Why do speakers improve with more powerful amps?

So, if I have a solid state amp that more than adequately powers a speaker, why do people recommend a larger more powerful amplifier to improve things?

Why do more powerful amplifiers impact speaker sound quality in a favorable way? Is it because more power is reaching the speakers? Mid and Tweeter drivers I was told receive a reduced signal versus bass drivers which receive relatively more power via crossovers.  All for the purpose of balancing a signal going to the various drivers.




They don't.  Many will tell you they do but they were probably told that by a salseman with a powerful amp.  Just had a friend over last night and he was blown away by my 2 wpc amp.  You listen to the first watt.  If it sucks, you don't need 299 more of them.  

People have loved to brag about how many watts their system has for decades.  I did it in college. Now I know better.

I had a name brand 300 wpc, 120 lb amp and decided I needed new speakers. Put my speakers on the market and a guy came over to listen.  He brought his SET amp and we turned it on and I listeded 2 minutes and said, "I"ll honor my offer to sell these to you but if you don't buy they are off the market".  He didn't, maybe partially because he realized I wanted to keep them, and the big amp was sold within a week and with a quality SET the speakers shine.

2 nights ago I watched Guardians of the Galaxy with my son at theatre sound levels and my HT system is set up to  drive the front speakers with the SET.  The house shakes during battle or rocket scenes and the SET could go even louder.   You need 1 good watt with sensitive speakers, perhaps 5-50 good watts with less sensitive speakers.

"headroom" is also a marketing term.

I'm sure that there are many about to argue with me: think about it, unless you are listing at ear bleeding levels, your 300 watt amp is putting out .5 to 5 watts and I say that if you have a good 5 watts, then how can the other 295 which are not being used affect the sound?  


With high efficiency speakers, one can compare high and low powered amps without unfair prejudice against the low-powered amp.  My preference tends to favor low-powered tube amps.  Tube amps tend to sound more alive and engaging at lower volume levels than solid state.  I don’t like most high-powered tube amps because the sound tends to be a bit harsh.  

My speakers are about 99 db/w efficient.  The amp I am currently running puts out about 5.5 wpc.  That is enough for me.


+1!!! My listening experiences and progression through the years mirror what you have described. Without question it depends upon the specific speakers utilized. Certain designs do require/ benefit from higher power output and current capability.

If the speaker is appropriate I find that I prefer the presentation and sound quality provided with high quality low power amplifiers (Particularly DHT tubes).  There are numerous ways to achieve very satisfying sound quality via one’s audio system. Higher powered amplifiers as the better option by default is not a position I agree with. It depends on the specifics of the circumstances one faces.


The answer is very common: " It depends. " An inefficient speaker with a low impedance is not going to work very well with a 2W SET amp. Thats a fact. Paired properly, an amp/ speaker combo CAN sound wonderful with just a few watts. It all comes down to proper matching.... There is certainly a need for power in many applications.

Two points,

(1) The philosophy is clear. An affordable speaker with decent amplification (and source) makes more sense than an expensive speaker with a cheap amp (and source).

(2) Amplifier power ratings: Watts per channel specs alone are useless . It is high current delivery (amps) that needs to be examined. Although it’s less of an issue now compared with the Jurassic era days (70’s) of valve amplification, if your speakers are demanding to drive, you’ll need a suitably muscular / beefy amplifier to support them.

Don’t look only at the headline power figure - see what happens when the impedance drops to four ohms. If the number nearly doubles, then your amplifier has good current delivery and will be capable of driving more demanding speakers.

@jumia ….

Why do more powerful amplifiers impact speaker sound quality in a favorable way?

They don’t. Not always anyway. Several things should be considered. In example:

1. Amplifier power rating vs. speaker sensitivity

2. How does an amplifier handle impedance dips that some speakers present as a challenge to the amplifier. Some speakers with nominal 4ohm impedance may dip below 2ohms and not all amplifiers can or will handle it gracefully.

