YouTube, any of them, is a really flawed way to try to show how things sound. What you get is so contaminated by a lot of other stuff, you have no real idea what you are listening to, and some of th emost important parts ar elost due to the process.
dave
Almost all amplifiers will clip at some point. Given power needed grows exponentially, how an amplifier clips, how it recovers, is probably more important than the specified power.
Also notable is that amplifers are rated into resistors, but we use them with loudspeakers which typically do not look anything like a resistor. This leads to cases where small amplifiers can play louder than much larger amplifiers before audibke clipping. In the specific test that started me out a 20w amp vrs 200w amp. May seem a big difference in power, but it is 10dB, seemingly 2x as loud.
And then there is the point at which the specifier decides to say the power has maxed out. A good example is the Pass XA25, rated at 25w into 8Ω, Stereopile measures on the order of 50/100/200 8/4/2Ω
dave
Most loudspeakers, but not all. And more here diyed that do not have to have a voltage amplifier.
dave
Ah, I see where you're going with the crest factor -- if you're looking at RMS values, then the peaks could be anything. Which is why oscilloscopes are so handy, albeit unfashionable.
I was looking at another thread with a 200W amp using banks of paralleled MOSFETs, and thought gosh, at least 195 of those watts are only ever going to be needed for the turn-on thumps, and occasional gunshots and explosions on movie nights, which are not so loud these days after putting the kids to sleep. Or worse: when the kids start turning the volume to 11 for fun. I'd rather spend 95% of the effort on 1W, and maybe give it another 1 to 9W overhead. The "cost" of heat sinks, idle power, and having to use grunty IRF240's instead of say, IRL510's skyrockets with every 6dB. If I have time, I might build an amp with a soft saturator to compress the occasional booms into just a few extra volts.
Abstract,
I said oscilloscope alone is not sufficient/enough.
I disagree peaks can be anywhere, my files have been analysed and i know rms value as well as peak beforehand, volume is used to compensate the intrinsic loudness of tracks: high dynamic range (typically classical) are close to zero db attenuation on level control as they need the high crest factor to be in target rms spl at listening position, low dynamic range material ( pop, metal, edm) see as much attenuation needed for their rms level to match the target @ listening position (~75/77dbc) which can be eg: as high as -17db for metallica's 'death magnetics' first mastering.
So headroom vary with material played.
Have you read the links i posted in message #41. It all explain the how and why.
I have the kind of feature you talk about ( peak limiters) on my dsp and bypass it. The headroom ( 'non used over') is here for that reason.
It's a way to do it. Ymmv of course.
I said oscilloscope alone is not sufficient/enough.
I disagree peaks can be anywhere, my files have been analysed and i know rms value as well as peak beforehand, volume is used to compensate the intrinsic loudness of tracks: high dynamic range (typically classical) are close to zero db attenuation on level control as they need the high crest factor to be in target rms spl at listening position, low dynamic range material ( pop, metal, edm) see as much attenuation needed for their rms level to match the target @ listening position (~75/77dbc) which can be eg: as high as -17db for metallica's 'death magnetics' first mastering.
So headroom vary with material played.
Have you read the links i posted in message #41. It all explain the how and why.
I have the kind of feature you talk about ( peak limiters) on my dsp and bypass it. The headroom ( 'non used over') is here for that reason.
It's a way to do it. Ymmv of course.
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So there is a case for the 1 watt and 5 watt amplifier. So we are discussing what average SPL for the bass, and does it go through walls? That could be a problem.
So you are using a separate amplifier for each set of speakers? Any details? I always liked the idea of using sub with low powered speakers, but the sub would also be low powered or low cost, actually, doable. If you see these 2.1 computer speakers with a sub, they seem to have a separate amp for the subwoofer. A large surround system I took apart had this. Can you use a class D for the sub? Distortion?
Here the typical 2.1 kit is 3 x 2030 / 2050 / 1875 (all Chinese), and a 4558 to drive the woofer, it gets the signal from the other channels, filtered for frequency.
One chip for each channel, and the third is for woofer.
Conservatively, 10 to 12W per chip, enough for most people.
Sound quality is very much dependent on your speakers....
The kits start about $2.5 US, populated board with connections for volume, bass, treble, signal in (stereo) and speaker out.
Power is usually 18-0-18, or 12-0-12 / 3A, gives about 19V at the chips.
Heat sink is included.
All you need to do is wire it up. The boards with Keltron capacitors are more expensive than those with Chinese capacitors.
4.1, 5.1 and 7.1 boards with a similar design are also commonly sold.
One chip for each channel, and the third is for woofer.
Conservatively, 10 to 12W per chip, enough for most people.
Sound quality is very much dependent on your speakers....
The kits start about $2.5 US, populated board with connections for volume, bass, treble, signal in (stereo) and speaker out.
Power is usually 18-0-18, or 12-0-12 / 3A, gives about 19V at the chips.
Heat sink is included.
All you need to do is wire it up. The boards with Keltron capacitors are more expensive than those with Chinese capacitors.
4.1, 5.1 and 7.1 boards with a similar design are also commonly sold.
All above small wattage funs are very welcome to FirstWatt forum.
https://www.diyaudio.com/community/forums/pass-labs.8/
There are numerous small wattage amplifiers are yours to explore and build.
https://www.diyaudio.com/community/forums/pass-labs.8/
There are numerous small wattage amplifiers are yours to explore and build.
Truth be told, it reads a bit pseudo-sciencey. Like the averaging of the VU and SPL meters so that it 'looks' about right for speech. What about when the signal crosses over zero? So a 1kHz sine wave goes from peak to zero power and back again 2000 times a second, yet has zero dB dynamic range? An SPL meter won't show you this, but a scope with a linear scale will show you the whole thing on the same scale. That's the irony.Abstract,
I said oscilloscope alone is not sufficient/enough.
