4 dual 3012lf T30s

Is this amp OK?
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Rickwired
Posts: 26
Joined: Wed Dec 05, 2018 1:26 am
Location: Fresno CA

4 dual 3012lf T30s

#1 Post by Rickwired »

Hey guys planning on running 4 Dual T30s and need advise on amps..
I want to run them on 1 amp if possible. So I’m thinking of running them all in parallel which puts us down at 2ohm if I run 2 per channel.. any amp that can do that comfortably?

If I decide to run them in series internally and then paralleled would that put me at 8ohm per channel and if so how does the voltage work? By my calculations I’d be running them at 100v.. also are there any amps that could do that comfortably?

I’m currently running 2 dual and 2 single loaded t30s on a xti4002 and haven’t had a problem yet. (3 - 3012lf per channel)

Any advise would be awesome thanks guys
4- 29” tuba 30 w/ dual kappalite 3012lf
2 - 18” tuba 30 w/ 3012lf
4 - OT12 w/ 3012HO and crossfiring tweeter array

2 more OT12 w/ 3012HO and tweeter arrays in progress

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: 4 dual 3012lf T30s

#2 Post by Grant Bunter »

Can you run an amp down to 2 ohms? If it's 2 ohm stable/it's specs say so, sure.
Should you? Perhaps not if you can avoid it. It places maximum strain on the amp and it's power supply.
And you don't want that amp failing during a show because it's stressed to it's limits.

You already mentioned series/parallel wiring, and, correctly, come up with 100V. Or, 1250W@8ohms. So that's one figure to go looking for. But give that figure a bit of leeway, say 1400W/8ohms
Or check out the 4 channel amps which are dropping in price all the time.
1 cab per channel (eg 50V or 625W/4ohms).

Price range will vary a lot, starting with perhaps a couple of Behringer NX4-6000D's to higher end options like lab gruppen or powersoft...
Last edited by Grant Bunter on Mon Jul 01, 2019 4:02 pm, edited 1 time in total.
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...

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: 4 dual 3012lf T30s

#3 Post by Bruce Weldy »

Rickwired wrote: Mon Jul 01, 2019 2:34 am
I want to run them on 1 amp if possible. So I’m thinking of running them all in parallel which puts us down at 2ohm if I run 2 per channel.. any amp that can do that comfortably?
First question is - what other amps are you currently running for your tops and are they going to live next to the sub amp(s) in the rack? You want to make sure that you go for an amp with the same airflow direction as the ones you have to insure proper cooling. You can mix most anything together except Crowns - they run front to back airflow (which makes the most sense). Most all other brands run the other way.

I would either run two amps or a single 4 channel. Mostly because it's always a good idea to have at least half your subs running if you lose an amp.

Beware of Behringer in that their power ratings are outright crap. I ran a test on one with a volt meter and had to shove the input all the way to clipping before reaching anywhere close to their claims.

I'd suggest a pair of QSC GX7s or one of the QSC PLD 4 channel amps. Two of the GX7s would probably be cheaper to find.

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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Seth
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Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
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Re: 4 dual 3012lf T30s

#4 Post by Seth »

Rickwired wrote: Mon Jul 01, 2019 2:34 am ...how does the voltage work?
Volts to Watts
Volts x Volts / ohms = Watts
100v x 100v = 10000... 10000/8ohms= 1250 Watts

Watts to Volts
SqRt of the product of (Watts x ohms) = Volts
1250Watts x 8ohms = 10000... SqRt of 10000 = 100v
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

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

Re: 4 dual 3012lf T30s

#5 Post by Rickwired »

Bruce Weldy wrote: Mon Jul 01, 2019 7:51 am
Rickwired wrote: Mon Jul 01, 2019 2:34 am
I want to run them on 1 amp if possible. So I’m thinking of running them all in parallel which puts us down at 2ohm if I run 2 per channel.. any amp that can do that comfortably?
First question is - what other amps are you currently running for your tops and are they going to live next to the sub amp(s) in the rack? You want to make sure that you go for an amp with the same airflow direction as the ones you have to insure proper cooling. You can mix most anything together except Crowns - they run front to back airflow (which makes the most sense). Most all other brands run the other way.

I would either run two amps or a single 4 channel. Mostly because it's always a good idea to have at least half your subs running if you lose an amp.

Beware of Behringer in that their power ratings are outright crap. I ran a test on one with a volt meter and had to shove the input all the way to clipping before reaching anywhere close to their claims.

I'd suggest a pair of QSC GX7s or one of the QSC PLD 4 channel amps. Two of the GX7s would probably be cheaper to find.
Currently have a crown 2002xti for the 4 tops..
4- 29” tuba 30 w/ dual kappalite 3012lf
2 - 18” tuba 30 w/ 3012lf
4 - OT12 w/ 3012HO and crossfiring tweeter array

2 more OT12 w/ 3012HO and tweeter arrays in progress

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

Re: 4 dual 3012lf T30s

#6 Post by Rickwired »

Grant Bunter wrote: Mon Jul 01, 2019 4:27 am Can you run an amp down to 2 ohms? If it's 2 ohm stable/it's specs say so, sure.
Should you? Perhaps not if you can avoid it. It places maximum strain on the amp and it's power supply.
And you don't want that amp failing during a show because it's stressed to it's limits.

You already mentioned series/parallel wiring, and, correctly, come up with 100V. Or, 1250W@8ohms. So that's one figure to go looking for. But give that figure a bit of leeway, say 1400W/8ohms
Or check out the 4 channel amps which are dropping in price all the time.
1 cab per channel (eg 50V or 625W/4ohms), 2 amps

Price range will vary a lot, starting with perhaps a couple of Behringer NX4-6000D's to higher end options like lab gruppen or powersoft...
For the lab gruppen and powersoft any recommendations?
4- 29” tuba 30 w/ dual kappalite 3012lf
2 - 18” tuba 30 w/ 3012lf
4 - OT12 w/ 3012HO and crossfiring tweeter array

2 more OT12 w/ 3012HO and tweeter arrays in progress

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: 4 dual 3012lf T30s

#7 Post by Grant Bunter »

Rickwired wrote: Mon Jul 01, 2019 12:15 pm For the lab gruppen and powersoft any recommendations?
Nope. It's just a suggestion.
You're going to have to do the hard yards there for yourself, as I have no idea what the US market is like...
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...

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: 4 dual 3012lf T30s

#8 Post by Bruce Weldy »

Rickwired wrote: Mon Jul 01, 2019 12:14 pm
Currently have a crown 2002xti for the 4 tops..
Well, that changes everything. You probably should stick with Crown then.

2 more XTi 2002 amps should do the trick. 56 volts per channel at 4ohms should be ok if you are limiting at 50volts.

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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