Watt nonsense!

[HidetheHiFi]

TL;DR - Is stated power output highly overvalued?

I don't suppose I'm the first person to comment on this, but as someone still in the honeymoon period of vintage audiophilia, I'd be interested to hear some community wisdom on the question of power output. Or more specifically, its relationship to "how loud the thing goes", if that's not too crude a term.

The context: my love affair with hifi re-ignited over the 2020 lockdown and has been focussed on 1970's kit, and specifically, Japanese-made receivers. In a relatively short space of time (they're not making any more, quick, you might never see that one again!) I acquired a number of units from Pioneer, Yamaha, Rotel and Luxman, all rated between 25 and 50 watts.

The confusion: The two more powerful units (sx780 and sx750) did sound louder than the 25/30w units, and so with some excitement, I sold my old Saab (wasn't getting used) and increased my budget to some upper-mid level machines, notably a Marantz 2285 and a Luxman R-1120. With 85w and 120w respectively, I assumed these were going to offer intoxicating, near limitless reserves of power.
I was wrong.
They sounded maybe a "bit" louder than the two Pioneers, but not my much. In fact it may have been wishful thinking as I'm not completely convinced the Sx780 doesn't still have them both beat for sheer grunt.

The research: so I started to read up on the relationship between power output, and decibels, and decibels and sound pressure. I got confused. But my take away from that was this: a 40w amp is certainly not twice as loud as a 20w amp. It's really only a little bit louder. If you want to get an amp that sounds twice as loud - then you'll need a 200w amp.

The questions:
1. That may be over simplistic, but my experience seems to suggest it may not be far off the mark. Can any of AK's more technical members corroborate that ballpark 10:1 power output ratio required to double perceived volume?

2. Also, if that is the case - and apologies if my post starts to trespass here into values territory - why the huge premiums paid for high power machines if the difference is volume is really quite modest? I realise some of the bigger receivers have better tuners and more speaker outputs, but it seems equally true, especially for, say, Marantz, that the lower power machines sounds just as, if not, sweeter than their bigger brothers.

3. I have also noticed that the CD out signal (from a Marantz CD73 and Philips CD160) sounds noticeably louder than other sources such as the built-in tuner or playing my iphone via iFi Zen Blue DAC into aux. Why is that? Because it's a higher voltage? Could you increase the voltage on any source (eg a DAC) and reap similar "gains" in volume? Is there any risk to amp/speakers from "louder" sources?

4. I also read - on AK I think - that Pioneer tended to calibrate the volume control so that most of the welly comes before the midday position, and after that, there's not much to give. Is there any truth in that? It's hard for me to test as most of the units I have are already pretty damn loud by that stage and I wouldn't want to risk blowing up anything by going into the afternoon, as it were. How many on here regularly crank up the volume past the half way mark?

5. I read people talking about "headroom" and how good it is to have power in reserve, but is there any science in that? I mean it's not like we're driving and we need power in reserve to overtake. If you had a blind test with an sx450 playing at 50% and an sx950 playing at say 30%, so that the sound level seemed the same, would you be able to tell the difference?

Thanks in advance for anyone with the patience to read this far and consider any of these rather ill-informed queries. It would help me allay current suspicion that, for the great majority of speakers, especially if only one pair is connected, having anything over 50 watts is probably overkill.

Craig

ps 1. I appreciate this is not a very sophisticated line of questioning, and that volume/power output is only one part of a system's ability to entertain, but who doesn't enjoy that moment when the volume dial is only at 2.5 and you can feel the floor vibrating already ; )
ps 2. Receivers normally tested with Celestion Ditton 25s, but also Beovox M70 and S45, and a modern pair of Monitor Audio (Monitor 50). The woofers on the Dittons are nearly 50 years old and positively heroic in their ability to move air

 

[rothwellaudio]

Some people aren't bothered in the slightest by how loud it will go because they never play it very loud anyway. For them (and me) almost any amplifier will have enough power. One less thing to worry about.

