I do and I use it. It's just that I understand what Pano's test is trying to do and I know that unless the amplifier is going to go into current limiting before it hits the voltage limits, that Pano's test is just as good as using the scope.
In fact Pano's test is somewhat better then using the scope and here's why.
Using the scope with music and watching the wave forms is a bottoms up way of doing the test. That is, I can watch the scope trace and look for any clipping but it's heavily dependant on the music being played. That is music starts at silence then goes its merry way reaching certain peaks. What I really need to do, to make sure that I will be clip free at that volume, is play a sine wave sweep but start right at the top, that is 0dB. If the sine wave sweep played at the maximum digital amplitude for that given volume ends up clip free on the scope then I'm home dry.
Pano's test goes about finding this exact same level at 0dB, but does it without the need for a scope.
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What 5th is saying is correct but it does not apply to what Tom and I are speaking of ....
5th your are applying the fix digital signal as supplied by pano after using an variable analog signal to set gain with no reference . The best way to do this correctly is to use the scope , your zero db reference is nothing more than the loudest volume reached it does not represent the max of anything more than the limit acceptable by the user on a specific recording ....
Pano should do a recording to be used by all , along with the test tone , if not we have no reference so the numbers are useless for comparisons or any conclusions...
5th your are applying the fix digital signal as supplied by pano after using an variable analog signal to set gain with no reference . The best way to do this correctly is to use the scope , your zero db reference is nothing more than the loudest volume reached it does not represent the max of anything more than the limit acceptable by the user on a specific recording ....
Pano should do a recording to be used by all , along with the test tone , if not we have no reference so the numbers are useless for comparisons or any conclusions...
Tom, with all due respect, you simply do not understand this test. I respect your experience and designs, but you are not understanding the test - and I don't know why. 
Please read post #277, all you need is contained therein.
The first sentence of post #279 may also help.
BTW, there has been no resistance to looking at a 'scope by those who own them. None. The only thing close to that is that one doesn't need a 'scope for this test. Nothing wrong with using one if you have it.
Please read post #277, all you need is contained therein.
The first sentence of post #279 may also help.
BTW, there has been no resistance to looking at a 'scope by those who own them. None. The only thing close to that is that one doesn't need a 'scope for this test. Nothing wrong with using one if you have it.
Yes, the test results will be the same voltage. However, if you set your levels with Floyd, then your 1812 levels will probably be too low, by ear. The test tone won't care a bit.
So if you want to know how much voltage you need not to clip very dynamic tracks, then set the volume with the 1812 overture.
The object of the test is not to determine what SPL is "Loud Enough" for you and your system, but what voltage your amp puts out once you have reached that level.
So if you want to know how much voltage you need not to clip very dynamic tracks, then set the volume with the 1812 overture.
This says to me that you don't understand the test. Yes, I could supply a recording, but what good would that do? Don't you already own recordings? Can't you pick a few typical or dynamic ones and set your "As Loud as I like it" volume? The SPL is beside the point. The point is, "this is my highest volume setting" no matter what recording.
The object of the test is not to determine what SPL is "Loud Enough" for you and your system, but what voltage your amp puts out once you have reached that level.
buying a scope is one of those things that I keep on postponing. I oscillate between an used Tek/HP/etc, a brand X one, a USB scope and a digital Chinese scope until I get bored and give up
I can't see how one can follow the waveform on the scope display to catch clipping
btw I just realized that we're going on about clipping when it wasn't even mentioned by Pano.
my thoughts exactly, I somehow have the feeling that there's a lot of confusion floating around but can't put my finger on it. maybe it's me who doesn't get it.
And with all due respect, neither of you have understood this test.
There isn't supposed to be a reference that's the point. No one knows how loud it is in decibels because they do not need to.
The reference point in this case is set by the listener at their listening levels. This is the important part. It is done with music, not with a sine wave or with pink noise, but set realistically by using the most realistic thing you can get, music. One sets the volume level by setting it to the max that they would ever listen at.
