Cubo Sub

The 9601 and 9001 are both top notch drivers, that swapping one for the other doesn't make that much of a difference on full power. The 9601 will have a small dip at 50 - 80 Hz, about 1 dB deep, the rest is the same.

The 9001 is designed for reflex, the 9601 for small cabinets and (high output) horns but considering the high overall standards of the drivers both could be swapped at most designs. Cubo 21 is in between reflex and horn anyway, so both reflex and horn drivers apply, both accentuating a different part of the design.

If you ever switch to a different design in the future and that design is going to be a reflex, choose the 9001, if anything else the 9601.

I don't see a real difference between reflex, band pass horn or horn, in that they're 3 points on a somewhat straight line. Reflex having a large chamber and a (very) small port/ horn, BPH having medium chambers and medium sized ports/horns and horns having largely port/ horn and often (very) small chambers.
To say that a large chamber, small port/horn will behave the same as a medium chamber, medium port/horn in the low end, is imo an over-simplification but good for short answers

Best regards

Cubo

Hello Cubo,

Thanks for your reply regarding the 21" Cubo Sub. Understand what you are saying about the bracing, however the speakers that you have linked me to are both 18" and not 21".

Having read this very informative site (pbsong.com/speakers.html) I am becoming less inclined to go for more power i.e. purchasing the RCF LF21X451 and instead just go for increased efficiency. I was wondering whether it might be a good idea to put acoustic wadding on the inside of the compression chamber to stop reflections back onto the speaker cone...?

This is the speaker I have at the moment - a Precision Devices ET211S - 750RMS, 1500 Prog. but we'd like it to have a bit more of a throw.



Not quite sure what you mean when you said

Extensions on hybrids and tapped horns give more output in the low end but excursion will raise to do so.

Hi cubbo,

I am thinking of 4 cubo sub loaded with a b&c 18tbw100 or rcf lf18x451 like driver. I know these two are real sub drivers.
But how would the cubo sub perform with one a side, and a 12/1 frontloaded top crossed @100Hz? Would there be a gap in the overall frequentie response?

A sub that i like is de dynacord fx20, has nice spl that really can be felt, and they almost can go down to 30 Hz.

Would the cubo sub be a match?

Thanks Cubo, i'll probably go for the 9601 then assuming itll give the same or deeper bass than the 9001 in this design, and that im planning on throwing alot of power at them, my main concern was that the reflex element of the cubo was what was responsible for the deep bass extension, which i thought may have made the 9001 better for deep bass

@space141:

however the speakers that you have linked me to are both 18" and not 21"

I haven't linked you to any speakers, that part of the message was aimed @ kriptech.

Not quite sure what you mean when you said Extensions on hybrids and tapped horns give more output in the low end but excursion will raise to do so.

An (horn) extension will usually do the following:

- Lower the lowest reachable frequency by increasing the horn length
- Raise overall sensitivity
- Give more direction to the overall sound and/or are more directional down to a lower frequency

On hybrids and tapped horns the lower cut off and raised sensitivity (when using extensions) comes from an increase in excursion ( for the lowest frequencies) and not so much from an increase in efficiency. If your goal is only to reach higher directionality, barn doors can be of assistance. If you also want to raise sensitivity an extension might be a better option.

I was wondering whether it might be a good idea to put acoustic wadding on the inside of the compression chamber to stop reflections back onto the speaker cone...?

For a sub, the wavelengths of the frequency range involved are to large (11.5 metres for 30 Hz) to be affected by wadding, nor is the reflection effectively out of phase with the front wave to be of interest. It can help to remove higher order distortion products from the drivers non-linear movement, although these even order harmonics are often deemed OK sound-wise.

@Sound96 (no longer a reply to space141

But how would the cubo sub perform with one a side, and a 12/1 frontloaded top crossed @100Hz? Would there be a gap in the overall frequentie response?

100 Hz might be a bit high (as it's for most true sub enclosures), 80 Hz would be a more practical crossover in my opinion. Almost all 12"/1" tops are capable of crossing at 80 Hz, which means they'll take care of the fundamental part of the kick in the system. One Cubo Sub per side would already give optimal results and is a good match for a 12"/1" top caninet.

Are you from the Netherlands by any chance?

A sub that i like is de dynacord fx20, has nice spl that really can be felt, and they almost can go down to 30 Hz.

The spec sheet says -10 dB@30 Hz, so I expect Cubo Sub to have a bit more sub, it can be felt as well. The FX20 being a PWH at the top end of the frequency range might be a bit louder there, as it's larger then Cubo Sub.

@Nocturnal92: Good choice

Best regards

Cubo

@cubo15

I'm indeed from the Netherlands
At the moment i have two 12"/2" horn loaded mid-highs laying around.
They go pretty loud, but they only can be used for 150 Hz and up.

At the moment i have 4 X15Hl subs, and there is the problem that they can play till 120 Hz.
Also some more SPL is needed, thats why i'm searching for a solution.
I could get 4 extra X15Hl subs, but with 8 of them, it's not really practical.

With both subs (X15hl and cubo sub) i need a kick bin to cover the gap (cubo kick would be an option).

I am searching for al kinds of sub drivers, some are better then others of course.
What would be an option for approximately 350,- per driver. Maybe is buying in a foreign country an option (Blue Aran)?

Cubo Kick 15 or Cubo Kick Medium with a 12" driver would be an option, for the 80 - 160 Hz gap.

I don't have experience buying at Blue Aran, from the contact I've had with them so far they seem reasonable. However at Thomann, they got the B&C 18SW100 for just a few Euro's more or the RCF LF18X401 for a few Euro's less. Both are real sub drivers that will have the extra needed SPL as well.

Best regards

Cubo

I currently have 4 WBins with JBL 2241H drivers in them that are a true pita to move around and I was considering building these Cubo Sub cabinets for them. However I'm kind of lost since the official plan doesn't show any specific driver requirements apart from a high xMax.

Do you guys think these would be a good match? I would use 4 of these in a 4-way system with Cubo kicks (15" 15ND930).

www.jblpro.com/pages/pub/components/2241.pdf

Thanks!

Hi again Cubo im just looking at amps to power the 9601s with, the model im looking at will be able to put the full 3600w program power (listed by 18sound) to 1 9601 on each side, but im wondering if the amount of power they can take or the amount of excursion is affected by the Cubo Sub design at all

@Tempest: The JBL 2241H will work in Cubo Sub, for which no specific driver requirements are added as about every 18" PA-driver (with very few exceptions) will work in this enclosure. The easiest way and primary specification that rules a PA-driver in or out in this case is the Xmax. Using the method of adding 1/4 gap depth gives 7.5 mm for the JBL, denoting that it's on the light side for Cubo Sub but considering that it's a 600 W driver that's to be expected.

I'm not sure what size the JBins are so I can't comment on the relative ease of transport that the Cubo Sub will or won't give. I will put you attention on Cubo 18 Extended for a brief moment though, as that is pretty much a bliss to move around imo.

Regardless of your choice for Cubo 18 or Cubo Sub, 4 cabinets will be a good match for 2 Cubo Kick 15.

@Nocturnal92: The electrical power a driver can take, or the excursion it makes is affected by the design it's in, whether that's a horn, reflex, or Cubo Sub. I would look at an amplifier that can deliver around 2000 - 2500 W per 9601. If you truly use the extra power (only) as headroom 3600 W is OK. Don't forget to set a high pass tho.

Best regards

Cubo