 

[Mearle]

my opinion is that you need double power for every 3db SPL increase, so if your music has a 30 db range and you want to play the softest sound at 1 watt, you would need 10 power doublings to produce an unclipped Output at the 30db level, 1W, 2W, 4W, 8W, 16W, 32W, 64W, 128W, 256W, 512W, = 10 doublings to have the headroom to cover a 30db range referencing a 1W starting point. If the amplifier peak capacity is not there to cover the full dynamic range, the peaks will cause the amp to clip, thus sending a DC component to the speaker, this low power "clipped" signal is the quickest way to smoke a voice coil, ie; blowing speakers with low power rather than the safer hi-headroom clean output. (the speaker depends on a fully non clipped signal for constant motion to cool the voice coil, a DC portion of the signal causes the voice coil to have a degree of non motion and insufficient cooling = charcoal in some cases)

It is an interrelation thing, dynamic range of the music in question, levels of listening taste, and power handling capacity of the speakers when matched to the suitable amplifier, be it a power amp or receiver. Personally I do not get the "peak power" output that I feel comfortable with from any traditional receivers and opt to use the receiver section as part of the PRE-amp stage, to feed multiple amps that power individual speaker match ups...

From Web:
DYNAMIC RANGE AND MUSICAL GENRE
All music has some degree of level fluctuation, but some genres tend to have broader dynamic ranges than others. Recorded pop, rock, R&B, hip-hop and country music usually have a relatively modest dynamic range — typically around 10 dB, although there are exceptions. Electronic dance music (EDM) probably has the smallest dynamic range — often in the 6 dB neighborhood — but makes up for it by creating contrast with its almost infinite array of instrument colors and textures coming from synthesizers and samplers.

On the other end of the spectrum are jazz and classical music, which can have considerably large differences between their quietest and loudest parts. In jazz, uptempo songs typically go from loud passages played on brass and saxophone instruments to quiet piano and bass solos. Even in jazz ballads, the dynamic range is usually relatively wide. A study of dynamic range in different musical styles conducted in 2016 revealed that dynamic ranges in jazz generally varied from 13 dB to 23 dB.

As a group, classical recordings have the widest dynamic range of any genre. The same study cited above found that recorded classical music typically offers between about 20 dB and 32 dB of dynamic range. While that might seem like a lot, it’s still quite a bit smaller than that of a live symphony orchestra performance, which can be as large as 90 dB.

 

[Powertech]

O.K. Let's try this step by step.
Point No1. - (and probably the most important) - Remember that high fidelity sound reproduction is more about quality then quantity - you are not running a PA system in your living room. Refer back to the old adage - the most important watt is the first one.

You power ration of 10:1 is probably about right. How loud a system goes is as much about the efficiency of the loudspeakers as the maximum output power of an amplifier. Input sensitivity will also play a major part in this as will amplifier gain factor You will see an output power rating in watts and an input sensitivity in millivolts (mV). Low efficiency loudspeakers require far more input power to produce the same audible sound level as a high efficiency loudspeaker. Again you 10:1 ratio applies.
example:
Amplifier A - Input sensitivity 250mV for full output of 50watts.into an 8 ohm load.
Amplifier B - Input sensitivity 500mV for full output of 100 watts into an 8 ohm load.

I you feed both these machines with a 200mV signal, amp A will probably produce about 40watts, amp B will probably produce about the same. look at the relationship between input sensitivity and output power in each case.

CD players do tend to have a higher output than most other sources. There is no advantage in trying to increase the output of other devices. They are what they are and largely you have to live wit this.

Headroom. You run a hi-fi amp at a relatively low average power level. I have a rule of thumb that says 'If you need to run an amp at above 50% volume setting it's not big enough'.
If you are running a music signal at a reasonable power level and a loud transient occurs in the music (a load bass drum or similar), although the average power level is hardly affected, the amplifier will be required to draw a large current for a very short period to enable the output voltage to correctly follow that transient. That ability to draw extra current for a very short period without clipping is called 'headroom' and it's also where your 10:1 power to volume ratio applies.

I hope this helps to at least start to answer you questions. This is just skimming the surface as I have tried not to be too technical for you.

 

[wyn palmer]

TL;DR - Is stated power output highly overvalued?

I don't suppose I'm the first person to comment on this, but as someone still in the honeymoon period of vintage audiophilia, I'd be interested to hear some community wisdom on the question of power output. Or more specifically, its relationship to "how loud the thing goes", if that's not too crude a term.

The context: my love affair with hifi re-ignited over the 2020 lockdown and has been focussed on 1970's kit, and specifically, Japanese-made receivers. In a relatively short space of time (they're not making any more, quick, you might never see that one again!) I acquired a number of units from Pioneer, Yamaha, Rotel and Luxman, all rated between 25 and 50 watts.

