# surround question

Discussion in 'Archived Threads 2001-2004' started by EarleD, Sep 18, 2001.

1. ### EarleD Supporting Actor

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I recently added another set of surround speakers to my 3200. I just paralled off the back of the reciever. Is this going to hurt my reciever? Should I wire them in series instead. The extra speakers I had are made by Rock Solid, does anyone have any info on these? I think they are 4ohm speakers. Thanks in advance
Earle

2. ### Bob McElfresh Producer

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Putting speakers in parallel can draw a lot more current from your receiver than is normally safe.
For 2 speakers in parallel (assuming they are 8 ohms each) the receiver will see:
Resistance = 1 / (1/R1) + (1/R2)
Resistance = 1 / (1/8) + (1/8)
Resistance = 1 / (2/8)
Resistance = 1 / (1/4)
Resistance = 4 ohms
Your System: Let's say you had 8 ohm speakers, and wired in some Rock Solid speakers that are 4 ohms. Your receiver will then see:
Resistance = 1 / (1/8) + (1/4)
Resistance = 1 / (3/8)
Resistance = 8/3
Resistance = 2.6 ohms
This will draw a lot of current causing your receiver to over-heat.
I think you are getting away with it because for most movies the rear speakers only see signals about 10-30% of the time.
I'd suggest re-wireing in series.

3. ### Ted Lee Lead Actor

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i understand how hooking up more than one set of speakers to the same terminals can damage an amp. i also (pretty much) understand that using 4-ohm speakers only makes the matter worse.
but, i don't understand the terminology of series vs parallel? could someone explain that to me? i'm just curious...
tia
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4. ### Ted Lee Lead Actor

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i'm not getting the parallel vs. series terminology here. can someone clarify? just curious...

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5. ### John Garcia Executive Producer

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+ to + and - to - vs crossing + to -
The results will also vary depending on how you have the rears set. If you have them set to small, they will not draw as much current, as they are not working as hard.
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[Edited last by John Garcia on September 19, 2001 at 05:23 PM]

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