Audio Artifacts on Isolated Bass Tracks??

[groovaholic]

I've been on a bit of a listening binge lately, checking out isolated bass tracks.
This is part of my effort to find ways to make the bass fit more naturally when recording my band.

It's been really informative, hearing how different our perception of the isolated sound is compared to how we perceive it in the mix.

Sometimes it's tough to believe that it's the same track as the one that ended up in the mix, and I've gone so far as to listen to the isolated track, then plug those same headphones into my iPod and listen to it in context.

Generally, I'm hearing compression artifacts that go unnoticed in the mix, a thinner tone than I'd expect, and clipping. Sometimes it also appears to have a light reverb added.

A good example is "The Righteous and the Wicked" by the Red Hot Chili Peppers (off Blood Sugar Sex Magic) where you get a couple seconds of Flea with the drums, then the band kicks in.
The differences were subtle, but noticeable.


My question is, am I hearing the real picture unmasked, or does the act of isolating the tracks create these tonal artifacts?

 

[ddnidd1]

A lot of what you're hearing is due to frequency masking. The frequency ranges of the instruments and vocals broadly overlap each other.

So what may stand out when an instrument is soloed is masked when its in the full mix. In the same way the sound of your bass when playing alone at home has nothing to do with how your bass sounds in a full live band mix.

Its the way our brains process sounds.

Also you may be hearing sound from another source bleed through into a mic or if it was originally recorded to tape, bleed through from one tape track to an adjacent one.

 

[seamonkey]

And loudness masking. Louder sounds mask quieter ones. Like Water features in parks mask a lot of other noises.
With recording there's a lot of sidebanding going on. It can be a lot of sidebanding the bass in favor of a bass drum in dance music. Other music you may duck the drum in favor of the bass for melodic parts.

 

[EastCoastThump]

Are you getting the isolated tracks online? Sometimes those "isolated" tracks actually originate from Rockband or somesuch. But even when they're the real deal, they're compressed for posting—and that compression is sometimes pretty brutal.

 

[Mattster]

I have the Jammit free app. You playback songs (that you buy iTunes style from a not so extensive list) through a mixer interface with sliders for the tracks. I'm always struck by how much more "sloppy" the bass playing sounds when you can hear all the finger noise, fret buzz and general cllckity-clack on the isolated track.

 

[megafiddle]

If the original song was multitracked, and the isolated bass track is the original recorded track, it could well have been altered during mixdown.

If it was extracted from a recording, then it can contain artifacts from the extraction process.

-

 

[EastCoastThump]

If it was extracted from a recording, then it can contain artifacts from the extraction process.

I've got to know: what would that extraction process be?

 

[groovaholic]

I've got to know: what would that extraction process be?

Thank you -- that's the simplest way to ask this question!

It seems like there is some processing going on that isolates a track by applying frequency specific phase cancellation (if there is such a thing) as the resulting tracks often have that thin, out of phase sound.

This all started with me making some recordings with my GK amp (where previously I'd used tubes in my signal path) and wanting to listen to some other tracks where I know a GK was used and got a sound that I liked.

Specifically, my tonal goal would be a synthesis of Flea and Justin Chancellor; so I listened to their isolated tracks.

Considering how mighty Flea sounds in the mix, I was surprised to hear his tracks.
His playing is a study in focus, serving the song, and picking your moment; he's very restrained -- until he isn't, and then he's every bit the attention grabbing bada$$ we know and love.
But his isolated tracks were thinner than I expected for something that commands so much attention in the mix.

On the other hand, from a sonic perspective, Justin's tracks sound exactly like I'd expect.
Performance-wise, his playing is even more nuanced than I'd anticipated; there are a TON of variations and small asides in his lines that make them completely listenable all by themselves.

If anything, I'm even more impressed by both of them -- but for different reasons than I initially would have guessed.

 

[ddnidd1]

It seems like there is some processing going on that isolates a track by applying frequency specific phase cancellation (if there is such a thing) as the resulting tracks often have that thin, out of phase sound.

There is NO way to completely isolate a bass track from a mixed song.

When you do hear a completely isolated track it is the dedicated bass track from the studio.

Isolated tracks simply sound Distinctly different than when they are mixed in with the band.

 

[silky smoove]

There is NO way to completely isolate a bass track from a mixed song.

When you do hear a completely isolated track it is the dedicated bass track from the studio.

Isolated tracks simply sound Distinctly different than when they are mixed in with the band.

Well to clarify, there have been a lot of isolated tracks posted since people started hacking into Guitar Hero and Rock Band games and extracting files. These were taken from the original studio multitracks for the licensed songs, and the "done in the style of" versions were made for the game, and as such the multitracks were readily available. That type of thing is very different than using an audio tool to "extract" something from a stereo mixdown.

 

[ddnidd1]

Well to clarify, there have been a lot of isolated tracks posted since people started hacking into Guitar Hero and Rock Band games and extracting files. These were taken from the original studio multitracks for the licensed songs, and the "done in the style of" versions were made for the game, and as such the multitracks were readily available. That type of thing is very different than using an audio tool to "extract" something from a stereo mixdown.

I was only referring to the original tracks from the original artist.

 

[silky smoove]

Even the original tracks by the original artists in those games are being done with the multitracks, not processing the audio of a stereo mix down.

 

[EastCoastThump]

Yes. My question was a polite way of asking megafiddle, "Say what?"

B/c instruments overlap one another in a mix, AFAIK no currently available software can faithfully produce an isolated audio file of one instrument from an audio file of a full band mix. It's not a matter of bandpassing frequencies from 80-250 Hz to produce a bass track. In a typical band mix, the bass is overlapped at every point in its frequency range by at least one other instrument; and it's overlapped over much of its range by almost every other voice in the band.

 

[megafiddle]

There was a topic here once about software that some were using to listen to bass parts in recorded songs. I'll see if I can find.

Anyway, that's what I was referring to.

-

 

[silky smoove]

Yep, that's very much a thing.

Extracting multitrack sourced files from Guitar Hero and Rock Band is another.

A distinction needs to be maintained between the two for the purposes of this discussion.

 

[groovaholic]

Well, for instance, I know that lots of the Zeppelin, Metallica, and RHCP iso tracks came from Guitar Hero or Rock Band.

But I've also seen live footage of The Who and John Entwistle's bass track was isolated and in sync with the video, so that suggests a method of extraction or isolation other than the source tracks in the games...

 

[silky smoove]

Correct. There are programs that make clever use of EQ to extract one instrument from a mix with varying degrees of success. In those cases, there are bound to be tons of artifacts as the sheer amount of overlap in a mix can be staggering, especially a live one. I would not consider those to be any realistic representation of a solo'd instrument's tone.

 

[ddnidd1]

Well, for instance, I know that lots of the Zeppelin, Metallica, and RHCP iso tracks came from Guitar Hero or Rock Band.

But I've also seen live footage of The Who and John Entwistle's bass track was isolated and in sync with the video, so that suggests a method of extraction or isolation other than the source tracks in the games...

Again the only way to have a totally isolated bass track is from the discrete bass track from a multitrack recording.

There is no magic extraction software or technique.

 

[EastCoastThump]

But I've also seen live footage of The Who and John Entwistle's bass track was isolated and in sync with the video, so that suggests a method of extraction or isolation other than the source tracks in the games...

Actually, sounds like you're thinking of the isolated Entwistle tracks that come from the 1978 Shepperton concert. That was a multitrack session put on to capture material for Jeff Stein's band bio, The Kids Are Alright.