Speaker or Amplifier - which should be more powerful?

[jay]

Just to clear this dilemma of mine...

When I connect my deck through an Amp whose RMS should be more - Speaker or Amplifier?

And what does impedence mean or do? Its said that 8 ohms need to be impedence to get a better output.

Plesae clarify.

 

[alphacentury100]

The amp should always be more powerful than the speaker. The more powerful the amp is, the better control it can have over the speakers. If the amp is less powerful, then it will tend to clip, which may damage the speaker.
And regarding impedance, it is always better to have speakers with higher impedance like 8ohms or more and amplifiers with support for lower impedance like 4ohms(at least) or less.
Hope that helps!

 

[koushik]

Hi Jay

I know your question is little funny to our members but I will ans your ques.
See your handling capacity of your speaker should be little more than your amp or they both should be balanced to each other.
Secondly you were talking about the impedance of the speaker * Ohms speaker is a standard rating of a good speaker if you see back side of the amp where the speaker terminals are there you will see that it is written there
8~16 ohms or 4~16 ohms where the impedence of your speaker should be min 8 ohms or 4 ohms.

regards

homiyar

I beg to disagree. The amp should be more powerful ideally.

And to the other question, speakers' nominal impedance should be greater than the output impedance of the amp.

 

[Thad E Ginathom]

A 100-watt lightbulb gives out a lot more light than a 40-watt lightbulb --- but it is not like that for speakers. Speakers do not have power, they have the capacity to handle power.

I wish I had an audio component for every time I've overheard a salesman telling a customer to buy the "higher powered" speakers because "they'll go louder." No wonder it is so hard to get to understand these things: there is so much misinformation about!

 

[mpw]

the speaker DRAWS power from the amp. Visualize the amp as a well of water.. more water..means more irrigation for the crops.

crude analogy ..

the problem in the mind is that folks think the amp DELIVERS power to the speaker.

you are better off with an amp in the higher range of the speaker power handling as defined by the speaker manufacturer - at the same impedance level

mpw

 

[vijwilso]

In some of the cases , additional head-room is good than the mimimum recommended value . Amplifier will be able to drive easily and supply the surge of power when required . But need to care-full with the volume knob.

 

[Thad E Ginathom]

the speaker DRAWS power from the amp. Visualize the amp as a well of water.. more water..means more irrigation for the crops.

crude analogy ..

the problem in the mind is that folks think the amp DELIVERS power to the speaker.

now I'm the confused one. (Again!)

Surely the amp pumps power into the speaker. At extremes, too much power means the speaker blows up. Bear in mind that the volume control is at the amplifier end of the speaker cable, not at the speaker end.

But am I saying this just because I don't understand impedance?

Hows this idea...

If you short out the speaker terminals, then the amplifier blows up, but that doesn't mean that your shorting wire is drawing power from the amp --- but that the amp is putting out power, and, meeting no resistance, puts out more, and more and more and ouch.

???

 

[Kushanava]

Simple way to understand impedance in audio.Think of impedance as elasticity..the more elastic the rubber band ..much easier to pull or push..so less power reqd.So 8 ohm speakers are usually easier to drive than 4 ohm ones.So you would ideally need sufficient power to pull the rubber to a point where it can still retain its elasticity.The power rating of a speaker or an amp only indicates the max operating margin..but each will have its own optimum rating beyond which distortion sets in..So you should hav an amp that can drive the speaker to its optimum operating margin to maximise the sonic benifits of both.

 

[mpw]

meeting no resistance...

???

thats the key 3 words thad..

mpw

 

[reubensm]

Agree with the other posts above, I've always liked my amps to be more powerful than my speakers.

There is a theoritical side to it but practically, I have noticed that more powerful amps have richer sound at lower levels, whereas when you use low power amps, you'd have to crank up the volume bringing distortion into the mix. Also speakers have to be driven well to perform well and if they are not, what you hear is something that is not going to be too impressive

 

[longshanks]

Amplifier.

 

[john_k_antony]

Amplifier. I have already burnt my speakers by driving them with low power amp and the amp clipped at high volume frying the speakers.

 

[koushik]

Agree with the other posts above, I've always liked my amps to be more powerful than my speakers.

There is a theoritical side to it but practically, I have noticed that more powerful amps have richer sound at lower levels, whereas when you use low power amps, you'd have to crank up the volume bringing distortion into the mix. Also speakers have to be driven well to perform well and if they are not, what you hear is something that is not going to be too impressive

+1

This because of the availability of high current and very very low distortion as it is being driven much lower than its rated power. That is advantage of powerful amp with high current.

 

[jay]

So the verdict is Amps need to be more powerful than speakers in an audio setup.Thanks to all.

