Pre-Build questions- OT12, DR280&300

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burnsze15
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Pre-Build questions- OT12, DR280&300

#1 Post by burnsze15 » Tue Apr 21, 2020 8:11 am

I’m going to be purchasing flats for a build. 6-8 cab build of whatever I finally decide on.

A few questions for the experts:

-Im building a scalable rig that can accomodate smaller outdoor live events as well as scale up to several thousand. I want to cry once, and not find myself wishing I built something more substantial

1. I would consider building the OT12 with the Kappa12 and NSD however, what are you guys doing about the lack of flat response from 100hz to 200hz? I want to cross at 100hz and no higher, 110 absolute max to try and keep the directivity of the LF source down. My horns have an effective passband to 120hz and then they roll out of their wheelhouse fast. Want to keep a safe distance from the 120 by HP at 100. So the response graphs for the OT show a 6dbdb rise from 100hz at 97db to its average sensitivity level of what I see being 103 (105 peak) (w/ASD). Thats a 6-8db rise from 100-170ishHz. What are you guys doing in the 100-200hz range? PEQing a small shelf? Thats steering me away from the OT a bit, but as many do I love it for its size and ease of build.

2. The DR300 has a very clear message that it ahouldnt ve used inside 30’ or crowds less than 800. What it the coverage pattern and beamwidth like for these? It must be super narrow to enhance its directivity and gain? What would the effect be at say 40’ with 2-4 cabs? I’d like to build the best and most capable cab I can, however Im thinking the 280 with premium components may be a better scalable choice for a mix of large and small events and crowds? Seems the 280 is a bit more manageable as well in terms of lifting and maneuvering.

Thanks in advance.

jimbo7
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Re: Pre-Build questions- OT12, DR280&300

#2 Post by jimbo7 » Tue Apr 21, 2020 9:13 am

If you wanna be scalable you might need to build more than 1 model top or sub. Just for the sake of mobility and saving a few bucks. You're also gonna need a whole lotta equipment, too.

The OT's are more than capable of the smaller gigs, but if you're providing sound for J.Lo you'll need a whole lot more OT's than DR's. What events you gonna be doing that have 1000+ people?

There's a few people here that have a whole lotta cabs and use them frequently. They'll have better answers and more experience to help you compared my my little house party setup.
BFM builds:
XF212
T24 BP102 24"
2x SLA's 6-5" mids, 9- gt-302's
2x AT 14" MCM 55-2421
TrT 5" MCM 55-2421
AT 18" JBL GTO804
2x OT12 flat array
2x SLA Pro 2-Alpha 6's 2-Goldwoods
2x T39 24" 3012lf
Simplex 10 BP102

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Seth
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Re: Pre-Build questions- OT12, DR280&300

#3 Post by Seth » Tue Apr 21, 2020 10:58 am

Hey, how's it going...

Here's Bills response on the DR's from the FAQ's, Which DR for me?

I'm not sure the NSD is an option, unless you've found some stock somewhere. Pretty sure they were discontinued.

I can't speak to the OT12's, but it sounds like you're on the right path.
Last edited by Seth on Tue Apr 21, 2020 11:29 am, edited 1 time in total.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Bruce Weldy
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Re: Pre-Build questions- OT12, DR280&300

#4 Post by Bruce Weldy » Tue Apr 21, 2020 11:04 am

Before helping you decide, it would be good to know exactly what you will be doing with them. What type of music? How spread out is the crowd? Do you have the ability to fly the system? Will it be ground stacked? Do you already have scaffolds, etc....

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

burnsze15
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Re: Pre-Build questions- OT12, DR280&300

#5 Post by burnsze15 » Tue Apr 21, 2020 5:38 pm

Hi guys, well after doing some additional research, I found that purchasing flat paks from SpkHrdwre will be my best option, and having said that the DRs are out as an option. Scratch build isnt in the cards for me.

So, it looks like the OTOP15 will be the option should I continue on this path, as I probably will.

There isnt a flat pack for dual 12s for the OT12 so thats out.

Here’s my remaining questions on the OT15 for those in the know, btw thanks already to those that have weighed in, this is a great group here.

