cubo 12

Cubo15 wrote: The plans for Cubo 12 Mod are available only through e-mail (questionsaboutcubo at gmail dot com).

Cubo

  thank you sir , i built the cubo 12 and i love them will soon post my build log

All right, looking forward to your log.

Cubo

i am here under lock down and i am toying around with the frequencies on my CUBO 12  and it can get pretty low when it backs up on a corner i am getting some 40hz -50hz and it sounding GREAT i just love how the bass is coming out of these bad boys

just wondering if anyone has extended the scoop of the Cubo12 to make it taller like the hog scoop design. if so what would that impact?

That's where the efficiency of this particular designs is located, if all else equal, it's mainly increasing the sensitivity near the top end of the response and might raise the lower f3 a bit.

  this is true... what if you kept the Cubo size but faced it downwards and extended the sides to add that scoop feature? would it only serve an aesthetic purpose or lessen the quality?

It would act as an horn extender for Cubo 12, the effectiveness of which in my experience s hard to predict or simulate.Without the trickery what is that you truly want?

Would the RCF L12P110K be an extremely efficient driver for the Cubo12 mod (going for 40Hz) when power is limited to max 150 watt compared to the RCF MB12N251? 

L12P110K specs:

• Resonance frequency: 44 Hz
• Mechanical factor: 4.3
• Electrical factor: 0.14
• Total factor: 0.13
• BL Factor: 25 T · m
• Effective Moving Mass: 55 g
• Equivalent Cas air load: 98 liters
• Effective piston area: 0.053 m²
• Max. linear excursion (mathematical): 3.0 mm
• Max. excursion before damage: 48 mm
• Voice - coil inductance @ 1kHz: 1.0 mH
• Half-space efficiency: 5.75%
• Calculated EBP: 338.5

MB12N251 specs: 

• Resonance frequency: 50 Hz
• Mechanical factor: 5.4
• Electrical factor: 0.36
• Total factor: 0.34
• BL Factor: 15 Tm
• Effective Moving Mass: 49 g
• Equivalent Cas air load: 83 litres
• Effective piston area: 0.053 sq m
• Max. linear excursion (mathematical): 4.8 mm
• Max. excursion before damage: 38 mm
• Voice - coil inductance @ 1kHz: 1.3 mH
• Half-space efficiency: 2.70%
• Calculated EBP: 147

Efficiency is the key factor mostly above 100 - 200 Hz, below that excursion (Xmax, etc.) becomes gradually more important. I consider around 3% effciency as a good driver choice for most Cubo models. The L12P110K is perfect for a highly efficient (horn) top that does 200 Hz and up at the expense of everything below that. Funnily enough the Xmax is calculated 'going down hill' on the L12 while it's calculated 'going up hill' for the MB12. Also when it comes down to power compression, for up to 150 W there's no real benefit going for a 4" VC vs a 2.5" VC. So everything is favoring the MB12N251 in this case.

Best regards

[H]ardBASS Loudspeaker Specification Sheet Sunday, July 17, 2016
hardline Miami Series12-L500Miami Series 12” Woofer
Introduction:
The hardline 12-L500 is a Miami Series 12” Woofer designed for the vibrant midrange and pronounced mid-bass performance made iconic by the 80's Miami nightlife.
Specifications:
500W Program Power / 250W RMS Power Rating
50 Oz Ceramic Ferrite Magnet / 2.5” Copper Voice Coil
96dB SPL Sensitivity / 50Hz to 4,500Hz usable frequency range
8 ΩNominal impedance
Thiele/Small Parameters
fs 41 Hz
Sd: 523 cm2
re: 5.0Ω     BL product: 13.93 T/M      
Qms: 6.09
Qes: 0.36
Qts: 0.34
Compliance Equivalent Volume, VAS: 106.63 Ltr
Mechanical Compliance of Suspension,Cms: 274.75uM/N
Diaphragm Mass including airload, Mms: 54.58 g
i am using this speaker but not enjoying the low end of it
it sounding like the speaker is bottoming out