The confusion: The two more powerful units (sx780 and sx750) did sound louder than the 25/30w units, and so with some excitement, I sold my old Saab (wasn't getting used) and increased my budget to some upper-mid level machines, notably a Marantz 2285 and a Luxman R-1120. With 85w and 120w respectively, I assumed these were going to offer intoxicating, near limitless reserves of power.
I was wrong.
They sounded maybe a "bit" louder than the two Pioneers, but not my much. In fact it may have been wishful thinking as I'm not completely convinced the Sx780 doesn't still have them both beat for sheer grunt.

The research: so I started to read up on the relationship between power output, and decibels, and decibels and sound pressure. I got confused. But my take away from that was this: a 40w amp is certainly not twice as loud as a 20w amp. It's really only a little bit louder. If you want to get an amp that sounds twice as loud - then you'll need a 200w amp.

The questions:
1. That may be over simplistic, but my experience seems to suggest it may not be far off the mark. Can any of AK's more technical members corroborate that ballpark 10:1 power output ratio required to double perceived volume?

2. Also, if that is the case - and apologies if my post starts to trespass here into values territory - why the huge premiums paid for high power machines if the difference is volume is really quite modest? I realise some of the bigger receivers have better tuners and more speaker outputs, but it seems equally true, especially for, say, Marantz, that the lower power machines sounds just as, if not, sweeter than their bigger brothers.

3. I have also noticed that the CD out signal (from a Marantz CD73 and Philips CD160) sounds noticeably louder than other sources such as the built-in tuner or playing my iphone via iFi Zen Blue DAC into aux. Why is that? Because it's a higher voltage? Could you increase the voltage on any source (eg a DAC) and reap similar "gains" in volume? Is there any risk to amp/speakers from "louder" sources?

4. I also read - on AK I think - that Pioneer tended to calibrate the volume control so that most of the welly comes before the midday position, and after that, there's not much to give. Is there any truth in that? It's hard for me to test as most of the units I have are already pretty damn loud by that stage and I wouldn't want to risk blowing up anything by going into the afternoon, as it were. How many on here regularly crank up the volume past the half way mark?

5. I read people talking about "headroom" and how good it is to have power in reserve, but is there any science in that? I mean it's not like we're driving and we need power in reserve to overtake. If you had a blind test with an sx450 playing at 50% and an sx950 playing at say 30%, so that the sound level seemed the same, would you be able to tell the difference?

Thanks in advance for anyone with the patience to read this far and consider any of these rather ill-informed queries. It would help me allay current suspicion that, for the great majority of speakers, especially if only one pair is connected, having anything over 50 watts is probably overkill.

Craig

ps 1. I appreciate this is not a very sophisticated line of questioning, and that volume/power output is only one part of a system's ability to entertain, but who doesn't enjoy that moment when the volume dial is only at 2.5 and you can feel the floor vibrating already ; )
ps 2. Receivers normally tested with Celestion Ditton 25s, but also Beovox M70 and S45, and a modern pair of Monitor Audio (Monitor 50). The woofers on the Dittons are nearly 50 years old and positively heroic in their ability to move air

I like to listen at live symphony concert levels. Based on my own measurements that is c. 87dBSPL average and 102dB peak where I sit in my usual concert hall. My speakers produce 91dBSPL @1m for 1W equivalent at "8 ohms" 1m distance, that's 11dB less than the max of 102dB, but I listen at 3m from the speakers, so that requires c. 10dB more power, so we're talking about 21dB more power than 1W. if 3dB is a doubling this is about 128W (7 fold doublings), and that assumes an 8ohm speaker. If it's 4 ohms- which it nominally is-, then the power is doubled to 256W, and if the impedance/phase angle drops at any point it can be significantly more.
My amps can deliver c.360W into 4 ohms per channel, and they never clip. But there are times it gets close, and when I just had a single unit rather than the dual mono it was not uncommon for the clip indicator to light up.
So, it really depends on what you listen to and how you want to listen.

 

[robert_kc]

OP: Welcome to AK!

There are existing threads on this topic. I suggest that you google something like:

“amp power needed site:audiokarma.org”​

Some of my thoughts about amplifier power requirements are posted here: One watt...

FWIW, about 10 years ago I collected many of the TOTL 1970s monster receivers (e.g., Pioneer SX-1980, Marantz 2325, Kenwood KR-9050, Pioneer SX-1010, Marantz 2285B, etc.) – and then I sold them all.

