Record players on boats

[Ronaldo47]

The PVC used to insulate electric cables does exude minute amounts of corrosive chlorine compounds, but in a non-hermetically sealed environment it can disperse harmlessly. However, high reliability electronic  equipment for use in aircraft and for military purposes is often constructed in hermetically-sealed enclosures to maintain the internal pressure at ground level pressure, and the use of PVC insulation is prohibited for these.

 

When I was an engineer at Plessey many years ago, we were shown the consequence of a careless repair on a sealed avionics radio module  where some  PVC - insulated wire had been used  instead of the specified PTFE stuff. Because the corrosive  gases evolved from the PVC insulation could not escape, they had built up over time and had liquified the plastic of the polystyrene capacitors. This is why, when you buy electrical stuff that is packed using expanded polystyrene packing, you normally find that any PVC  leads are enclosed in  polythene bags to prevent their coming into contact with the polystyrene packing. 

 

I don't recall if the problem arises from  the PVC plastic itself, or the plasticisers used to give it the flexibility needed for electrical cables.

Edited November 3, 2023 by Ronaldo47
typos, plasticiser comment added

[David Mack]

3 hours ago, Ronaldo47 said:

Because the corrosive  gases evolved from the PVC insulation could not escape, they had built up over time and had liquified the plastic of the polystyrene capacitors. This is why, when you buy electrical stuff that is packed using expanded polystyrene packing, you normally find that any PVC  leads are enclosed in  polythene bags to prevent their coming into contact with the polystyrene packing. 

And why boats with expanded polystyrene insulation should have conduit or some other means to separate the EPS from electric cables.

[Tigerr]

 I put one of my old albums on my brother's deck a few weeks ago. 

Jeez, it sounded awful. Hiss and crackle. plenty of analogue 'atmosphere' noise there. But wow, did we really listen to stuff as degraded was that? 

I didn't play anything with a fag burn on it, obviously. 

But my own impression is that the quality of the average persons music experience has improved beyond all recognition. I did know people who had entire walls filled with hi fi tech, vast double reel grundigs, but mostly they were rather odd males. 

The loss of this area of obsession might possibly have let some very odd men out to explore other less harmless outlets though. 

Meanwhile, earbuds are brilliant too. As are those brilliant bluetooth earphones. 

The best thing about old LP's is of course the album covers which are probably a more lasting cultural contribution and will become the antiques of the future long after the albums themselves went to landfill. 

[GUMPY]

Anyone who thinks MP3 are worth listening too even at the highest bit rate needs new ears.

[IanD]

4 hours ago, GUMPY said:

Anyone who thinks MP3 are worth listening too even at the highest bit rate needs new ears.

Anyone who thinks they aren't hasn't done proper comparisons using high quality headphones or speakers... 😉

[rusty69]

16 hours ago, GUMPY said:

Anyone who thinks MP3 are worth listening too even at the highest bit rate needs new ears.

Anyone over 60 probably needs new ears anyway, most of them are deaf.

[booke23]

17 hours ago, Tigerr said:

But wow, did we really listen to stuff as degraded was that? 

 

No, they sound perfect when they are clean and unscratched. 

[GUMPY]

13 hours ago, IanD said:

Anyone who thinks they aren't hasn't done proper comparisons using high quality headphones or speakers... 😉

Is a Quad 34/405 with Quad 11 speakers high enough quality?

I did a blind test with the same track and it was easy to tell which was which.

 

 

[IanD]

51 minutes ago, GUMPY said:

Is a Quad 34/405 with Quad 11 speakers high enough quality?

I did a blind test with the same track and it was easy to tell which was which.

 

What bit rate? Which encoder? Constant or VBR? Were they level matched and used the same DAC? Was it really blind or did you know which was which? Was this an A/B/X trial?

 

When I was looking into ripping my CD library I did a lot of tests with material I knew was  challenging for MP3 encoders, including recordings of our band with multiple hard-to-encode instruments where I had the studio masters as well as the CDs.

