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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment.

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Old 15th Feb 2019, 12:25 am   #81
TIMTAPE
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Default Re: Distortion problems

Quote:
Originally Posted by mhennessy View Post
The thing is, the pop CDs will have the same peak levels as the classical CDs.

Often yes, but that's not what I said. I said the pop music will generally reach peak level, more often. The figures you cited only gave the highest single peak in each track, not how frequently those sorts of peak levels occurred within that track.

The more often distorted peaks occur, the more likely listeners will notice the distortion.

Last edited by TIMTAPE; 15th Feb 2019 at 12:32 am.
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Old 15th Feb 2019, 4:33 pm   #82
mhennessy
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Default Re: Distortion problems

Sure, but how frequently the peaks occur is not really related to how audible they are.

Classic example: Money For Nothing, which is apparently 134 BPM (I'm not a musician). Rip the original 1985 release and examine it in your audio editor of choice. The snare nearly peaks full scale, and the average/RMS level is somewhere between 20 and 30dB below full scale.

You can apply clipping to the track in the audio editor to reduce the amplitude of the snare. It's amazing how much you can apply before you start to notice that it sounds different, and you have to keep going for many more dBs before you decide that it's distorted.

This, BTW, has huge implications for power amplifier design, who have to realise that clipping is a more frequent thing that they might otherwise expect, so they'd better pay close attention to the clipping behaviour of their designs

By contrast, take a flute, which has a reasonably sinusoidal waveform - certainly when compared to a snare drum. That would only have to clip mildly to be noticeable - and only one brief clipping event in the whole track would be distracting.

I could provide many examples, but in short, it's very easy to make generalisations about music genres and distortion, but it's a risky business! As I say, it's safest to not draw too many conclusions about this problem based on the music choices reported earlier.

Mark



PS: Here's a good demonstration of distortion audibility by Audio Precision. They demonstrate clipping and crossover distortion. Different track, imperfect conditions, but the same conclusions - it's surprising how much you can clip some tracks before distortion is noticeable.

https://www.youtube.com/watch?v=2V6YN-mshmY
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Old 15th Feb 2019, 11:03 pm   #83
TIMTAPE
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Default Re: Distortion problems

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Originally Posted by mhennessy View Post
Sure, but how frequently the peaks occur is not really related to how audible they are...
In this thread we are trying to determine the source of the OP's reported audible distortion. An example of a level of (clipping) distortion that is inaudible is, I would have thought, irrelevant here.
This is not about peaks as such, but about distortion that is audible, at least for some people under some conditions.
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Old 16th Feb 2019, 2:27 pm   #84
mhennessy
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Default Re: Distortion problems

Sorry, but you've completely missed the point I'm making - but as it's not important to the OP, I'll give up trying to explain further in this thread (but am happy to chat further via PM if you like).

To move forward, we really need Linnovice to do the tests some of us suggested earlier (output of each Linn amp in turn into a full-range speaker or headphones or similar). Until such time, it's just speculation.
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Old 16th Feb 2019, 5:55 pm   #85
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Default Re: Distortion problems

I've been reading this thread with some interest, I'm not sure if it will be concluded as such. In my time I've come across two instances of audio distortion where some perceived it and others did not.

The first was a pair of Celestion Ditton 15XR speakers. The user had owned them since new (35 years+) and now complained that they sounded too bright. I tested them against another pair and could not find any problem. The user phoned me a month after collection and said they were fine... It was his hearing that was now diagnosed as defective. But the first thing to highlight this was his Hi-fi system...

The second was an actual hardware fault. An audio amp had distortion reported on one channel only. Out of ten of us, only two could hear this and that included me. The actual fault was slight crossover distortion due to the base bias resistors of the drivers that were changed to 10x their normal value.

What I'm trying to say is that our perception of distortion seems to vary from person to person. Even when there is a actual 'fault' not all of us can hear it.

Linnvoice please don't think that I'm criticising your hearing, I'm not. My hearing used to extend to 17Khz, now it's 8Khz with a permanent 5Khz pure whistle in each ear from Tinnitus!

Many years back I went to a very loud rock concert, my ears went into a severe clipping, I could not make out the music at all. I left with severe ringing in my ears that took a week or two to clear. Maybe some damage was done...

As Mark has pointed out, our hearing is a complex subject and what we hear is subjective due to wide range of different factors. SJM

Last edited by samjmann; 16th Feb 2019 at 6:05 pm. Reason: Typo error
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Old 16th Feb 2019, 7:02 pm   #86
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Default Re: Distortion problems

Good evening Gentlemen. I’m afraid I’ve not made much progress to date. I had a hearing test on Tuesday last as I mentioned. My hearing is dodgy on the right side as I suspected but the program specifically to listen to music that was supposed to included with my new aids wasn’t. This means if I listen with aids it’s not very good and if I listen without I can’t hear any distortion anyway (or much top end). The search for my distortion problem therefore is going on hold for the time being.
Thank you for all your contributions though. In the words of the great cyborg . . . I shall return. 🙄😉
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