 

[vnmathur57]

Through my experience only over last many years, I can say that amplifier must be more powerfull than the speakers. Generally, while buying a stereo setup, we buy the speakers first and then buy the amp having sufficient power to drive the speakers effortlessly.

 

[haisaikat]

Through my experience only over last many years, I can say that amplifier must be more powerfull than the speakers. Generally, while buying a stereo setup, we buy the speakers first and then buy the amp having sufficient power to drive the speakers effortlessly.

Absolutely true. Also please check this older thread on similar topic http://www.hifivision.com/surround-...44-underpowered-amps-vs-overpowered-amps.html

 

[jls001]

http://www.hifivision.com/surround-...44-underpowered-amps-vs-overpowered-amps.html

Is it true (as asserted in some posts in the above thread) that when an amp is operated beyond its linear operating range, the output distorts/clips and contains high level of DC components that can damage the speakers? I understand the clipping/distortion part but the DC part is something new to me. How does DC get introduced (if at all) when an amp is overdriven?

A related observation: as the evening grows older and closing time gets nearer in a night club, the music gets ever louder and the amount of distortion, especially in the bass, gets progressively more obnoxious, despite the deleterious affect of the spirits in addling the brain. The speakers or amp is clearly working beyond their rated linear range, without either getting blown. How do these PA setups manage this?

 

[Thad E Ginathom]

as the evening grows older and closing time gets nearer in a night club, the music gets ever louder and the amount of distortion, especially in the bass, gets progressively more obnoxious...

And I've even seen this done to classical music At a wedding, so I suppose the sound guy thought that was how all music should sound.

I've often heard of the dangers to speakers of a clipping amplifier, but who, in their right mind, would want to drive a domestic amplifier to clipping? Perhaps some head-banger, but, surely, no music lover, whatever their chosen music genre!

Seems to me that "watts," in audio, is the most useless specification in the list, and serves mostly as a tool for ignorant salesmen to sell ignorant customers the "louder" equipment. It is, perhaps, nice to know that an amplifier is not going to blow up your speakers if some fool turns the volume right up. Apart from that, I have completely given up thinking about "watts" since I took a 50w amp home, and found it incomparably better than the 120w amp it replaced.

If people want to talk "powerful" about speakers, then surely it is the sensitivity they should be quoting, not the watts. And if people want loud, then it is definitely the sensitivity they should be looking at.

"Watts" is the most over-rated speaker (and amp) specification: "Sensitivity" is the most under-rated, to the extent that it barely gets talked about except by the tube-amp people.

 

[kanwar]

I understand the clipping/distortion part but the DC part is something new to me. How does DC get introduced (if at all) when an amp is overdriven?

When non-symmetric clipping occurs, such as in asymmetric voltage amplification stage designs in amplifiers or designs which don't have symmetric clipping, the net averaged output signal experiences a shift in offset which results in DC component appearing in the output during severe clipping which can cause damage to tweeters and in high power applications can alter driver's magnetic flux strength if exposed for enough time to result in change.


From asymmetric clipping i mean the both polarity halves of AC signal are not clipping at same ratio but with different rate which results in DC error.


Apart from that even in symmetric clipping, the AC signal when clips, it gets chopped off from top and bottom , resulting in flat line at top and bottom of clipped wave which is nothing but DC voltage for a specific time interval.


Pro- amplifiers have dedicated clip limiters which prevent the amplifier from clipping even if you overdrive the volume knob.

 

[IndianEars]

jls001 said

Is it true (as asserted in some posts in the above thread) that when an amp is operated beyond its linear operating range, the output distorts/clips and contains high level of DC components that can damage the speakers?

I understand the clipping/distortion part but the DC part is something new to me.

How does DC get introduced (if at all) when an amp is overdriven?

jls, the DC component is just a mathematical remainder !

Fourier the mathematician put out a theorem that ANY periodic ( periodic = repeating again and agin with a fixed time interval) waveform can be mathematically broken up into :

1. A Sine wave and multiple frequencies of that sine wave ( called Harmonics).

PLUS

2. A Remainder term which is the DC component, ie it has no frequency or repetition.

(Just as 3 divided by 2 leaves a remainder of 1 )


When an amplifier is over driven into clipping, the waveform may not be symmetrical... the Top Half of the wave form may be taller than the bottom half of the waveform.

The unsymmetrical extra is the DC portion

If the amplifier clipping is completely symmetrical, there is Zero DC.


Incidentally, a DC portion does occur all the time even at low listening levels..... Most natural sounds and musical notes gradually decay ( their amplitude progressively falls.... often quite rapidly. In this progressive ( natural ) decay, the bottom half of the same cycle is ever so slightly less than the top half of the cycle (or visa versa). This again yields a DC component

So dont worry about the DC component. Eventually the AC and the DC Both, produce heat in the speaker voice coil. The DC also causes a mechanical offset / shift of the speaker cone, from its free standing position.