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Audio Systems/Amplifier for 3 different pairs of speakers?


As my amplifier from a Sony FH-15R stereo is functioning only some times and sometimes not, I am pondering about buying a new one.
I would like to continue to use my 3 different pairs of loudspeaker boxes, resp. at least 2 pairs at the same time.
Could you give me any recommendation whether this is sensibly viable, and what I need to look for in a new amplifier to get a suitable one.
Many thanks in advance!

ANSWER: In driving multiple loudspeakers it is important to match the load impedance to the amplifier which is driving the speaker loading.  As a general rule it is not recommended to connect two loudspeakers in parallel to the amplifier output UNLESS the impedance of each speaker is twice the rating of the amplifier.  For example if you amplifier has an output specification of 4 ohms for full power rating then you can connect two speakers of 8 ohm ratings in parallel.

The best solution is to have one stereo amplifier for each pair of speakers - properly matched.  That way you are alway safe.  Amplifiers are very inexpensive now days and it is often a good solution since each amplifier can be lower in power. In your case since you want to drive 3 pairs of speakers you could use three 100w amplifiers rather than one 300w amplifier.

Hope this helps. Let me know if you have further questions.

---------- FOLLOW-UP ----------

QUESTION: Thanks for your answer!
The impedance of my speakers is described as 6 Ohms, 6 - 8 Ohms and 8 Ohms.
Could I use them with an A/V Receiver (5.1 or 7.1) with 8 Ohm?

A good quality receiver that is rated for 8 ohm speaker loads should be alright with 6 ohm speaker.  Loading an amplifier with an impedance less than the rated can be dangerous, especially when the speaker is less than half of the rating of the amp.  For example a 4 ohm speaker connected to an amp rated at 8 ohms could cause burnout when the power is pushed to high levels.  Similarly, two 8 ohms speakers connected in parallel which presents a 4 ohm load would be equally dangerous.  Higher is no problem.  If the amp is rated for 8 ohms and the speaker is rated at 16 there is no problem.

Sony makes a fine product and they know that some users may be connecting various speaker impedances so they design the amplifier circuits to be tolerant to a wider range of loads than some less conscientious manufacturers.

Hope this  helps.  

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Audio Design Engineer; systems, loudspeakers, cd/dvd players, etc. I am knowledgeable in all high end audio equipment and installations. MAKE SURE YOU GIVE A MAKE AND MODEL NUMBER AND CAR IF IT IS AN AUTO QUESTION. Note: I am getting some who ask good questions that take a lot of time to research but then the questioner fails to read the answer. Please don't ask questions unless you are seriously looking for an answer. If you find an answer to your question otherwise then let me know with your reply. Thank you.


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