I disagree peaks can be anywhere, my files have been analysed and i know rms value as well as peak beforehand, volume is used to compensate the intrinsic loudness of tracks: high dynamic range (typically classical) are close to zero db attenuation on level control as they need the high crest factor to be in target rms spl at listening position, low dynamic range material ( pop, metal, edm) see as much attenuation needed for their rms level to match the target @ listening position (~75/77dbc) which can be eg: as high as -17db for metallica's 'death magnetics' first mastering.
So headroom vary with material played.
Have you read the links i posted in message #41. It all explain the how and why.
I have the kind of feature you talk about ( peak limiters) on my dsp and bypass it. The headroom ( 'non used over') is here for that reason.
It's a way to do it. Ymmv of course.
I'd say: We can measure way beyond the hearings ability (freq, level and time/phase) but we cant seem to interpret the measurement in terms of how they relate to our hearing at all times...
The net result may be the same but there is a distinction that may be interesting to observe...
//
Hi,
Pseudo sciencey is a bold statement.
I mean B.Katz is who he is ( is there people which get unanimous acceptation?), you can disagree with his pov but telling it's pseudo science is a wrong and unfair statement.
Even more from an article serving the purpose to democratize a technical practice to peoples (which are not ( all) as technically minded as he is*) and to solve a real issue most professional have to face daily, most listeners keeps on complaining about and which is a dead end for the whole industry ( and this even have a name: 'the loudness war').
If you allow me a comparison: would you consider saying same thing after the read of one of Nelson Pass' s diy oriented white paper or articles?
I mean, in the F5 manual there is a whole presentation comparing transistors to water faucets.... would you judge Nelson's technical knowledge (and technical probity) with only this as reference?
I would not. Even more since it's a so clear explanation through a bunch of sentences of something some teachers tryed to explain me without success for days...
If i had made the same statement as you did about Nelson in here i would expect to be sacrified on public place ( and it would be justified as it would be unfair for M.Pass...).
I hope you get my point on this.
Maybe google his name, takes a look at one of his youtube video,... get who the guy is and what are his motivations.
You can even try by yourself the solution he offer: there is a 'honor roll' section where you got 'reference' album with their intrinsic level and volume used for playback given. ( you even have the universal identifying codes of each albums not to have wrong settings because of different mastering...).
Just try it for sake of experimentation/curiosity and make your mind by yourself. It could even make you discover some nice music as it was for me ( salsa is not a genre i know a lot and there is some nice things in this style for example).
Your question makes me feel you did not get the idea behind what is presented and i think this is where irony is ( i keep on using the word 'headroom' because it is a technical term which refer to a concept you don't get imho). I won't repeat it, it doesn't make sense to me to be an echo chamber.
I've got nothing against oscilloscope, i've got one plugged in in my workshop and at one point into my studio too. I'ts a nice tool, it helps solve issues and investigate the electronic side of things in a signal path being it a circuit or whatever.
When i look at the whole signal path of a signal to my brain i can identify parts of the way which are not electronic. If i want to investigate this side of the signal path my oscilloscope would not be of any help.... for this i need other tools: spl meters, mic and software to analyze data collected.
From where i stand, when you say you only need an scope, it give me the feeling you don't take into account what happen once we are after the loudspeaker's driver.
In my view it's letting about 2/3 of the signal path to my brain outside of the equation ( 1/3 being loudspeaker design/technology related, the last 1/3 related to room acoustic).
It might satisfy you, it doesn't for me.
I'm not saying you are right or wrong in doing so, neither my approach is 'The right one'.
It's just where i see ( or think) i see where there is a difference in our approach to this.
*As an apart, let's say Mastering Engineers are often seen as Obsessive Compulsive Dissorder driven 'nerds' in the audio industry, as they often ( not always) push past what is seen reasonable in term of technical approach to recording or mixing engineers... ME are the 'picky' ones, whinning for a 0,001% tolerance in their setup...
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^ and you think we don't know?
I mean we don't know all for sure but it doesn't mean we don't know what are the mains ( and a bit more) principle at work?
Don't take it for you ( it's a general comment not directed at you) but sounds like if there was a 'conspiracy' to me.
And my experience with it let me think once people are into this 'conspiracy suspicious' state of mind it is easier to keep things in a blurry/confuse state... this usually serve some vested interest ( and not surpisingly we 'll often find the same people starting those conspiracy idea to be the same which have vested interest).
M. Cowan just had a public exposure about his work ( deserved imho) and there is a thread about it in here atm. He made some comments about all this measurements things. Worth a read imho.
Message #54
https://www.diyaudio.com/community/...-danley-featured-in-stereophile.395906/page-3
As Stereophile's interview of M.Dunlavy ( rip). It put things in perspective imho.
https://www.stereophile.com/interviews/163/index.html
I mean we don't know all for sure but it doesn't mean we don't know what are the mains ( and a bit more) principle at work?
Don't take it for you ( it's a general comment not directed at you) but sounds like if there was a 'conspiracy' to me.
And my experience with it let me think once people are into this 'conspiracy suspicious' state of mind it is easier to keep things in a blurry/confuse state... this usually serve some vested interest ( and not surpisingly we 'll often find the same people starting those conspiracy idea to be the same which have vested interest).
M. Cowan just had a public exposure about his work ( deserved imho) and there is a thread about it in here atm. He made some comments about all this measurements things. Worth a read imho.
Message #54
https://www.diyaudio.com/community/...-danley-featured-in-stereophile.395906/page-3
As Stereophile's interview of M.Dunlavy ( rip). It put things in perspective imho.
https://www.stereophile.com/interviews/163/index.html
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