It seems I only use 1W of amp power.. Can it be right?

[dakku]

It sounds like many of us have done a similar test and reached similar conclusions 🙂

I suppose next question is, would a ~35W amp provide enough headroom for low-moderate volume levels?

 

[catalin]

Hello .I have a 92 db SPL speakers from Focal and listen to them in a room about 26 square meters .In day to day listening I use maximum 1 watt rms power .The peak power gets to 5-10 watts depending on what I listen .But this is listening for ambiance .
I use a 2*20 W amp solid state amp (supplied at +/-20Volts) .
But at each 2 weeks I listen a little louder (classical music which is more dynamic) and rarely I get the amp to clip.I think that the minimum power should be at least 50 watts in my case.When I had Dynaudio Contour speaker with SPL about 86 db the same amplifier was a joke for the speakers .
So if for 92 db SPL a 50 watts would be enough then for each -3db the power of the amp need to be double.Example : 89db ,amp with 100W .86db with 200W amp ..etc

 

[KatieandDad]

50W is fine for general listening as has been proven by many many designs that use this sort of power level.

If you push it to moderate volume then I've found you need about 100W.

Subwoofers need more if you need them but about 100-150W for general listening is adequate.

 

[AndrewT]

...... 92 db SPL speakers ........ room about 26 square meters........ I use maximum 1 watt rms power .The peak power gets to 5-10 watts depending on what I listen .............I think that the minimum power should be at least 50 watts in my case..........
So if for 92 db SPL a 50 watts would be enough .............

If you listen @ 8feet or 2.4m then your combination of 50W+50W into 92dB/W @ 1m speakers will give a maximum of around 104dB at yoiur listening position.

If you listen at an average level of -20dB then you are listening at 84dB. That is a lot louder than two folk talking to each other.
That 84dB would require average inputs to your speakers of ~1/2W.

The typical listening data you give seems to indicate that you listen at 70 to 85dB and that leaves 20 to 30dB to replay dynamic peaks and to turn it up a bit when you want to listen at averages approaching 90dB (Very Loud).

 

[chris661]

Oh yea, if a sub needs 1000W, it is a very poorly designed sub.

Its just an choice as part of Hoffman's Law. I wanted small and low, and got precisely that. The design does everything I want of it, so why is the design "poor"?

 

[catalin]

Yes Andrew ,correct ,only sometimes I need more dB(almost 90 ?) in my listener position .So the power of the amplifier in listening session may vary with various items :
- Room volume and dimensions
- Speakers SPL
- Speakers distorsions
- Room treatment & reflections & absorption
- Material (which type of music ),until now the classical music seems to have the highest dynamics .
- Mood of the listener 😀
May be there are others ...

Calculations can be done here http://www.hometheatrebasics.com/home-theatre-tools/spl-calculator/
http://www.chuckhawks.com/speaker_spl_amp_power.htm

I think that the correct amp should be capable to create 90 db in peaks without distortions at the listener place .In this case I would need 100W amp ?

 

[Richard Ellis]

Try thinking about the scenario of the "Garage band" some of us have experienced.
The three piece Garage Band who strikes up their practice session on a Saturday afternoon.........the Garage door is open & the sound "fills the neighborhood" for blocks in all directions.
Upon inquiring about the equipment, you find the lead guitar has a 30 Watt "head", the bass guitar has a 50 Watt head, & the vocals are on a 20 Watt amp.
A hundred Watts are lighting up the neighborhood....The key is those Guitar drivers are rated at 102-107 Db per Watt.........do the math! Likely they are not maxing those amps out neither.
Truly Hi-fi loudspeakers exist with ratings of 102 to 106Db.....with this much efficiency, amp power becomes less & less of an issue.
The "holy grail" is an "accurate", Hi-fi loudspeaker with a 105 to 110Db rating.........with this kind of performance, amplification to "un-comfortable" levels is a matter of milliwatts.




