Solved! Is it possible to connect two passive speakers to only one amplifier output?

Julle1409

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I have a Edifier S330D subwoofer with an inbuilt amplifier. The subwoofer does only have speaker outputs for 1 speaker. It connects with speaker wire. Would it be possible (and safe) to plug both two speakers into only one port? I was thinking that maybe I could plug two wires in all the ports (both of the speakers left negative in the left negative port, both of the speaker wire left positive into the left positive port etc.) Would that be possible?

I tried to draw it to give you a better understanding of what I mean. Here's what i made: https://www.dropbox.com/s/i6lwizbgmlclvp5/Speaker%20question.jpg?dl=0
 
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No, it does not halve the power of the amp. In fact, it usually doubles it. But not in this particular case, as I'll get into presently.
I don't suppose those satellite speakers have the ohms rating on the back, do they?

Running speakers in parallel (like your graphic) reduces the total load on the amplifier. This increases the amount of current the amp has to provide. This increases the amount of wattage your amp must provide. But, your configuration is generally about 3db louder overall (ceteris paribus).

But you won't get any more bass out of your particular system. Your sub amp has a crossover built in. Meaning, very little bass goes to your satellite speakers. Adding more satellite speakers will increase the volume for...
Hi, in all honesty i would not do that. The amp is designed to run with the one sub, and two speakers. The power out put of the amp is only 18w per channel, and if you add two more, this becomes probably less than 9w. Also the resistance will halve. Dont get me wrong, it would work at low volumes, but you certainly would not be gaining anything as all you are doing is halving the power of the amp, and gaining no extra volume or sound improvements. If the amp is driven with double the load, and at some volume, you run a real risk of damaging the internal amp.

Hope this helps!
K.
 

Julle1409

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Thank you. So doing it would be a bad idea? And at how much volume would i be able to play at, without damaging the amp?

 
Hi, no problem! It would be futile, as you will not be gaining anything, and will probably get a worse sound quality. In effect halving the power of the amp, but doubling the number of speakers. You could probably turn it up a fair bit, but the amp would be working way beyond its normal threshold and below the recommended Ohm rating, plus sacrificing quality. To have the optimum amount of volume and quality, i would stick with the two speakers the amp is made for. At least that way you can relax and turn it up! ;)

Kenton.
 

Julle1409

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Okay, thank you for the help!
 

jdlech

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No, it does not halve the power of the amp. In fact, it usually doubles it. But not in this particular case, as I'll get into presently.
I don't suppose those satellite speakers have the ohms rating on the back, do they?

Running speakers in parallel (like your graphic) reduces the total load on the amplifier. This increases the amount of current the amp has to provide. This increases the amount of wattage your amp must provide. But, your configuration is generally about 3db louder overall (ceteris paribus).

But you won't get any more bass out of your particular system. Your sub amp has a crossover built in. Meaning, very little bass goes to your satellite speakers. Adding more satellite speakers will increase the volume for your midrange and treble, but not your bass. You're stuck with what you have.

The good news is that it's the bass that consumes much of the power. And since the Edifier S330D won't send any bass to your extra satellite speakers, you shouldn't have any problems with adding 2 more satellites. Just don't expect any bass to come out of them. Assuming whatever satellite speakers you add are rated the same as the ones the system came with, you should get about 3db more midrange and treble without any loss in sound quality. (just don't try adding anything that is rated 4 ohms or less).
 
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Julle1409

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The speakers that comes with the sub has an ohm rating om 4ohm. The other speakers that I also want to connect are 8ohm.

So would it bedre possible (and safe) to plug them in? Would it work?
 
jdlech said: "Running speakers in parallel (like your graphic) reduces the total load on the amplifier. This increases the amount of current the amp has to provide. This increases the amount of wattage your amp must provide"

Slight contradiction no?....

And i never mentioned the bass side of the system.

I generally try to run systems as they are designed to be used.

 

jdlech

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Load is defined as the total resistance of a circuit. So reducing a load literally means reducing the total resistance of the circuit. No contradiction there at all. And you didn't need to mention the built in crossover. I got that by looking up his amp and reading the owners manual.

A 4 ohm and an 8 ohm speaker in parallel yields a 2.66 or 2 2/3 ohm load. Quite low, but without any bass, it should be acceptable. Expect your amp to run on the hot side and give it plenty of ventilation. Again, I would be worried about your amp *if* it had to feed bass into such a low load.

BTW, the math for determining the total load of a parallel circuit is 1/((1/R1)+(1/R2)+...(1/Rn). In your case it's 1/((1/4)+(1/8)), or 1/(.25+.125) = 1/.375 = 2.66... ohms.

To complicate things for you (just for an example of the math). If you were to buy another set of 4 ohm speakers and wire them in series with your two parallel speakers, you would get 4+(1/((1/4)+(1/8), or 4+2.66 or a 6.66 ohm load. Wired in series is strictly additive while parallel wiring follows the reciprocal formula. Wiring them all in parallel would reduce the load to just 1.6 ohms, dangerously low for most amps.