orchardaudio
Regular
How do you like them apples?
Posts: 146
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Post by orchardaudio on Feb 5, 2020 21:36:46 GMT
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Post by macca on Feb 6, 2020 8:31:36 GMT
I was pondering this the other day. I already know from measuring previously my usual listening level is around 75dB constant (obviously peaks go higher). Speakers are 90dB (so 93dB for the pair. I sit about 20 foot from the speakers and have always worked on a fifty watt minimum i.e the amp will clip on peaks if it has less power than that. But I have a couple of amps with level meters and they show I am barely using 1 watt most of the time. Even on peaks the first stage indicator lights on the KSA50s rarely light up. And they go on if power output exceeds 750 milliwatts.
But I rarely use my 4 watt valve amp because it runs out of steam...
So I don't know anymore.
You didn't include room gain btw, isn't that worth about another 6dB?
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Post by dsjr on Feb 6, 2020 8:43:15 GMT
When I had that 50S, the mid level lights came on at little more than a whisper level for me and when it was used in the workroom into 87db? IMF Compacts, the high level (cooking temperature) lights came on and often stayed on. I can't play at ATC-deafening levels now either and the Spendors I was using them would bottom out if I pushed it. I suppose an estimated 85db mean level for me.
The nominal impedance of your speakers will also indicate when the bias on the Krell ramps up. With 4 Ohm speakers, you need more power than with an 8 ohm load to switch up the plateau bias lkevels and it's much higher power into a 2 ohm load. May be explained better in the Stereophile measurements...
Please remember, that double the power is only 3db increase in level and you can easily mop it up in a good music session with the neighbours out. I haven't read the article yet as I have to go out, but also, increasing listening distance requires ever more power as well, so if you're blessed with a fair size listening room, don't be surprised if you'd ideally need 200WPC these days... |
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orchardaudio
Regular
How do you like them apples?
Posts: 146
|
Post by orchardaudio on Feb 6, 2020 12:01:03 GMT
I was pondering this the other day. I already know from measuring previously my usual listening level is around 75dB constant (obviously peaks go higher). Speakers are 90dB (so 93dB for the pair. I sit about 20 foot from the speakers and have always worked on a fifty watt minimum i.e the amp will clip on peaks if it has less power than that. But I have a couple of amps with level meters and they show I am barely using 1 watt most of the time. Even on peaks the first stage indicator lights on the KSA50s rarely light up. And they go on if power output exceeds 750 milliwatts. But I rarely use my 4 watt valve amp because it runs out of steam... So I don't know anymore. You didn't include room gain btw, isn't that worth about another 6dB? Yes there will also be room gain due to reflections, but it is very difficult to tell exactly what that number is. It also heavily depends on the type of speaker, ported ones will behave differently. With efficient speaker 20 feet away is pretty far, so I see how 4W is enough |
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Post by macca on Feb 6, 2020 12:18:03 GMT
The nominal impedance of your speakers will also indicate when the bias on the Krell ramps up. With 4 Ohm speakers, you need more power than with an 8 ohm load to switch up the plateau bias lkevels and it's much higher power into a 2 ohm load. May be explained better in the Stereophile measurements...
Please remember, that double the power is only 3db increase in level and you can easily mop it up in a good music session with the neighbours out. I haven't read the article yet as I have to go out, but also, increasing listening distance requires ever more power as well, so if you're blessed with a fair size listening room, don't be surprised if you'd ideally need 200WPC these days... The speakers are 4 ohm dropping down to just over 2 ohm in the bass. And the room is 29'x12' so not small. The Black Tulip amp currently in the system rarely puts out more than 1 watt according to its VU meters... |
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Deleted
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Post by Deleted on Feb 6, 2020 14:51:59 GMT
Realistically unless you live in a barn or have a listening room 30 by 25 then a quality 100Wrms of solid state or 30-40Watts of valve power unless using ultra efficient speakers.
Although if like a lot of so called audiophiles who feel that unless .75Kw is showing on the badge then it must be quite ordinary
The key to look for is transient current response not how many megawatts you can generate
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Post by dsjr on Feb 6, 2020 17:58:21 GMT
Valve power over solid state power doesn't exist you know, but masses of low bass distortion and compression due to soft clipping does and of course when most solid state amps are overdriven, it's nasty usually. According to BBC research done ages ago, 'we' can tolerate up to 10db of compression before we really notice it. Rock music producers have I'm sure, been aware of this for ages. So 'your' 40W valve jobbie if compromised right, will 'appear' to be like a 150W ss amp, even if the highest volumes will be full of 'nice' distortion. A solid state equivalent is the Naim Nait mk1, offering 20WPC with the wind very heavily behind it and sounding louder than it really was as it soft clipped its way through all adversity  |
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Deleted
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Post by Deleted on Feb 7, 2020 12:54:19 GMT
Hello Dave
I would like to respectfully disagree, however I will stipulate we are talking about correctly design amplifier variants, not overly warm fruity valve amps or hard as nails solid state that can strip the inner wax from your tympanic membrane.
So if we eliminate the the less desirable brands such as naim, quad, chord etc and instead concentrate on correctly designed amplifiers that utilize topology in more thought out carefully considered fashion.
You can easily have a a low powered valve amp say 8 watts of single ended using either el34 or 2A3 valves easily match a solid state at say 55-80Wrms If you carefully select your speakers with a appropriate impedance say 6 to 8 ohms nominal with a partnering sensitivity of around 95dB+
In a similar vein when using quality solid state of say 80Wrms you could look at speakers with a range of 4 ohm nominal and a sensitivity between 87-90dB the results will be similar in volume and both have respectable tight and lucid bass without overhang or conversely the upper frequencies will not be gently rolled off or harsh in any way.
Now the listener may have a preference for one sound or the other I grant you, but you need to appreciate the context of the statement.
My own amplifier has an output of 55Wrms, for my room size, 22' by 14' it generates plenty of output easily reaching 92dB with out fatigue (when the wife is touring!) do I wish for anything more in power? If I changed rooms and sizes then possibly yes.
On the flip side my brother has some those freaky looking D'agostino amplifiers which go louder than most PA systems in small venues I have listened to in the last few years he has a large house so he feels they are right for him.
I would say it boils down to amplifier speaker impudence matching with of coarse includes the speaker cable as this is part of the measured circuit.
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