file Can they?

12 years 8 months ago #14133 by bitzo
Replied by bitzo on topic Can they?

nickyburnell wrote: Top bloke, keep the knowlege coming smiley20

+1 smiley20

nickyburnell wrote: These MS18 mods the same ones I did?

If lev is talking about my mods, yes is the same that you did plus others, but the internal layout is very similar to mk1.

JJD, in your opinion at 1m using y tag, is that a good approximation of ground coupling? Did you get a better method? I'm just rember something in mighty dubpass thread.

Rog I tryed to model your double 18" reflex tuned at 34hz with your port dimension.
Internal volume is about 481 litres, without driver volume and port volume, am I right? if you don't want to give other details about your cab...could you post a .csv file with the spl graph 1w loaded? may be I'm asking too much smiley17

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12 years 8 months ago #14134 by nickyburnell
Replied by nickyburnell on topic Can they?
@ Its better, but still no double 18” reflex killer. Any thoughts as to why not.


Absolutly none scientifically. Have a friend who has lots (and I mean lots) of Opus 2x18's. His take is that his horn loaded stuff (modded USB) although a lot less of it, cuts through the crowd in dense situations better, giving the perception of a louder rig.
Pehaps this just isn't measurable?

One thing for sure though, having ES18, Cubo and having owned MS18 and Rhino: Nothing sounds anywhere near as good as my 2x18's, not even close.

Not owned Shorty, but if is more reflex than horn (Only speculation as I believe design still commecrcial) perhaps this Scoopflex (Saul) name really has something.

I only have XB's here, I am however going to try the RCF design, which seems to be a crossbreed, for fun, and see what that is like against the 2x18,s (Gsub) I have here.

If anyone is reading this and thinking why is he bothering with all this front facing design stuff, why not do a SBH, or 186 or what ever: It is simply becuse I have stock of XB's and their cone is ribbed, ergo suited to this stuff. Plus I like the non colured sound of reflex, so trying to see if extra spl (or perhaps its throw lol) is available in this format.

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12 years 8 months ago #14135 by saul
Replied by saul on topic Can they?

nickyburnell wrote:
Absolutly none scientifically. Have a friend who has lots (and I mean lots) of Opus 2x18's. His take is that his horn loaded stuff (modded USB) although a lot less of it, cuts through the crowd in dense situations better, giving the perception of a louder rig.
Pehaps this just isn't measurable?


i think it probably is

soon as you introduce any type of horn, surely throw increases, as directivity increases. Rog perhaps could expand on this.

this would explain why roots man prefer a mini over a double 18 in a venue.

but i do wonder which box would really be the loudest at 1m.

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12 years 8 months ago #14137 by Gee136
Replied by Gee136 on topic Can they?
My sound is a roots soundsystem, & we use double 18's, on our bass section (not a scoop in sight) for many years I've been in & around various roots sounds, most of them using scoops, when we built up our sound Goverment a few years ago, we decided that we wasn't going to transport a 4ft bass box with one driver in it, as opposed to two drivers!! Now this was for many reasons, one main reason that I've notice over the years is how deep a reflex box can play!! The ease of achieving our specified deepness without stressing the box (speakers ain't crying!! smiley36 ) Also the main factor was cost, check the equation: x1 PD 1850 in a decent scoop £700 as opposed to x2 XB's in a double box (Gsub) £450 enough said!!!

When we play out, more often than not, soundmen are surprised!! Now I'm saying that they are stupid, but what I've notice in the soundsystem game over the 26 years I've been following sounds, is that everybody follows everybody smiley36 !!! Only a tiny minority will do their own live testing & specification gathering (We did before we decided to build our sound) to assess what is required for them!! Oh and another thing, we play our soundsystem 2way through a pre amp!! Our set will stand up against any sound playing 5way, 4way or 3way!!!

As my Dad (RIP) used to say: experience over enthusiasm always prevails!!!!


Peace.............................................. smiley1

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12 years 8 months ago #14139 by JJD
Replied by JJD on topic Can they?

JJD, in your opinion at 1m using y tag, is that a good approximation of ground coupling? Did you get a better method? I'm just rember something in mighty dubpass thread.

No, I don't think the Y tag is good for that. If port coupling make difference at 1 meter in the response curve, it must be the same at 10 meters. If you make the sim at 1 meter, then if you put the port at 2 meters high, you can see the level decrease in lower bass. But if you make the same sim at 10 meters, you see only a minor difference, because I think akabak just change gain from distance of the virtual mic measurement sim, and not from coupling. When the mic is at 10 meters, the difference path between speaker and port at 2 meters high is not very different, but if you put the mic at 1 meters, yes it makes a big difference. It's just geometry.

Akabak is very powerfull but got some limits. I' haven't found a good solution to sim multiple cabinets and benefits of coupling.

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12 years 8 months ago #14143 by bitzo
Replied by bitzo on topic Can they?
Gee136, I agree on "following", and I respect the root way in soundsystem thing. We played with JahObserver a few times, and last year I had the honour to help Steve and Austin to bring up their soundystem. I learnt so much in those days. On other side, the knowledge about this stuff isn't very easy to acquire, following the others is easier so just the empirical method give you some answers, and once you built your cabs, is pretty difficult to change.

Gee136 wrote: .....Also the main factor was cost, check the equation: x1 PD 1850 in a decent scoop £700 as opposed to x2 XB's in a double box (Gsub) £450 enough said!!!

This belongs on the brands and in what country you live. In England pd cost less than rcf, in Italy is the opposite. But to me the equation is a bit more complex,I mean the same driver driven with same watts how do it perform in a mini scoop or in double reflex (same external dimension)? Does the way of stacking affect so much the performances? Indoor or outdoor what is better and why? ...and we can continue for hours and we are for that smiley2

Thanks JJD very clear. Do you know a software that can take care of ground coupling issue?

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12 years 8 months ago #14144 by nickyburnell
Replied by nickyburnell on topic Can they?

Gee136 wrote: My sound is a roots soundsystem, & we use double 18's, on our bass section (not a scoop in sight) for many years I've been in & around various roots sounds, most of them using scoops, when we built up our sound Goverment a few years ago, we decided that we wasn't going to transport a 4ft bass box with one driver in it, as opposed to two drivers!! Now this was for many reasons, one main reason that I've notice over the years is how deep a reflex box can play!! The ease of achieving our specified deepness without stressing the box (speakers ain't crying!! smiley36 ) Also the main factor was cost, check the equation: x1 PD 1850 in a decent scoop £700 as opposed to x2 XB's in a double box (Gsub) £450 enough said!!!

When we play out, more often than not, soundmen are surprised!! Now I'm saying that they are stupid, but what I've notice in the soundsystem game over the 26 years I've been following sounds, is that everybody follows everybody smiley36 !!! Only a tiny minority will do their own live testing & specification gathering (We did before we decided to build our sound) to assess what is required for them!! Oh and another thing, we play our soundsystem 2way through a pre amp!! Our set will stand up against any sound playing 5way, 4way or 3way!!!

As my Dad (RIP) used to say: experience over enthusiasm always prevails!!!!


Peace.............................................. smiley1



Well put. I have just cut up for another 2x18's on the strength of this. Brought me down to earth with a bump.
4 x 2 x 18, good enough. smiley20

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