What voltage should I limit my...

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What voltage should I limit my...

#1 Post by Pabloaguas »

Hello Everyone,

I'm wondering at what voltage to limit my B&G 12BG76 inside a Tuba 45. Yes, the volume of the sealed, inner portion of the Tuba is halved to accommodate the parameters of this driver.

I have attached the datasheet, as this drivers' power handling specs are just as cryptic as any other speaker... 500W nominal 1000w continuous with continuous being defined as "nominal +3db" :roll: Well, amp is Powerlight 340 so I won't want to limit more than 800 watts probably anyway right? Or is this an amp that "likes" to be pushed? ... I guess the question is: do I limit for 500w or 800w (or something else) and does an extra 300w really matter anyways and do I calculate with the minimum impedance on the graph, even tho its at my crossover frequency and I have my EQ set to -12db at 100Hz and +12db at 30Hz (just to have a flat response)? (I'm steeply high passing at 30hz BTW)

Also- at what frequency should I measure?

Ok, after writing this I realize i'm opening a can of worms but I would really like some various opinions from y'all so please lets hear all the angles on this :)

Thank you,


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Bill Fitzmaurice
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Re: What voltage should I limit my...

#2 Post by Bill Fitzmaurice »

The limit voltage is based on the driver xmax, not the thermal power rating. It's explained in your plans in the 'Protecting Your Drivers' section. With 9.5mm xmax your driver has the same 50v limit as the 3012LF.

Grant Bunter
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Re: What voltage should I limit my...

#3 Post by Grant Bunter »

Last edited by Grant Bunter on Fri Jan 13, 2023 7:35 pm, edited 1 time in total.
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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Re: What voltage should I limit my...

#4 Post by Seth »

Don't hold back, Grant. Tell 'em what you really think.

(Someone, get a Snickers bar, STAT!)
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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