Otop 8

High power and fidelity from an easy to build cabinet.
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Bryan Cox
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Location: Owensville, Mo

Otop 8

#1 Post by Bryan Cox »

I haven't seen any Otop 8 build threads. Has anyone built them? Seems like a cool project for the future. Would it be possible to flip the tweeter array 90° and hang the speakers horizontally like other line arrays speakers?
Otop 12 x 4 (Delta Pro 12-450a) 2x melded, 2x straight
Titan 39 x 4 (3012LF) 20" wide

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Bill Fitzmaurice
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Re: Otop 8

#2 Post by Bill Fitzmaurice »

If you do that you halve the dispersion of the woofers and reduce the number of elements in the array. The entire point of the OTop 8 is to have a narrow cab, where the OTop 12 is wider than you want for esthetic reasons. .

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Bryan Cox
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Location: Owensville, Mo

Re: Otop 8

#3 Post by Bryan Cox »

Dumb question I guess. Just trying to maximize vertical space. I'm not really concerned about asthetics here. I've seen that most commercially available line array speakers are mounted horizontally. I thought it was a fair question.
Otop 12 x 4 (Delta Pro 12-450a) 2x melded, 2x straight
Titan 39 x 4 (3012LF) 20" wide

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Bill Fitzmaurice
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Re: Otop 8

#4 Post by Bill Fitzmaurice »

It's not a dumb question, because so many commercial arrays are that way you'd think there's a good reason for it. The reason is since their woofers aren't horn loaded there's no way to place the HF horns in front of the woofers. There are a few that do have a tweeter line in front of the woofers, but those use very shallow dome style tweeters, not horn loaded tweeters, so they not only don't have the higher sensitivity of horn loaded woofers, they don't have the higher sensitivity of horn loaded tweeters either.

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Bryan Cox
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Location: Owensville, Mo

Re: Otop 8

#5 Post by Bryan Cox »

Ah okay. Thank you, Bill for the education.
Otop 12 x 4 (Delta Pro 12-450a) 2x melded, 2x straight
Titan 39 x 4 (3012LF) 20" wide

Grant Bunter
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Location: Ilfracombe Queensland Australia
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Re: Otop 8

#6 Post by Grant Bunter »

Go back to the SPL charts for the Otop 8.
You'll notice, in some spots, the response from the Otop 8 is around +10dB compared to the JBL product.
Across a large chunk of the chart it's +10 to +5dB.
That's, depending on frequency, twice as loud, to (almost) a doubling of cabs.
2 a side would still be better off than a maximum of 6 per side (according to the JBL site), for a lot less money and cranking FOH tops...
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 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Bryan Cox
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Re: Otop 8

#7 Post by Bryan Cox »

Sold! Bought the plans. And I build them after I build my subs. Thanks for the info!
Otop 12 x 4 (Delta Pro 12-450a) 2x melded, 2x straight
Titan 39 x 4 (3012LF) 20" wide

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Bryan Cox
Posts: 447
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Location: Owensville, Mo

Re: Otop 8

#8 Post by Bryan Cox »

The performance quotient of the Otop 8 is a 7, compared to the Otop 12 at 8. Would using the higher end woofers increase performance quotient or is it more a product of design?

Bill, how do you quantify the performance quotients?
Otop 12 x 4 (Delta Pro 12-450a) 2x melded, 2x straight
Titan 39 x 4 (3012LF) 20" wide

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Bill Fitzmaurice
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Re: Otop 8

#9 Post by Bill Fitzmaurice »

It's a 7 because you can't get the equivalent of a KappaLite 3012HO in an eight inch driver. Well, maybe you can, but it's still going to be an eight, so it won't match a 3012HO. A 10 is the best I can come up with, the rest are compared to that. I don't do a 4. You have to buy off the shelf for that. :wink:

CoronaOperator
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Re: Otop 8

#10 Post by CoronaOperator »

Bigcox4002001 wrote: Sun Dec 09, 2018 9:55 pm I've seen that most commercially available line array speakers are mounted horizontally.
They are but then they are designed to be hung with 16-20 elements a side so they get their vertical height using many cabinets. You want that tweeter array as high as possible to get the vertical dispersion down to keep sound off the ceiling and floor. The higher the array the narrower the dispersion. With the orientation of the otop 8 you get a decent tweeter array height with only 1 cabinet.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

CoronaOperator
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Re: Otop 8

#11 Post by CoronaOperator »

Bigcox4002001 wrote: Sun Dec 09, 2018 9:55 pm I've seen that most commercially available line array speakers are mounted horizontally.
They can get away with reduced woofer dispersion in the horizontal because you don't have your audience 8 feet away from a 20 foot tall line array.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

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Bill Fitzmaurice
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Joined: Tue May 02, 2006 5:59 pm

Re: Otop 8

#12 Post by Bill Fitzmaurice »

CoronaOperator wrote: Sun Oct 20, 2019 4:54 pm They are but then they are designed to be hung with 16-20 elements a side so they get their vertical height using many cabinets.
For the most part they don't horn load the woofers, so they have to use twice as many. That also makes necessary compromises that horn loading the woofers avoids.

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Bryan Cox
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Location: Owensville, Mo

Re: Otop 8

#13 Post by Bryan Cox »

Thanks for the responses, fellas.

Do I gain anything from the Otop 8 over the Otop 12 other than aesthetics?
Otop 12 x 4 (Delta Pro 12-450a) 2x melded, 2x straight
Titan 39 x 4 (3012LF) 20" wide

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Bill Fitzmaurice
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Re: Otop 8

#14 Post by Bill Fitzmaurice »

Not really. The OTop 8 was created to fill a request for an OTop with a narrower profile than the OTop 12, strictly for looks, by a wedding DJ.

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Bryan Cox
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Location: Owensville, Mo

Re: Otop 8

#15 Post by Bryan Cox »

Ah okay. Seems like a fun future build. But I'll shelf it for now. Thanks, Bill.
Otop 12 x 4 (Delta Pro 12-450a) 2x melded, 2x straight
Titan 39 x 4 (3012LF) 20" wide

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