Series and Parallel

[r0ry]

1.So if I have an amplifier which gives 100W at 8ohms, I should be able to connect 2 100W 4ohm speakers in series, is that right? Also can I connect 2 50W 8ohm speakers in series , or 25W 16ohm?

2.With that same amplifier 100W 8ohm, will it be ok if I connect 2 100W 16ohm speakers in parallel, or 200W 8ohm ... etc.?

I'm sorry if this was discussed before but I'm verry confused at this poin.

 

[Pyrrho]

You should forget about the power ratings when thinking about what can and what cannot be hooked up to each other.


Most of the time, you want to hook up one pair of speakers to a stereo amplifier. However, there are occasions when one may wish to hook up more speakers. In such cases, one should focus on the impedance that will be presented to the amplifier, as well as the impact of the interaction of the speakers with each other when hooking things up in series.

If the speakers are all the same, then it is simple: Hooking a pair up in parallel halves the impedance, and hooking them up in series adds the impedance. If you hook up three in parallel, you have 1/3 of the impedance of one of them; 4 in parallel gives you 1/4 of the impedance of one, etc. Again, this is how one can think of it if the speakers are all identical.

If they are different, however, then things get more complicated, as the nominal impedance of a speaker does not tell you the impedance of the speaker at any particular frequency. Speakers vary in impedance by frequency, and the "nominal" impedance is supposed to be what you can pretend it is overall when matching it up with an amplifier. But this is going to matter if one is hooking up a bunch of different speakers in a complicated manner with some being in series with some, and in parallel with others. And this is a good reason to not do it.

For some more reading on this subject, see:

Electrical characteristics of dynamic loudspeakers - Wikipedia, the free encyclopedia

Wiring Loudspeakers in Parallel | Audioholics


If you have more questions, ask.

 

[r0ry]

Ok so impedance is more important than power. But why I should forget about power. I mean can't I blow up my speakers if there is too much power , and still is the above that I wrote true or false ?

 

[markw]

The two most importanrf facts you should take away from this thread.

Ok so impedance is more important than power. But why I should forget about power. I mean can't I blow up my speakers if there is too much power , and still is the above that I wrote true or false ?

Connecting speakers in parallel decreases the impedance and, particularly if you're using four ohm speakers, can prove dangerous to your amp. THAT can kill an amp real quick. You might be able to get away with it with 8 ohm speakers.

As for too much power blowing your speakers, if you use your noggin and turn it down if it starts to sound bad you should be fine.

Do you even have 16 ohm speakers? I haven't seen these since tube amps were popular.

Do yourself a favor and read those links Phyrro gave you before asking any more questions. A little bit of effort on your part and you just might learn somethong.

 

[Pyrrho]

Ok so impedance is more important than power. But why I should forget about power. I mean can't I blow up my speakers if there is too much power , and still is the above that I wrote true or false ?

Sure you can destroy your speakers with too much power. But how much power your amplifier is putting out at any given time is a function of several things, including the input level and the volume control. (It does not simply put out the maximum rated power all the time.) If, when turning up the volume, it starts to audibly distort, you should turn down the volume. You can use speakers rated for much less than what the amplifier is capable of delivering without any problems at all. Of course, if you crank the volume all the way up, then you may cause damage. But you may cause damage doing that even if the speaker is rated to take the power that the amplifier is rated to deliver. It is a good idea to gradually turn up the volume with a source that is at an approximately constant level to see what it can do, but in all cases, when it audibly distorts, you should turn down the volume to avoid damage.

 

[3db]

I would never hook multiple speakers up in series if each speaker contains a crossover. The time/phase skewing would be dreadful. It can be done from an impedance/pwer thing but from a sonics point of view would sound dreadful. Not recommended.

 

[kzaudiovideo]

I have been reading the discussion. Thanks for sharing the links guys.