1. Looking for curves with the various drivers installed, specifically the KappaLite 15. Thats a very capable driver and I’ve modeled it in high output MTH kind of designs before.
2. Going ASD to NSD, I can see the spec differences, but again wondering what a pair of the NSD vs ASD will get me other than greater headroom and capability/output. The ASD curve doesnt look bad at all.
3. My LF horns (Not BFM) have an effective upper end of 120 and then they go out of passband very steeply as folded horns typically do. That being said, looks like the 100Hz number for whatever driver is installed in the SPL curves posted here and on the BFM OT15 site is about 100 or so db at 1w/1m. Is it fair to say to flatten the response curve within about 2db or so that we will be at an average of about 103db? The intended crossover point should be about 100Hz. My 4 (as of now) folded horns combined have a 1m sensitivity of about 115. 4 of the OT15s should have a sensitivity of about 115 as well, 6 somewhere around 118. I believe we should have a well matched system with max burst output of the LF at about 150db and the HF OT rig should be around 145 for 6 cabs, so I think this is a good match.

Now as for use? Listen it could be something around 100 ppl outdoors up to possibly 1000-2000 very very rarely at an outdoor Fair or event. The content will be Country or Pop-Country with emphasis on bringing out the vocal in the mix, 500-2000hz, so having a quality box that natively has great dynamics and detailing will be a huge asset to this rig. Of course you can never have enough kick drum, so that lower end will probably grow next year when theres some funds available again.

I can array them yes. For a really large event (rare) Scaffold or even a lift is possible if they can be flown, which im not seeing hardware for, so a stack on a scaffold with 8degree arraying would be best. Normally having them stacked 2-3 aside will be the norm.

Thanks again, and I am open to all ideas and feedback. Only other option is having one of the builders build up some 280s for me to finish and load and paint, but Id have to think that cost is pretty high.

Grant Bunter
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Re: Pre-Build questions- OT12, DR280&300

#6 Post by Grant Bunter » Tue Apr 21, 2020 7:54 pm

G'day,
Righto, a few things;

I reckon 103dB as an average is a good call for the Otop 15 and 100Hz will be fine to cross from subs.

It's important you make a driver choice in terms of build (because of Phase plugs on the baffle).
Have you contacted Leland from Speakerhardware.com to see if a 2 x 15 could be done as a flat pack?

NSD's, unless you have them already, are pretty much gone as per:
viewtopic.php?f=2&t=25248
It's ok, another option is in the same thread.
Dual ASD's have a higher cross, about 2K. So, if a lower 1.2K cross is a preference, then the new option in the thread above is for you.
Also, Eminence are shut down at this time. So you will only get stock held on the shelf of the purchase place.
I imagine no drop shipping for now.

Flying, there's no flying hardware as these cabs are not designed to be flown as such.
You would need to employ an engineer that would design and sign off a system that wholly encloses the cabs.
Add the cost of that in your calculations.
Having said that, the Otops15's are flat boxes, so stack nicely vertically, and that would work well on scaffold, but not so well if you wish to introduce splay. AFAIK, the Otop12's are the only cabs that have been modded to J arrays.

Finally, it's the design that dictates response, not the driver(s). Putting in "better" drivers simply increases power handling.
So, response curves can essentially be used for any driver you opt for.

Hope this helps.
Keep asking questions :)
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting "like"s would be most appreciated...

Bruce Weldy
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Re: Pre-Build questions- OT12, DR280&300

#7 Post by Bruce Weldy » Tue Apr 21, 2020 8:00 pm

The NSD is no longer available, but there is a substitute available. The important thing is to go with that driver instead of the ASD to get the lower crossover on the horn....

Personally, I'd do a bunch of OT12s. I'm biased as that's what I use. They are lighter, smaller and can handle down to 100hz. Plus, the OT15 requires two horns per box, so that doubles the price of the compression drivers. There just isn't any reason for the OT15. Cross the subs at 100hz and the tops at 110hz. You'll have all the frequency coverage that you need.

I run two a side, but doing 3 or 4 is going to be a lot of noise. Build 'em with the 3012HO and the F151M-8 compression driver. You'll find that these are probably the best sounding vocal box you've heard. I'll take 'em over all of the bigger more expensive boxes that I've run on over the years. The OT12 sounds better than the JBL SRX series and QSC powered boxes - and I've mixed a lot on both of those.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

burnsze15
Posts: 41
Joined: Wed Nov 12, 2014 2:44 pm

Re: Pre-Build questions- OT12, DR280&300

#8 Post by burnsze15 » Tue Apr 21, 2020 8:37 pm

Grant and Bruce, thank you both for your feedback. It was absolutely perfect! Spot on what I was looking for. Thanks also for your patience.

