...I think that the advantage of the Realist and Full Circle is that their output is hotter to begin with, so it just takes longer to reach that crossover timber change. Ric
Ric,
I don't think the greater output level of those pickups is what produces the difference. Here's why. Gain is gain. All other things being equal, and issues of signal-to-noise ratio aside, whether a certain level is achieved as a combination of a higher initial output followed by less amplification or a lower initial output followed by greater amplification is of little to no consequence.
The truth is that all other things are likely not equal. That is, the spectral (frequency) profiles of the Full Circle and Fishman are likely quite different from each other and from other pickups.
Let's take a closer look at this phenomenon that many of us experience wherein as the level of amplification is increased, the sound often becomes more objectionable. Often, what is objectionable is the preponderance of midrange frequencies.
Now, starting at a low level of amplification, if we consider only the output of the rig, then increasing the gain will affect all frequencies equally. It will not, however, affect the perceived loudness (a psychological quantity) of all frequencies equally. In fact, as the level is raised, the predominance of the midrange frequencies will become
less and less (see
here), exactly
opposite to the common experiences reported.
So, what is it that explains our common experience? Here's my theory. As players, when the level of amplification is low, we hear and feel a mix of the energy of the bass itself along with the rig. That's true for the audience as well, especially in a small group setting. As players, the effect is pronounced as a result of our proximity to the bass and the fact that we are often behind the cab so that we hear less of the higher-frequency content.
Now, as the level of amplification is raised, the output of the rig dominates and, frankly, the amplified sound of our favorite piezos just isn't all that satisfying. Consistent with this are recordings I've heard of my own playing in a combo setting. I'm always less happy with the character of the sound than I was at the gig. I think that's because what I hear in the recording is essentially only the rig.
What may add to all of this is that, at low levels of amplification, the temporal peaks are what are "popping up" as audible. When the amplification is increased, the flat temporal attack/decay that is actually uncharacteristic of the instrument itself becomes dominant. This relates to the position stated
here, with which many seem to agree.
Enter the Ehrlund pickup. I won't reiterate here what's been discussed in the dedicated threads but, suffice it to say, it is a different animal than the piezo pickups usually discussed, both in terms of its spectral profile and the temporal attck/decay profile it transduces. I think that's why when you increase the amplified signal of the Ehrlund it doesn't become objectionable.
