Dual 12" + 2" Comp designs

[billfitzmaurice]

His designs show the vent immediately behind the woofer.

Whoever 'he' is would fail Acoustical Engineering 101.
He wouldn't be the first designer who was not familiar with basic concepts, I'm afraid.

[Sydney]

...Best implemented LA I've ever heard was Phish in 09 I think (oops.... shhh).. it sounded like a CD... even better than the VIP section for Pink Floyd '95. I think I stood there for a full set with my eyes closed.. and the most sober I've ever been at a show... tyvm! The worst case unfortunately was Staind at IRP... not their fault... a cold front came in with 20mph wind... the temp and wind shear destroyed the mix.... I spent most of my time by the delay stack.

Sounds like you may have some "Road Dog" in ya
You have probably noticed how some venues and arenas shouldn't really have music events, because no sound system can overcome the inherent bad acoustics.
And some bands have consistently had better tech and could dial in a system within the 1st song.
And perhaps you have met the guy touting his experience - perhaps claiming he was a roadie for ( famous group ) or worked countless shows, only to find out it was hype.

[john kokavec]

If you have overlapping coverage, and all CD horns do, there will be comb filtering. When you place cabs side by side the midrange dispersion will be halved. Both those concerns are solved with vertically array cabs. In cases where extremely wide dispersion is required, as in wider than 120 degrees, the cabs can be rotated to different axis, creating an axial array.

bill thats is the y i pickt the round horns thay do a lot better job thin most

[Taterworks]

Boy oh boy, did this thread ever go off the rails.

Scott, if you're interested in building either of the two cabinet designs you proposed (and this thread hasn't yet left a bad taste in your mouth from all the impractical suggestions) then build version A of your cabinet (per the attached PDF file) with front-exiting ports. Stick with the trapezoidal shape because it's conventional, and allows splaying of multiple cabinets if necessary. It probably wouldn't be the end of the world if you ported out the rear, but directing all the available energy to the front of the speaker cabinet just makes intuitive sense, and you won't have to wonder if midbass energy from the ports will be shadowed by the baffles of multiple splayed cabs. If you look at what's out there, most designs use a pair of triangular ports located in the areas of the baffle that are not taken up by the cone area.

Some people here seem to think they know better than John Meyer, who patented a trapezoidal arrayable speaker cabinet. I'd bet money that they don't, because John Meyer has sold quite a few more speakers. Comb filtering between HF sources will be minimized if you use a square rotatable horn flare with a 60x40 coverage pattern and rotate it so that the 40-degree pattern is oriented horizontally when running multiple cabinets in an array format. (When running single cabinets, use the horns with the 60-degree pattern oriented horizontally.) The ability to form arrays like this is one of the reasons for pattern-control horns on HF devices used in pro audio.

[Sydney]

Boy oh boy, did this thread ever go off the rails.

Yes; Perhaps somewhere on the first page where the replies began attacking the design concept?

I totally agree with your paragraph on Meyer ( and his employees )
The Meyer Sound Design Reference is in my library.

[billfitzmaurice]

Some people here seem to think they know better than John Meyer, who patented a trapezoidal arrayable speaker cabinet. I'd bet money that they don't, because John Meyer has sold quite a few more speakers. Comb filtering between HF sources will be minimized if you use a square rotatable horn flare with a 60x40 coverage pattern and rotate it so that the 40-degree pattern is oriented horizontally when running multiple cabinets in an array format. (When running single cabinets, use the horns with the 60-degree pattern oriented horizontally.) The ability to form arrays like this is one of the reasons for pattern-control horns on HF devices used in pro audio.

You can patent anything. You can sell just about anything too.
Minimizing HF comb-filtering is best accomplished via cross-fired elements, which, BTW, you see used in the midrange sections of most line array cabs. And no matter how you cut it even when drivers are close enough to be fully coupled dispersion remains inversely proportional to the width of the source.
Only one point source speaker that I'm aware of gives competition to the line array. It comes from Tom Danley, and it does not employ CD horns. If there is someone who knows better than John Meyer he would certainly be one.

Yes; somewhere on the first page where the replies began attacking the design concept.

The OP asked for advice, it was given.