For the classical music that I love, the most natural sound is delivered via modern (i.e., recorded in the last dozen years or so) hi-res multi-channel classical recordings (e.g., Blu-ray and SACD) and vintage tube amps driving large Klipsch speakers. Because of the sensitivity of high-end Klipsch speakers, 30wpc of tube power can deliver plenty of dynamic range. The combination of modern multi-channel Blu-ray recordings (DTS-HD MA 5.1), vintage tube amps (I prefer 6L6GC), and high-end Klipsch speakers does an excellent job of creating the illusion of being in the symphony hall or opera house. (I attend more than 2 dozen world-class classical concerts in world-class venues (no use of sound reinforcement system) each season, so I know how natural music sounds.)

Based on the genre(s) of music you listen to, your listening room, your preferences, and your budget and other constraints - YMMV.

 

[ernieb1536]

O.K. Let's try this step by step.
Point No1. - (and probably the most important) - Remember that high fidelity sound reproduction is more about quality then quantity - you are not running a PA system in your living room. Refer back to the old adage - the most important watt is the first one.

You power ration of 10:1 is probably about right. How loud a system goes is as much about the efficiency of the loudspeakers as the maximum output power of an amplifier. Input sensitivity will also play a major part in this as will amplifier gain factor You will see an output power rating in watts and an input sensitivity in millivolts (mV). Low efficiency loudspeakers require far more input power to produce the same audible sound level as a high efficiency loudspeaker. Again you 10:1 ratio applies.
example:
Amplifier A - Input sensitivity 250mV for full output of 50watts.into an 8 ohm load.
Amplifier B - Input sensitivity 500mV for full output of 100 watts into an 8 ohm load.

I you feed both these machines with a 200mV signal, amp A will probably produce about 40watts, amp B will probably produce about the same. look at the relationship between input sensitivity and output power in each case.

CD players do tend to have a higher output than most other sources. There is no advantage in trying to increase the output of other devices. They are what they are and largely you have to live wit this.

Headroom. You run a hi-fi amp at a relatively low average power level. I have a rule of thumb that says 'If you need to run an amp at above 50% volume setting it's not big enough'.
If you are running a music signal at a reasonable power level and a loud transient occurs in the music (a load bass drum or similar), although the average power level is hardly affected, the amplifier will be required to draw a large current for a very short period to enable the output voltage to correctly follow that transient. That ability to draw extra current for a very short period without clipping is called 'headroom' and it's also where your 10:1 power to volume ratio applies.

I hope this helps to at least start to answer you questions. This is just skimming the surface as I have tried not to be too technical for you.

Great explanation ! I run my 80 wpc receiver on average 1-10 watts witch is usaully between 8-9 nine o’clock on the volume min is 7 max is around 1 o’clock for most sources but that’s crazy loud speakers are very efficient with a 60 watt max input 92 dB efficient when I ran a 45 wpc kenwood had similar volume but the bass was not as strong and at higher volumes didn’t have as much detail

 

[Chris Brown]

The two more powerful units (sx780 and sx750) did sound louder than the 25/30w units, and so with some excitement, I sold my old Saab (wasn't getting used) and increased my budget to some upper-mid level machines, notably a Marantz 2285 and a Luxman R-1120. With 85w and 120w respectively, I assumed these were going to offer intoxicating, near limitless reserves of power.
I was wrong.

why the huge premiums paid for high power machines if the difference is volume is really quite modest? I realise some of the bigger receivers have better tuners and more speaker outputs, but it seems equally true, especially for, say, Marantz, that the lower power machines sounds just as, if not, sweeter than their bigger brothers

Thanks in advance for anyone with the patience to read this far and consider any of these rather ill-informed queries. It would help me allay current suspicion that, for the great majority of speakers, especially if only one pair is connected, having anything over 50 watts is probably overkill

Part of the issue here is that receivers have never really been high-end. They have always been a compromise, packing multiple components into a single package. The high-end has always been about separates. A dedicated pre-amp that handles volume control, source switching, phono preamp, etc. A separate tuner if needed. An amp (or several) that does absolutely nothing other than act as an amp. 85-120w is pretty modest in any situation where you actually need significant amp power.

