Very Quick and urgent speaker amp question please

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Philip Newton

Guest
My Denon 2802 only has 1 centre rear surround output but in the instructions it says it is better to use two speakers. Is it saying that I should use two speakers out of the one speaker output on the back or use another amp to power the seventh speaker because I can't do that.
 

Ian J

Banned
Dolby have recently changed their thinking on extended surround. Originally they said that one centre rear speaker was best now they have changed it to two.

You don't need an extra amp as you can wire them both from the same speaker outlets.

I can't remember whether you should wire them in series or parallel but the subject has been covered a few times before so hopefully a search will come up with a few interesting threads for you.
 
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bob007

Guest
You can run two speakers from one output, but your best connecting them in parallel/series, think it's series, that way the inpedance is not halved but doubled, but check on that. The other way is to run the 7th channel via a pre-amp.

Some say running 2surround backs make a difference some prefer just the one, down to personal preference. I use a single SB and I'm happy with it. Lots of debates on which is best, especially as the spec have changed and the 2surround back speakers should now be placed side by side, both speakers are producing the same signals (mono), so my way of looking at it is why have two speakers doing the same job when one is quite sufficient.
 
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Philip Newton

Guest
I think its cheaper to buy a pair of speakers so I thought I may as well use both. I will try both ways and see thanks Ian I found some cool threads that explained everything. Thanks again bob for your help on this and on yesterdays questions.
 

lynx

Moderator
I don't know the quality of the output devices on your Denon but i'd be wary of presenting the load of a parallel conection.However i would imagine that they would not be used at exessive levels so in reality it may not be a problem.Sorry if that sounds like sitting on the fence. :)
 
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Philip Newton

Guest
I have set them up in Parallel using 2, 8 ohm speakers the amp says it can output 6-16 ohms is this ok, or should I do it in series many thanks
 
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fastedd

Guest
Wire them in series 8+8=16ohms not in parallel (4ohms). (Nominal :D)
 

Reiner

Active Member
If both speakers are 4 Ohm wire in series.
If both speakers are 8 Ohm wire in parallel.
 
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Philip Newton

Guest
I have them amp + to speaker 1 + and amp + to speaker 2 + and same with the -ve. Both speakers are 8 ohms is this the correct way? and is this safe as i was confused by what fastedd said
 
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bob007

Guest
Top is in series and the bottom in parallel.



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Philip Newton

Guest
thanks bob. is it safe to do in parallel based on my speakers and amp as described above
 
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bob007

Guest
Your amps states 6-16ohms, if you wire in series you will get an inpeadence of 16ohms which your amp will cope with easily, if you wire in parallel you will half the inpeadence to 4ohms, your amp states 6ohms minimum, though it should still run even at 4ohms, stick with the higher ohms, less work for the amp to do, and safer.
 

garmtz

Standard Member
The problem with wiring in series, is that your bass will suffer immensely, as the amplifier cannot control the bass drivers properly, because of a very low damping factor. Because the output impedance of the amplifier will be the impedance of the first speaker, the damping factor will be 8 ohm/8 ohm = 1, which is very bad for the bass.

I would connect the speaker in parallel and have good ventilation for the amplifier.

The reason to use two rear speakers has to do with psychoacoustics. A sound source directly behind the listener is very hard to discern from a sound source directly in front of the listener. Placing the speakers at about 150 degrees referenced to the center speaker, you will have a much better sensation of sounds behind you, especially when these speakers are decorrelated.
 

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