Power amplifiers and lower listening levels

Clipdat

I have sensitive hearing, so I tend to do my listening from 60-75db. Of course, I still like to crank it up and maybe hit 90+ from time to time, because who doesn't?! However I'd say 95% of my serious listening is done from 60-75db.

I started thinking about what makes an amplifier perform well at lower volumes, and I was hoping to ask all of you if you could help shed some light on this subject for me.

I'm sure we've all heard the quote "The first watt is the most important watt.", implying that the overall quality of the amplifier's "watts" is more important than their overall quantity. Naturally, this brings to mind the Pass Labs class A approach to their amplifier design, and specifically their First Watt line.

Their design philosophy points to the overall/total watts per channel not mattering as much, especially for listening at lower levels.

I've also read various reviews as well as commentary from members here, about how as you get up into the higher WPC amplifiers such as 100-200+, that these amplifiers actually provide a more delicate and nuanced listening experience specifically when listening at lower volume levels. Going against the common misconception of "more watts" really only being good for higher listening levels.

So, is this particular behavior a side effect of these higher power amps' rated WPC output, or is it related to their build quality/quality of internal components? When you're listening at 60-75, aren't you only using that "first watt" anyway?

Anyway, it just got me thinking about amplifier design, and if there were some specific things to look for in terms of evaluating whether or not an amp would do well at lower listening levels, or if there was a "genre" of amplifiers specifically designed for this.

BlueFox

Well, most of the time I listen to classical with the volume in the low 70s, and my amps have 1200W/ch with my 4 ohm speakers, and I think it sounds fantastic. Power is like money. It's better to have a lot, with some in reserve, than not have enough.

joecoulson

What a perfect comment blue. Same applies to horsepower, food and women....wait scratch the last one

Drew I am very inexperienced compared to most on this forum and am still very young in my journey ( and wonder if like @darkknight said in the speaker wire thread, if there is some gear head along side the audiophile in me if I’m being perfectly honest) but subscribe to the theory of having way more wattage in power amplification than needed or necessary. To me it would make sense to reduce intermodulation distortion and have more power available for transients. To each is own. On paper, bi-amping my system looks like a waste, in practice (a/b testing with the single monoblocks and then both) it sounds much deeper. Full symphonies sound better going from very quiet sequences to the large fully engaging ones. I could try and explain with words why it sounds better, but again like the cables thread, it would just be my opinion and they are like a——s everyone’s got one.

mhardy6647

The "first watt" philosophy (espoused - in slightly different language - long ago by Col. Klipsch* and more recently, Dick Olsher** and of course Mr. Pass) is a little misleading but on point (IMO) in the sense that -- if one uses high sensitivity loudspeakers, the electrical performance of an amplifier at very low output power levels (tens of milliwatts) really, really matters.

High power amplifiers co-evolved with low sensitivity loudspeakers -- i.e., the driver for high performance at low output power was pretty much removed in those days. To this day, I don't think most (but, of course, not all) amplifiers (at least, any with outputs of more than ca. 10 watts per channel) are designed nor constructed with much regard to their performance at 20 milliwatts.

This is my rambling way of saying that the trick is to find an amplifier that sounds really good at really low output levels.

In fairness, the OP's situation is (probably) a little different in that he's (presumably) got more typical, modern low sensitivity loudspeakers and he's asking about playing them at low levels. The requirements of such loudspeakers make the common mantra of "headroom, headroom, headroom" much more important than if one's low-level listening is done on 100-plus dB sensitive loudspeakers! It's all in the physics. At low SPLs, a low-sensitivity loudspeaker is working against dynamics due to its power (and/or current) requirements. Yeah, one can work around this with more power -- is that the best approach? Well, obviously, yes, for some folks. Others may feel that
letting the loudspeaker do the work is a better philosophy. Both can be rewarding, so, despite my personal preference, I cannot really recommend one over the other.

I guess my question to the OP is: have you heard good high-sensitivity loudspeakers on a good low powered amplifier? IME, the ability of such systems to sound really, really good at astonishingly low levels (e.g., a track fadeout on a studio recording) is remarkable.


______________
* https://www.klipsch.com/quotes-anecdotes
** http://www.firstwatt.com/

mhardy6647

FWIW -- I think for me the automotive analog would be, e.g., a Caterham Seven vs. a Dodge Hellcat. These two automobiles take very different approaches to the philosophy of high performance driving. Both would be very different types of fun to drive -- but both could be fun.

delkal

Clipdat wrote: »

So, is this particular behavior a side effect of these higher power amps' rated WPC output, or is it related to their build quality/quality of internal components? When you're listening at 60-75, aren't you only using that "first watt" anyway?

If you are have 90 db efficiency speakers.........

