Splitting sound layers off of a CD?

[devroger]

Question: Is there a way to split the sound layers off of a CD? For example, is there a way to get just the drum track off a normal music CD?

Here’s why I ask: I once had a portable CD player that I used for jogging and one day the output jack “broke”. I wiggled it and it started working again, but about a week later something strange happened. The output jack was cracking and then suddenly I only heard the drum tracks on the CD. This amazed me and I loved it because, as a drummer, I want to hear just the drums. This CD player has since gone missing—I’m assuming my wife was doing some spring cleaning—and now I want to reproduce that, but am not sure where to start.

Are there any tools to reproduce this?

Thanks!

[I_Forgot]

When the jack breaks, one of the signal connections is lost. If it is the "hot" connection to a channel that breaks, then that channel will just go dead and you'll only hear the output in one channel. If the "ground" pin, which is common to both channels breaks, you may hear the difference between the two channels, and you'll hear it in both ears.

Since voices are typically mixed to the "center" and in-phase in both channels, the difference will usually wipe out the voice and anything else mixed to the center leaving the things that are mixed to either side more audible.

Try lifting the ground off the jack or cable on your headphones and you may get the same result. Don't do it to your power amp- they often don't like the complex load that this presents. The vocal zappers that are sold at music shops do this sort of thing at the input to your amp.

I_F

[Duo]

Lifting the ground, for example, on a power amp and running the speakers in series is perfectly fine.

It is the same as bridging the amplifier, and being that the speakers are now both in series, the impedance seen by each output channel is the same as if the ground was connected and the speakers were driven separately.

This is the effect sometimes referred to as a hafler matrix; where the signal is processed before amplification. It has been used in some cases to generate a surround sound effect by sending this difference channel to the rear speaker. (Single rear).

[I_Forgot]

The Hafler circuit leaves the left and right channel speakers connected and adds a pair of series connected speaker between the right and left channels. The load seen by the amps is mainly determined by their respective speaker loads.

With what our friend wants to do, I think it would not be wise to simply connect the hot leads of a power amp to one speaker. The odd impedance seen by each amp may cause them to oscillate, destroying the speaker or amp quickly.

Bridging an amp requires that the inputs be fed from a mono signal (or one channel of a stereo pair) in-phase in one amp and out-of-phase in the other. Not all amps handle the load between the hot output terminals well. If an amp is designed to be bridged then it is probably OK, but the vast majority of consumer amps haven't been designed for that sort of operation. Some may work, other may not. Testing it by connecting a good speaker is a high risk way to find out if the amp is OK that way. It is much safer to make the connection at line level.

I_F

[Duo]

The very nature of the output of a voltage output audio amplifier allows it to be bridged or run loaded by another channel.

[lucpes]

Originally posted by devroger
Question: Is there a way to split the sound layers off of a CD? For example, is there a way to get just the drum track off a normal music CD?

Here’s why I ask: I once had a portable CD player that I used for jogging and one day the output jack “broke”. I wiggled it and it started working again, but about a week later something strange happened. The output jack was cracking and then suddenly I only heard the drum tracks on the CD. This amazed me and I loved it because, as a drummer, I want to hear just the drums. This CD player has since gone missing—I’m assuming my wife was doing some spring cleaning—and now I want to reproduce that, but am not sure where to start.

Are there any tools to reproduce this?

Thanks!

Don't know if this is allowed (directing to another forum) but this is more a question for the http://www.hydrogenaudio.org forums as it is more software related.