[john kokavec]

You can patent anything. You can sell just about anything too.
Minimizing HF comb-filtering is best accomplished via cross-fired elements, which, BTW, you see used in the midrange sections of most line array cabs. And no matter how you cut it even when drivers are close enough to be fully coupled dispersion remains inversely proportional to the width of the source.
Only one point source speaker that I'm aware of gives competition to the line array. It comes from Tom Danley, and it does not employ CD horns. If there is someone who knows better than John Meyer he would certainly be one.
The OP asked for advice, it was given.

yes bill you are so right i have herd lots of toms cabs and thay are gr8 sounding cabs

[Sydney]

The OP asked for advice, it was given.

Scott's first post was

using the B&C ME60 horn w/ either a B&C or Selenium driver. the 12" i am not sure of just yet.

So it was a just driver selection issue?

I would welcome a open objective discussion of the merits of your assertions. Not on this thread; perhaps on your forum.

[Mipsconsult]

Re-read the original post. There was a statement made. No information was requested.

How is anyone supposed to answer a question that was never asked? The only option was to comment on the design.

He got honest responses. Where's the problem?

[billfitzmaurice]

I would welcome a open objective discussion of the merits of your assertions. Not on this thread; perhaps on your forum.

I'm sure you would, since you were removed from there because you consistently refused to play by the rules. For those unfamiliar with my forum, the rules there are simple:
The purpose of the forum is three-fold. We're here to help prospective builders choose their BF cabs, to build them, and to use them.
You did not go to my forum for any of those reasons. You only went there to push your own agenda. You were like a guest in my home who complained over everything from the taste of the food to the color of the walls. I regret that I put up with your boorish ill mannered behavior as long as I did. Now why don't you sidle on over to the Klipsch (or any other manufacturer support) forum and tell everyone why they should buy something, anything, other than Klipsch (or whatever brand said forum represents) and see how long you last there? Not nearly as long as I put up with you, I'm sure.

Of course you're free to say anything you like here, as this is not a support forum. And I'm free not to have to view it, so to my Iggy list you go.

[Sydney]

How petty to attack and insult personally on this public forum.
I didn't raise any BF forum issues here, you did; and your allegations are merit-less and have no place here.
I joined your forum when I bought your T24 plans in 2006 - that was my agenda
I've had many members of your forum thank me for my contributions there, and listen to many of them commiserate, and enter into discussions and ask me questions they were afraid to ask on the forum.
I did noticed you kept the Education Links I provided when you flushed the rest of my posts down the "memory hole" like a modern "Winston Smith", just like you did to others "banished" prior.
If I'm truly on an ignore list, all the better, it will eliminate the impetus to launch into an insulting tirade.

[Taterworks]

Looks like I've suitably stirred the pot; my work here is done. This place is a tinder box.

To the OP, who seems torn between Selenium and B&C drivers, I'd personally recommend a cast-frame Eminence driver of sufficient power handling and sensitivity for the application (probably not any with the 'LF' designation), and then use the least expensive ferrite B&C 2"-exit driver (DE85) on top. Eminence knows how to build a good functional cone driver, and they won't be extremely expensive either for the raw chassis or for subsequent recones.

[BElstro]

Sounds like you may have some "Road Dog" in ya
You have probably noticed how some venues and arenas shouldn't really have music events, because no sound system can overcome the inherent bad acoustics.
And some bands have consistently had better tech and could dial in a system within the 1st song.
And perhaps you have met the guy touting his experience - perhaps claiming he was a roadie for ( famous group ) or worked countless shows, only to find out it was hype.

Ohhh, a bit , hope to do 6mo out and 6mo home this year... I need the time off to play with speakers... . Funny how you mention dialing the system in, its how I was picked up for a tour this year (ran sound check, handed the reigns over to the BE and walked away... unbelieveably he didnt have to change a thing and is currently their TM so he asked me along). Oh, but I know George Jones and Bob Geddes too....... neither of which knows a thing about designing speakers!!! lolol

[BElstro]

Boy oh boy, did this thread ever go off the rails.

Scott, if you're interested in building either of the two cabinet designs you proposed (and this thread hasn't yet left a bad taste in your mouth from all the impractical suggestions) then build version A of your cabinet (per the attached PDF file) with front-exiting ports. Stick with the trapezoidal shape because it's conventional, and allows splaying of multiple cabinets if necessary. It probably wouldn't be the end of the world if you ported out the rear, but directing all the available energy to the front of the speaker cabinet just makes intuitive sense, and you won't have to wonder if midbass energy from the ports will be shadowed by the baffles of multiple splayed cabs. If you look at what's out there, most designs use a pair of triangular ports located in the areas of the baffle that are not taken up by the cone area.