 

Lower rate MP3s were dead easy to spot, and VBR was worth one extra step in bit rate. I found that 320k fixed rate and 256k VBR were both indistinguishable from the original. This agrees with findings from other blind trials.

Edited November 5, 2023 by IanD

[GUMPY]

I took a WAV files of Dire Straits Telegraph Road and Pink Floyd's Wish You Were Here, both tracks I know very well, created  256kbit files of them.

Played back  through the system and switching between identical tracks, I didn't know which version was playing. Yes it's not easy to tell when lots going on and the quiet guitar bits are easier to tell. It does help if you know what you are listening for.

 

Remember what I did for a living 😎

 

 

[booke23]

I wouldn't even bother with MP3 in this day and age, you might as well just use uncompressed formats as storage on devices these days is huge.....20 years ago it made sense when a lot of us were still on dial up internet with 56k speeds and had computers with 1gb hard drives. Now, even my phone has 512GB of storage and my laptop 1.5TB. The only thing stopping MP3 becoming obsolete is that there is so much legacy music still sold in MP3 format, as that's what it was ripped to 20 years ago. 

[Puffling]

18 minutes ago, booke23 said:

I wouldn't even bother with MP3 in this day and age, you might as well just use uncompressed formats as storage on devices these days is huge.....20 years ago it made sense when a lot of us were still on dial up internet with 56k speeds and had computers with 1gb hard drives. Now, even my phone has 512GB of storage and my laptop 1.5TB. The only thing stopping MP3 becoming obsolete is that there is so much legacy music still sold in MP3 format, as that's what it was ripped to 20 years ago. 

Not everyone streaming music lives in a country with high speed broadband. The mp3 format is popular in countries such as India for that reason.

 

I wonder why I'm the only one talking FLAC on here? You can shrink a 24-bit audio file (a five minute track comes in around 5GB uncompressed) to half that size. Even on a 2TB SSD that allows more music per storage unit.

[IanD]

2 hours ago, GUMPY said:

I took a WAV files of Dire Straits Telegraph Road and Pink Floyd's Wish You Were Here, both tracks I know very well, created  256kbit files of them.

Played back  through the system and switching between identical tracks, I didn't know which version was playing. Yes it's not easy to tell when lots going on and the quiet guitar bits are easier to tell. It does help if you know what you are listening for.

 

Remember what I did for a living 😎

 

 

256k fixed rate MP3s can *just* be distinguished from the original -- that's what you found, that's what I found, that's what other blind trials have found.

 

256k VBR and 320k fixed rate are another step up, and tests have found they can't be reliably distinguished from the original. That's what I found, that's what other trials have found, but you didn't try it... 😉

 

So your blanket "MP3s are rubbish, anyone with a good pair of ears can tell the difference" is clearly not true, is it?

1 hour ago, Puffling said:

Not everyone streaming music lives in a country with high speed broadband. The mp3 format is popular in countries such as India for that reason.

 

I wonder why I'm the only one talking FLAC on here? You can shrink a 24-bit audio file (a five minute track comes in around 5GB uncompressed) to half that size. Even on a 2TB SSD that allows more music per storage unit.

My music library stored as 256k VBR MP3s just fits on a 128G SD card or USB stick, the WAV files would need 1TB which is still expensive and too big for a lot of players to recognise.

 

Computers will play FLAC but many other sound sources won't, including those in cars (both ours!) and some smart speakers and streaming devices.

Edited November 5, 2023 by IanD
TB not GB...

[PCSB]

17 minutes ago, IanD said:

...

 

Computers will play FLAC but many other sound sources won't, including those in cars and many smart speakers and streaming devices.

Many of the top end "speakers" do, our Naim MuSO does - streamed of course, they just play what they are given. I can stream ripped cd's in flac direct from pc or via the app from the web streaming source.

 

I'm getting older so the hearing isn't quite what it was, suspect too many rock concerts and playing drums without ear pugs has hastened their demise. Still I can still hear the difference (just) but suspect the MP3's have been lower quality ones. I do hear the difference between standard Spotify and the high quality Tidal streaming services so no longer bother with Spotify.

