cubo 12

With the magnet inside the horn will give the deepest bass response, with the magnet in the chamber, you'll get less deep bass but a bit more extension in the higher regions. So something a bit more suited as a "kick bin" above a dedicated sub crossed at say 60 Hz. The Cubo 12, then a horn loaded 10" or 12" coming in around 140 - 150 Hz.

So for use in the house, I would use the magnet in the horn, no high pass (at low levels) or a high pass at ~25 Hz. Low pass at 60 -80 Hz. As the Cubo 12 isn't made for the deepest bass you might miss some low notes. In the house there are modifications (and might be ways of placement) possible to make it go 10 - 12 Hz lower To be honest, without those modifications I would not recommend it. Using Cubo 15 would give you a 10 Hz head start. Do you have space limitations or a preffered cabinet size?

Best regards

Cubo

Hi Cubo,

Many thanks for that info!

In regards to size, I want something as small as possible, as whilst space is not too much of an issue, i dont want something that looks too imposing/prominent.

What modifications would you recommend for the cubo 12 (rather than going for the cubo 15)? What placement/options are available to gain the extra depth?

Also - what does this sound like at lower volume levels?

Thanks for all the help.

Jat.

Cubo 12 is usable from about 40 Hz and up and very prominent from 50 Hz and up. personally I like a cabinet that is usable from 30 Hz and up for home usage. In the same sized cabinet it means you can "trade" efficiency for low end extension by minimizing the horn volume in exchange for more chamber volume. See the following post for the concept behind this behauviour:

www.freespeakerplans.com/index.p ... 9903#p9903

If you're interested I can send you a plan for a modificated Cubo 12 were this trade has been made. About 5 dB less output for 10 Hz of low frequency extension. On the other hand, you could make a reflex cabinet that is likely to be smaller and that will hit 30 Hz easily (just on a much lower level).

With regards to placement: Putting the Cubo 12 in the corner will lower the Fc by ~5 Hz. Note: A reflex will not lower Fc by placement in a corner as the cabinet priciple is different from the Cubo 12.

How it does sound at lower levels (or higher levels for that matter) is driver and crossover dependant. A driver meant for large excursion usually sounds a bit heavier then a midbass 12" which sound more "punchy". However the "lower levels" in this sentence makes me think you just might be satisfied with an reflex cabinet after all.

Best regards

Cubo

Thanks for the insights there Cubo.

To be hoenst, I am looking to use the P.Audio 12SB30 driver - and not really looking to try anyting different.

I would be open to a reflex design to suit this driver, or would be open to a modified Cubo12 as you mentioned. Would you be able to provide plans for both a reflex as well as the modified cubo?

Corner placement is what I was thining that you were talking about, and if it makes a difference (a benefit), I will place a cubo in the corner.

So please, let me know how you can help and I will then get going on this!

Thanks ahead for all your help.

Do you mean the PD 12SB30 by any chanche? If that's the case forget about a reflex as the Fs is to high imo. If it's a P. Audio driver I'm not aware of can you post the T/S-parameters?

The Precision Devices 12SB30 will be usable from the mid-thirties in the modded Cubo 12.

Best regards

Cubo

Sorry Cubo, I meant the PD SB1230 - my mistake!

If you could send over some modded plans, that would be great.

Thanks,
Jat

These are the first results of various testing I did on V-plating 2 x Cubo 12:

http://img163.imageshack.us/f/cubo12vplatedresults1.png/

img163.imageshack.us/f/cubo12vpl ... ults1.png/

As you can see there is some increase in output below 70 Hz and a decrease above 80 Hz. The decrease in kick bass when V-plated subjectively increases sound of the lower bass. However the true increase in low bass is minimalistic.

Personally therefore, I would not use V-plating on Cubo 12 to increase output (unless it's a 12 V rig, where every dB counts).

Next in line is V-plating Cubo 15 and 18. I expect slightly better results due to the larger increase in horn path.

Best regards

Cubo

Hi Cubo,

I'm interested in building this design. When you say "magnet inside horn" do you mean that the magnet is not visible in general ?

Also will MDF work to build these boxes ?
Good quality plywood is difficult to get in my country.

Thanks,

L

Magnet inside horn means the magnet is visible. It's possible to build from 15 mm MDF but like plywood this comes in a variety of quality grades (preferred brand/quality is Medite). If you use plywood, preferably use 7 ply or higher.

Best regards

Cubo

Added FAD's (most Frequently Asked Drivers) at the bottom of the plans.

Best regards

Cubo