_____________________________________________________Rick.......

 

[Vostro]

For me the room acoustics play a much bigger role than I thought before.
I'm one of those people that love to really turn my music up loud on occasion, maybe to loud.,cause sometimes I'm listening from another room, but that's just me.
I was using a 50w per channel av receiver with my stand mount Boston Acoustics A26, 87db/w/my.
I could hear it distort.
I replaced it with a diy amp running from +/-63Vdc rails, so let's call it 150W, and it's more than adequate, I do notice a difference. I did add a active sub to the mix also.

But if another person just loves there 1W Amplifier and it's just great for them, that OK too.

Edit: I do admit that under the normal situation, and not those crazy listening sessions, I use the amp at verrry little power.

 

[Cal Weldon]

are the extra WATTS a bit of "just incase" and a waste of money?

I would have worded it: are the extra WATTS a bit of "just incase" or a waste of money?
The answer is yes to the first and no to the second. In most cases I, like the rest here, use 1 watt or fewer. At other times, the power is simply needed due to the nature of the event. That's why I like to have the different systems, some small and some big. Just like autos. I don't take my city car into the bush and I don't drive my truck on the highway.

 

[Peter Pan]

There are a lot of considerations when it comes to power, and you're right that a lot of measurements can be confusing. To make it more head spinning, the type of signal has a huge affect on perceived volume. Take for example a typically highly compressed music source from on over the air source, of some busy pop music. Everything in that signal and its mix has been carefully engineered to sound maximally loud at a given power level. Were you to listen to a pure sine wave of say, 400hz, at that same power level, it might seem dismally low in volume by comparison. Part of that is because a RMS power level (the simplest way to accurately measure the single 400Hz tone case) is very different to the human ear to the "music power" rating, which is a better measure (though still an approximation) of that complex over-engineered pop music signal. Indeed, one watt of many sound sources through a decent speaker system can seem plenty loud!

On the other hand, and I'm not recommending you do this, directly plugging in a highly dynamic live instrument like a guitar or bass guitar through your stereo can quickly reveal how much more raw power it would take to get what seems like the same volume level, at which point it could quickly begin distorting or worse, blowing out your speakers. Thats the power of compression, EQ, and all the effects that go into mixing some music.

So all this to say, in addition to your normal listening level (home with one or two people, as opposed to having a dance party at your house) AND the kind of music you intend to listen too will ultimately prove whether a little power will go a long way, or whether you really need to consider more power. If you listen, for example, to raw recordings of live unprocessed instruments such as Jazz ensembles (complete with well miked drums and stand up bass), and you want to be able to crank it up, you may need to consider better speakers and or power. On the other hand, if you usually listen to processed pop or rock music, you may be able to rest, knowing the sound engineers have already multiplied your available apparent volume to the point where, as you inferred, one watt is generating some pretty good levels! 🙂

 

[dewardh]

Well . . . your speakers give you 91dB SPL at one Watt . . . that’s pretty loud as is, even for “peaks”, and your “average” listening level will typically be significantly less than that. Above that:
2 Watt 94dB
4 Watt 97dB
8 Watt 100dB
16 Watt 103dB
32 Watt 106dB
above that further then speaker breakup and distortion, and unpleasantly loud.
For less sensitive speakers you’d adjust power up accordingly . . . so for example speakers with 85dB sensitivity might call for a 120 Watt amp. The notion that there’s a need for “headroom” above that is audiophile myth given the compression/limiting built in to all recordings, and the negative “benefit” in driving your speakers into overload.

 

[Mooly]

I don't think anyone mentioned this as yet,
http://www.diyaudio.com/forums/mult...much-voltage-power-do-your-speakers-need.html

 

[AndrewT]

............I think that the correct amp should be capable to create 90 db in peaks without distortions at the listener place .In this case I would need 100W amp ?

you already have 104dB maximum with 50W.
100W would increase that by another 3dB to 107dB.

The peaks are yet another 3dB above the 104dB quoted for the maximum power.
All the above ignores power compression in your speakers.


I don't see where you are getting your 90dB from.

