cubo 12

Thank you for your reply.

I plan to cross the Cubo 12 with my 8"s at 150hz-160hz which means magnet in the chamber to achieve the 20hz higher as you've mentioned in one of your post.

Since the chamber's depth is 139mm, I'm pretty much limited to Faital's ferrite series. Now, If I opt for the 12FH520 or 12HP1020, which both have a depth of 143.30mm, are there any possible modifications in the chamber to fit the neodymium series for a "magnet in the chamber" configuration?

Hi Cubo and community

I'm planning to build a few Cubo 12 in the near future, I have a couple of questions I'd like to share and see if anyone can shed some light..

Material thickness : 15 mm or 18 mm? I have availability of both, I've seen some people has chosen to use 18mm plywood. I was wondering if this for a not having access to the 15mm one only or for robustness of the box and if this is really a significant improvement over the 15mm..
Original plan is for 15mm so I was thinking of going with that, just checking if I should consider the 18mm option...

I have built 2 Cubo 15 Extended which are working very well tuned around 35Hz to 180Hz....I'm thinking though of having a set of Cubo 12 ( probably 3 ) to use instead of the Cubo 15 which will be used on other configurations or events where I can use the help of other to move the sound system around.
The Cubo 12 seems bit more portable from a size/weight point of view.
If these will be the choice for the bass section of the system, would you suggest to use the Cubo 12 Mod plan, in order to reach a bit lower frequencies that the regular Cubo 12 plan ?
I;ve been looking at several 12" bass drivers and most of them range from 50Hz above which is the range for which the regular Cubo 12 works that is why I'm looking at the Mod version
I'm considering these : B&C 12PS76 12" 45 hz to 1000 hz or B&C 12CL76 12" Neodymium Woofer 45 to 3000Hz range...

thanks!

Oioi im not really the expert but I have built a pair of cubo12s with cheap 15mm ply with 1000 watt drivers and they sound solid. Quite surprised they do. Much tighter than other similar boxes when we lined the up next to each other once, you could really notice how solid the design and thus sound is. Point is, I think, being small and 12s, the max distance between each joint or brace is very little, so there are no panels big enough to impact the sound. Crossed at 50 since they dont go low and this is presumably a big factor.

Bottom line is I have done this and they sound fine.

I'm building another pair the same. Fact that each is light enuf for one person to carry up five flights of stairs is important to me.

thanks teknopaul for sharing your thoughts...
original plan was designed with 15mm plywood so I may just stick to it, lighter cabs are what I'm looking for.

checking the modfiied version of these as I would like to take them a bit lower than 50Hz...wanted to see if Mr Cubo can share some thoughts on this

For the record, my Cubo 12's were built using 12mm (1/2") Baltic birch. They seem very solid. Like teknopaul say, the panels are small and well supported. 15 mm, especially if it is quality plywood, is more than strong enough. 18mm would be overkill in my opinion.

good to know ! thanks for sharing...I think I'm going to stick to the 15 mm plywood. I have a couple of boards left over I can use and it's going to make it easier to follow plans as well instead of recalculating everything...

@Ikabod88: Neodymium versions tend to be deeper then the ferrite driver models for most brands. In this case one would simply make a 15 mm ring (out of the same material as the rest of the cabinet) to mount the driver on, besides that, the baffle itself also adds 15 mm.

Regardless, generally speaking using a Cubo 12 up to 150 Hz is no good. Then again, what 8" warrants that you cross at 150 Hz?

I crossed my 8" closed cabinets at around a 100 Hz, in combination with Cubo 12's. The 8" were even coax drivers, so lacking Sd (no dustcap) and not prone to more then a few millimetres excursion at best and they still managed to sound very decent.. Even 4" drivers for PA tend to be crossed at 180 Hz these day's, so do you really need to cross at 150 Hz?

@Ricosound: Well, let me start by saying that I'm surprised your Cubo 15's sound good up to 180 Hz, most people tend to cross below 110 Hz. Similarly with a Cubo 12, I would aim at crossing below 120 Hz, so it will be difficult to guarantee it will sound good up to the same crossover.

From the B&C's the 12PS76 has much better excursion parameters, otherwise they would fit equally well.

Three Cubo 12's should deliver about equal SPL as two Cubo 15's but from 50 Hz and up instead of 40 Hz. Cubo Mod will also work from ~40 Hz and up but at considerably lower SPL. I would bring about 1.5 times as many Cubo Mod's to make up for the loss in SPL.
Cubo 12's are a lot more portable than Cubo 15's. With a handle right in the middle, I could transport 1 Cubo 12 in each hand, so 2 at the time, or 1 Cubo 15 at a time.

Best regards

Cubo

hi Cubo thanks for the reply as always...

I think i typed the frequency on the cubo 15 wrong, we crossed them at 135Hz not 180..I just have been thinking at the rest of the set up while typing.

thanks for the comment on the drivers, I will look in to it. I like the portability of the Cubo 12 still debating if doing the modified version or not....it's 52 cm vs the 62 cm of the Cubo 15, so I wonder if this is going to make that much of difference between the two from a portability point of view.
Regular Cubo12 is smaller and from your words seems very portable...I just need to make up my mind if I want to sacrifice lower freq level vs portability.

I guess I need to try and see...in your experience do you think you would hear the difference between 3 cubo 12 vs 2 cubo 15 in terms of low frequency response ? I mean from a listening experience in a gig/bar type of placement ?

at the end if I need to carry 4 cubo12 mod is not going to be much less in volume than the 2 cubo15 I already built...

I'm planning to put a couple of 12" kicks on top of this ( 3 cubo12 or cubo12 mod ) and 2 mid-tops cabs that I'm currently building ( plan from the SMT212 ) but I did a modified version with only one 12" and 1" comp driver

Thank you for your reply, Johan.

140 hz HP setting for the Sls920 as listed on the Community website (tunings).

If you say it's no good for the Cubo 12 to set at 150hz then I must add the Cubo kick 12 as upper bass to fill in the missing frequencies. I don't want any bass reflex, pls.

May I now if the Cubo Kick 12 and 15 trapezoidal drawings are ready?

@Ricosound: I think I could hear the difference between Cubo 12 and Cubo 15 given the right music styles. Cubo Mod has the same overall cabinet volume as a Cubo 12, so I guess that with the right handle placement I could also hold a single Cubo 12 Mod in each hand. That being said:

I would only change your current setup for either 3 x Cubo 12's or 4 x Cubo Mod's if you're going to use drivers that are equally or better in quality as your current drivers and your going to give them in total, equal or more power then your current setup.
So in that case, say 3 x Cubo 12 with 1000 W each or 4 x Cubo Mod with each 1000 W, will give more output as 2 x Cubo 15 with a 1000 W each. This comes down to the fact that the power applied has increased whilst the power compression is equal or lower.

Still with any crossover over 100 - 120 Hz, I think it's a gamble, as personally I don't like the sound of many drivers to far over 100 Hz in most bass/ sub cabinets.

@Ikabod88: Well, in the SLS920 spec sheet It says the +/- 3 dB point is 120 Hz, so that's around where I would cross it. As apparently it's horn loaded, I would pair each SLS920 with 2 Cubo 12, loaded with the 12HP1020 (high power) or 12FH520 (medium power), both with the magnet in the chamber.

If that isn't cutting it (I would try this first), then I would add one Cubo Kick 12, loaded with the 12FH520 per side.

The Sketchup model of Cubo Kick 15 Trap should be somewhere on this forum. I haven't even started on 12 Trap and don't see much free time this month either.

Best regards

Cubo