This is primarily directed at scotch
The whole deal with this HPF-Pre, well, don't knock it til you tried it. It does not affect the tone Pre se, of a sustained bass notes. That moment when we pull our finger across the string, our skin grabs and releases the string several times, maybe dozens, like a very short bow on an upright (I'll get to the upright in a moment). I have done extensive playing with all series of the F-Deck and I can break down what it does.
With the U-bass and electrics, 2 main things. First, especially In all passive basses, that attack I was talking about is a mechanical phenomenon on the instrument with the strings being pulled and released, and with our amp and speaker reproducing (or trying to) all that. There are high (click, scratch) artifacts and low (think thuds) ones that are produced. The low ones could be desirable to a point, but it is stuff that generally robs the rest of our tone of clarity. The filter, even set at its lowest point, cleans that up for us and let's a great full range tone through. Remember the roll-off STARTS at 35 Hz. Roughly low D. It slopes down from there into invisible low frequencies, but when our amps see those and try to put them through our speakers, they jump around and move air that interferes with our audible, desirable bass frequencies. Our low B is what, ~30 Hz? That point would only be 3-5 db cut. No one I have heard of has notices a difference or like that range is missing its beef. I find it clearer and tighter for the above reasons. And since furthermore our speaker tend to drop off around 55 Hz, that filter range is already 10-15 db low on output, and it compensates by accentuating upper harmonics, and it becomes a mushy mess from a speaker mechanical standpoint. So without it, it is possible we are using up a lot of wattage so we can push muddy stuff out of our rigs. That recent country song about just wanting' to roll the windows and drive.. It is in Bb, and the bass plays low Bb (28ish Hz) the whole time, and all I hear is the second harmonic (F, ~86 Hz). It is louder than the fundamental!
The second thing is that some rooms have standing waves that multiply and muddy things up. Turning up the filter can compensate and lessen the actual reverb of the bass (that is produced by upper harmonics of very low frequencies) without taking away any of the fundamental oomph of your tone.
With the upright, it is the same, just with a physical sound board and longer scale, the low low part of the attack lasts a little longer (thump thump
) and at loud volumes the HPF-Pre is better than a compressor. The U-Bass's strings mimic this slower attack.
It's only a hundred bucks or less it's at least worth a shot. I personally prefer series 2 on my piezo equipped instruments. Series 3 is excellent for loud volumes and electric. But no one would noticed without a direct comparison.