There were only a few receivers that had amp sections that were comparable to a good dedicated separates amp. Receivers such as the SX-1980 that was rated for 270wpc. They are super rare and almost never worth the price they go for these days. Many of them have not proven to be very reliable over the years. The #1 enemy of an amp is heat and packing an amp into a receiver with multiple other components is simply not ideal. Many people who go for these do it mainly for the nostalgia factor or because they are a hipster. It's not uncommon for people to buy them and rarely even use them, instead keeping them on the shelf like some kind of trophy to brag about.

When it comes to separates amps, it's not hard to find amps that offer power comparable to the biggest monster receivers, and often much cheaper. If your existing receiver has pre-amp outputs, then you can simply use it as a pre-amp. The modular nature of separates amps also gives you more flexibility when extreme amounts of power are required, so you can do things like bridge a pair of amps.

Take the Yamaha P2200/P2201 amps for example, released in 1976. They are good for over 240wpc into 8-ohms in stereo. When you bridge a pair, they are good for over 700wpc. That's some serious power that you aren't going to get with any receiver. They have been so reliable for me, even under heavy abuse, that I run 4 of them in my rack now. The Yamaha P3500 at the bottom of my rack is good for 500w into 4-ohms and powers my two passive sealed 15" subwoofers. The sealed subs are so inefficient that they are like a black-hole when it comes to amp power and they can use all 500w pretty easily.

So you are right that there is not a huge difference between the power output of a Pioneer SX-780 compared to a Marantz 2285. The people with a true need for large amounts of power output are/were not buying receivers, even back in the 70's.

 

[ernieb1536]

Part of the issue here is that receivers have never really been high-end. They have always been a compromise, packing multiple components into a single package. The high-end has always been about separates. A dedicated pre-amp that handles volume control, source switching, phono preamp, etc. A separate tuner if needed. An amp (or several) that does absolutely nothing other than act as an amp. 85-120w is pretty modest in any situation where you actually need significant amp power.

There were only a few receivers that had amp sections that were comparable to a good dedicated separates amp. Receivers such as the SX-1980 that was rated for 270wpc. They are super rare and almost never worth the price they go for these days. Many of them have not proven to be very reliable over the years. The #1 enemy of an amp is heat and packing an amp into a receiver with multiple other components is simply not ideal. Many people who go for these do it mainly for the nostalgia factor or because they are a hipster. It's not uncommon for people to buy them and rarely even use them, instead keeping them on the shelf like some kind of trophy to brag about.

When it comes to separates amps, it's not hard to find amps that offer power comparable to the biggest monster receivers, and often much cheaper. If your existing receiver has pre-amp outputs, then you can simply use it as a pre-amp. The modular nature of separates amps also gives you more flexibility when extreme amounts of power are required, so you can do things like bridge a pair of amps.

Take the Yamaha P2200/P2201 amps for example, released in 1976. They are good for over 240wpc into 8-ohms in stereo. When you bridge a pair, they are good for over 700wpc. That's some serious power that you aren't going to get with any receiver. They have been so reliable for me, even under heavy abuse, that I run 4 of them in my rack now. The Yamaha P3500 at the bottom of my rack is good for 500w into 4-ohms and powers my two passive sealed 15" subwoofers. The sealed subs are so inefficient that they are like a black-hole when it comes to amp power and they can use all 500w pretty easily.

So you are right that there is not a huge difference between the power output of a Pioneer SX-780 compared to a Marantz 2285. The people with a true need for large amounts of power output are/were not buying receivers, even back in the 70's.

It’s all relevant to what you need volume wise room size and speakers you are driving ! Have s 140wpc carver nice strong receiver still prefer the sta2080 80 wpc it can also drive my Mach 2 and klh to very loud levels !

 

[Chris Brown]

It’s all relevant to what you need volume wise room size and speakers you are driving ! Have s 140wpc carver nice strong receiver still prefer the sta2080 80 wpc it can also drive my Mach 2 and klh to very loud levels !

Yeah it's always important to understand how much power you need, and if your current gear gives you that despite modest ratings then that's fantastic. My power requirements are higher because I listen to a lot of bass-heavy music at very loud volumes, which is pretty close to a worst-case scenario in terms of power required. Everyone has a different idea of what "loud" means. When I measure using dBC I can exceed the 130dB limit of my SPL meter and I have to straighten the furniture upstairs afterward.