Some people here seem to think they know better than John Meyer, who patented a trapezoidal arrayable speaker cabinet. I'd bet money that they don't, because John Meyer has sold quite a few more speakers. Comb filtering between HF sources will be minimized if you use a square rotatable horn flare with a 60x40 coverage pattern and rotate it so that the 40-degree pattern is oriented horizontally when running multiple cabinets in an array format. (When running single cabinets, use the horns with the 60-degree pattern oriented horizontally.) The ability to form arrays like this is one of the reasons for pattern-control horns on HF devices used in pro audio.

A voice of reason has risen from the ashes!! I hope all this hasnt discouraged the OP from trying them, even if the arguements are somewhat valid to the design process....well, most of it. I originally posted because I had a similar design in mind, but had all these old drivers around so I built a 15/2 variant. Let us know what you do!

[scottcameron]

i posted here just for some feedback and others experience with similar designs. everyone has their own thoughts on what sounds good and what does not. i did receive the information i was looking for.

i've played drums for 28 years so i feel i have a vast amount of knowledge. i always meet another drummers views with an open mind. no matter how you look at it, there will always be someone out there with more knowledge or is a better player then you, so you must never stop learning.

[Sydney]

no matter how you look at it, there will always be someone out there with more knowledge or is a better player then you, so you must never stop learning.

Well put Scott.
People are not born brilliant or obtain omniscience, they draw from others. Jimi Hendrix was chided for "slumming" and listening to club bands, but he remarked that you can learn something from anyone.
Edison was aghast that Einstein didn't have the speed of sound memorized.
I doubt that anyone would conclude that Edison was smartest on that basis. Smartest is a nebulous concept.
Tom Danley has shared stories of being timidly in the presence of those he learned from.
I can appreciate the contributions of both Dave Rat and Bob McCarthy. Dave for his real road experience and McCarthy for the way he has simplified design calculus to create an approach that allows him to conduct seminars around the world on sound design and system implementation.

[wg_ski]

Starting a new 2x12/2" build which I'll need on the 13th next month. Delta Pro 12 woofage, D3305 driver. I already have these components and I'm committed to using them. I'll be putting together a PE order later this week for unrelated items, and I'm wondering about the horn. I have a pair of older 2" Eminence 90x40 I could use and is "nominally" the right pattern, but was wondering if there would be any compelling reason to go to something perhaps 'better'. The cabs will never be splayed or otherwise arrayed - this is for strictly stand alone use as an SPL upgrade from a 2x10/1" with the HM2525 horn.

[AMC]

Starting a new 2x12/2" build which I'll need on the 13th next month. Delta Pro 12 woofage, ...

For my money, I don't think there is a much better all around mid woof then the delta pro. Better, sure, but for the money?

No opinion on your horn query, but do you plan on a tww or wtw arrangement?

[wg_ski]

WTW, on poles. I may mock up both out of OSB to do initial measurements. I plan on having a bypassable passive xo.

[mdocod]

been working on a couple dual 12 cabinets with a 2" comp. using the B&C ME60 horn w/ either a B&C or Selenium driver. the 12" i am not sure of just yet. I was thinking the daytons for a cheap version or a B&C for an expensive option. I'll just change the depth of the port according to what driver i use. the cabinet is net 3.9 cuft before any blocking and driver displacements.

For a system with a sub planned, I think the Dayton 12" drivers are sort of a waste of box size/weight. They have useful bandwidth to around 50hz. That bandwidth is "purchased" at the cost of efficiency in the band they would actually be used in if there is a sub. If there is no sub, then I'd say the Daytons make a pretty good choice as they can carry down to ~50hz- low enough for many PA needs.

A single RCF L12L750, crossed to a sub at ~90hz, can deliver the same SPL for the same power input as a pair of the dayton 12" PA drivers. The box size can be about 1/4 the size/weight you are building currently. Vented is actually preferred here to buy the bandwidth needed from the RCF to hit the 90hz x-over.

Regards,
Eric