cubo 12

Hello everybody,
got some questions.
Is an Oberton 12 B 450 a good Speaker for Cubo12, you can watch the specs on:
www.pa-jack.de/shop?page=shop.product_de...d=34&category_id=129
Is it possible to use Cubo12 up to 200-250Hz?

Many Thanks

Tom

Hi All,

I'm trying to make a Cubo 12 out of 18mm birch ply (cant get 15MM ply locally for love nor money)!

I read earlier on in this thread HERE but I'm not 100% sure I understand Cubo's instructions to increase certain dimensions by 3mm?

I've attached a PDF of a mock up drawing that I done in Google Sketchup. Could anybody possibly help me and advise if my drawing is correct?

Thanks

Ok,
Spent another evening teaching myself CAD using the simplest program (sketchup), and I think I have now nailed it.

See attached PDF with updated measurements. Showing Cubo-12 made from 18mm ply.

What does everybody think?

Is an Oberton 12 B 450 a good Speaker for Cubo12

For that price it's a beauty.

However if you look at this measurement, you can see the response is at least 10 dB down @ 200 Hz, so I wouldn't recommend it, if you're planning to use it much higher than 125 Hz.

www.freespeakerplans.com/images/stories/...ed.ic.5__REWPREw.jpg

I read earlier on in this thread HERE but I'm not 100% sure I understand Cubo's instructions to increase certain dimensions by 3mm?

Calculating back what I said, that's pretty much what I ment. If nobody else disagrees, I would say: go for it.

Best regards

Cubo

Hello

I am planning to build a compact and cheap PA system, for some small events like 20-80 peoples. This will only be used occasionally, so I want to keep costs down as much as possible.
I’m considering the Cubo 12, and would like to know if this unit from P.Audio would perform okay in a Cubo12?


P.audio FL-12LF Series II

Nominal Impedance: 8 Ω
Power: 800 Watt (rms)
SPL: 1W@1M average sensitivity 95 dB
Frequency Response: 60Hz - 2000Hz

Voice Coil Diameter: 101.6 mm (4 inch)

Resonance Frequency Fs: 55 Hz
DC. Resistance Re: 6.1 Ω
Coil Inductance Le: 0.767 mH
Mechanical Q Factor Qms: 5.58
Electrical Q Factor Qes: 0.32
Total Q Factor Qts: 0.30
BL Product BL: 26.1 Tm
Effective Moving Mass Mms: 100.6 g
Equivalent Cas Air-Load Vas: 32.9 Liters
Effective Piston Area Sd: 0.0550 Sqm
Half-Space Efficiency Eff: 1.69 %
Airgap Height Hag: 10.0 mm
Voice Coil Height Hvc: 26.0 mm
Voice Coil Overhang Xmax: 8.0 mm

Regards RuneRH

That is a good driver. Seems to rely a bit more on excursion than efficiency though. Excursion-wise it's one of the heavier drivers I've seen. That also means it will need quite some power to get going.

Best regards

Cubo

First of all great work on the Cubo series, it's great to see you helping out everyone with what seems to be a very good design. I decided to build a Cubo12, to use in combination with my Boominator when I'm in need of some bass.
This requires the need for a portable system so I was thinking about a 1x600W into 2 ohm sure electronics amplifier. However, using a 8 ohm load , the maximum power drops to 200W. So I would like to use a 4 ohm woofer for about 300W, although a 8 ohm driver would also be an option since the system will probably be running at lower powers mostly. Efficiency is very important so I would like to use a +95dB/W woofer. I was thinking about using a Faital Pro 4 ohm woofer with a neodymium magnet to save some weight.

This one:
www.parts-express.com/faitalpro-12fh500-...ofer-4-ohm--294-1246
Or this one, lower efficiency, more expensive and heavier though and VAS too low?:
www.parts-express.com/faitalpro-12hp1060...ofer-4-ohm--294-1256

They look like to should work according to your design guidelines, but will they work with 300W maximum to produce a deep bass? Any thoughts are welcome

I'm using 2 x Cubo 12 on my 12 V system. I only use ~90 W per driver and have them wired in parallel. Gives plenty of deep bass but I might be using EQ, because usually a Cubo 12 doesn't sound to deep and these do.

I would use the first driver, any 12" driver with n0 between 2.5 and 3% (or higher). The second driver not likely for 12 V PA unless output is not so much of an issue.

Best regards

Cubo

Hi all,

I apologize for asking, but I have looked at the "Plans" page and the "Downloads" page and I cannot find the plans for a Cubo-12. I see the Cubos -15, -18, and -21 (and extended versions) but I am not finding plans for the 12. Will someone please let me know where I can download the plans and maybe explain to me how stupid I am for missing them there? A working link would be most appreciated.

Anyone have a clue if the EV DL12BFH drivers I have in a pair of Electro-Voice Sb120s (same as the driver in the Sx-200s and Sx-300s I think) would be a decent fit for the Cubo 12? I have 2 - Sb-120s and 4 of the Sx-200s. I only ever use one pair of the 200s with the pair of 120s. I want to build a Cubo-15 or two to replace the Sb-120s for use with a pair of the Sx-200s. This potentially leaves me with 4 extra DL12BFH 12 inch drivers. Although I am not likely to take apart the extra pair of Sx-200s without a very compelling reason. Let's just say I have two extra DL12BFH drivers then. Or, if anyone has a different creative idea of how I might effectively put these assets to work, I'm all ears.


DL12BFH specs per EV web site:

Nominal Cone Diameter 12in. , 305mm
Nominal Coil Diameter 2.5 in. , 63.5 mm
Nominal Impedance 8ohms
Frequency Range 60-2500 Hz
Power per EIA-RS426A 300 Watts
1w@1m (db SPL) 96.0


Thiele-Small Specs

Fs 60.04HZ.
Qms 9.611
Qes 0.317
Qts 0.307
Mms (g) 56.58
Cms (mm/N) 0.124
Vas (CuFt) (l) 1.943in, 55.02mm
Rms (Mech Ohms) 2.221
Re 4.400 Ohms.
Bl (Tesla-Meters) 17.214
Xmax 0.160in. , 4.06mm
Xlim 0.500in. , 12.70mm
Effective Rad. Diameter 10.500in. , 266.7mm

Oh, and Cubo... I simply must express how impressed I am with, not only your designs (which are brilliant in their balance of function and simplicity), but also with how gracious and generous you are with your knowledge and time. Although I have yet to build one of your creations, I cannot thank you enough for the kindness you display by sharing your experience and knowledge with the rest of us. This kindness becomes even more apparent as one reads through these threads and sees how many times you answer the same questions over and over again without arrogance or attitude. You have my gratitude and great respect. Thank you.

Thanks to all for tolerating us nubes.

Take care, Keith

CUBO12 Plans