Scaling way back! Lots of questions

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Tom Smit
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Re: Scaling way back! Lots of questions

#46 Post by Tom Smit »

Bill Fitzmaurice wrote: Mon Jul 27, 2020 9:11 pm
SethRocksYou wrote: Mon Jul 27, 2020 7:06 pm More specifically, the dispersion angle of the mid range. Enclosure width wouldn't matter?
It does. The narrower the enclosure the wider the dispersion. This applies down to the frequency where the enclosure width is one wavelength. At that point dispersion is 180 degrees. Below that you lose axial output, because the dispersion is wider than 180 degrees, so this sword has two edges.
The difference is about 200hz between the OTop8 and the OTop12. I get that. But, I am not understanding what "axial output" is (even after I did a quick search).
TomS

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J_Dunavin
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Re: Scaling way back! Lots of questions

#47 Post by J_Dunavin »

Side question on the T48:
If my maximum width for my pack space is 18” should I go with a 15” driver? 18” would be the narrowest, I feel like it’s right on the line and could go with a 12 or a 15, guess a 15 would yield more output.
2 - OTop8
2 - T39
8 - DR200
2 - DR250
9 - T24
6 - T45
1 - Auto Tuba

Grant Bunter
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Re: Scaling way back! Lots of questions

#48 Post by Grant Bunter »

SethRocksYou wrote: Mon Jul 27, 2020 4:46 pm Hi Grant :wave:
G'day Seth :)
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 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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Bill Fitzmaurice
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Re: Scaling way back! Lots of questions

#49 Post by Bill Fitzmaurice »

Tom Smit wrote: Mon Jul 27, 2020 11:05 pm I am not understanding what "axial output" is (even after I did a quick search).
The output on a straight line out from the speaker. It falls off below the baffle step frequency, where the baffle is 1 wavelength, as below that the sound wraps around the speaker. It's the same effect as when you go from half space to full space boundary loading.

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J_Dunavin
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Re: Scaling way back! Lots of questions

#50 Post by J_Dunavin »

Ok guys it’s official, listed all my speakers and amps for sale here, on eBay, and Marketplace.
AND got my plans for the T48 and Otop 8 😁
2 - OTop8
2 - T39
8 - DR200
2 - DR250
9 - T24
6 - T45
1 - Auto Tuba

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Tom Smit
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Re: Scaling way back! Lots of questions

#51 Post by Tom Smit »

Thanks Bill.
TomS

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Chris_Allen
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Re: Scaling way back! Lots of questions

#52 Post by Chris_Allen »

J_Dunavin wrote: Tue Jul 28, 2020 4:04 pm AND got my plans for the T48 and Otop 8 😁
"Scaling way back"
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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J_Dunavin
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Re: Scaling way back! Lots of questions

#53 Post by J_Dunavin »

Mostly back, ha! 😄

Well if I only had a slim pair of T48s and a pair on Otops8s at least I could fit that in my basement. Currently that’s not an option.

Going back a touch... if 18” was my max width should I go with the 15” driver option?
2 - OTop8
2 - T39
8 - DR200
2 - DR250
9 - T24
6 - T45
1 - Auto Tuba

Bruce Weldy
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Re: Scaling way back! Lots of questions

#54 Post by Bruce Weldy »

J_Dunavin wrote: Thu Jul 30, 2020 9:54 am

Going back a touch... if 18” was my max width should I go with the 15” driver option?
It's right there on page one of the plans.....you can put a 15 in an 18 inch wide cab.

And on the next to the last page of the plans - the voltage limit for the 15s are higher than the limit for the 12s......so yeah, use the 15.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
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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J_Dunavin
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Re: Scaling way back! Lots of questions

#55 Post by J_Dunavin »

Lightweight amplifier recommendations?
Thoughts on the QSC GX amps?
2 - OTop8
2 - T39
8 - DR200
2 - DR250
9 - T24
6 - T45
1 - Auto Tuba

Bruce Weldy
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Re: Scaling way back! Lots of questions

#56 Post by Bruce Weldy »

J_Dunavin wrote: Sun Aug 02, 2020 4:08 pm Lightweight amplifier recommendations?
Thoughts on the QSC GX amps?
GX3 and 5 are not light. GX7 is.....it's an entirely different amp from the other two..

I've always used the Crown XLS series - very light and have served me well. But, the QSC GX7 are really nice amps....I've run those in another rig for several years.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
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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J_Dunavin
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Re: Scaling way back! Lots of questions

#57 Post by J_Dunavin »

Ok fellas, I had a guy come over this morning for a demo, and we got the cops called on us!!! Most epic!
The cops were totally cool with it all, I should of asked for a picture with them. Oh well maybe next time😄
Me and my little helper, in the back!
Attachments
79266513-CF2E-4364-A53D-EFC5EB1A96EE.jpeg
2 - OTop8
2 - T39
8 - DR200
2 - DR250
9 - T24
6 - T45
1 - Auto Tuba

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J_Dunavin
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Re: Scaling way back! Lots of questions

#58 Post by J_Dunavin »

price lowered, also sold one pair of DRs

viewtopic.php?f=11&t=25789
2 - OTop8
2 - T39
8 - DR200
2 - DR250
9 - T24
6 - T45
1 - Auto Tuba

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J_Dunavin
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Re: Scaling way back! Lots of questions

#59 Post by J_Dunavin »

Well the system is sold😢 time to think about rebuilding 😄.
So we’ve gone over the T48 and a pair of 3015 loaded is probably the best bang dollar per size.
I wonder How four slim T39s would compare loaded with the kappa pro 10lf?
2 - OTop8
2 - T39
8 - DR200
2 - DR250
9 - T24
6 - T45
1 - Auto Tuba

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Seth
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Re: Scaling way back! Lots of questions

#60 Post by Seth »

Four 10" loaded (Not the 3010LF, but response should be relatively similar) T39 slims compared to 2 18" T48's @ 2.83v.

(Edit: Changed to 18" T48's after re-reading the thread)



Adding 24dB to the T39 trace for max output, 26.5dB to the T48 for it's max



To my eye, looks like the T39 slim is the better option.
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

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