Cubo Kick

To be honest, it's a far cry from the original 18FH500. The Vas is huge and the Qts is high, meaning it performs best in enclosures with a very large rear chamber. The other T/S-parameters are OK but it will have quite a peaky response in the small rear chamber of Cubo Kick 18 (EQ strongly recommended).

It's 16 Ohm by the way.

Hello Mister Cubo,

First of all, thank you for making the Cubo designs available to the DIY community. I have spent quite a bit of time reading through the Cubo plans and forum discussions and have learned a lot from your work.

I am planning to build a sound system based on Cubo 18 subs and I am currently evaluating the Cubo Kick 15 for the kick section.

I already own several older DAS Audio drivers and would like your opinion before starting construction.

The drivers available are:

* 4 × DAS 15G (from DAS RF-215.96)
* 4 × DAS G35 (from DAS ST 152)

From the documentation I found, the DAS 15G has approximately:

* Fs = 35 Hz
* Qts = 0.26
* Vas = 225 L
* EBP ≈ 129

The DAS G35 appears to be around:

* Fs = 32 Hz
* Qts = 0.27
* Vas = 270 L
* EBP ≈ 90-95

Unfortunately, the drivers are still installed in their original DAS cabinets and I only have access to the published specifications and information available online. If necessary, I can take additional measurements later in the project.

My goal is to build an outdoor sound system for house, tech-house and techno music. I would also like to experiment with surround-style speaker placement in open-air environments.

The smallest configuration would be:

* 4 to 6 × Cubo 18
* 4 × Cubo Kick 15
* 4 × tops

The Cubo Kick 15 would be used as a dedicated kick section between the Cubo 18 subs and the tops.

My questions are:

1. Based on these parameters, would the DAS 15G be a suitable driver for the Cubo Kick 15?
2. Between the DAS 15G and DAS G35, which one would you personally choose?
3. Would you recommend the standard Cubo Kick 15 design or any modifications for these drivers?
4. What crossover range would you suggest between the Cubo 18 and Cubo Kick 15 in this application?
5. For a system with 4–6 Cubo 18 and 4 Cubo Kick 15, do you feel the ratio is appropriate for outdoor electronic music?
6. Is there anything in the available specifications that would make you avoid either of these drivers for the Cubo Kick 15?

Thank you very much for your time and for all the knowledge you have shared over the years.

Best regards,

Alex

Hi guys,
I'm building 2x Cubo Kick 15 with 18Sound 15ND930 drivers. My goal is maximum punch and chest pressure, especially around 120 Hz, while still having good sound quality.
Amp for kicks + tops:

DAP SI 4-900 (4-channel Class D): 900W @ 4 ohm / 600W @ 8 ohm per channel or another powerful 4-channel amplifier.

I will run one kick per channel and use a DBX DriveRack PA2 for DSP.
Question: Should I choose the 4 ohm or 8 ohm version of the 15ND930 to get the most output and impact from only two kicks?
Real-world experience with these drivers in Cubo Kick (especially with different power levels) would be greatly appreciated!
Thanks in advance!

@Alexalfa:

The 15G would be my first choice out of the two, however the G35 should have an EBP of ~113. Stlll, the higher EBP driver with the lowest Vas seems like the best deal here.
For techno and alike the 4 to 6 ratio is a bit heavy on the kick, so you could add 2 more Cubo 18 in the future. Considering you have slightly more kicks than needed, 80 Hz is my first bet for a crossover.

@Petersen1234:

The 4 and 8 Ohm versions of the 15ND930 are pretty on par with each other. Around 600 W per driver is enough, so between 600 and 900 W should be used for headroom. Headroom will generally promote sound quality if used as such, if continuously pushed it will more likely deteriorate SQ. Having up to 1.75 dB extra on kicks will give it more SPL potential. 
For most output, stacking the kicks will have a big influence. All reviews I've heard about the 15ND930 in Cubo Kick are positive

Best regards

Cubo

Hello everyone.

As I could not manage to find RCF MB15N401 at a reasonnable price, I'm looking to build a Cubo 15 kick with the Beyma 15MC700Nd.

I think it looks good on paper, but I wonder if anyone as experience with this driver inside a Cubo 15 kick. I am also worried about the size of the driver inside the box, it seems to be a long one with a 175 mm depth.