At 60 dB's you are using 0.001watt
At 70 dB's you are using 0.01watt
At 80 dB's you are using 0.1watt

Do you think the extra power at max makes any difference at your listening levels? It is all about the build quality, design, and quality components.

tonyb

You just can't put the finger on only the amplifier when you want to better your low level listening. Lots of variables here. Your speakers sensitivity, how hard they are to drive, impedance mismatches within ones system, and even cables will play a role in this as well.

You may often at times hear us say....HT is easy, 2 channel is a ****, and with good reason as the thread topic suggests.

My opinion, start with the easiest steps first if you want to increase your lower level listening, and that's by using OCC copper speaker and IC cables. They let more threw, like taking your thumb off the end of a garden hose.

delkal

mhardy6647 wrote: »

FWIW -- I think for me the automotive analog would be, e.g., a Caterham Seven vs. a Dodge Hellcat. These two automobiles take very different approaches to the philosophy of high performance driving. Both would be very different types of fun to drive -- but both could be fun.

Unfortunately if you were listening to these at 60 dB's it would be like driving in a crowded parking lot

mhardy6647

delkal wrote: »

mhardy6647 wrote: »

FWIW -- I think for me the automotive analog would be, e.g., a Caterham Seven vs. a Dodge Hellcat. These two automobiles take very different approaches to the philosophy of high performance driving. Both would be very different types of fun to drive -- but both could be fun.

Unfortunately if you were listening to these at 60 dB's it would be like driving in a crowded parking lot

I don't disagree (although that simile makes my head vibrate!) -- and, in that case, I reckon the Caterham would be rather more adept than the Hellcat.

motorhead43026

That Caterham is oozing fun factor.

Clipdat

mhardy6647 wrote: »

This is my rambling way of saying that the trick is to find an amplifier that sounds really good at really low output levels.

How can one find an amplifier that excels at this? What specific traits about the amplifier should one be looking for?

mhardy6647 wrote: »

In fairness, the OP's situation is (probably) a little different in that he's (presumably) got more typical, modern low sensitivity loudspeakers and he's asking about playing them at low levels. The requirements of such loudspeakers make the common mantra of "headroom, headroom, headroom" much more important than if one's low-level listening is done on 100-plus dB sensitive loudspeakers! It's all in the physics. At low SPLs, a low-sensitivity loudspeaker is working against dynamics due to its power (and/or current) requirements. Yeah, one can work around this with more power -- is that the best approach? Well, obviously, yes, for some folks. Others may feel that
letting the loudspeaker do the work is a better philosophy. Both can be rewarding, so, despite my personal preference, I cannot really recommend one over the other.

My speakers are Polk LSiM 703s, rated at 88db sensitivity. Can you expand on what you mean by "At low SPLs, a low-sensitivity loudspeaker is working against dynamics due to its power (and/or current) requirements." and "Others may feel that letting the loudspeaker do the work is a better philosophy"?

mhardy6647 wrote: »

I guess my question to the OP is: have you heard good high-sensitivity loudspeakers on a good low powered amplifier? IME, the ability of such systems to sound really, really good at astonishingly low levels (e.g., a track fadeout on a studio recording) is remarkable.

The only time I have is when I heard the 105db sensitivity $95k Destination Audio horns being powered by their tube amps, filling the room with sound at ~95db from under a watt.

Clipdat

tonyb wrote: »

My opinion, start with the easiest steps first if you want to increase your lower level listening, and that's by using OCC copper speaker and IC cables. They let more threw, like taking your thumb off the end of a garden hose.

I'm using Audioquest King Cobra RCA cables and MIT Terminator 2 bi-wire speaker cables. Before the MITs I was using Audioquest Bedrock speaker cables.

Clipdat

delkal wrote: »

If you are have 90 db efficiency speakers.........

At 60 dB's you are using 0.001watt
At 70 dB's you are using 0.01watt
At 80 dB's you are using 0.1watt

Do you think the extra power at max makes any difference at your listening levels? It is all about the build quality, design, and quality components.

Not quite sure of why you asked the rhetorical question, but that is exactly what I am hoping to figure out by making this thread.

I'm trying to figure out if build quality/components matters more/less/equal than overall WPC. Or, as it seems in some cases, the two are directly linked.

For example once you start looking into amps like these:

https://www.musicdirect.com/power-amp/Esoteric-S-03-Power-Amplifier

https://www.musicdirect.com/power-amp/bat-vk-655se-power-amplifier

delkal

Clipdat wrote: »

delkal wrote: »

If you are have 90 db efficiency speakers.........

At 60 dB's you are using 0.001watt
At 70 dB's you are using 0.01watt
At 80 dB's you are using 0.1watt

Do you think the extra power at max makes any difference at your listening levels? It is all about the build quality, design, and quality components.