 

[kouiky]

Most of my listening is at .003W, which translates to about 64dB at my seated position. Sometimes I do go a little louder than talking, but if I am on my own, I never use even 1W. Right around 80dB is where I find pain begins to set in, and anything louder is far too much for me and detracts from the experience.

 

[AndrewT]

................... then you are listening at 84dB. That is a lot louder than two folk talking to each other.
That 84dB would require average inputs to your speakers of ~1/2W.

..................at averages approaching 90dB (Very Loud).

Most of my listening is at .003W, which translates to about 64dB at my seated position. Sometimes I do go a little louder than talking, but if I am on my own, I never use even 1W. Right around 80dB is where I find pain begins to set in, and anything louder is far too much for me and detracts from the experience.

I agree. That is what I said first time around.

84dB from 1/2W average is already loud. (this leaves 20dB for transients)
90dB from 2W is very loud. (this leaves 14dB for transients)

 

[vdi_nenna]

Everyone talks about headroom...😉

 

[wg_ski]

Those levels simply cannot be sustained, and expect any dynamics out of the music. With a 100 watt amp running with the clip lights just barely flashing, you are NOT putting out 100 watts. Ears respond to the average SPL, and for music (not junk associated with the loudness wars) the average level is about 15dB down from the peak. Listen at two meters instead of one and now your 100 watt amp can barely do 90dB cleanly. You may think that it's hitting 110dB because you see the clip lights, but put an SPL meter to it and you'll see closer to 90.

A 1 watt amp is plenty if you really do listen at 50 milliwatt levels - and for a lot of people, 70 dB is loud enough.

So why are the required peak levels so high? A 100 watt amp can put out 28V before clipping. That will play 2 25 watt tones simulataneously (14V each, but the peaks will periodically align). Down to 50 watts from 100 just like that. If each tone consists of a fundamental and dominant harmonic, that doubles the voltage requirement again. Now you're down to 25 watts average power with no dynamics at all. If you just had initial transients 6dB above the sustained notes (typical boooomm, boooomm, boooomm and a rapper clipping his mic pre), you'd be at 6 watts average power with a 100 watt amplifier clipping. Compressed music will approach levels like that, but uncompressed requires even more headroom.

And a 100 watt amplifier might do 1 to 2dB higher for peaks in the waveform, but it isn't going to do anywhere near 10 more dB.

 

[tvrgeek]

Its just an choice as part of Hoffman's Law. I wanted small and low, and got precisely that. The design does everything I want of it, so why is the design "poor"?

Distortion. As Klipsch papers show, distortion and efficiency are inversely proportional. On top of that, the distance the VC has to move to push that much air will be way out of the linear range. You may get a low note, but it won't be alone. A classic example of how bad a sub can be was the Sunfire.

 

[tvrgeek]

Everyone talks about headroom...😉

Yes we do; because when an amplifier clips, it makes very pleasant sounds. The best case is so much overkill (headroom) you never clip.

So, you want headroom. There is more than one way to get it. If it is really transient, as listening at reasonable levels suggests it will be, then you can scrimp on the transformer and heat sink, but you still need big caps, sufficient output pairs and a high enough voltage. The next step up is the transformer than could sustain that level of power. Many companies did funny power supplies or outputs to do this. NAD boosted rails, Class G amps and so on. My personal choice is for the bigger amp with no fancy do-dads.

 

[catalin]

you already have 104dB maximum with 50W.
100W would increase that by another 3dB to 107dB.

The peaks are yet another 3dB above the 104dB quoted for the maximum power.
All the above ignores power compression in your speakers.


I don't see where you are getting your 90dB from.

If we take in consideration the details we can get those 90db(at peak) :
Listener distance 3.7 Meter (my real case)
RMS program power 2 watts
Speaker sensivity/SPL 92 db
Amplifier headroom(HR) 15 db
Type(mono/stereo) 3 db
Placement,Reflexions 3 db

Maximum level at listener(db) Average: 74.64626548 Peaks: 89.64626548

I created a excel calculation to help us .Rename file.txt to file.xlsx