Omni 212?

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Count Bassie
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Joined: Wed May 28, 2008 6:04 am
Location: Smithfield, RI

Omni 212?

#1 Post by Count Bassie » Sat Feb 02, 2019 8:39 pm

I'm hating having to post/ask this, especially since I've never built my Omni 15TB! Man, having daughters, a historic house to be after, and living paycheck-to-paycheck keeps you a good distance from your own "Happy Place" projects. But, as I would like to do this this year if I can, I thought I'd venture out here...
Is there a mod to the Omni 15 plan, so that it can be built as a 212? I have an Acoustic Control Corp 370 bass head, and it likes to run at 4 ohms. It REALLY likes to run at 2 ohms, but if I could build a 4 ohm cab, I'd be pretty much ruling my small world here.
Is this a thing, or did I just dream it up?

Thanks for your time.
"Whatever we do, it is what it is, and we do it".
-The Grubs

Trace Elliot AH250SMX
'83 Hamer Cruisebass, modded
Ibanez BTB405M

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Bill Fitzmaurice
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Joined: Tue May 02, 2006 5:59 pm

Re: Omni 212?

#2 Post by Bill Fitzmaurice » Sat Feb 02, 2019 9:14 pm

Count Bassie wrote:
Sat Feb 02, 2019 8:39 pm
Is there a mod to the Omni 15 plan, so that it can be built as a 212?
Only for the last 12 years or so. :roll:

Grant Bunter
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Location: Ilfracombe Queensland Australia
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Re: Omni 212?

#3 Post by Grant Bunter » Sat Feb 02, 2019 10:29 pm

Count Bassie wrote:
Sat Feb 02, 2019 8:39 pm
I have an Acoustic Control Corp 370 bass head, and it likes to run at 4 ohms. It REALLY likes to run at 2 ohms, but if I could build a 4 ohm cab, I'd be pretty much ruling my small world here.
Bit if a side note here, relative to your question about the Omni 2 x 12, but could you explain why?
My analytical side says 2 ohms loads on that amp produce less voltage than at 4 ohms, (there's only a few volts difference) and raise current output from the amp, essentially working the amp harder than it needs to...
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...

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Bill Fitzmaurice
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Re: Omni 212?

#4 Post by Bill Fitzmaurice » Sun Feb 03, 2019 9:16 am

A solid state amp will produce the same voltage into any impedance load. If all else is equal, and it seldom is, halving speaker impedance increases sensitivity by 3dB. The downside is that halving the impedance load doubles the current draw on the amp, which the amp may not be happy about. Another factor is that increasing speaker sensitivity via lowering impedance does not increase maximum SPL. That's limited by driver displacement, Vd, which is unaffected by impedance.

Bruce Weldy
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Re: Omni 212?

#5 Post by Bruce Weldy » Sun Feb 03, 2019 11:50 am

Count Bassie wrote:
Sat Feb 02, 2019 8:39 pm
I have an Acoustic Control Corp 370 bass head
Brings back memories.....my bass player who passed away in 2017 played Acoustic amps way back in the 70s.

He started with a 360 and added a 370 playing through them both at the same time. There really wasn't any PA support back then except for touring acts. He could rumble along with those 100 watt Marshall stacks the guitar players were using.

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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