Not quite sure of why you asked the rhetorical question, but that is exactly what I am hoping to figure out by making this thread.

I'm trying to figure out if build quality/components matters more/less/equal than overall WPC. Or, as it seems in some cases, the two are directly linked.

For example once you start looking into amps like these:

https://www.musicdirect.com/power-amp/Esoteric-S-03-Power-Amplifier

https://www.musicdirect.com/power-amp/bat-vk-655se-power-amplifier

Sorry, I guess I needed to find a sarcasm smiley. It is all about the build quality, design, and quality components. At the levels you listen to max WPC means nothing and is more of a marketing ploy (within reason).

treitz3

I am not gonna mention anything about a high current amp. Nope, not me. Just not gonna do it.

Tom

mhardy6647

Clipdat wrote: »

mhardy6647 wrote: »

This is my rambling way of saying that the trick is to find an amplifier that sounds really good at really low output levels.

How can one find an amplifier that excels at this? What specific traits about the amplifier should one be looking for?

Pair of speakers, source and program material (recordings) and amplifier. Test.
Repeat until satisfied with one. There's no a priori way to do it, other than experience (or to leverage the experience of others).

...
My speakers are Polk LSiM 703s, rated at 88db sensitivity. Can you expand on what you mean by "At low SPLs, a low-sensitivity loudspeaker is working against dynamics due to its power (and/or current) requirements." and "Others may feel that letting the loudspeaker do the work is a better philosophy"?

I need to work at this -- but consider an 88 dB sensitive loudspeaker vs one at 104 dB. The difference in sensitivity is 40 fold in terms of power requirements. To get 104 dB of SPL from the 104 dB loudspeaker (my Duplexes, e.g.) takes one watt (2.83 AC volts into 8 ohms); to get 104 dB SPL from your Polks takes approximately 40 watts. That you knew already, though!

I'll get back to you with some (ahem) amplification of this topic.

...

The only time I have is when I heard the 105db sensitivity $95k Destination Audio horns being powered by their tube amps, filling the room with sound at ~95db from under a watt.

And did you get a chance to hear these at the very low levels you say you enjoy for listening?

And...

Did you like what you heard? That's the important question. And did you hear it at low levels? I've never heard of Destination Audio, though I can tell you that you can get 105 dB senstivity for a good deal less than $95k, new or vintage (and with superb audio quality, from my perspective). Doesn't much matter if you didn't like what you heard, though.

mhardy6647

A comment about SPL. 70 dB is pretty quiet. Not sepulchral, but not very loud, either. 50 dB is generally (last I knew) a pretty standard background level in a home environment. 20 dB more than that would be 4 times louder, give or take.


source: https://www.osha.gov/SLTC/noisehearingconservation/loud.html

joecoulson

Here is a couple more to add:

rpf65

I say get a 200 watt amp, crank it up to 85 dB, and put on some harbor freight ear muffs on. Pretty sure you’ll get similar results.

Clipdat

Not helpful but thanks for playing.

delkal

mhardy6647 wrote: »

A comment about SPL. 70 dB is pretty quiet. Not sepulchral, but not very loud, either. 50 dB is generally (last I knew) a pretty standard background level in a home environment. 20 dB more than that would be 4 times louder, give or take.


source: https://www.osha.gov/SLTC/noisehearingconservation/loud.html

What a lot of people don't realize is to go up one notch on this chart (10 dbs) means you need 10 times the power from the amp. So using your 90 db speakers which need 1 watt to get to 90 dBs (rounding up from 88 to make the make the math easier).

At 100 dB's you are using 10 watts
At 110 dB's you are using 100 watt
And at 140 dB's you would need a 100,000 watts amp and speakers that will take it.


My point is that human hearing has a huge dynamic range. And you can also see you get to the point of diminishing / unrealistic returns logarithmicaly for max loudness.

The good news is most audiophiles never listen over 10 watts. And most of the time around 1 watt. Make those the ones that count.

mhardy6647

That's exactly what it means, indeed.

Clipdat

mhardy6647 wrote: »

Pair of speakers, source and program material (recordings) and amplifier. Test.
Repeat until satisfied with one. There's no a priori way to do it, other than experience (or to leverage the experience of others).

Sounds like it involves a lot of time and money to do that for your self first hand! I have a feeling I would like the sound of those high efficiency full range crossover-less drivers.

mhardy6647 wrote: »

And did you get a chance to hear these at the very low levels you say you enjoy for listening?

And...

Did you like what you heard? That's the important question. And did you hear it at low levels? I've never heard of Destination Audio, though I can tell you that you can get 105 dB senstivity for a good deal less than $95k, new or vintage (and with superb audio quality, from my perspective). Doesn't much matter if you didn't like what you heard, though.