Now how loud this is isn't important. Not to you, not to me, heck, not even to them. What's important is that their volume control is set to 5 and they know that they never listen to music any louder then 5 and that they only ever listen to music through their CD player.
You cannot get any louder, nor any larger in signal level, or larger dynamic peak, then is replayed at 0dB.
Ergo if you play a signal of 0dB though your system at volume setting 5, and the amplifier doesn't clip, then nothing you ever care to play through the system at volume 5 and below will make the amplifier clip (providing current limitations within the amplifier are ignored).
Tell me what is it about the above that you object to. What scenario can you invent where we are now going to cause the amplifier to clip with the volume set at 5? We've already shown that it wont clip with a 0dB signal, so what is it you think is going to come along that will make the amplifier magically start clipping?
what do I win? an oscilloscope by chance?
anyway I didn't expect this to turn into such a puzzle.
what do I win? an oscilloscope by chance?
anyway I didn't expect this to turn into such a puzzle.
I can highly recommend Tek scopes btw, I've got a second hand 2225 and its marvellous.
I didn't expect this to turn into such a puzzle either. My guess is that people are looking at this from the wrong direction and instead of realising exactly what it is we're trying to do here are vastly over complicating things and it's this that's causing the issue.
It puzzles me that it is such a puzzle. 
It's such a simple test I don't see how it can be so hard to understand.
Maybe folks are thinking there is some reference SPL in this test. There is not. It does not matter if "Loud Enough" for you is 70dB, 107dB or 45dB. All you are asked to do is find "Loud Enough" by playing a few good recordings. The absolute SPL does not enter into it.
Forget what books, papers, websites and reference material tell you should be your reference level, set it yourself with music. Although it may be interesting for you to know how that level compares to other sounds, that is not the point of this test. See post #291
It's such a simple test I don't see how it can be so hard to understand.Maybe folks are thinking there is some reference SPL in this test. There is not. It does not matter if "Loud Enough" for you is 70dB, 107dB or 45dB. All you are asked to do is find "Loud Enough" by playing a few good recordings. The absolute SPL does not enter into it.
Forget what books, papers, websites and reference material tell you should be your reference level, set it yourself with music. Although it may be interesting for you to know how that level compares to other sounds, that is not the point of this test. See post #291
It puzzles me that it is such a puzzle.
Your not kidding! the instructions in post no.2 are as clear and concise as can be. To be honest, reading through, I've found the confusion/OT nonsense very distracting. It made me think I had not understood the test!
The test is this: play a known sample at preferred max volume and measure = the max voltage your speakers will need - then post your results
Please please please tell me thats right
I propose to carry out a test for you all to consider.
I will turn the test back to front.
I normally listen sensibly with an average voltage to the speaker of 100mVac to 1Vac.
If I turn these speakers up louder I can hear the sound becoming "loud" due to the increase in distortion. I can turn it louder yet, but it is not nice to listen to. The average level is now 5Vac to 6Vac. This is more than 12dB below the maximum amplifier output, i.e. the amp can push more than 22Vac into these 89dB/W speakers.
That's the background.
The test.
What power of amplifier do you suggest I use for the test tone? 1W or 2W or 5W or 10W or 20W? I will build the amplifier to suit the majority view.
Then I will run the music at the level I think is nice but not distorted and give you both the average level and the test tone level. Then I can turn it up and measure the new average and test tone levels.
From there we can see what conclusions we can come to.
I will turn the test back to front.
I normally listen sensibly with an average voltage to the speaker of 100mVac to 1Vac.
If I turn these speakers up louder I can hear the sound becoming "loud" due to the increase in distortion. I can turn it louder yet, but it is not nice to listen to. The average level is now 5Vac to 6Vac. This is more than 12dB below the maximum amplifier output, i.e. the amp can push more than 22Vac into these 89dB/W speakers.
