What's the sweet spot for an amplifier? 

Finally solves the mystery of what the Loudness button actually does... fantastic

Fascinating. I’m 42 years old, I’ve been interested in HiFi since I was a teenager and not until now did I fully understand this topic. Thanks Paul.

Superb question and answer thanks a lot!

Thanks for another great video. Just referbished an old Rotel receiver with tone controls & a loudness button. Now i know how & when to use it ( at low levels) , i'll get the most out of it.

Thanks for that explanation of what a loudness control button does. Now I can know how to properly use it. Russell Schmidt

Always appreciate your videos!

Paul... Fletcher and Munson did their studies with men only. Churcher and King did their studies on equal loudness with both men and women and their curves came out a bit different. It's fun to see the difference in the curve sets.

Hello Paul, This may also relate to the issue of "attenuator controls" on the input of the power amplifier. That control has the potential for altering the sound from the amplifier. This matter was well discussed in your earlier response.

Had a Yamaha CA-1000, purchased in 1976. It had a continuously variable loudness control. Worked beautifully. That amp had a wonderfully musical sound.

Fantastic explanation. Many thanks Paul.

Wow, thank you so much Paul for exquisite answer!

Thank you for covering the Fletcher Munson Curve accurately! Fun fact, both Fletcher and Munson were each convicted of seven counts of murder.

Great explanation, thanks Paul !

Pula it’s always great to listen to your. Experience. But I just wanted to maybe point out another way to look at this question a lot of amps are designed to perform to a max wattage of output V-peek let’s say a 100 watts were the audio signal will clip. I was always thought that a good rule of thumps to having the sweep spot on the amps was some were between 60 to 75 % of the volume range and to be exact on RMS max power use a O-Scope to adjust gain to just before clipping and mark it for good references. Thanks for listing.

Great news! High Definition Vinyl Is Happening, Possibly as Early as Next Year!! Austrian company going for it.

A loudness that "fade itself away" depending on the volume is harder to get than than it sounds since the loudness must bee tailored to that speakers sensitivity. I mean, there are speakers with a sensitivity of low 80 db/w and others with over 110 db/w so the loundess can't "fade itself away" after a "standard curve" on the volume-button.

This is amazing

Wow. Enlightening! Thanks for another great one Paul.

Great explanation, Paul! I always like these video's.

Some speakers perform better at more moderate volumes, so it's not particularly an amp issue.

Also, Fletcher+Munson was revised in the nineteen fifties. Robinson+Dadson IIRC.

Denon and Marantz use a feature called dynamic eq to compensate for this.

Brilliant! Thanks for this.

A whole video on appropriate "loud" eq boost at low volumes would be fantastic, loved that little piece at the end

very nice explenation,thank you Paul

Great explanation! Thanks for posting.

Great explanation. Never knew that.

I miss the loudness buttons on new equipment. I think Yamaha used to have a variable loudness button that was very useful for low volume listening. Why did they stop including loudness controls on new equipment?

Great info!

FYI, the FM Curve is older gen, the current version is the Equal Loudness Contours.

I have a Bose classic ipod player . What kind of adaptor do I need to buy to play my new ipod/iphone

Great explanation

strange that i've never experienced such a thing. whether it's at a near-silence, moderate or deafeningly loud volume i still hear all the same (my system is a modified, cheap, crappy computer speaker set, no way there's a loudness circuit in there). on the other hand, i used to own an integrated amp that had a loudness control. with the loudness on, it sounded... well, muddied at every volume level. to me, loudness is just another tone control that boosts bass and treble.

I hear that loudness tilt up even at low volume. Loudness buttons don't work for me.

Suwun paul, awakmu memang joss tenan..

ice noticed on my Yamaha integrated amp has loudness gain controls and I found in mine the 7-8 is the sweet spot highest level being flat it was designed for low volume listing about to do a utube video on the subject

if you have a typical class ab amplifier it could be argued that it sounds worst at the volume level where a certain ammount of the signal is higher than the amplifier is biased (from my limited experiance i would guess as the rms voltage approaches the bias level), but sounds better above that as the crossover distortion is a less significant portion of the signal. i have a carver m400a that i got from a flea market, and when i got it the bias of the right channel was too low so it had plainly audible crossover distortion. If the volume was low enough it sounded perfectly fine, but as the volume was raised transients would get a tizzz to them, then above that the tizz would creep into the main signal untill it was unbearable (coincidentally this was right at where my listening volume is) but as you turn the volume up more the tizz starts to dissapear, or more precisely it stayed the same volume as the music got louder.

Excellent info

If Paul wasn't into audio he'd be a preacher. if an amp is designed to produce 100 watts, that's what it's best at. the volume control is an attenuator. it prevents the amp from producing it's max output. it's a choke. Ps I run my carver wide open, it runs cooler, sounds better.

Is the same true for speakers too or do they sound better when they are driven by an amp at a certain power ?

Hi, need help I am using yamaha a-s201 amp. It played very well with monitor audio and b&w speakers (both 8ohm) I tried yamaha nsf51 (6ohm) and where with 8ohm speakers at 50db was fairly loud, with nsf51 at same volume 50db is very quiet. At maximum loudness far from what i had with monitor audio/b&w speakers. On the back of A-s201 states 8ohm minimum. Ok I understand maybe they didn’t match well, even tho i was advised 6ohm speakers will play even louder. Now i got wharfedale 11.3 (4-8ohm). So a-s201 should have no problem right, as the speaker is fully ok to be matched with 8ohm amp. But unfortunately exactly same problem with loudness as when it was with nsf51 speakers. What is happening here? Many thanks!