Here are some specs : 
 - 8 ohm
- 700 W AES
- 3 in coil
T&S :
FS : 49 Hz
QES : 0.34
QTS : 0.31
VAS : 105 L
EBP : 144
xmax : 7mm

You can find the complete sheet with measurement here :
www.beyma.fr/wp-content/uploads/2021/07/...quency-15MC700Nd.pdf

Would love to hear feedback on this, thank you very much for your time.

Have a good day,
Mat

According to Beyma it's a 'low & mid frequency transduser', which is formal slang for kick driver. It yells reflex 6th order band pass horn to me.

Considering it's a neo 3" VC motor, I think it will fit, with room to spare. Mount the bracing on the rear panel, once the driver is fitted on the baffle (taking a side panel off before its glued). That way you can avoid the bracing touching the driver anywhere.

Cubo

Hi Cubo,

Thanks for your great job sharing always all this knowledge with us. Three years ago I designed a second Reggae sound system project that included two Cubo Kick 15s. I loaded them with Eminence Kappa Pro 15As (using them as a kick section on top of some Mogale scoops loaded with PD.18C003s), crossed over between 80 and 220 Hz. To be honest, I’m really happy with them — they match very well. The system sounds complete and balanced with modern music, but with the Reggae records I play (mainly 70s stuff), they don’t quite perform at their full potential. After listening to other sounds, I’ve concluded that this music needs a heavier output in the 80–100 Hz region. Now that I’m looking to make more boxes for the sound, I’ve been thinking about building two Cubo Kick 18s instead of adding more 15s.

1- Getting to the point, what do you think about making that change? Do you think two 15" kicks and two 18" kicks would match well within the same frequency range when performing together?

2- Do you think the present Cubo Kicks 15 would perform better in the 80–100 Hz range with a Kappa Pro 15LF or an Oberton 15NMB1000 more than with a 15A?

3- Do you think an Eighteensound 18LW2400 would work well in the new Cubo Kicks 18? I’d prefer the B&C 18PS76, but it has been discontinued and there are only a few units left for sale. I’m not sure if there’s a better replacement from B&C that you’re familiar with or have experience with. Also, maybe I need an speaker that match good with the other 15" rather than the perfect 18" speaker for a ideal cubo kick.

Thanks!! Bests,

Alex

Cubo Kick 15's improve in the 80 -100 Hz area by stacking them close together. Cubo Kick 18's are tuned a bit lower, so they're king in the 80 - 90 Hz frequency range but might EQ to get the most out of them. The Kappa Pro 15A has a little Xmax, the 18LW2400 has heaps (and heaps) more displacement, plus a low Le and medium Vas so it looks like a good kick driver. However there are plenty of 15" drivers that have double the Xmax as the Kappa Pro and are still good kick drivers. Xmax is the limiting factor in the 80 - 110 Hz range but you probably need a bit of EQ to utilize it. The 18" will be the lower kick king but EQ will really bring it to the next level, just like the 15's.

I've never heard of the Oberton 15NMB1000 (up to 600 I think), 18Sound has one though, so which one is it? Anyway, the 15NMB600 has a 4" VC which will be a big step up from the other 3" VC drivers. The ultra low Qes means that it likes to be used in stacks but it has 'brutal kick driver' written all over it

Cubo Kick 15 + 18 should work decent together but replacing all the drivers in your Kick 15's and adding a bit of EQ would probably be easier and cheaper?

Thanks for the reply Cubo,

Yes sorry I was talking about 15NMB1000 18sound, because oberton 600 is discontinued.

So, what drivers you recommend the most for cubo kick 15 regarding 80-100hz performance? As you say, it would certainly be cheaper for me to keep building Cubo Kick 15s and replace the drivers with better ones. I usually apply good graphic and parametric EQs but I don't know what more can I do with the Kappa Pro 15A. This driver quickly reaches its maximum excursion and starts to sound distorted when I need good response in that range, even though I’m using good amplifiers (Powersoft K2 in this case) with the limiters properly set. That’s why I was considering going for a deeper kick response with 18" drivers, but means that I have to work de kick range (80-220hz) with cubo kick 15 and 18 at the same time for the same freq range, or maybe split it in two parts (80-130 / 130-220hz), but I don't think if this is gonna work.

It may be that the Cubo Kick 15 can actually cover that range perfectly well and that I don’t need to move to the Cubo Kick 18, but I would need driver models that perform much better specifically in that frequency range.

What do you think?