3. The size of a listening room and listening levels preference

Quality vs. quantity of watts and a proper matching based on the speakers you’re driving and size of your room are the most important considerations.
Just like with anything in this hobby, synergy is key.

The OP has just been presented with the reality that opinions vary widely on this subject.  And, there are a ton of variables to consider -- the speakers involved, their sensitivity and the load they present; the listener's desired volume; the size of the room being used; the performance capabilities of the amp involved; and so on.

For my two systems, I've found that I don't need a lot of power. I use a 20 watt/ch Aegir in my main system that I prefer to the much higher power amps I previously had. In my sunroom system, I'm using a 10 watt/ch Gjallarhorn. Both sound wonderful and provide all the volume I desire with no sign of stress or lack of dynamics. And, no, I do not have high sensitivity speakers. But I'm also not a headbanger when it comes to volume.

We circle round to the main point -- figure out what you enjoy and go with it. Attempting to impress others or change their minds results in meaningless debate and frustration, both a waste of your time.

So why the hell do people buy inefficient speakers?

So many issues with powering them, and yet so many people with positive feelings about amplifiers putting out a quality 50 W.

It's just nuts, and the communication about why this is is wacky.





Loudspeaker design nearly always involves trade-offs regarding sensitivity, size, bass extension and dynamics.  If you don't think a loudspeaker the size of a large refrigerator is too big, then you can have all four.  Lo wattage and high wattage systems have their pluses and minuses and either approach can deliver excellent sonics.

I recently asked a very similar question at DIYaudio and got some really in-depth responses which I felt really got to the root of the amplifier/speaker matching problem.

Take a look:



In support of what others have said, such as Carls, I have a 100 watt amp, and I bet I am only using the first 15 watts.  I think where it becomes more confusing is when a passage has huge bass it or huge horn entry, does the amp have the ability output alot of current in a short period of time.  This is where I could notice a difference between an AVR and my AHB2 although both has a similar wattage value.  

It's the quality of the signal powering the speakers that would seem to be very important.  A large reservoir of power well designed within an amplifier allows for the frequency demands to be there when you need them.  Presumably a higher powered amplifier would achieve this better than a lower powered amplifier.

Are there other factors that improve a speakers performance when an amplifier offers more power?? And why is this

Dear @jumia  : Speakers does not ask for watts but for current, so watts is useless in your question but manufacturers normally does not gives amp current delivery but watts that has a close relationship in between.

Now, through our audio life normally we can change 2,3 or four times our speakers so to own a high current or high watts amp specs is really favorable. Always is way better the headroom necessary in the amp when the speakers and the SPL we choose need it.

High watts amps does not damage any speaker when low watt amps can do it: clipping and at those SPL your tweeters disappears/destroy.


Regards and enjoy the MUSIC NOT DISTORTIONS,










From my experience, blanket statements should be avoided at all costs.

The fact that "your speakers" and "your amplifier" worked in "your listening space" with "your music", doesn't mean much when you change all the parameters and certainly shouldn't be the basis of a recommendation to someone else.

In my case, the increased power from 50WPC to 200WPC made a significant improvement. My speakers have an efficiency of 85dB.

The correct answer as is often the case is “it depends”. It depends on the overall design of the amp, the speakers used with, how loud one wants to go, how big a room, how far away from the speakers, and yes even the kind of music and recording being listened to.

I think that pretty much covers it.

Not to mention each person’s personal preferences alone might lead them any which way.

In any case it’s always better to have more power than needed than less. That’s called headroom and is a real engineering concept and not just marketing. You can look it up!

Too little power means clipping occurs. Clipping is a signal processing concept that you can also look up and is good sound public enemy #1. Most tube amps and many Class D amps and a few others soft clip which at least makes some clipping listenable but it is still a defect in the reproduction of the sound and should always be viewed as a negative to be avoided.

Any discussion about power without reference to clipping is basically useless. More power can be viewed as an “insurance policy” to avoid clipping.

Case closed, right?




@jumia -- "So why the hell do people buy inefficient speakers?"