[IanD]

41 minutes ago, PCSB said:

Many of the top end "speakers" do, our Naim MuSO does - streamed of course, they just play what they are given. I can stream ripped cd's in flac direct from pc or via the app from the web streaming source.

 

I'm getting older so the hearing isn't quite what it was, suspect too many rock concerts and playing drums without ear pugs has hastened their demise. Still I can still hear the difference (just) but suspect the MP3's have been lower quality ones. I do hear the difference between standard Spotify and the high quality Tidal streaming services so no longer bother with Spotify.

Of course many do, but also many don't -- including both our cars where we listen to music a lot. I'm not going to store and maintain two different format music libraries when I can find one format that does everything I need it to... 😉

 

Spotify standard even on the highest quality -- if that's available! -- is not as good as 320k MP3s (or 256k VBR), Spotify Premium on the highest quality is but costs more...

 

I expect a lot of the "MP3s are rubbish" views are based on listenong to low-rate MP3s -- don't forget, 128k is still the most common rate -- and these do sound pretty bad, especially on music that shows up their limitations. Double the bit rate to 256k and use VBR encoding and you get something that sounds as good as the original but needs less than a fifth of the storage space. Which doesn't matter if it's on a computer HDD, but does if you want to store it on smaller things like SD cards and USB sticks for plugging in to other players.

 

Of course if storage space doesn't matter, there's no need to do any encoding at all, just use the original PCM/WAV files 🙂

[cuthound]

3 hours ago, Puffling said:

Not everyone streaming music lives in a country with high speed broadband. The mp3 format is popular in countries such as India for that reason.

 

I wonder why I'm the only one talking FLAC on here? You can shrink a 24-bit audio file (a five minute track comes in around 5GB uncompressed) to half that size. Even on a 2TB SSD that allows uhd more music per storage unit.

 

15 years ago I ripped my CD collection to ALAC (typically up to 1414kbs) to stream to my hifi and also to 320kbs MP3 to use on my portable devices. I am in the process of converting ALAC to FLAC as it is a more compatible format for newer audio equipment.

 

More recently I have begun to use Amazon's 24/192 UHD service (typically 3,000kbs) for streaming, although despite a claimed 70 million tracks I have over 20 ripped CD's that are not in their collection.

 

I find that a well recorded piece of music sounds better at at ALAC quality than a poorly recorded piece ay 24/192 UHD. However a well recorded piece of music at UHD sounds simply stunning, often revealing new information on high quality headphones despite me being very familiar with the piece, having listened to it countless times over the last 50 or so years. 

[Ronaldo47]

Some 20 years ago I and my 18 year old son, who was about to start studying music technology at university,  attended a public lecture held by the then IEE (now renamed the IET) on digital audio technology that was touring the country. What both I and my son found remarkable was the degree of compression that could be applied to music before degradation became apparent. The sound was reproduced using a  high quality sound system's loudspeakers in a lectrure theatre. Perhaps the onset of degradation would have become apparent earlier when using high quality headphones to eliminate the effects of room acoustics.

 

My hearing was good then: now that I can't hear anything above about 5kHz in my right ear, and the left isn't much better at 8 kHz, I no longer need hi-fi audio!

Edited November 5, 2023 by Ronaldo47
typos, headphone comment added

[IanD]

16 hours ago, cuthound said:

 

15 years ago I ripped my CD collection to ALAC (typically up to 1414kbs) to stream to my hifi and also to 320kbs MP3 to use on my portable devices. I am in the process of converting ALAC to FLAC as it is a more compatible format for newer audio equipment.

 

More recently I have begun to use Amazon's 24/192 UHD service (typically 3,000kbs) for streaming, although despite a claimed 70 million tracks I have over 20 ripped CD's that are not in their collection.

