50. Help!

those speakers only have a xmax of 8mm and the spec some how always not right for that price u can get the 18sound lw2400 that work well in the cubo sub..
Posted: 3 months 4 days ago by valmiki77 #22766
valmiki77's Avatar
Cubo, do you think these prv's will cut it in the cubo sub?
www.parts-express.com/prv-audio-18sw3000...ofer-8-ohm--294-2755
How low do you think I'll get with them? I already have the subs in a Yorkie ls608 enclosure but I need to go lower than 50hz. These subs roll steep below 50. Help!
Posted: 6 months 1 day ago by Kvdb013 #22599
Kvdb013's Avatar
3 sheets -2 subs ;)
Posted: 6 months 1 day ago by Discosucks #22597
Discosucks's Avatar
Wow only seeing these for the first time now!

they look proper neat! and all from one sheet!!!
Posted: 6 months 2 days ago by Cubo15 #22593
Cubo15's Avatar
Those 18 1500's look the business, true sub drivers.

Ever heard of Cubo Kick 15, they stack nicely with Cubo Subs ;)

Best regards

Cubo
Posted: 6 months 1 week ago by Discosucks #22560
Discosucks's Avatar
Ok so im going to start work on 4 of these soon

I have 4 Fane colossus 18 1500's in my cbe's that i will be loading them with

The plan is to use 4 pd156 loaded es18's over them and my martin h3's ( will be changing the h3s for something , hopefully f1 res3's down the line) .

Should be a hard hitting system :)
Posted: 1 year 1 week ago by DJLink1 #21951
DJLink1's Avatar
Can't Seem to post pic on here but I posted pics and vid on my like page facebook.com/DJLinkone
Posted: 1 year 4 weeks ago by cvbaudio #21903
cvbaudio's Avatar
Dear Cubo

I have 2 18sound 21LW1400 and are looking for a good building plan

Thiele Small Parameters
Fs 28 Hz
Re 5Ohm
Sd 0,1662 sq.mt. (257,6 sq.in.)
Qms 9,32
Qes 0,242
Qts 0.235
Vas 385 lt. (13,6 cuft)
Mms 296 gr. (0,65 lb)
BL 33,5 Tm
LinearMathematical Xmax ± 9,5mm(± 0,37 in)
Le (1kHz) 2,85mH
Ref. Efficiency 1W@1m(halfspace) 98,0 dB


Would the CUBO SUB be suitable ?

If so Could you please send me the plans
Posted: 1 year 4 weeks ago by Cubo15 #21871
Cubo15's Avatar
Picture or it didn't happen ;)

Best regards

Cubo
Posted: 1 year 1 month ago by DJLink1 #21866
DJLink1's Avatar
Hey just built my first pair cubo sub tested them today and I am speechless. Shook everything in my house. Just need to do cosmetics and they are good to go.
Posted: 1 year 1 month ago by ldimebagl #21856
ldimebagl's Avatar
yes, is compact but powerful,18Sound logos I made myself with a photo color and epoxy resin ;) once again, thank you for this design Cube!
Posted: 1 year 1 month ago by Cubo15 #21853
Cubo15's Avatar
That must be a small but powerfull system, where did you get those 18Sound logo's from? I think they're kinda cool.
Posted: 1 year 1 month ago by ldimebagl #21836
ldimebagl's Avatar
Now...here my sound system,18Sound 18LW1400,18Sound 12MB600,B&C DE250

Posted: 1 year 1 month ago by Cubo15 #21803
Cubo15's Avatar
You can upload to: www.imagevenue.com/ and post a link or thumbnail.

Best regards

Cubo
Posted: 1 year 2 months ago by ldimebagl #21802
ldimebagl's Avatar
I can not post pictures
Posted: 1 year 2 months ago by ldimebagl #21801
ldimebagl's Avatar
Here my sound system,18Sound 18LW1400,18Sound 12MB600,B&C DE250
Posted: 1 year 4 months ago by Cubo15 #21576
Cubo15's Avatar
@Gfoster: I do not have a list of suitable drivers other than the drivers mentioned in this thread. If you want to know if a particular driver is suitable, you can either ask in this thread or e-mail me at questionsaboutCubo[at]gmail[dot]com.

I expect a list to appear in the future, so that the plans get more self-sustained.

Best regards

Cubo
Posted: 1 year 4 months ago by Cubo15 #21575
Cubo15's Avatar
This graph shows the difference between different Cubo Sub prototypes either with the magnet in the chamber (MIC) or magnet in the horn (MIH). As can be seen, MIH gives the most output down low, while MIC gives the most output from ~ 50 Hz and upwards. This can be both measured and heard as a notible difference.

www.freespeakerplans.com/media/kunena/at...Cubo%20Sub%20123.PNG

Cubo Sub 1, 2 and 3 are the first to third prototype respectively, all with an 18" driver. Different drivers can be best viewed as a single driver with larger or smaller Sd. Larger Sd will often, though not always increase output around 60 - 80 Hz.

Best regards

Cubo
Posted: 1 year 5 months ago by deejay skillz #21548
deejay skillz's Avatar
Hi cubo, I don't know if I got it right from the preliminary results posted i.e the cubo sub 18 magnet in chamber gives most around 60hz?. An index would be ideal. a quick guess subject to confirmation here we go....cubo sub 1 ( double15 inch version ) cubo sub 2 ( 18 inch version ) cubo sub 3 ( 21nch version )

Best regards
Skillz
Posted: 1 year 5 months ago by gfoster #21540
gfoster's Avatar
Hi, I am looking to build the Cubo sub, what difference do you get with the driver in the chamber or outside showing? also do you have a list of drivers suitable?

Gareth
Posted: 1 year 5 months ago by Cubo15 #21517
Cubo15's Avatar
I think all Cubo models can be used together, up to the point of certain boundries. For example if you can physically seperate them, say the Cubo 15 left and right and Cubo Sub in a centerstack, that would always have my personal preference. If you're gonna mix them in a single stack, I don't necessarly expect trouble but since there are so many variables you never know for sure. If you're going to use the same high pass for both I would make it as high as possible and steep.

The thing with the JBL of course is that it's more of a bass driver than a sub driver, Xmax is speced as 5.5 mm, T/S-parameter-wise it will work but the mechanical power handling will be less than optimal.

Best regards

Cubo