• Welcome to the all-new HUG. All content has been converted from the old system, and over the next days we will re-style HUG in a more familiar way.

"Fluidity"? >>> clipping & amp sonics

Status
Not open for further replies.

A.S.

Administrator
Staff member
Hot plus more hot ....

Hot plus more hot ....

... And I certainly agree that we should be using material that should be more "blameless" in this regard. This particular track only entered the discussion because it's the track that first convincingly opened my ears to this particular issue.

It's a shame that we only have access to the published CD. But, as I said earlier, comparing the released version to a version that has been clipped by an amplifier does yield audible differences, so it's a valid - albeit non-perfect - demonstration. A good starting point.

For me, there are two distinct threads to this investigation:

1. Clipping happens more often that we might expect - especially with well-recorded material.
2. When it occurs, it isn't always noticeable as obvious distortion, but it can change the character of certain instruments.

Earlier I mentioned "Money For Nothing" - the original 1980s release has an astonishing Peak to Mean Ratio for a contemporary release, and I'm pretty sure that there is no clipping inherent in the recording. Trying to play that at reasonable volume via my 50 watt setup definitely resulted in very visible clipping - and it was audible too. But I'm not convinced that a snare drum - no matter how well recorded - will help to demonstrate point 2 here :)

I think your knowledge of classic music is wider than mine - my collection is roughly 5:1 in favour of non-classical works - so I'm thinking that having identified brass as a potentially good way to demonstrate this effect, there must be some examples of brass-rich music from the classical repertoire that would have been recorded in a more sympathetic manner, and these might be a more appropriate choice for further investigations. I'll have a think.

Any suggestions? I welcome the chance to broaden my CD collection!

All the best,

Mark
All noted. To be fair though, brass that is recorded/reproduced that 'hot' (i.e. with absolutely no dynamic headroom at all) is likely to take on a sonic characteristic unlike a real brass instrument played in a nice acoustic, with the microphone a distance away, and captured at a loudness which leaves enough dynamic headroom in reserve regardless of the capabilities of the amplifier. That a small amplifier driven hard by such a 'hot' recording is going to add another layer of mangling to the sound isn't to be doubted as 'clipping' by definition, will take the audio experience away from what one would hear live and into an unpredictable sonic region.

The problem as I see it is that listening to this track on your small amp (driven hard) gave you a subjective experience that you did not like. But it would be a very bold man that could say with certainty, that what he didn't like was just the sound of the amp in clipping, as opposed a combination of very hot recording pushing the sound to be as loud, and sellable, as possible plus the limitations of the amp. The amp and the recording together would, I suggest, be sonically intertwined and inseparable from each other. Isn't that the case?

I believe that a simple visual peek at the waveform in Audition or similar waveform editor tells you at a glance whether a recording is likely to be in the high fidelity class or not. If the levels are rammed hard up against the wall - the modern way - then one has to ask if that recording is worthy of replay on even the finest high fidelity system, which is capable of so much more dynamics potential. A great high fidelity recording should only rarely use the full dynamic range i.e. touch the 0dB limit lines just a few times during a performance.

I am often told how the HUG is read as a factual, objective, impartial, non-marketing insight to the truths of hearing and audio. If that is the case, we've achieved our objective of creating content of lasting value to the ordinary, non-technical reader, a task which, I truth, is surely the remit of the audio media, not us. However, we are here now and we have an opportunity to maximise. I think what we should do is fork this thread, back up a bit, and make a fresh start having accounted for confounding variables that have unwittingly crept into this otherwise thought-provoking analysis. If we can set this analysis on solid foundations, other researchers can replicate the experiments, and we put ourselves beyond petty, ill-informed criticism.

I am still of the opinion that we have within our grasp an insight to the matter of amplifier sonics of real value.

How does that seem to you?
 

mhennessy

Member
The recording, or the amp - or both?

The recording, or the amp - or both?

The problem as I see it is that listening to this track on your small amp (driven hard) gave you a subjective experience that you did not like. But it would be a very bold man that could say with certainty, that what he didn't like was just the sound of the amp in clipping, as opposed a combination of very hot recording pushing the sound to be as loud, and sellable, as possible plus the limitations of the amp. The amp and the recording together would, I suggest, be sonically intertwined and inseparable from each other. Isn't that the case?
Just to clarify, while I noted a difference between clipped and unclipped, I didn't have a subjective preference for either, and couldn't tell by ear which was which. I needed a 'scope to reveal that the difference between the two versions was clipping.

I tend to feel that a clipped recording might sound different if clipped some more; you only have to listen to a transistor radio with a 1 watt output stage to see how this hypothesis could hold water. As a counter-argument though, you could suggest that the bulk of the damage has been done by the initial clipping, and perhaps a bit more clipping might not alter things all that much? Intuitively, I can't help feeling that this might be the case for a solo instrument, but that things are much more complex when you have a complete mix as your source material.

Trying to pin this down with hard science and numbers would be challenging to say the least. That's not to say that we shouldn't try :)

I believe that a simple visual peek at the waveform in Audition or similar waveform editor tells you at a glance whether a recording is likely to be in the high fidelity class or not. If the levels are rammed hard up against the wall - the modern way - then one has to ask if that recording is worthy of replay on even the finest high fidelity system, which is capable of so much more dynamics potential. A great high fidelity recording should only rarely use the full dynamic range i.e. touch the 0dB limit lines just a few times during a performance.
Yes, but we are getting into the murky areas of genre with this. For many "rock and pop" recordings, the engineers will want the loudness to be essentially the same throughout - perhaps with variations during choruses or the break. Others will have a wider range for artistic reasons. Even a good classical recording will be "compressed" (usually manually by a musically trained engineer who is intimately familiar with the score) as few would welcome the entire dynamic range of an orchestra at home in their listening rooms.

I suppose it's a question of accepting that the released CD is what it is. The finished product might not meet the standards we hope for, but it might still have other merits. Ultimately, some non-ideal CDs could be suitable for subjective testing, but I certainly agree that it would be nice to separate out the recording from the amplifier if that were possible.

I am often told how the HUG is read as a factual, objective, impartial, non-marketing insight to the truths of hearing and audio. If that is the case, we've achieved our objective of creating content of lasting value to the ordinary, non-technical reader, a task which, I truth, is surely the remit of the audio media, not us. However, we are here now and we have an opportunity to maximise. I think what we should do is fork this thread, back up a bit, and make a fresh start having accounted for confounding variables that have unwittingly crept into this otherwise thought-provoking analysis. If we can set this analysis on solid foundations, other researchers can replicate the experiments, and we put ourselves beyond petty, ill-informed criticism.

I am still of the opinion that we have within our grasp an insight to the matter of amplifier sonics of real value.

How does that seem to you?
OK - lead the way!
 
Status
Not open for further replies.
Top