Amp vs Speaker - Which Has More Effect on Pitches Sounding Distinct From One Another

[Nebadon2000]

Preamp in Bass head's Job is to accurately reproduce input from Bass Guitar; Amps Job is to accurately amplify that input and Speakers Job is to Accurate reproduce sound sent to it.
Unfortunately the environment can present challenges even for the Best.
Headphones are not affected by environment

 

[el murdoque]

IMHO a good cab generally has more impact on the sound than the amp.

But you are talking about installing a different speaker in the Kickback. I am referring to getting a higher quality cab.

This.

In guitar amplification the cabinet is a box that has mainly two jobs:
1. Hold the speaker upright
2. Protect the speaker against bumps.

In bass guitar amplification, the cabinet and the speaker form a unit.
The speaker moves air, the cabinet directs that flow. The interaction between those two is is on a totally different level than it is with other speaker systems.

You can swap out a guitar speaker and expect the result to sound differently, but equally good. Don't expect that from a bass cabinet.