Buying amplifier for low watt speaker?

harish99

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Jan 14, 2012
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I have a Sony Hi-Fi system that I bought long ago. It has 2 speakers along with the Hi-Fi system body (which has the tuner and the cassette slots) to which the speakers are connected. Recently the circuit in the hi-fi system was damaged, but the speakers work fine. The System is Sony CFS-715S

The manual says the power output is 12W + 12W which, if I am correct, are the individual power rating of the speakers. The impedance marked in 6 ohms

I am a beginner to these audio equipments. So please help me with my doubts.

How do I go about buying an amplifier for the speakers?
I was browsing for a model online and found a mini amplifier which said it has 2 output channels with 30W each and impedence range of 4 - 8 ohm. Is it safe to use that amplifier with my speakers which has rating of only 12W? Its here in the link: http://www.amazon.in/Generic-Motorcycle-Hi-Fi-Stereo-Amplifier/dp/B011ECOCHY/ref=sr_1_1?ie=UTF8&qid=1466020070&sr=8-1&keywords=lepai
Thanks in advance!
 
Solution
You can run those little amps off a 12v 5a transformer fine which cost a few dollars max.

I bought similar to power a pair of 20w 6ohm speakers in my sun room.

You'll be fine powering those old Sony speakers off it , as stated just watch the volume control on it.
Probably ok on the impedence. Not sure about the wattage - probably too much and you are likely to damage the speakers.

Here is why via a very short concise explanation:

http://fluance.com/home-theater-resources-knowledge-center/2015/12/31/matching-speaker-and-receiver-power/

There are other explanations and more technical details online if you wish to dig into the complexities.

For example:

https://www.audioholics.com/loudspeaker-design/truth-about-matching-amplifier-power

Your Amazon link is for a 12v car/motorcycle amp. Do you really intend to use a 12v power source? Or a amplifier that plugs into a wall outlet?
 
Agree with ien2222's post.

However, would not leave such things to chance with respect to the volume control: little hands about, prankster friends, someone dusting and cleaning, or someone partying a bit much and the volume control ends up in a max setting.

Speakers may be able to absorb a "blast" or two so may not be an issue. Over the longer run who knows? Still would not temp "Mr. Murphy".....
 

ien2222

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You misunderstand, amp ratings are what they play up to a certain level distortion but they can output more. That means a 5 watt amp can quite possibly output 10 watts with a whole bunch of distortion and clipped signals which is damaging to speakers, in fact it's more damaging to tweeters than having a more powerful amp and having distortion that results from reaching the mechanical limits of the speakers.
 

Rocky Bennett

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May 25, 2016
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Ralston18, I don't think that you understand amplifier ratings, ien2222 is absolutely correct.

To the OP, you are linking up to a mobile 12 volt amp, is that what you want? What kind of source component are you using?
 
You can run those little amps off a 12v 5a transformer fine which cost a few dollars max.

I bought similar to power a pair of 20w 6ohm speakers in my sun room.

You'll be fine powering those old Sony speakers off it , as stated just watch the volume control on it.
 
Solution
This then being the basis:

"At the end of the day, a basic rule is to work out your speaker(s) RMS power rating and impedance loading on each amplifier channel, then make sure the amplifier is capable of delivering 50 - 100% RMS power above the speaker(s) RMS power rating. An example would be, 1 x 200watt RMS 8ohm speaker per channel should have an amplifier capable of delivering 300 - 400watts RMS per channel at 8ohms, and if you use 2 x 200watt RMS 8ohm speakers per channel, you then have 400watts RMS of speaker power handling to play with, this time with a 4ohm amplifier load, and you require an amplifier capable of delivering 600 - 800watts RMS at 4ohms, and so on. NEVER work on Peak Power Values, as these are several times the RMS rating, and you are very likely to destroy your speakers!"

Source: Soundhire

Trying to clarify my thinking/understanding here. Thanks.