Simple, I like the way my Ohms (main system) and Spendors (2nd system) sound. I prefer them to the many more sensitive speakers I've heard over the years.

I'm not here to impress you or anyone else, nor to change anyone's mind about their audio preferences.  While it is fun to talk about our hobby, there are tons of opinions out there but it is up to each individual to decide what works for them.


There is a lot of contradictory and attitude coming from different camps in this string.


It sounds like you generally understand. A higher powered amp (in current) with the same sound quality will typically sound better than a lower powered one. This is particularly true with solid state amps. Solid state amps react incredibly fast to demand… which can deplete their reserves (not just for bass). So you get greater solidity and ease. Tube equipment is slower (but often much more realistic sounding, and less prawn to run out of power).

Speaker designers are trying to go for the very best sound they can achieve, and a cone that can snap back quickly generally means greater accuracy… but to move it, that required more power.

I quickly learned in the late 70s that if I wanted to enjoy the current guzzling electrostatic speaker (a different reason for needing massive current) I needed to most muscle available (at the time Threshold s500)… which I took out my first loan to buy.

I am now using a tube amp in triode mode with only 70 wpc. While it generates 140 wpc in linear mode… it sound better in triode mode because it sounds more musical and natural. Then my speakers are 90db. You can see my system under my user ID.


I remember when I had my Adcom setup GSA 555-2 (250 wpc).  They were bridgable mono's, so I purchased another one of the same amps and series.  The end result?  My system sounded like a PA system.  Loud as hell and very unpleasant (sibilant).  I still like a lot of power because I like to feel the orchestra or the rock band playing, but now it's with tubes.


Very nice main system and the space, lots of audio research very Tubi. The room looks dead quiet. Another world.

Also like the Tiffany lamp, and really love the doggie.

Use of the meridian processor and speakers for Home theater is interesting, not many of these systems are out there.  I like the idea of separating the HDMI signal which I believe is how it works. Wish more systems would do that sort of thing. 


I'd love to answer but there are so many variables it would take a small book. But all things being equal my friend George Bischoff who built triode tube amps(Melos) with over 400 watts/channel always said a good big amp will beat a good small amp every time. Notice the word good which encompasses many things. But it will always include a superior power supply which is costly and can be compromised without affecting standard specs. 

"headroom" is also a marketing term.

Utter garbage! Don't make wild, unsubstantiated assumptions. If you don't understand the term, it's not that hard to find an explanation. You don't even need a book. Just a computer and browser, so there can be no excuse.

Correct questions should be "why some speakers need more powerful amps whereas some other speakers don't?" Because choice of a speaker is a highly personal one like finding your spouse. Once you find the speaker of your choice, next you try to assemble rest of the equipment including the amplifiers to get the "best possible" sound from it.

Two factors determine whether you need a powerful amp or not: Internal impedance and sensitivity of the speaker. If you have highly efficient speakers >90dB, then you don't need a powerful amp. If you have an inefficient speaker <90dB with impedance dropping below 2 or 3 ohms, then you will need an amplifier that can supply current at these loads, i.e., more powerful amp.

There are many variations in between these two scenarios, but you get the idea. The nominal impedance 8 ohm or 4 ohm does not tell you the whole story. Internal impedance change with frequency and can be resistive only at resonance frequency, but rest of the time it is either capacitive or inductive. Some speakers have a nominal impedance of 4 ohms, but minimum impedance at certain frequencies can drop below 3 ohms or even  2 ohms! So amplifier need to provide sufficient currents to these inductive/capacitive loads and at the same time should provide enough dynamic currents for the music.

As you can see, we can only decide what works best by listening. In the end, only you can decide what is best for you. These are just guidelines so that one can navigate and resolve any inadequacy in the audio chain. 


A Cornwall 100+ db is never gonna sound like a Revel Salon 85db. Pick your poison. 

