4 speakers on a 2.1 speaker system

[pineorange]

Hi everyone,

I am new here and I hope you will be able to help me.

I have a LG multimedia speaker system (LH70B) which is a 2.1 speaker system.
I also have another pair of these exact same speakers and I would like to connect them to the system which would make 4 speakers connected to the unit.

I have heard it is possible if the impedance is respected.

Here are the specs:

Power Consumption
- 20 W

Impedance:
- Subwoofer: 6 (Ω)
- Satellite: 8 (Ω)

Frequency response
- Subwoofer: 55 Hz~ 104 Hz
- Satellite: 40 Hz ≤ 20 kHz

Total Max. power
- 70 W (THD : 10 %)

Signal to noise ratio
- 75 dB

Could you please let me know if it is possible to connect 2 extra speakers and if so, how?

Thanks for your help!

Oliver

 

[jay32267]

Here's the issue....we need to know the output impedance of the amp.

I went to the website and it's not listed (as I expected).

So the best we can do is assume the amp is matched to the speakers it comes with (which is most likely the case anyway).

There are only two ways to hook the speakers up. In series and in parallel.

If you hook them up in parallel....the impedance will go in half and you risk drawing to much current and frying the amp.

So the only way to do this and be safe is to hook them up in series.

This will work....but you MAY not get the volume you want....OR.....you may.

You have to try it to find out.

Just remember....connect them in series if you want to be safe.

So you will have two in series on the left.....two in series on the right.....and you can even try the two subwoofers in series.

 

[pineorange]

Here's the issue....we need to know the output impedance of the amp.

I went to the website and it's not listed (as I expected).

So the best we can do is assume the amp is matched to the speakers it comes with (which is most likely the case anyway).

There are only two ways to hook the speakers up. In series and in parallel.

If you hook them up in parallel....the impedance will go in half and you risk drawing to much current and frying the amp.

So the only way to do this and be safe is to hook them up in series.

This will work....but you MAY not get the volume you want....OR.....you may.

You have to try it to find out.

Just remember....connect them in series if you want to be safe.

So you will have two in series on the left.....two in series on the right.....and you can even try the two subwoofers in series.

Thank you for your quick reply jay32267!
I guess in series will be fine since I am not planning to push the volume to its limit.

Now, I just found out a small issue, I cannot hook up the speakers together.
They do not have a negative wire and a positive wire but only one cable.
And the amp has only one hole for left and one hole for right).

I am thinking about putting Y splitters on both left hole and right hole of the amp.
Does it make the speakers in series or in parallel?

Thanks again

 

[jay32267]

"They do not have a negative wire and a positive wire but only one cable."

There HAS to be a negative and a positive wire inside that cable.

If you look at the plug....it is a two conductor plug correct?

You can't do splitters.....that would be parallel.

If you want to do this.....you are going to have to cut the plugs off.....strip the wires....connect them properly.....and then put a plug on at the end.

Putting the plug on might be tricky if you aren't used to doing this sort of thing.....and soldering is also good to know.

 

[kerberos_20]

first post has info from amp (not speakers)
anyway front channel is rated for 15watts @ 8ohms
soo if u want to use 2 speakers, their total power shouldnt exceed 15watts (2x7.5watt speaker on left or right channel)
u can use slightly stronger speakers together for short duration and not on full volume
if u put too strong speakers, amp may overheat and barbeque itself

as far as i can see, it uses rca connectors, so ull need two rca Y cables (1male to 2female)
https/www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=rca+y+cable+male+to+2+female&rh=i%3Aaps%2Ck%3Arca+y+cable+male+to+2+female

 

[jay32267]

"first post has info from amp (not speakers)"

If so, it doesn't matter, what I posted still applies.

"soo if u want to use 2 speakers, their total power shouldn't exceed 15watts"

The power rating for the speakers doesn't matter as long as it's over 15.

"if u put too strong speakers, amp may overheat and barbeque itself"

This is only true if the impedance is too low. The power rating doesn't matter as long as it's over 15.

"so ull need two rca Y cables"

as I said before, you cannot use Y cables as this puts the speakers in parallel and you risk frying your amp

 

[kerberos_20]

but to connenct them in serial, he will need to cut open speakers
hence paralel with 7.5w each

 

[jay32267]

"but to connenct them in serial, he will need to cut open speakers
hence paralel with 7.5w each"

Yes....he could do parallel....and yes....they would be 7.5 watts each maximum....but he risks frying the amp.

 

[americanaudiophile]

All the information above is correct.
Adding the additional speakers will not improve the sound quality at all. If you have to hook them in series you will not even get an increase in volume in using four. At best it will spread the sound out a bit if you spread out the speakers. Not worth the effort.
Get better quality speakers.

 

[Phillip Corcoran]

I agree with americanaudiophile - - - it's not worth the effort, and by the time you find that out for yourself you will have messed up all the speaker wires and plugs for no good reason.

 

[jsmithepa]

If you insist: amp(+)-------(+)Spkr1(-)------(+)Spkr2(-)------(-)amp.

 

[pineorange]

Hi everyone and thank you all for your contribution.

The reason why I need more speakers is because I need to cover a very large space.

Initially, I had this 2.1 system for a 12 x 8 sqm patio and it did the job perfectly. Now I have extended this surface to 28 x 8 sqm.
Since I already have this same 2.1 system in my room, it would solve my issue at low cost.

Again, I do not need to increase the volume but just enough sound to put on a nice atmosphere.

What do you think?

 

[americanaudiophile]

An RCA splitter is simple but would connect them in parallel which would not be safe.
If you hook them in series as jsmithepa shows then it will be safe. The RCA plugs are wired so that the center pin is positive and the outer ring is negative. A VOM might make it easier to identify which wire is which. You want to make sure you get it right.
The overall volume may go down but it will spread out more.