Multiple cabs

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Grant Bunter
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Re: Multiple cabs

#16 Post by Grant Bunter » Mon Aug 13, 2018 4:48 am

commander_dan wrote:
Sun Aug 12, 2018 7:32 pm
Looks to be on paper that the regulars can take more volts.
Dan,
There's a little trap here.
The lab 12 C has lower impedance. So it has a lower voltage limit than the regular lab12. But, output is the same!

I reckon the answer to the lab12C hitting harder than the regulars for the OP (based on previous threads) is that he isn't limiting the lab12C's any lower, ie he is almost giving them to much, just not quite enough to blow them.
Built:
DR 250: x 2 (melded array) with March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
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DJStubbs
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Re: Multiple cabs

#17 Post by DJStubbs » Wed Aug 15, 2018 3:49 pm

Sorry yes I meant the 12c seems to have more output. I only have 4 cabinets that have regular lab12s out of 10.
18x Tuba 60 - Dual 12" LAB
4x Renkus Heinz ST6
5x DR280 - Melded 22 piezo array
1x Lab Gruppen PLM10000Q
2x QSC PLD4.5
2x QSC PLD4.3


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Grant Bunter
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Re: Multiple cabs

#18 Post by Grant Bunter » Thu Aug 16, 2018 4:11 am

DJStubbs wrote:
Wed Aug 15, 2018 3:49 pm
Sorry yes I meant the 12c seems to have more output. I only have 4 cabinets that have regular lab12s out of 10.
Please bookmark this thread now, and keep referring back to it.

In this thread:
viewtopic.php?f=2&t=24492&p=271537&hilit=lab12c#p271537
Bill Fitzmaurice wrote:
Wed Aug 30, 2017 5:37 pm
That applies to the Lab 12, which is a 6 ohm driver. The limit on the 4 ohm Lab 12C is 45 volts.
If you're running dual loaded lab12c cabs to the same limit as regular lab12's then, if your current limit is 90V, then you are running the lab12c lab loaded cabs to their limit!
At 90V for the regular lab12 cabs, there's still room for more voltage, so they are not as loud, they are not hitting their limit.
That's why the lab12C loaded cabs are hitting harder!

Here's why you should replace all the 12C's with regular lab12's:

2 x dual loaded lab 12 serial wired cabs, wired together in parallel, is a 7 ohm load. That is what the amp "sees".
100V (the voltage displacement limit) at 7 ohms (or 1429W) on a amplifier should also have a pull of 12.5 amps on each channel.

2 x dual loaded lab12c serial wired cabs, wired together in parallel, is a 5 ohm load. That is what the amp "sees".
90V (the voltage displacement limit) at 5 ohms (or 1620W) on an amplifier should also have a pull of 18 amps on each channel.
Yep, the voltage limit is lower for these cabs, but you need more power for them to be as loud!
While Watts isn't a whole lot greater between the 2, amps is significantly higher.

It's better for the amps and the cabs to be operating somewhere near 8 ohms, than it is to be operating somewhere near 4 ohms, especially when you're doing it like you do, for 12 hours at a time...
Built:
DR 250: x 2 (melded array) with 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...

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DJStubbs
Posts: 162
Joined: Tue Oct 04, 2016 3:51 pm

Re: Multiple cabs

#19 Post by DJStubbs » Thu Sep 13, 2018 3:28 am

So I have ran into some issues now. I have recently just bought 6 more tubas which I opened today and found out they are Lab12c. Will I be able to run 12 cabs with c versions off of my lab gruppen plm10000q? A couple of cabs were blown I guess from the original owner. Because I got no reading off a multimeter. I am considering reconing into regular lab12s. But either way it’s going to be expensive and if I were to just recone all of my woofers to regular labs but that’s going to be like 20-24 woofers that need to be reconed. It may be cheaper to just recone the non c versions for the c version. Which would be like 14-16 woofers.
18x Tuba 60 - Dual 12" LAB
4x Renkus Heinz ST6
5x DR280 - Melded 22 piezo array
1x Lab Gruppen PLM10000Q
2x QSC PLD4.5
2x QSC PLD4.3


https://ibb.co/e0Uazv
https://ibb.co/bUxmJQ

Klarity Audio & Lighting
https://www.facebook.com/KlarityAudio/

Grant Bunter
Posts: 5933
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: Multiple cabs

#20 Post by Grant Bunter » Thu Sep 13, 2018 4:15 am

DJStubbs wrote:
Thu Sep 13, 2018 3:28 am
Will I be able to run 12 cabs with c versions off of my lab gruppen plm10000q?
According to https://www.labgruppen.com/Categories/L ... ans(en|en) yes you can.
The proper question is, Can I drive 12 cabs up to their limits with this amp?
The answer is no.
2350 watts into 2 ohms is 63V
DJStubbs wrote:
Thu Sep 13, 2018 3:28 am
I am considering reconing into regular lab12s. But either way it’s going to be expensive and if I were to just recone all of my woofers to regular labs but that’s going to be like 20-24 woofers that need to be reconed. It may be cheaper to just recone the non c versions for the c version. Which would be like 14-16 woofers.
Re read the post I made before.
12 cabs running off the lab gruppen amp near an 8 ohm load will be around 90 something volts. Getting closer to the lab 12 limit.
You need lab 12's, not lab 12 C's.
Suck up the cost, it's part of your bad choices and lack of understanding...
Built:
DR 250: x 2 (melded array) with 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...

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