Tuba 30” driver question

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Rickwired
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Location: Fresno CA

Tuba 30” driver question

#1 Post by Rickwired » Wed Jan 09, 2019 4:51 am

Anyone ever use a B&C 12BG100? All the T/S parameters seem to be within the specs but with a RMS of 1000 watts... wondering if I should go that route for some 20” tuba 30s.
1 - 29” tuba 30 w/ dual kappalite 3012lf

CoronaOperator
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Location: Medicine Hat, Alberta, Canada

#2 Post by CoronaOperator » Wed Jan 09, 2019 5:19 am

The performance of a subwoofer is usually limited by displacement (xmax), not rms wattage rating. The B&C doesn't have much more xmax (~1mm) to justify spending almost twice the price on it.
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

Rickwired
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Joined: Wed Dec 05, 2018 1:26 am
Location: Fresno CA

Re: Tuba 30” driver question

#3 Post by Rickwired » Wed Jan 09, 2019 12:28 pm

So my kappa lites should be ok? Or maybe should I move to a Lab12 since more displacement?
1 - 29” tuba 30 w/ dual kappalite 3012lf

Grant Bunter
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Re: Tuba 30” driver question

#4 Post by Grant Bunter » Wed Jan 09, 2019 3:21 pm

Rickwired wrote:
Wed Jan 09, 2019 12:28 pm
So my kappa lites should be ok? Or maybe should I move to a Lab12 since more displacement?
Same same.
With a dual loaded cab, changing to lab12's will add 28 pounds in weight compared to the 3012lf, and net you, at best, a few dB.

You'll notice that Bill calls limiting "Voltage Displacement Limiting", which invariably gets shortened to voltage limit.
The lab 12 has greater Vd, but it's impedance is lower, compared to the 3012lf.
The two most important criteria in voltage displacement limiting are impedance and Xmax, with the rest of the TS specs following on in lesser importance.
Therefore, a lab 12, with 6 ohms nominal impedance, but the same limit as the 3012lf, wins, just slightly, by around 1 maybe 2dB in greater output for a single driver.

Also, did you wire your 2 x 3012lf's in parallel?
If yes, that's a nominal impedance of 4 ohms per cab.
If you change to lab 12's, is your amp capable of 2 ohm outputs per channel? 2 x lab 12's in parallel is a nominal impedance of 3 ohms.

It's said so often here though, don't try and eke out every possible ounce of output you can get from any one cab. If you're hitting the limiter regularly (presuming you have one set up, and, if you don't, you should), then the answer is turn down, or add more cabs...
Built:
DR 250: x 2 (melded array) with March 2012 plans. 2 more under way with CD horn
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...

Rickwired
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Location: Fresno CA

Re: Tuba 30” driver question

#5 Post by Rickwired » Thu Jan 10, 2019 2:48 am

Yeah I have a Peavey 7500 amp... The current dual T30 is wired in parallel so 4ohms..
I’m currently building another T30 the same way with another pair of 3012lfs. I was just wondering because after this I’m building 2 more but slimmer I think 18” (for easier packing and smaller venues).

Also, how should I wire those boxes if I have 2 dual and 2 single to run at the same time?

Gonna get a DBX driverack this weekend before I run it them again at a show.
1 - 29” tuba 30 w/ dual kappalite 3012lf

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Tom Smit
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Re: Tuba 30” driver question

#6 Post by Tom Smit » Thu Jan 10, 2019 9:15 am

Rickwired wrote:
Thu Jan 10, 2019 2:48 am
Also, how should I wire those boxes if I have 2 dual and 2 single to run at the same time?
Build a couple of boxes, one for each channel, with 3 Speakon connectors. One Speakon is the input; the other two Speakons are outputs that are wired in series with each other.
TomS

Bruce Weldy
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Re: Tuba 30” driver question

#7 Post by Bruce Weldy » Thu Jan 10, 2019 10:34 am

Tom Smit wrote:
Thu Jan 10, 2019 9:15 am
Rickwired wrote:
Thu Jan 10, 2019 2:48 am
Also, how should I wire those boxes if I have 2 dual and 2 single to run at the same time?
Build a couple of boxes, one for each channel, with 3 Speakon connectors. One Speakon is the input; the other two Speakons are outputs that are wired in series with each other.
Really not necessary with that amp. It's 2 ohm capable and has way more power than the Tubas need to reach their limit. Running three 8 ohm 3012LFs parallel shouldn't be any problem at all. Just daisy chain a dual and a single on each side of the amp. But, you definitely need a limiter - that amp has a lot of power.

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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Tom Smit
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Re: Tuba 30” driver question

#8 Post by Tom Smit » Fri Jan 11, 2019 12:32 am

Bruce Weldy wrote:
Thu Jan 10, 2019 10:34 am
Really not necessary with that amp.
Yup.

I just answered the question.
TomS

Bruce Weldy
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Re: Tuba 30” driver question

#9 Post by Bruce Weldy » Fri Jan 11, 2019 9:47 am

Tom Smit wrote:
Fri Jan 11, 2019 12:32 am
Bruce Weldy wrote:
Thu Jan 10, 2019 10:34 am
Really not necessary with that amp.
Yup.

I just answered the question.
I'm not understanding why you think he should wire in series? That amp can handle 3 - 8 ohm drivers in parallel without having to build a box. Daisy-chaining would be the easiest solution unless I'm missing something....

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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Tom Smit
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Re: Tuba 30” driver question

#10 Post by Tom Smit » Sat Jan 12, 2019 12:35 am

Hey Bruce, I only answered the question with a response that is a "cover-all". I didn't check on the amp specs, and thus wasn't aware of it's capabilities.
TomS

CoronaOperator
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Re: Tuba 30” driver question

#11 Post by CoronaOperator » Sat Jan 12, 2019 3:19 am

Rickwired wrote:
Thu Jan 10, 2019 2:48 am
Gonna get a DBX driverack this weekend before I run it them again at a show.
You better get the limiter in place, that amp can put out double the voltage that those drivers can take.
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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Re: Tuba 30” driver question

#12 Post by Bill Fitzmaurice » Sat Jan 12, 2019 8:55 am

That's a good reason for series wiring the drivers.

Bruce Weldy
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Re: Tuba 30” driver question

#13 Post by Bruce Weldy » Sat Jan 12, 2019 9:13 am

Tom Smit wrote:
Sat Jan 12, 2019 12:35 am
Hey Bruce, I only answered the question with a response that is a "cover-all". I didn't check on the amp specs, and thus wasn't aware of it's capabilities.
Gotcha' - just wanted to make sure I wasn't missing something - didn't want to make it harder than it should be for the OP.

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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Tom Smit
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Re: Tuba 30” driver question

#14 Post by Tom Smit » Sat Jan 12, 2019 11:37 pm

OH good! We're still friends?LOL
TomS

Bruce Weldy
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Location: New Braunfels, TX

Re: Tuba 30” driver question

#15 Post by Bruce Weldy » Sat Jan 12, 2019 11:57 pm

Tom Smit wrote:
Sat Jan 12, 2019 11:37 pm
OH good! We're still friends?LOL
Sure. I'll buy you a beer next time you're in Texas. :cowboy:

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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