I think speakers reflect the amplifier, in the last three years my speakers have remained (Sonus faber Olympica Nova V) and have used 3 amps where the sound difference has been dramatic:

  1. McIntosh MC300
  2. Moon 400m
  3. Moon 860A v2

My current amp is the ‘least powerful’ at only 225 watts into 8 ohms and it’s the fastest, most dynamic and detailed amp of the bunch. 

a good amp is a good amp - watts/amps are simply ways to measure but there’s most to the design and build then just 1 measurement. 

Let’s take a look. You have an MC611 and a 1.25. Their sound signature is quite similar but the dynamics, bass and everything else imaginable to your ears is galaxies better with the 1.25. While I don’t know the technical reasons why, I know for a fact it is incomparable better. So in this case, the one watt story and why you would need another 1199 of them more makes perfect sense.

@riie MC611 is a lesser quality amp than amp than the 1.25 - compare the MC611 to a Boulder 300 watt amp and I think you’d be surprised on the sound. 

Why do speakers improve with more powerful amps?

They don't. It's a common misconception that fails the common sense test. If that were the case, a Decware Zen Triode, at a whopping 2 wps, would sound lousy. 

It's baffling why so many people believe such ridiculous things. 

Why do more powerful amplifiers impact speaker sound quality in a favorable way? 

There isn't an equation written that can explain why, my experience is the soundstage gets more like it was in the studio when you add "enough" power. Once you get to "enough" you can park it there and more power than "enough" is basically a waste.

Roger from Rogers High Fidelity had an interesting comment somewhere about amps operating in their "sweet spot" of sort of a median power delivery, and noted as an example that very powerful amps into efficient speakers don't get the amp into its best tone zone. Not his exact words but I get it.

It's the old DQ 10's analogy I hear in the DQ 10 group I read info in.  "You need a minimum of 200wpc 'to make them sing' " Garbage.....  Mine sound fabulous with a 40 wpc Proton D540. Sister company to the early NAD company. But it's capable of 160 wpc for music transients when called for.  That's at 8 ohms. It's all about the current it was explained to me. I don't listen loud....so no need for a heat producing beast.

I agree with the posters who indicate "it depends". My current Revel speakers are rated at 6 ohms with 87db sensitivity. They were initially being driven with a 50 WPC Arcam and I needed to push the amp pretty hard to get the speakers to sound their best. I switched to an 80 WPC Cambridge Audio amp and the speakers came alive. I noticed it especially in the lower frequencies. But there was also the matter of synergy. The CA amp, being a little more forward sounding, meshed better with the laid back sound of the Revels.

I had been using the Arcam with a pair of Paradigms that were rated at 92db at 8 ohms. That was another great synergy system. 50 watts was more than enough to make those sound great. 

It depends.

The efficiency of the speaker and how the amp reacts to the load. It's as simple as the amp asking the speaker to move, or telling it to move. We talk about watts as if they are all the same. !00 volts at 1 amp is 100 watts, but 25 volts at 4 amps is also 100 watts. P = I X E. The more amperage an amp can put out the more control it has over a driver, specially large drivers with heavy cones.

@jumia   Why buy low efficiency speakers?


Because like everything else in life, it's a tradeoff.  It is easier to build drivers with high sound quality if they are inefficient.  It's against engineering principles as well as natural logic to have the best SQ and the best efficiency in the same design.  Think about it - if it were possible, everyone would be doing it.

Through the years I've went from 80 watts, to 140, to 200, to 300 and now at 600 and 1000 Amps. (Legacy IV 2 and IV 5 Amps). At normal listening, like a movie at slightly spirited volumes there is a difference, although slight. TURN it up, like listening to a Video Concert, and there is no comparison. One sounds like a recording, and one sounds like your THERE! 

While it is fun to talk about our hobby, there are tons of opinions out there but it is up to each individual to decide what works for them.

No one would deny that "each individual to decide what works for them."

The point of these discussions is to understand some of the scientific principles so that individuals spend less time looking for needles in haystacks. Thus, it’s not just frivolity ("fun"), it’s about community inquiry and fact finding, where possible.

