Repeating Notes, different pitches

Have you checked your intonation?

 

Assuming your fretting finger hasn't moved, the second note cannot be "higher" (in pitch) -- but it might be louder, or you might be holding the note longer (or shorter), or your attack might be different. It's just a matter of practice to make them sound the same. With a pick it's very much the same problem -- i.e. making downstrokes sound the same as upstrokes.

 

Sorry, thought you were talking same note, different octave.

 

Any kind of backing track might make the two notes sound different even if you're playing them the same way. I would try playing without a backing track first to make sure the notes sound the same without any background, and then proceed to figuring out whether you're actually plucking the notes differently or whether they just sound different against the background.

 

This can't happen in isolation, so it is something you are doing. Are you inadvertently bending the strings as you play? It might be worth checking in a mirror or pointing a video camera at your hand just to see what is going on.
Another possibility is that you are, again unintentionally, pulling back on the neck as you hold each note...
Either way, try loosening your left hand grip...

 

I ran into some issues with this a number of years ago with a couple string patches in Reason. My bass was in tune just fine but the patch was a few cents off giving that out of phase sound. We were so adamant about the using those specific string patches. I tried re-intonating my bass for a tempered “Buzz Feiten” tuning and voila.

 

Panning is not the answer. Better would be to EQ the signal going to the modulation effects such that only the mid and high frequencies are processed. Then put on a HPF to remove the deep bottom end and create sonic space for the bass.

 

Can you put a soundbite in here? Hearing it for ourselves would help us help you.

 

A tip to check out: When you play a note, there's an attack (few ms of very loud transient), then there's a sounding tone. The sounding tone has some pitch. After about a second, the pitch gets few cents down. The louder you pluck, the bigger the pitch difference. Softer strings probably do it more than stiffer. With longer string lenght, the pitch changes more (at least that's the case when I compare my bass guitar and my double bass).

This is physics thing and at least I can't really hear the difference. Perhaps the ear learns to get used to it when learning to recognize the sounds of instruments? Or, we don't pluck unnecesarilly loud for just this reason? - I've met people who play fast notes when tuning, saying that it helps the tuning presicion.

I'm using this Android tuner, where you can nicely see it.

Don't know whether this helps, but it's interesting.

 

Technique.
Same fret? Technique.

A B is a B is a B. Only difference in timbre, is how and where you hit the string.

 

Try it with a capo.

 

Other than doing something physical to the bass, it could be a perception artifact based on the background harmonic context and your expectations.
There's a jazz piece by Wayne Shorter called Nefertiti (the name of the Miles Davis album it's on) it's like a mobius strip-every time you play it it seems to rise a step. But it doesn't. It's the same notes every time. btw, the only improvisation on Nefertiti is from the drums Tony Williams, it's a drum show.

 

I 2nd that. Play in front of a mirror or record it on your phone. If this is actually happening it’s because you are either pushing to hard and it’s bending sharp or you are bending laterally. The other thing to note is that the attack of a note is always slightly sharp, this is visible on something like a strobe tuner. That’s a natural and inescapable fact of physics.

 

When you say “strings playing in the background” are you talking about stringed instruments, like cello, violin, etc.
If so, they are likely using heavy vibrato, which is a technique that slightly changes pitch in a rhythmic pattern.

I play a little violin, and my playing didn’t sound “violin like” until I learned to do vibrato. It is used much more than you think to get that classical sound.