The OT12 is the right box, just needed to get that feedback from you. The lower crossover point is a must for me, puts more of the vocal in the horn, and thats important.

The KappaLiteHO and new Eminence should perform well. My concerns about the 100-150Hz response seems to be unfounded with the 100-120Hz mixed cross. Should be a seamless transition without losing any 100-150 content (upper snap spectrum of kick drum so its important)

I will ask Leland about a double 12, but I feel like that may just outrun the single CD capability and be a significant investment for little benefit. I agree this driver combo is the sweet spot.

Here’s one more question, and maybe Bill needs to look at it, but I have a few B&C DE250s sitting here, could these be utilized at the 1.2 xover point? They are flat, 108.5 sens and have a 60w RMS (120 program) power rating. And, as I said I already have three. Can’t find its resonant freq data though.

Thanks much gents. Much appreciated.

Grant Bunter
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Re: Pre-Build questions- OT12, DR280&300

#9 Post by Grant Bunter » Tue Apr 21, 2020 9:52 pm

^TS parameters are essential. That's what the design is built on.

I can't find TS specs, but I did find the recommended crossover for the DE250 from B&C, and that's 1.6K...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting "like"s would be most appreciated...

Bruce Weldy
Posts: 7594
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Pre-Build questions- OT12, DR280&300

#10 Post by Bruce Weldy » Wed Apr 22, 2020 8:55 am

Grant Bunter wrote:
Tue Apr 21, 2020 9:52 pm
^TS parameters are essential. That's what the design is built on.

I can't find TS specs, but I did find the recommended crossover for the DE250 from B&C, and that's 1.6K...
But with Bill's higher slope crossover, it should handle 1.2k just fine....maybe Bill will chime in....

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Bill Fitzmaurice
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Re: Pre-Build questions- OT12, DR280&300

#11 Post by Bill Fitzmaurice » Wed Apr 22, 2020 9:52 am

I'd say it will. Based on the spec sheet SPL and impedance charts the Fs of the DE250 is 900Hz.

burnsze15
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Re: Pre-Build questions- OT12, DR280&300

#12 Post by burnsze15 » Wed Apr 22, 2020 5:23 pm

Bill Fitzmaurice wrote:
Wed Apr 22, 2020 9:52 am
I'd say it will. Based on the spec sheet SPL and impedance charts the Fs of the DE250 is 900Hz.
That’s great news!!! Thanks Bill.
I assume there is enough physical clearance for it behind the horn?

Bruce Weldy
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Re: Pre-Build questions- OT12, DR280&300

#13 Post by Bruce Weldy » Wed Apr 22, 2020 7:50 pm

burnsze15 wrote:
Wed Apr 22, 2020 5:23 pm
Bill Fitzmaurice wrote:
Wed Apr 22, 2020 9:52 am
I'd say it will. Based on the spec sheet SPL and impedance charts the Fs of the DE250 is 900Hz.
That’s great news!!! Thanks Bill.
I assume there is enough physical clearance for it behind the horn?
Look up the specs for that driver and the NSD2005....if it's smaller than the NSD, then it will fit. I say look up the NSD because it's a little bigger than the new replacement I believe.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

burnsze15
Posts: 41
Joined: Wed Nov 12, 2014 2:44 pm

Re: Pre-Build questions- OT12, DR280&300

#14 Post by burnsze15 » Fri Apr 24, 2020 6:03 pm

Ok Im down to ordering the Flat Packs. Im deciding between JArray and Squares. Im never going to attempt to fly these for various reasons. Having said that, take a 100yard field, standard ball field width. If 8 (4xSide)of these cabs (comp horns) were to be put on 5’ scaffold would stacking the squares to form an 8’ beamheight work or would the signal just mostly propogate over everyones heads? Maybe a touch of downtilt and get them up higher? I would put another pair of Piezos at ear height under those comp horns for nearfield.

Thoughts on best array of straight boxes?

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Bill Fitzmaurice
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Re: Pre-Build questions- OT12, DR280&300

#15 Post by Bill Fitzmaurice » Fri Apr 24, 2020 9:28 pm

JArrays are the better choice when the lowermost cab is at least eight feet off the ground, which would require down tilting of the lower cab or two to cover the close in audience.

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