[grimtales1]

Hey,
I'm not sure if this should be in this forum or Music
I was just putting on The Seekers CD "The Ultimate Collection" and noticed the songs played slightly lower in pitch than I had heard before or sounded slower (some songs such as World of our Own or The Carnival is Over sounded better)
The player is just connected to the mains normally and theres no speed altering thing on the set, so I dont understand why it sounds lower.
Any ideas?

[Andy Carlton]

Quote:

Originally Posted by grimtales1

Hey,
I'm not sure if this should be in this forum or Music
I was just putting on The Seekers CD "The Ultimate Collection" and noticed the songs played slightly lower in pitch than I had heard before or sounded slower (some songs such as World of our Own or The Carnival is Over sounded better)
The player is just connected to the mains normally and theres no speed altering thing on the set, so I dont understand why it sounds lower.
Any ideas?

Is it because you have been used to hearing these tracks on a turntable which is faster? This has happened to me a lot a few years ago when i made the switch from Vinyl to CD.

The old BSR decks were known for speeding up as they got older.

[grimtales1]

I don't think its that (I'm not that old) . Some of the clips I heard on YT seemed to play faster so it could be that

[stargirl 2]

i got that cd hun think it may be because originally they were done in mono sound only hun xx

[grimtales1]

Thanks
I didnt know that, how can changing from mono to stereo have an effect on the speed?
x

[chrisjr]

Quote:

Originally Posted by grimtales1

Thanks
I didnt know that, how can changing from mono to stereo have an effect on the speed?
x

If the original was mono then I suspect the CD is mono. It may have two channels but it is still mono as the same information is contained in both channels.That won't affect the speed at all. Well actually there is an effect you can create if you take a two channel track and play it as if it were a single channel track. But that halves the effective playback speed so would be pretty noticable

In fact it is a bit more complex to varispeed a CD than a vinyl record. It takes a bit more than simply slowing down the disk spinning. if you do that the chances are the laser would lose synch with the disk and even if it didn't the Digital to Analogue converters will probably throw a wobbly as it would play havoc with the effective sample rate coming off the disk.

More than likely if they sound different it is down to the way the tracks have been mastered onto the CD rather than anything in your equipment.

[Nigel Goodwin]

Quote:

Originally Posted by chrisjr

More than likely if they sound different it is down to the way the tracks have been mastered onto the CD rather than anything in your equipment.

I would agree, it's probably been made like that, and may well be correct while the old memories are wrong.

However, depending on the chip set used, it might be VERY simple to vary the playback pitch - Elektor did just such a project many years back. DJ CD players commonly do the same thing as well.

[bobcar]

Quote:

Originally Posted by Nigel Goodwin

However, depending on the chip set used, it might be VERY simple to vary the playback pitch - Elektor did just such a project many years back. DJ CD players commonly do the same thing as well.

It's easy to do deliberately (providing it's designed into the chipset) however very unlikely to happen accidentally whereas a turntable or cassette can more easily speed up/slow down.

[soulboy77]

An easy way to prove that pitch issue is not a fault with the player is to put the CD on another machine to see if it replicates the problem.

[Orbitalzone]

Could it also be if the youtube clips were taken from TV clips, which might have been taken from a carpenters film? (no idea if they made films or film based 'pop videos'

When converting film to PAL TV they speed up films from film's 24 frames to PAL's 25frames per sec resulting in inreasing pitch by about 5% if I recall.

Or could have been a poorly transcoded yutube clip.

[chrisjr]

Quote:

Originally Posted by Nigel Goodwin

However, depending on the chip set used, it might be VERY simple to vary the playback pitch - Elektor did just such a project many years back. DJ CD players commonly do the same thing as well.

I was comparing it to varispeeding to a turntable. Any turntable can varispeed. Just switch off the motor and turn the platter by hand!

But with a CD it is rather more complex. Varying the speed of the disk spin may have no effect at all. If the servo controlling the laser can keep up then it will read the data off the disk OK.

It won't be at 44100 samples per second necessarily but all you need is a big enough buffer to clock the data in at one rate and out again at 44.1 kHz to feed the D to A converter. Net result no change in speed or pitch (which are not necessarily the same thing either)

So to slow down a CD you need to be able to clock the D to A at a different rate. At the most basic level anyway.

And a pitch shifer can alter pitch without slowing or speeding up the playback.

In fact with a combination of varispeed and pitch shifting you can slow something down then increase the pitch to compensate so the track plays longer but at the same pitch as the original (if that makes any sense).

So assuming grimtales1 CD player is fairly bog standard it is very unlikely to play just the one disk at the wrong speed.

[bf1gun]

Quote:

Originally Posted by grimtales1

Hey,
I'm not sure if this should be in this forum or Music
I was just putting on The Seekers CD "The Ultimate Collection" and noticed the songs played slightly lower in pitch than I had heard before or sounded slower (some songs such as World of our Own or The Carnival is Over sounded better)
The player is just connected to the mains normally and theres no speed altering thing on the set, so I dont understand why it sounds lower.
Any ideas?

Its because you are playing The Seekers. Your hi-fi is so embarrassed that it is trying to save your dignity by restricting the output to your ears only!!