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Old 10th October 2006, 06:36 AM   #1
eddi0 is offline eddi0  United States
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Default ISOBARIC 16 ohms load powered by 8 ohms Amp

Hello,

This is my first post. I would like to know if I run dual 8 ohms 18s in an isobaric configuration it will produce 16 ohms load and if I want to run my QSC RMX 1450 mono bridged @ 8ohms it produces 800 watts is this possible, or will it produce distortion.

If this does not work then I would have to buy (2) 4 ohms 18s and connect it in an isobaric configuration to produce 8 ohms load, then I can use my amp.

Please let me know your input.

Thanks,
Ed

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Old 10th October 2006, 06:43 AM   #2
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It depends on how you wire the drivers:
http://www.bcae1.com/

Two 8ohm drivers can be wired as a 4ohm load or a 16ohm load.

Two 4ohm drivers can be wired as a 2ohm or 8ohm load.

Your best bet is probably two 4ohm drivers wired for an 8ohm load.
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Old 10th October 2006, 06:54 AM   #3
eddi0 is offline eddi0  United States
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Default Hrmmm...

I agree with you but since this is an isobaric setup.....I can't wire it to a 4 ohm setup. It has to be 16 ohm.

Thanks for the reply.

Ed
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Old 10th October 2006, 07:29 AM   #4
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You have two drivers, right?

You can wire them in series or parallel for either a 16- or 4-ohm load. The fact that it's an isobaric setup doesn't enter into it.

If you want an 8ohm load for your amp, then your best bet is to get two 4ohm drivers and wire them in series. Unless you come across a 16ohm driver that you really like. They're fairly rare though.
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Old 10th October 2006, 12:16 PM   #5
forr is offline forr  France
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Be aware that an isobarik configuration using two 18' implies an important moving mass. Some people on this forum have complained of moving subs enclosures. The ratio between the moving mass and the mass of the enclosure was the first reason.
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Old 10th October 2006, 02:32 PM   #6
eddi0 is offline eddi0  United States
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Yes....Moving mass? hrmmm I'm not sure I understand you clearly....

Ed
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Old 10th October 2006, 02:32 PM   #7
eddi0 is offline eddi0  United States
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Yes! Parallel would give a 4 ohm load for out of phase.....what was I thinking, but I am interested in the moving mass theory? Is that when the subs are too powerful.....the cabinet moves?

Edward
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Old 10th October 2006, 06:14 PM   #8
audioPT is offline audioPT  Portugal
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Quote:
Originally posted by eddi0
.....the cabinet moves?

It's more like shaking!

The amount of air pressure is so intense that if the cabinet weight and size are small, two things can happen:
1 - Running Sub or
2 - Broken Sub

Don't you have a pic of the sub?!
And dimensions of the enclousure?!
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Old 10th October 2006, 08:19 PM   #9
forr is offline forr  France
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The cabinet may move :
subwoofer moving on the floor...
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Old 10th October 2006, 10:08 PM   #10
audioPT is offline audioPT  Portugal
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If you have possibilities, try this:

Screw the sub to a base board and put only 3 feets or spikes.

If the sub stand still...
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