 

[BamaBilly]

One simple difference is some speakers want WAY more than 85wpc. Sure 85 will drive them but will never make the most of them. There is a long list of such speakers.

 

[ernieb1536]

Yeah it's always important to understand how much power you need, and if your current gear gives you that despite modest ratings then that's fantastic. My power requirements are higher because I listen to a lot of bass-heavy music at very loud volumes, which is pretty close to a worst-case scenario in terms of power required. Everyone has a different idea of what "loud" means. When I measure using dBC I can exceed the 130dB limit of my SPL meter and I have to straighten the furniture upstairs afterward.

Had I had that much power at a younger age I’d be hard of hearing by know ! Lol

 

[Mearle]

Part of the issue here is that receivers have never really been high-end. They have always been a compromise, packing multiple components into a single package. The high-end has always been about separates. A dedicated pre-amp that handles volume control, source switching, phono preamp, etc. A separate tuner if needed. An amp (or several) that does absolutely nothing other than act as an amp. 85-120w is pretty modest in any situation where you actually need significant amp power.

There were only a few receivers that had amp sections that were comparable to a good dedicated separates amp. Receivers such as the SX-1980 that was rated for 270wpc. They are super rare and almost never worth the price they go for these days. Many of them have not proven to be very reliable over the years. The #1 enemy of an amp is heat and packing an amp into a receiver with multiple other components is simply not ideal. Many people who go for these do it mainly for the nostalgia factor or because they are a hipster. It's not uncommon for people to buy them and rarely even use them, instead keeping them on the shelf like some kind of trophy to brag about.

When it comes to separates amps, it's not hard to find amps that offer power comparable to the biggest monster receivers, and often much cheaper. If your existing receiver has pre-amp outputs, then you can simply use it as a pre-amp. The modular nature of separates amps also gives you more flexibility when extreme amounts of power are required, so you can do things like bridge a pair of amps.

Take the Yamaha P2200/P2201 amps for example, released in 1976. They are good for over 240wpc into 8-ohms in stereo. When you bridge a pair, they are good for over 700wpc. That's some serious power that you aren't going to get with any receiver. They have been so reliable for me, even under heavy abuse, that I run 4 of them in my rack now. The Yamaha P3500 at the bottom of my rack is good for 500w into 4-ohms and powers my two passive sealed 15" subwoofers. The sealed subs are so inefficient that they are like a black-hole when it comes to amp power and they can use all 500w pretty easily.

So you are right that there is not a huge difference between the power output of a Pioneer SX-780 compared to a Marantz 2285. The people with a true need for large amounts of power output are/were not buying receivers, even back in the 70's.

That was exactly the indirect point I was trying to make, I use A Sony STR receiver for pre-amp and selector modes only, I DO, take the centre and rear signals off it only if I need it for that, I run the PRE-out through a headphone amp with 4 stereo output level controls so I can send the individually calibrated signals to 4 CDi 1000's, the bench testing on these CDis' has suprised me by putting out DOUBLE the advertised peak of approx 475W per side into 8 ohms, I am running each crown to a separate set of speakers, some in 4 ohms since the Crowns have no issue with 2 ohm loads...

I have found that Receivers, really dont have the umph to deliver much for substantial SPL, you can of course listen at nice safe clean low levels or turn them up after a few drinks and possibly smoke your prized vintage speakers. To me Amp headroom is like Horse power, just because I have it doesnt mean I use it, until I want to....

Anyway your overall point is jamming a phono preamp, tone section, tuner and power amp into a receiver doesnt leave much real-estate to produce the "real" power needed for my application. They are pretty though, I use an old 2385 Marantz that I picked up in the 80's still working fine @ 135 WPC 8 ohms, I use it only for the satellite speakers around the house that outputs to a 10 channel speaker selector box for distribution. I use a Sony STR series 5.1 for the Side rear if I ever use them, but its main function is the selector aspect for signal sources because it has a remote, phono, CD, Spotify wireless....

 

[justjed2]

About twenty years ago, I decided that, for my listening habits, and gear, 125wpc would probably be enough. It's been plenty, and I haven't blown any tweeters yet.

 

[Mearle]

O.K. Let's try this step by step.
Point No1. - (and probably the most important) - Remember that high fidelity sound reproduction is more about quality then quantity - you are not running a PA system in your living room. Refer back to the old adage - the most important watt is the first one.

