b&c Dub Sound System-thoughts

hello everybody,
it's my first topic in this forum.
i just ask you for advice.
one of my friends and me are trying to build a dub sound system composed by these elements:
-2 MID/TOP is an B&C project - bcspeakers.s3.amazonaws.com/2013/02/12/16/15/30/395/file with b&c 12pe32 and b&c de610 drivers + b&c me90 horn
-2 MidBass is a Microscoop - hornplans.free.fr/microscoope.html with B&C 15PZB100 (still have to buy it)
-2 Sub is this project here : hornplans.free.fr/cb18_cyclops.html with b&c 18nw100 (still have to buy it)

what do you think about this? for the amplifiers we have already a qsc rmx4050(we thougt to use it for the subs) and we are waiting to buy 2 crest audio,one cc2800 and one cc4000.

tell me what you think this project and how can we improve it better?
thank you all !

Need more info about your intentions really to give any clear-cut answers.

If you’re doing this for a bit of fun and just want a great sounding system to play at parties then most of what you suggest will be fine.

If you intend to compete with this system and clash against other sounds, then it needs a serious rethink. Looking at what other sounds use in battle will give you an idea as to what can work in these situations.

I’ll take it that you are going for the first option. The B&C DE610 is a really lovely sounding comp driver. It’s not offensive when matched to a good horn and has a lot of HF extension. If you get the right horn on this driver you won’t need 350 piezos to give some air. I’ve not used an ME90 horn, so can’t comment on how well it will work with the DE 610, it all depends which horns B&C intended the 610 to be used with, if it was the ME 90 then should be a good match.

Depending on you enclosure type the 12PE32 could also sound and perform really well. If you don’t need massive SPL levels and don’t need it to play too low then your intended reflex would be an option. The 12PE32 would not really be my first choice for a reflex box, it’s a bit too tight and has low Xmax. I would not want to cross it over any lower than 180Hz in a largish reflex box. If your upper bass can play and sound good this high then its an option, but I think the 12PE32 in a horn like an MT121 would make better use of it.

The jury is still out on whether rear loaded horns are the best option for upper bass. Some people love it and get away with it in some of the famous older style dance stacks, others, myself included don’t think it’s a good idea. The horn isn’t going to operate in much of the band you want to cover, so I don’t see the point of having it there. There also that ‘soft’ kind of sound associated with rear-loaded horns that you might or might not like in your intended pass band. If you want the kick to be a bit more in ya face and hard, then a short bandpass horn might be more to your liking. But choose a good design otherwise your get colorations above 140hz.

Never heard a CB18, so can’t comment on how well this would work for your requirements. People who run them seem to like them, so I don’t think there bad, just not sure if they can enhance dub styles of music. Its interesting why you didn’t go for the obvious, an 18” scoop.

Nothing wrong with QSC and Crest amps. You could do better with a higher budget, but you could also spend the same amount as you will on the QSC and Crest and do a lot lot worse. So go with it if your aim is sound quality over SPL.

Rog.

Another thing I would say is that before you decide which type of enclosure and which drivers you are going to use, you must decide on the SPL and dispersion. You are designing a whole system here, not just one part of it, so need to think a bit differently.

When I start out designing a complete system I think coverage. That’s the only thing I’m worried about at this stage. Coverage will have sub sections like dispersion and SPL. These can then be broken down into how many parts the system needs to successfully meet the coverage requirements. So what is coverage. I see it as the area the system needs to be able to provide for. The area will have dimensions and also a head count and an SPL per head. So if we take your planned system for example, I would think you are thinking about designing a system that can play in small to medium size venues to around 300 to 500 people. I won’t go into details like how many sq meters you need to cover or SPL per person as it will get too complicated.

So if you are going to be using 2 stacks, then it looks like you need each stack to have a dispersion of a minimum of 90 degrees, and this would only be of use in narrow long type venues, and a maximum of around 150 degrees for very wide and short type venues. Note here that in an ideal world the same system cannot or should not be used for both venue types. You could go for 120 degrees and sort of get it right for both types of venue, but this all depends on how much you want to compromise. Next thing is how loud do you want each person to experience this system. More SPL will dictate more speakers and each will need to have a narrower dispersion. It’s all about density, with fewer wider dispersion speakers giving less density and more narrower dispersion speakers giving high density. Both will cover the same area width wise, but more speakers into the same dispersion are obviously going to be louder and carry further. Yes this is throw.

The above is only talking about frequencies above say 100Hz, as below that you really don’t have much control of dispersion unless you get very technical. In fact it’s hard to control frequencies below 500Hz, so as a DIY builder all you can do is have control of the HF horns and the different dispersions they have. So if you were planning on using just a single midtop speaker in each stack using the ME 90 you would have 90 degrees dispersion. But the density would be very low. At most I would say a single 12PE32 and ME610 per stack would be good for around 100 people per stack, so 200 people for a stereo system. It would be the 12” section here that is limiting, as the HF section could provide a lot more SPL than the 12” section. I would think that a DE610 on an ME90 horn could provide enough SPL for two 12PE32’s, so you could design an enclosure like the X12. I’d say you could cover 200 people with each X12 if you used 1 per stack, so if you are thinking about a total coverage of 300 to 500 people, then your not far off. You would have to play these midtops at approaching full SPL all the time though, so reliability would not be good and you don’t get any headroom, so for me it’s a non starter.

The next step up would be to use two X12 type cabs in each stack. So four 12PE32’s and 2 HF’s. You would need to use a different HF horn as 90 degrees would be too wide. A 60 degree horn would work well here and if splayed correctly would give you 120 degrees dispersion, which is very useful for a lot of venue types. I would say that two X12’s with 60 degree dispersion would provide enough SPL for around 350 people comfortably. So if you used this system for 300 to 500 people you would have headroom, so could provide some serious SPL’s if you needed to.

Next set up would be going to a more narrower dispersion type enclosure. For this you would need some control over the 12” driver as well. So we are talking about a horn here for both HF and 12” section. To give 120 degrees dispersion would require three 40 degree dispersion cabs. If you can find a good HF horn with a 40 degree dispersion that works well with the DE610 and mount it in a MT121 cab, then three of these per side would work very well. You should be able to cover 500 people with each stack easily and if you ever needed to play in a narrow and long room then just use 2 cabs per stack.

So I hope you can see the kind of questions you need to be asking at these early stages. The better you can answer these questions the better and more refined your system can be. I’ve only covered midtop speakers here, for bass you would just keep adding more cabs until you kept up with your midtop coverage requirements. You would not add more bass cabs for dispersion sakes, just for more SPL to cover the larger area. If you were going to use a good performing 18” scoop with premium driver, then 4 per stack should be enough to keep up with the coverage of three 40 degree MT121’s.

Rog.