What is this? (image inside)

[Vitor Machado]

This song is Wishing Well by Terence Trent D'Arby (Sananda Maitreya). It's not a bad quality rip, this is playing from an original CD.
 
As you can see, there's a continuous ~15KHz (the spectrogram is linear) signal. It's very faint, I can't distinguish it with my equipment.
I've seen this in a couple other songs, but I can't remember now...
 
Anyone know what might have caused this in the recording? The album is from 1987 if it helps.

 

[XaNE]

It looks like a crt was on in the recording location.
a crt emits at 15.625 kHz

 

[necropimp]

some kind of interference could do it... i always have that happening at 30KHz and 40KHz on my needledrops
 
sometimes i've seen them in the audible frequency range but it's always so faint i can't actually hear it

 

[Vitor Machado]

Hmm, thanks guys.

 
Quote:

It looks like a crt was on in the recording location.
a crt emits at 15.625 kHz

Yeah I know what you're talking about, I can hear this noise when an older CRT is on nearby.
Can't hear it through this recording though, probably too faint.

 

[bigshot]

A simple notch filter would fix that with the added benefit of preventing headaches when listened to on headphones at loud volumes. Most folks can't hear 15kHz unless it's fairly loud. But it can still mess-up your ears even if you can't hear it. If I owned this CD, I would apply a notch filter and burn a corrected CD. I'd probably mail the original disk back to the record label with a nasty letter. This kind of sloppy engineering is unacceptable.

 

[Vitor Machado]

Quote:

A simple notch filter would fix that with the added benefit of preventing headaches when listened to on headphones at loud volumes. Most folks can't hear 15kHz unless it's fairly loud. But it can still mess-up your ears even if you can't hear it. If I owned this CD, I would apply a notch filter and burn a corrected CD. I'd probably mail the original disk back to the record label with a nasty letter. This kind of sloppy engineering is unacceptable.

Probably has to with the fact it's an 1987 album. Did they had equipment, like spectrograms, back then to easily detect this problem? And maybe no one heard it either...
Only two other songs in the album have this, but it's even fainter...
Label is Columbia Records.
 
I've found another album with this problem, Live at Montreux by Darol Anger & Barbara Higbie. Only on the second track, "The Lights in the Sky Are Stars". Funny because it's a live album.
This concert is from '84, but the CD was released only in '90 I think. I have no idea if the LP has it also...
Label is Windham Hill Records.

 

[bigshot]

Since it's a continuous volume, it had to have been introduced in the mixing stage. It was probably mixed in a small studio or home setup without adequate isolation and grounding. Driving out all the noise hoodoos is a big job. That's why professional studios are worth the money. If the mixer didn't notice it, the engineer doing the mastering certainly should have caught it and fixed it.