# Complete noob needs help



## mmmkay777 (Jun 2, 2012)

Hi, I need some advice. I've just moved into a new house. There are 4 speakers in the ceiling they are Gale GA650'S:
Nominal Impedance 4 ohms
Power Handling 15 - 80 Watts 

I'm not sure how to work out whether I can run them in parrallel into the back of my amp: Cambridge audio Topaz AM1 integrated amplifier

Power Output: 20 watts (into 8 Ohms)
Frequency Response: (-3dB) 10Hz - 30kHz
Max. Power Consumption: 150W

or do I need to but a new amp. I know the speakers or amp aren't great quality but hopefully I can hook them up together safely? The amp just has a left and right out on the back with + and -ve terminals on both. so i was going to put 2 wires into each terminal (think this makes it parrallel)

Any help would be much appreciated as I don't now how to work out if it's safe.

Thanks.


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## phreak (Aug 16, 2010)

If you connect a pair of 4 ohm speakers in parallel you put a 2 ohm load on your amp and fry it. Connect 2 speakers in series on each amp channel for a 8 ohm stereo load. This will be safe for the amp. Try it out and see how it sounds.


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## mmmkay777 (Jun 2, 2012)

Hi, thanks for the reply. The problem I think with connecting them in series is that they are already installed and I'm not sure how easy it would be to guide the wires through the ceiling space. I thought the load would be 2 ohms, so if I get a new amp would it have to be rated to 4 ohms (2 x 2ohms into left and right) or 2 ohms (ie do you add the left and right together so you have a total load or is the number of ohms stated on the amp for each side/left or right. Not sure if that makes sense. Thanks


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## phreak (Aug 16, 2010)

The rating is per channel, so you ideally want some thing rated for at least 160 watts (2x 80W speaker) @ 2 Ohm, 2 channel driven. 
But it is not too late for the equipment you have on hand. Even though the wiring is already in place you can still do the series connection at the receiver. Choose the 2 speakers you want on the right channel. Speaker 1 positive to amp. Speaker 2 negative to amp. Speaker 1 negative to speaker 2 positive with a marrette (or any wire connector...I just don't trust twisting wires together and taping it). Repeat for the 2 speakers on the left channel. 
Try it out and see what you think. You may be surprised by your 20W amps capability.


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## mmmkay777 (Jun 2, 2012)

Hi, thanks for the reply. Sorry did say was complete noob and meant it! when you say speaker 1 negative to speaker 2 positive does that not have to be done on the actual speaker terminals, this I think is a problem as it means taking the speakers out and getting the wire between the speakers above the ceiling? Thanks


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## mmmkay777 (Jun 2, 2012)

O think I know what you mean now, the 2 wires that aren't connected to the amp join them together where they come out of the wall?


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## phreak (Aug 16, 2010)

mmmkay777 said:


> O think I know what you mean now, the 2 wires that aren't connected to the amp join them together where they come out of the wall?


Yes, exactly. Normal series wiring has 1 wire going from positive on one speaker to negative on the other. This is effectively the same but like using a really long wire between the 2. Do you know what wire size is installed? With 16 gauge you are safe, but any lighter and you will want to estimate the length of wire to each speaker. You would be doubling the length of wire for each "circuit" in this type of application. It usually isn't a problem for quiet background/ambiance, but can be a major issue if you are trying to blow the windows out.


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## mmmkay777 (Jun 2, 2012)

Cool, is it a safety issue or just a sound issue. The wire looks quite thin to me..


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## phreak (Aug 16, 2010)

Not a safety issue with your current amp. If you can find out the wire size and estimated length we can figure out if it is a potential sound issue or if it would be a safety issue with a bigger amp.


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