We listened to some at lower levels in the 75-85 range and although it sounded spectacular, it wasn't exactly my cup of tea for some of the types of music that I enjoy listening to. However for other genres it was pretty amazing.

So I guess to answer your question, yes, I liked it, but was it a religious experience that made me want to never again listen to anything but a horn speaker? No.

mhardy6647

OK, then -- I can't help much.
(although, again, in fairness, I've never heard the ones you mention, and price simply does not, for me, much correlate with what I really like (at least at extremes).

As to how to enable hearing lots of different stuff without breaking the bank?

Several ways to do that.

1) friends
2) small local groups
3) larger regional groups
4) local dealers (they do still exist; there are as I am sure you know, good ones in the Bay area, and there are also often very small, appointment only dealers that may be worth seeking out)

tratliff

delkal wrote: »

The good news is most audiophiles never listen over 10 watts. And most of the time around 1 watt. Make those the ones that count.

I would generally agree with this. My speakers are pretty efficient. I think 94db. It’s rare that I push the McIntosh meters to be consistently above 6 watts. They do peak higher but not really that much.

Now I can get heavy handed on a late night, after the bourbon is flowing, and they will hover around 60 watts but thats more the exception than the rule. And at that point it is so intense I’m not normally critically listening. It’s really about the experience at that point.

The point is the power reserve is what I think is important. The combination I have works well at a low, medium and high volume. But being able to have the ability to do all at your finger tips is key to system enjoyment.

mhardy6647

oops, I take it back.
coupla more comments.

I can't quantify this for you, but based on empirical evidence, I think (?!) it is safe to say that higher sensitivity loudspeakers are likely to sound more dynamic at low SPL than will lower sensitivity loudspeakers.

There are high-ish sensitivity loudspeaker options that don't use horns (well, at least, that aren't largely horn-loaded). Tekton, Zu, and Devore fairly leap to mind.

Full disclosure, the tweeters in many models from these companies are horn loaded -- "gently" so per Devore's advertising hyperbole

jdjohn

DSkip wrote: »

I would suspect that a class A design would do better for lower level listening as it will draw more current at a given power point due to the low efficiency design. I could be talking out my A$$ though because much of that current might be lost as well due to the low efficiency design.

I think that last phrase is more the case. I could be talking out of same said **** as well, but we all know that a lot of the current for class A is converted to heat, so it seems more power is needed in order to get sufficient playback juice for all frequencies.

And isn't the fleshing-out of all frequencies at a low volume what we're talking about and trying to achieve with this topic? Typical low-volume playback IME is that mids are the first to be heard, with lows and highs tailing-off on a typical bell-shaped curve. Trying to get those lows and highs fleshed-out at a low volume is the trick, right? And we are all familiar with the good ol' loudness button, which does exactly that. Of course it can also be achieved with an EQ at low volumes.

But getting back to power amp design, and specifically efficiency, I can say that I experienced very good low-volume playback with class D. Better than I had heard with class A or A/B.
When I first listened to my PS Audio S300, the low-level sound immediately struck me as improved. I was hearing a flat frequency response across the spectrum from the get-go. So it would seem that a high-efficiency pairing of both amp and speaker would yield the absolute best results.

cfrizz

My personal experience is that with a 50wpc Rotel amp, and a 110wpc Denon receiver, the sound was pretty equal, but I didn't know that I was missing quite a few details. I purchased a 205wpc Parasound 1500A amp, and it was an ear opening experience. My easy to drive Polk RTA-8Ts woke right up. I got the amp with the expectation of getting some LSI's, that went right out the window with the amp in place.

I will not ever have just a receiver powering my speakers ever again, nor will I ever have less than a 200wpc amp powering my speakers.

I don't worry about current, since with that much power the point is moot. Which is why I don't understand why some of you are always arguing this point.

You all go on and on about current, but forget that the industry itself pretty much only talks about wpc, so that is what people focus on.

We all know the current in receivers is minimal, and lower powered/cost solid state amps usually won't bring out all the details of what is on the recording. (in my experience)

Whether listening in 2 channel or HT, having ones speakers powered to operate to their full potential should be the goal.

But in the end it all comes down to what you want to achieve and if you think it's worth it to spend that much money. The vast majority don't think it's worth it.

F1nut

You all go on and on about current, but forget that the industry itself pretty much only talks about wpc, so that is what people focus on.

Consumer grade gear won't list it, but the better gear provides current specs. However, it's listed as amperes and/or peak to peak amps, which many don't realize means current.

joecoulson

So if an amp says input power is 400 watts max and it’s a 125wpc amp, that’s good right?
Or just about avg? Or I don’t know what I’m talking about?

treitz3

Current.....hmmm.What is that? This is new to me.

Tom