 

I find that a well recorded piece of music sounds better at at ALAC quality than a poorly recorded piece ay 24/192 UHD. However a well recorded piece of music at UHD sounds simply stunning, often revealing new information on high quality headphones despite me being very familiar with the piece, having listened to it countless times over the last 50 or so years. 

 

So apart from the obvious fact that a well-recorded piece of music sounds better than a poorly recorded one, have you ever done any blind tests to confirm whether you can actually tell the difference between any of these formats (and a 320k MP3)? Not just listening to one track a few times, you need to do enough trials to show whether any perceived difference is statistically valid or no different to flipping a coin.

 

Not saying you can't, just that -- like many other audio myths -- it been shown in the past that many people have opinions about many things to do with audio which fall to pieces when subject to proper testing... 😉

[booke23]

21 hours ago, Puffling said:

Not everyone streaming music lives in a country with high speed broadband. The mp3 format is popular in countries such as India for that reason.

 

The average download speed on the Indian broadband network is 59 Mbit/s. 

[cuthound]

1 hour ago, IanD said:

 

So apart from the obvious fact that a well-recorded piece of music sounds better than a poorly recorded one, have you ever done any blind tests to confirm whether you can actually tell the difference between any of these formats (and a 320k MP3)? Not just listening to one track a few times, you need to do enough trials to show whether any perceived difference is statistically valid or no different to flipping a coin.

 

Not saying you can't, just that -- like many other audio myths -- it been shown in the past that many people have opinions about many things to do with audio which fall to pieces when subject to proper testing... 😉

 

Yes I have done blind tests, by feeding two different sources (MP3 320kbps from my laptop and Amazon UHD from my streamer) in to my DAC and using a sound pressure level meter at the listening position to ensure both are played at exactly the same volume and getting my wife to switch between them so that I am unaware of the source. There is a tiny (but perceptible to me) difference in favour of the UHD music.

 

Incidentally if you are interested in hifi and want objective, measured reviews rather than the flowery ones from magazines, who cannot be too critical to their advertisers, try this site. 

 

https://www.audiosciencereview.com/forum/index.php

 

 

[IanD]

28 minutes ago, cuthound said:

 

Yes I have done blind tests, by feeding two different sources (MP3 320kbps from my laptop and Amazon UHD from my streamer) in to my DAC and using a sound pressure level meter at the listening position to ensure both are played at exactly the same volume and getting my wife to switch between them so that I am unaware of the source. There is a tiny (but perceptible to me) difference in favour of the UHD music.

 

Incidentally if you are interested in hifi and want objective, measured reviews rather than the flowery ones from magazines, who cannot be too critical to their advertisers, try this site. 

 

https://www.audiosciencereview.com/forum/index.php

 

 

At least you've tried to do a proper trial -- if it's not rude to ask how many tests did you do, and what was the statistical level of confidence in the results? How accurately did you manage to match SPL on a music track? (very small level differences can also make a difference -- I'm assuming the data was digital via the same DAC in both cases, otherwise DAC differences could kick in...)

 

When you're looking for small differences, it's really important to be sure that all other things would could affect the result are negligible.

 

I've been into hi-fi and pro audio for many years, I already knew about the audiosciencereview website, it is certainly one of the more objective ones around with rather less audio woo-woo bullsh*t than most... 😉

Edited November 6, 2023 by IanD

[cuthound]

Just now, IanD said:

At least you've tried to do a proper trial -- if it's not rude to ask how many tests did you do, and what was the statistical level of confidence in the results?

 

I've been into hi-fi and pro audio for many years, I already knew about the audiosciencereview website, it is certainly one of the more objective ones around with rather less audio woo-woo bullsh*t than most... 😉

 

I've only done it a couple of times over the years, once before deciding to re-ripped all of my CD's from 128kbps (the iTunes default setting) to ALAC (up to 1414kbps VBR) and more recently when my eldest son gifted me an Amazon Music Unlimited subscription which gave me access to the UHD music (Amazons terminology for 24 bit 192kHz sampled music).

 

My level of confidence is high because in both cases I could hear a difference, albeit much less so in the ALAC to UHD case.