Another explanation for this has to do with our human condition. All creatures that roam this earth have evolved to optimize the senses that help them survive. We human hunter gatherers have hearing that is tuned to the things we need. This includes the ability to hear our babies cry, or hear a lions roar. We therefore don't need to hear a crickets legs or a birds wings flapping. Eyesight is fine tuned in the same way. For this reason birds and insects can see flowers at a much greater range than we do. The loudness compensation boosts sounds below and above a certain threshold into the range of our normal hearing.

What is the best method of getting a question through to Paul? Writing an email on the website?

Just from the science, for any capacity amplifier, noise level is fixed. Higher volume produces larger Signal to Noise Ratio. Some amplifiers are quite linear and is listed as THD as non linearities are measured as distortion. Unfortunately high levels on large amps is damaging to speakers and hearing. Most living rooms should not have more than a 30 to 100 Watt RMS per channel amplifier. This is why most consumer grade big box store amplifiers contained in stereos are mostly under 20 Watts RMS per channel. Audiophiles prefer the headroom to cover extreme peaks. This requires an amplifier with better than normal SN ratio to be very low noise. Paul, covering the Loudness button on stereos is spot on. This EQ is effective at lower volume settings and is phased out as the volume knob is advanced. In stereos with a graphic EQ, this effect is often seen as a SMILE on the front of the EQ. Only problem with the graphic eq, is this setting remains when the volume is cranked up when it should be flattened out. This often result in distorted bass and blown tweeters as this EQ setting leads to clipping at high volume levels. To sound correct, the volume should be set to the original performance levels to sound natural. Unfortunately with the loudness wars and highly compressed content in mass market sound, this can not be achieved as compression rides the volume in the mastering.

Most People „need“ a pressure to „feel“ good Sound, so room acoustics and volume are related aswell...

Can it not also have something to do with the volume control, the pot? Louder volumen equal less influence from the pot.

Class AB1 amps have a level where THD is at minimum depending on biasing and the stiffness of the power supply. At low levels THD suffers due to crossover notch distortion and at high levels (before hard clipping) due to (relative) depletion of the power supply capacitors through compression and IM distortion. Not all amps I've measured show much of the later but minimum THD has been in the one third to two thirds range. I've also seen some that are all over the place with a sharp null lurking in weird levels which I could not explain. Guess which level I reported after service.

Do all digital volume controls lose information at low levels ?

Paul is like a white Morgan Freeman. Listening to his voice literally de-stresses me.

Very Interesting video today :)

Hi Paul I wonder...if you can answer me this question? Why don't we see wire wound volume or tone controls on amplifier, and what is the best type of volume control to get carbon or step or anything else... thanks.

YESSSS The word is Balance

Nice!

I have a Yamaha B-2 amp. I keep the LR volume knobs at max and adjust my overall volume with my preamp. This is correct, right? Maybe the guy with today's question has a receiver vs the separates that I have?

but why I almost never notice that rolloff on my headphones? only on my speakers?

Refering to the first comment women can hear higher frequencys to mean for whatever reason i auspect its something to do with kids crying or something not being a typical man its aimplyba scontific fact most men cant hear past a cert khz but most women can hear the wntite range of the frequencys humans can hear and also slightly louder to men

Turn it up to 11

Funny, I percieve it completely the opposite! Without exception I always percieve the mid range more at higher volumes, and low and high frequencies more at lower levels of volume. And such, "loudness" controls have always made it worse for me at lower levels of volume! Please tell me I'm not the only one! PS; this is on many different systems, but have felt some speakers and amp combos as more pleasing at lower volumes. Maybe that's what he is talking about?

the perfect volume isn't for the amplifier necessarily. it is more fort he actual piece of music on the recording being played back. each pies will have its best volume level that you need to find by experimenting. a big band performance just won't sound right at background level. vocals are a good example and when the right volume is reached, you will know it. go ahead, try it. ...hifitomnmy

That awful outro music has grown on me, maybe because of Paul's voice. I think I love it now.

Yeah and Howie Munson did studies on how not to get hurt while doing stunts.

I love my adaptive control botton on my technics sa ax6. Not apartment friendly at all💩

Pioneer audio calls it intelligent volume

or conversely, anyone with a Crown K2 does not need to address this issue

humanity is just to high volume levels.. lol

Rel make some good subs but Dali make some great subs and speakers

This bring's many Human Senses into Play .Every Human on the Planet Perceives -Taste/Smell /Vision & Audio Differently .Hence ; We all know it is an Apple only B-cause we were Taught that this is what an Apple -taste / smells & look's Like.Strangely enough it all Comes down 2 a point of Conjecture. A Rose by any other NAME ! Dou People Perceive High-End Audio Sound Waves Differently & How dou U deal with the Art of the Sale? Basically : How dou U Justify your Existence in-da World of Audio ? I am asking the unanswerable" Question , When is Enough- Enough ? O-Baby !!! The Quest. Will we ever Achieve -PERFECTION-? 8-Track 4-Ever...lol. YYZ-60+NOOB. Keep e'm Yaki'n .Luv U & what U Dou & God Bless Spellcheck ...

anyone with a Phase 400 knows this topic well :)

By evolution, a men has reached a level to hear the mid-range frequencies and tones best (less high, less bass), because they are the most common in nature and from these sounds, the greatest is danger and threat to man. That is the exact explanation of the problem and why a man hears in that way. Peace

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REL = poor bass definition. Bad choice.