You power ration of 10:1 is probably about right. How loud a system goes is as much about the efficiency of the loudspeakers as the maximum output power of an amplifier. Input sensitivity will also play a major part in this as will amplifier gain factor You will see an output power rating in watts and an input sensitivity in millivolts (mV). Low efficiency loudspeakers require far more input power to produce the same audible sound level as a high efficiency loudspeaker. Again you 10:1 ratio applies.
example:
Amplifier A - Input sensitivity 250mV for full output of 50watts.into an 8 ohm load.
Amplifier B - Input sensitivity 500mV for full output of 100 watts into an 8 ohm load.

I you feed both these machines with a 200mV signal, amp A will probably produce about 40watts, amp B will probably produce about the same. look at the relationship between input sensitivity and output power in each case.

CD players do tend to have a higher output than most other sources. There is no advantage in trying to increase the output of other devices. They are what they are and largely you have to live wit this.

Headroom. You run a hi-fi amp at a relatively low average power level. I have a rule of thumb that says 'If you need to run an amp at above 50% volume setting it's not big enough'.
If you are running a music signal at a reasonable power level and a loud transient occurs in the music (a load bass drum or similar), although the average power level is hardly affected, the amplifier will be required to draw a large current for a very short period to enable the output voltage to correctly follow that transient. That ability to draw extra current for a very short period without clipping is called 'headroom' and it's also where your 10:1 power to volume ratio applies.

I hope this helps to at least start to answer you questions. This is just skimming the surface as I have tried not to be too technical for you.

Well it wasn't me who asked the question, I think I am pretty clear in my mind on the overall subject.

I was also trying to make as simple explanation to the original question. and yes of course there are other subtleties such as speaker efficiency and amp to speaker capacity matching, to me using high efficiency speaker is only a way of getting SPL when the Wattage headroom is not there, and the highly efficient speakers likely dont have the high power capacity, that would handle real power. For instance, I have some outdoor, mid-high horn drivers their capacity is only 35 W continuous, but 350 W peak, that takes clean power

To me in the late 80's they started "cheating" by using smaller, what I always called "fake" integrated power stages in receivers (Power amp on a large 12 pin Chip) and putting out high efficiency speakers, the marketing likely worked because they must have sold millions to people who bought low power receivers with highly efficient speakers thinking they had a killer system. I know because I repaired so many blown power stages on these mid range receivers.

As far as input sensitivity and I/P amplitude, I myself individually control the signal from a 4 channel headphone amp to not only match the individual power amp but also to the speaker set that the amp is driving to create a good balance between the Amp/speaker sets as a whole. I always keep the the I/p signal as high as possible to maintain the S/N I/P ratio, Final tuning of the amp interaction is controlled by the Pwr Amp output level.... Bottom line is every 3db SPL increase requires a doubling of power, to me that was the simplest way to explain it.

 

[Snow]

Ok here is my take on it. Yes you need much more power to get double the volume going from 50 watts to 100 is not going to do much for you in the way of volume increase. For myself at least having an amp that produces 200 WPC or more as a rule makes the music sound better even at lower volumes and will replicate the music better then a lesser amp I can remember playing a track I have listened to many times before with all kinds of gear and I noticed this time with a new to me amp it was 300 WPC but doubled at 4 ohms and two ohms and one ohm a certain portion of the track had thunder in the background that lasted for a few seconds typically then stopped continued on for at least 5 seconds with this amp and was much more well defined. I also noticed in another song I heard this odd sound I had not heard before and it took me a couple of times listening to it to realize it was gourds being shook, it had always been on the song but I had not noticed it so I unhooked this amp and hooked up a different one and listened and yes the thunder was not nearly as defined and rolled off quickly and I simply could not heard the gourds at all, so all this time I had not been hearing the songs the way they were designed to be heard. This was at lower volumes.

Yes you can buy a preamp that will increase the DB level by up to 20 times more then what it typically is even with a low powered amp I had a SAE preamp once that had that feature but it did not help with hearing the music as it was designed like the 300 WPC amp did it only made it louder. I believe this 300 WPC amp had enough reserve and head room to make the thunder last much longer even at a lower volume due to it's head room where as the lower powered amps gave up trying to produce the deep bass much sooner and was unable to reproduce the sound of the gourds.