That's the background.
The test.
What power of amplifier do you suggest I use for the test tone? 1W or 2W or 5W or 10W or 20W? I will build the amplifier to suit the majority view.
Then I will run the music at the level I think is nice but not distorted and give you both the average level and the test tone level. Then I can turn it up and measure the new average and test tone levels.
From there we can see what conclusions we can come to.
I ran the test twice, once with a recording I made myself of the 2006 concert of Rumours mixed chorus for light music, and once with a quite dynamic commercial recording of Ravel's Bolero (ZYX classic CLS 4327, recorded in 1996).
The Rumours-recording has absolutely no dynamic range compression. The loudest peaks in the recording are just below clipping: these are the applause, a slamming door and a section of a second or so where all ladies scream.
I put the Rumours recording somewhat louder than I'm used to. I normally set the level such that I can just hear the announcer, this time such that the announcer is at a normal speach level.
Rumours:
5.06 V left, 6.36 V right (peak voltages 20.22 V and 25.46 V)
Bolero:
2.26 V left, 2.55 V right (peak voltages 9.05 V and 10.18 V)
Loudspeakers: QUAD ESL-63, having a rated sensitivity of 86 dB at 2.83 V extrapolated to 1 metre. Distance between loudspeakers and listener: around 2.5 metres. Living room size: roughly 8.5 metres by 4.5 metres, height 3.5 metres.
The Rumours-recording has absolutely no dynamic range compression. The loudest peaks in the recording are just below clipping: these are the applause, a slamming door and a section of a second or so where all ladies scream.
I put the Rumours recording somewhat louder than I'm used to. I normally set the level such that I can just hear the announcer, this time such that the announcer is at a normal speach level.
Rumours:
5.06 V left, 6.36 V right (peak voltages 20.22 V and 25.46 V)
Bolero:
2.26 V left, 2.55 V right (peak voltages 9.05 V and 10.18 V)
Loudspeakers: QUAD ESL-63, having a rated sensitivity of 86 dB at 2.83 V extrapolated to 1 metre. Distance between loudspeakers and listener: around 2.5 metres. Living room size: roughly 8.5 metres by 4.5 metres, height 3.5 metres.
Exactly, and testing at 0db is method I used here, with the proviso of disconnecting the speakers for the voltage test.
http://www.diyaudio.com/forums/soli...er-do-you-really-need-domestic-listening.html
some of the same arguments surfaced there too. Rereading that thread I came across this,
http://www.diyaudio.com/forums/soli...ly-need-domestic-listening-2.html#post2128057
Which may go some way to explaining the "higher than 0db" peaks I observed earlier in this thread,
http://www.diyaudio.com/forums/mult...ower-do-your-speakers-need-9.html#post2883059
That was something that really puzzled me as it contradicts my "cast in stone" saying about the 0db level being an absolute, however... this current thread is a perfectly valid and, I believe accurate (to all practical intents and purposes) method of arriving at the amplifier power needed to reproduce the maximum music level set by you on listening. The brief tests and checks I did with "Cool-edit" showed that all the CD's I tried (where I know where the loud bits are
peaked at around -1 to 0db. So the musics dynamic range below that level doesn't matter. If the recording is or is not very dynamic... it doesn't matter. Nothing on any of my music tracks seemed to peak over Odb in the way the white noise on the Philips player did. That anomaly really does seem player specific... but all that is another story and not for here. That's a great idea. I would think any normal amp (or chip amp ?) on a variable PSU would be adequate. If you have a variac it's even easier. Maybe just check with a scope to ensure it clips where expected.
You'd be amazed just how little you can get away with. This little PSU with it's 15-0-15 / 18va transformer (yes 18va) and 6800uF caps is one of my most useful test rigs... inherently SC proof up to a point... it will drive a stereo amp far louder than you might think. Great for initial design and development.
