cubo 12

Hi there,

I have two questions about the Cubo12:

1) Why are all the inner dimensions 1 mm short? Ex. 41,9 cm instead of 42 cm? Is it to get a better fit? Normally in other project I have no problem fitting together pieces that are the exact size.

2) I simply can't figure out where to put the small piece (41,9 x 2,5). I've spend two days just starring at the plans and I am so lost

Thanks!

41.9 cm is mentioned to give a better fit. Assuming that anyone who doesn't need it, doesn't use it.

You know pieces are hard to find on the plans, if the designer of those plans, refers to other plans, to show you where the piece is fitted:


It's fitted on the baffle (that angle counteracts the angle of the baffle), to support the grill (if used) on all 4 sides.

Best regards

Cubo

Thank you for the answer, Cubo

I just finished two cubo 12s loaded with some $50 Dayton PA310s. They aren't the lowest thing in the world but they do make a lot of sound on the cheap. I will be using these for a live act so they will go plenty low for what I need. Two of these placed against a wall will definitely give the dance floor more kick drum thump than the two JBL 18" BRs I was using.

I am using a driverack pa+ for as my dsp and am messing with the crossover points. When I cross at 100 the system sounds very nice, it is very musical like a home theater system but it is lacking kick. When I increase the crossover point to 130-140 the kick drum really comes alive but there is a bad sounding honk around the 120 range. If I eq that back a little, everything sounds great. Overall I am very happy with these, especially considering the size. I think 4 of these little guys really thump for a live band at an indoor bar type of show.

Hope someone can help. I'm a bit confused by the angles used in building the Cubo12. The cut lists only specify a 5 and 15 degree angles. But the drawing shows a 15/105 degree angle and then an 88.5 degree angle and an 85.5 degree angle. So I am a bit confused what to use for angles?
Thanks,

Use the angles from the cut sheet. It will make sense when you put them together.

1.5 degrees over 15 mm material depth results in a 0.4 mm difference, that's negligible, especially with an expanding/ filling type of glue. Even more so for a 85 or 85.5 degree angle.

Best regards

Cubo

Hey Cubo, thanks so much for responding and thanks for all your designs and support. Your a good person.

I had concluded that those angles were "close enough", and I think you mentioned previously that the crucial dimension was the 42 cm X 45 cm opening. Presumably the same is true for the 93cm X 111 cm dimension and so on?

One final question regarding the "filler" piece on the bottom. The plans list a width of 245mm, but the cut sheet lists 225mm? I assume the size of this is not crucial to the design?

Thanks again!

Presumably the same is true for the 93cm X 111 cm dimension and so on?

Yes, it's the horn cross sectional area that counts.

One final question regarding the "filler" piece on the bottom.

That filler makes the bottom piece, locally 2 times as thick. A panel twice as thick becomes 8 times as stiff. Or 8 times more resistant to be set in motion by the movement of the driver, resulting in less energy loss (more output, less colouration). Whether you make it 245 or 225 mm isn't important but the bigger the better.

Best regards

Cubo

Hi Mr cubo Ivery been looking at the cubo 12 threads I'm looking at extending the width of the cubo 12 to 460mm wide to match up to some other cabs on top of them would this alter the frequency response much?

No, you could alter the width to 46 cm without a problem.

Best regards

Cubo