Cubo 15

eminence, , Eighteensound, rcf, celestion, maybe Beyma, B&C Are the brands that i can find in Italy. I would like to spend around € 200-250. Even something more powerful might be fine. In the future I could change amps. Also, would it be possible to build a 15 cube with 15mm wood? so it would be lighter, but I don't know how it might sound. Thank you Cubo15

There are plans available for Cubo 15 from 15 mm ply but in that case 11-ply Baltic birch becomes the only sensible choice. Alternatively you can use an 18 mm ply that has a lower density as Baltic birch (spruce, pine, poplar, etc.), these will be lower toughness as Baltic but will be as light as a Cubo made from 15 mm Baltic birch. Send me an e-mail at questionsaboutcubo at gmail dot com for the plans.

As for suitable drivers:

- B&C 15NW100 and 15TBX100
- RCF L15P400 and LF15G401
- 18Sound 15LW1400
- Faital Pro 15HP1020
- Celestion FTR15-4080 (there's like four different versions that are all suitable)

The B&C and 18Sound drivers are a t the upper end of your budget but really worth it if you're going to upgrade your amplifier in the future. The RCF drivers are older models but look like great value for money within you budget.

Best regards Cubo

using 18mm wood, for example pine, how much could it weigh?

If I use B&C woofers, do I have to mount them in an extra extended cubo15? For example, the B&C 15NW100 has:
qts = 0.22
vas = 139dm3 (l)
So Qts x Vas = 30.58
Thank you

That depends, Pine is 500 - 650 kg/m3 also depending on shipment, manufacturer specifics and humidity. So for roughly an entire sheet of 18 mm ply --> 0.018 x 1.22 x 2.44 x density = 26 - 35 kg. As a reference Baltic is 650 - 750 kg/m3. If available I would also consider Meranti ply.

Cubo 15 Extra Extended is a safe bet as per rule of thumb, it will also work in Cubo 15 Extended though. If you're going for a high power driver like the 15NW100 and will sooner or later upgrade to a heavier amplifier I would consider using 15 mm Baltic birch (quality B/BB). Better safe then sorry.

Best regards Cubo

so, if I use the B&C 15NW100, would you advise me to build a Cubo 15 Extended anyway?

In this case I would advise Cubo 15 Extended for the 15NW100, although Extra Extended will also work.

Where do I download?

This CUBO 15 design looks good, but doesn't quite cover the range I need to go with my synergy horns. I need to cover from about 60 or 70 up to about 350 where the synergy takes over. Want good dynamics and pretty good efficiency, about 95 or so. This is only for home hifi, not pro sound reinforcement. Would like to use a 15", maybe a FaitalPro 15PR400, Eminence KAPPA LITE 3015LF, or B&C 15PS76. 

Danley Sound Labs makes a similar size synergy horn that is 3 way with 2-10" or 2-12" woofers that port into the horn. I'm not sure I want to try that, not sure the bass quality would be good enough. Thanks in advance for any suggestions.

Cubo 15 is not a mid bass cabinet in anyway, it's purely meant as a bass cabinet up to about 100 - 120 Hz. (driver dependent). For home hifi, any of the mentioned 15" drivers in a closed or ported cabinet will work (around 75 - 100 liter tuned to 60 - 70 Hz). This will give you the highest crossover that's unlimited by band pass effects of various other PA oriented designs and around 96 dB/ W/ m.

The only Cubo design that will get close to a 350 Hz crossover is Cubo Kick 12, you would have to close one or several of it's ports to tune it to 60 - 70 Hz though. Sensitivity is typically over 100 dB/ W/m, so if you only have 1 - 10 W available this might make a sensible choice. If power isn't the limiting factor I would look at one of those 15" PA drivers in a closed or ported cabinet though.

Best regards Cubo

Thank you for your quick reply and great advice. I will likely do a 75 - 100 liter ported cabinet with the Faital woofer.

Kind regards,
Richard