 

 

[IanD]

12 minutes ago, cuthound said:

 

I've only done it a couple of times over the years, once before deciding to re-ripped all of my CD's from 128kbps (the iTunes default setting) to ALAC (up to 1414kbps VBR) and more recently when my eldest son gifted me an Amazon Music Unlimited subscription which gave me access to the UHD music (Amazons terminology for 24 bit 192kHz sampled music).

 

My level of confidence is high because in both cases I could hear a difference, albeit much less so in the ALAC to UHD case.

 

 

That's not what I meant -- regardless of whether you *think* you can hear a difference, with any test you need to look at the results statistically to see if your belief is justified, and this depends on the number of trials -- then you can say that (for example) "the tests show that with 95% level of confidence I can hear the difference".

 

("level of confidence" here has a defined statistical meaning for tests and scientific trials, it's not a personal opinion)

 

I'm not just being picky here, the audio field is littered with examples of things where people claimed they could absolutely hear a difference which failed when analysed properly -- for example "I ran the test ten times and got the answer right 7 times, this shows I can tell the difference".

Edited November 6, 2023 by IanD

[Ronaldo47]

To do a proper comparison, I think you would either need to use headphones to eliminate room acoustics, or else clamp you head in a fixed position so that your ears remained in exactly the same location for the comparison tests.

 

Back in the days befire the BBC started broadcasting 24/7, they used to transmit test tones on FM for a while after shut-down for engineering tests and adjustments.  One evening I had fallen asleep with the radio on, and was woken by the test tones. As I got up out of my chair to turn the radio off, I found that, at some positions of my head, I could completely null out a tone in either ear. The continuous tones were obviously setting up standing acoustic waves in the room, with some positions where reflections from the walls completely cancelled each other out to silence, and others where they added, making the sound louder. I didn't have much furniture then, and the walls had recently been emulsion-painted, making them good sound reflectors.

[cuthound]

30 minutes ago, Ronaldo47 said:

To do a proper comparison, I think you would either need to use headphones to eliminate room acoustics, or else clamp you head in a fixed position so that your ears remained in exactly the same location for the comparison tests.

 

Back in the days befire the BBC started broadcasting 24/7, they used to transmit test tones on FM for a while after shut-down for engineering tests and adjustments.  One evening I had fallen asleep with the radio on, and was woken by the test tones. As I got up out of my chair to turn the radio off, I found that, at some positions of my head, I could completely null out a tone in either ear. The continuous tones were obviously setting up standing acoustic waves in the room, with some positions where reflections from the walls completely cancelled each other out to silence, and others where they added, making the sound louder. I didn't have much furniture then, and the walls had recently been emulsion-painted, making them good sound reflectors.

 

The problem for the average home listener is ensuring that the sound levels between the different sources are perfectly matched. Relatively easy to do with speakers (most smart phones can use apps which act as sound pressure level meters), less so (without specialist equipment) for headphones, where professionals use a "dummy head" which can measure sound pressure levels.

 

Unscrupulous HiFi salesmen surreptitiously turn up the volume on the equipment they want to sell you in comparison tests.

 

 

 

57 minutes ago, IanD said:

 

That's not what I meant -- regardless of whether you *think* you can hear a difference, with any test you need to look at the results statistically to see if your belief is justified, and this depends on the number of trials -- then you can say that (for example) "the tests show that with 95% level of confidence I can hear the difference".

 

("level of confidence" here has a defined statistical meaning for tests and scientific trials, it's not a personal opinion)

 

I'm not just being picky here, the audio field is littered with examples of things where people claimed they could absolutely hear a difference which failed when analysed properly -- for example "I ran the test ten times and got the answer right 7 times, this shows I can tell the difference".

 

The bottom line for most people is that they listen to what they are happiest with, be it type of music, quality of music or music with over emphasised bass and treble.

 

It is for the individual to decide what they like best, not you.

 

Edited November 6, 2023 by cuthound
To add spaces between merged posts