The conflation of inquiries into facts with some kind of abnegation of "individual decision making" is sort of dystopian; why would anyone suspect that?

@hilde45  I agree.  I've had a couple folks tell me in the 10's Dahlquist group TELL me I need 200 wpc and my amp will never drive them to their capability.  MY ears know what I'm hearing. How would they know? LoL  And being musicians ears that have listened to music since I was 13, I trust them.  I'm 68......

@carlsbad2 +1

I have a 450wpc amp that is outperformed by lower wattage amps. Many things are more important than power. This realization has me on the waiting list for a SET amp from Decware and I cannot wait!

I don't believe damping factor has been mentioned. Higher power amps tend to have a higher damping factor. With bass in particular, a higher damping factor provides better control of the driver and depending on the impedance of the speaker can result in more accurate reproduction.

So some people here would like for you to believe that Signal to noise ratio, Load on the power supply, ‘Q’ of an amplifier and probably a dozen other Electronic FACTs about amps has nothing to do with how they perform. Yes we have plenty of people here that make unsupported outlandish statement trying to make themselves s look like they actually know something about Sound reproduction. Talking about arbitrary factors that in them self have nothing to do with the argument. Try understanding what ‘HEADROOM’ is before opening your pie hole. And don’t be offended, I left out the juicy comments, but needless to say these types would have you believe that ALL of the specs published on your equipment is useless information.


I’ve had a couple folks tell me in the 10’s Dahlquist group TELL me I need 200 wpc and my amp will never drive them to their capability. MY ears know what I’m hearing. How would they know?

Here’s what they might know: they tried powering the speakers at 200 wpc level and it improved things for them.

This happened to me -- I had what I thought was a good level of power for my speakers. They sounded good to me.

Someone else said they would sound better with more power. I asked why?

They said, "Because I tried what you have and it sounded good to me, but when I tried it with more power, it sounded better in a way I could not have imagined."

This is why others’ experience is valuable. Because the metric of "good for me" may be limited, and others who have experienced more can help shine a light.

It’s not about them telling me "what I should hear."

It’s about them telling me that "there may be more to explore."

And that’s how they would know about your speakers.


Attempting to impress others or change their minds results in meaningless debate and frustration, both a waste of your time.

This should be emblazoned at the top of every thread!


@mapman Wrote:

In any case it’s always better to have more power than needed than less. That’s called headroom and is a real engineering concept and not just marketing. You can look it up!

I agree! See articles Below:




+2 @akg_ca

Roger from Rogers High Fidelity had an interesting comment somewhere about amps operating in their "sweet spot" of sort of a median power delivery, and noted as an example that very powerful amps into efficient speakers don’t get the amp into its best tone zone. Not his exact words but I get it.

@wolf_garcia I get it as well. I recently upgraded my tube integrated to a much more powerful Rogers EHF-200 MKII to power my Harbeth’s - what an idiot I am for buying such inefficient speakers:)

I now have the luxury of virtually unlimited headroom (yes, that marketing term again) and it definitely hits its sweet spot - but that is no where near its max rated output.

It’s apparent when one reads threads like this that everyone has an opinion but only some have science and facts to actually backup their opinions.

That’s just the way it is but my only suggestion would be everyone is always best served by at least valuing the science and principles that account for how things actually work and doing the best they can to apply common learnings in their case as best they can. That’s the happy path to success. Anything otherwise is a detour at best and a dead end road in the worst case.

@hilde45 Great points!  I appreciate that.  Had not thought about that side of the topic.I'm pretty much a 'noob' with regards to the technical side of this.  Have learned a lot from this forum though over the last couple years.  I read a lot but don't post much.  Thanks!

My 150 watt Herron M2 monoblocks sound better than 300 watt Ampzilla 2000 2nd edition monoblocks or PS Audio 350 watt M700 monoblocks with medium efficiency speakers. 

My 25 watt Quicksilver Horn monoblocks however sound better than the Herron amps with my Klipsch Chorus speakers.

Watts aren't everything.