The amp was a Sunfire 300 X 2 amp in case you wanted to know. Most damage caused to speakers come from distortion the more WPC your amp can produce lessens the odds of the music being distorted. I have owned some of the most powerful receivers ever made such as the Pioneer SX-1980 and it was not able to even come close to the sound the Sunfire 300 X 2 did either quality or volume. My suggestion is sell some of your receivers invest in a high quality high powered amp and preamp and Tuner if you listen to local radio much and you will be much happier because you can spend many thousands on receivers and never get the same results.


Regards Snow

 

[Audiofreak71]

About twenty years ago, I decided that, for my listening habits, and gear, 125wpc would probably be enough. It's been plenty, and I haven't blown any tweeters yet.

Tweeters are usually blown more often when underpowered and then trying to crank it.


Audiofreak71

 

[reggaenaut]

OP: Welcome to AK!

There are existing threads on this topic. I suggest that you google something like:

“amp power needed site:audiokarma.org”​

Some of my thoughts about amplifier power requirements are posted here: One watt...

FWIW, about 10 years ago I collected many of the TOTL 1970s monster receivers (e.g., Pioneer SX-1980, Marantz 2325, Kenwood KR-9050, Pioneer SX-1010, Marantz 2285B, etc.) – and then I sold them all.

For the classical music that I love, the most natural sound is delivered via modern (i.e., recorded in the last dozen years or so) hi-res multi-channel classical recordings (e.g., Blu-ray and SACD) and vintage tube amps driving large Klipsch speakers. Because of the sensitivity of high-end Klipsch speakers, 30wpc of tube power can deliver plenty of dynamic range. The combination of modern multi-channel Blu-ray recordings (DTS-HD MA 5.1), vintage tube amps (I prefer 6L6GC), and high-end Klipsch speakers does an excellent job of creating the illusion of being in the symphony hall or opera house. (I attend more than 2 dozen world-class classical concerts in world-class venues (no use of sound reinforcement system) each season, so I know how natural music sounds.)

Based on the genre(s) of music you listen to, your listening room, your preferences, and your budget and other constraints - YMMV.

Interesting 6L6GC observation.

 

[Chris Brown]

Tweeters are usually blown more often when underpowered and then trying to crank it.

Reminds me of my younger years, trying to power two pairs of Cerwin-Vega D-9's with a single Pioneer SX-1050. The Pioneer was no slouch, but these speakers had a nasty impedance curve that dipped down to 3-ohms and I was running two pairs. The face-plate light on the SX-1050 would dim every time a bass note hit. We were constantly resetting the circuit breaker on the tweeters (thank god they had a circuit breaker) until finally the 2.5A slow-blow fuse in the speakers started to blow. I emailed Cerwin-Vega and they told me to replace it with a 3A fuse. In retrospect, it's pretty amazing that nothing got destroyed. I learned that it's better to have more power than you need instead of potentially hitting the limits.

 

[HPMguy]

Lol, I've never felt the need for more than 50 watts per channel. Have more on a couple amps, but with the volume at anything over 10% on my KA-900 the rim strikes on my favorite Dire Straits album hurt my ears, and I have to turn it down.

I have HPM-900 speakers on that system, something like 92dB sensitivity, and that's well above the point were I will put in ear plugs. Not wearing ear plugs to protect my hearing while I'm listening to classical music at home, I have to wear them enough mowing grass (the lawn mower runs 90+dB). That means on amps with meters they don't move much, peaks are in the range of 1-5W, very rarely more. On my KR-930 with meters by the time the power meter is reading around 1 watt I have my fingers in my ears on the way to the volume knob, WAY too loud for comfort.

Once I get one of my 100w/channel amps up and going I'll see if they "sound better" with those speakers, but I'm willing to bet I won't hear any difference at all at the levels I normally listen. Will see what my buddies think when I have a "listening party" this summer and fall.

It's not what it used to be, but my hearing is still pretty good for 66, and I want to keep what I have left. Back in the day 35 years ago I could hear the extra loud phone ringing inside the house while mowing grass outside -- my housemate was going deaf. Used to driver her nuts, I'd shut off the mower and tell her to answer the phone, and when she went inside it was ringing. Probably can't do that now, but I don't want to lose any more.

I can still hear 14kHz on a good day, and I can hear 15Hz on my HPM-500's at about half the volume as 20Hz. I'd notice if the bass were lacking in any way for sure -- I can hear all sorts of odd things on bad recodings, like the AC blowing on the microphone or the hammers bottoming out on a harpsichord when the microphone is too close.