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question on 4channel amp

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Old May 2, 2005 | 04:27 PM
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Default question on 4channel amp

a dumb question, but something i'd like to know is

when the amp is rated at 50x4 @ 4ohms (which is the way i have it connected currently to some 4x6's in the rear and 6.5 components up front)

and then it says 75x4 @ 2ohms,

how do you have to connect the speakers to get them to run at the 75x4???

i dont know much about systems, just trying to understand. any help?
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Old May 2, 2005 | 05:19 PM
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If you connect a pair of 4 ohm speakers in parallel they have 2 ohm of resistance. The lower resistance allows the amp to put out more power.

You wouldn't normally want to do this as it increases your distortion level.

If you had a 2 channel amp you could run both pairs of your speakers at 2 ohm. But since you have a 4 channel amp I would leave it the way it is.

Brian
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Old May 2, 2005 | 05:27 PM
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You must connect 2 pairs of speakers that have an impedence of 4 ohms to channels in parallel. For example, you running 2 pairs of speakers rated at 4 ohms off your 4 channel amp using all 4 channels, you are feeding them 50 X 4 @ 4 ohms.
Now if you were to disconnect one pair of speakers and wire them prallel to your other 2 channels, then your resistence will drop to 2 ohms on the two chennels where now have 4 speakers connectect(2/channel). Under these circumstances those 2 channels will now be at 75 X2 @ 2 ohms.

Here is a little tutorial for you. Look at the single voice coils since those are the onces that apply to the mids and highs you are dealing with instead of the dual voice coils.
http://jlaudio.com/tutorials/wiring/index.html
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Old May 3, 2005 | 03:17 AM
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Been Answered above. I'll just clarify that you don't "make" speaker do this. The JL tutorial Posted by Tiburon will show you how it looks.

Also if the Question Pops in your head; Yes there are devices to connect to the Speaker to lower the Resistance to the Amp, BUT they are expensive and 00PewterSS said it best that they will usually increase the Distortion level of the Amplifier (Class A amps are the Exception and Rare). When THD rises it is due to the increase in heat. So that is the other Problem with running them Lower (4-2 ohm is usually called "lowering")

Plus it is usually the Same price or less to buy the Larger amp than to use impedenace matchers.
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Old May 3, 2005 | 08:09 AM
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got it,

i think i'll spend sometime in this section now.
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Old May 3, 2005 | 05:39 PM
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you ought to spend some time Here as well, if you want to really do some studying up on this kinda stuff
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Old May 5, 2005 | 09:31 AM
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Originally Posted by 02Z28LS1
you ought to spend some time Here as well, if you want to really do some studying up on this kinda stuff
Great site.... Another one in my favorites.
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