Dimensions of tone 2: timbre adjustment

[Rob A]

If youhaven't already, please have a look at dimensions of tone in which I explain the background of what is going on here.

In that thread, the question came up:

It would be fascinating to see a comparison of the same note, same strike dynamic, but with the tine/pickup intonation adjusted between the extremes of "more overtone" and "more fundamental," to see visually how the harmonic content changes with this basic Rhodes adjustment.  Thanks for sharing your analysis!

We should all be familiar with this, but in case you aren't here's the relevant figure from the service manual. Each note is separately adjustable in the manner described in the diagram.


The manual gets it right: let your ear be your guide. I just aim to help you visualize what it is you're hearing.

The procedure I followed was to take the same note F3 that we previously analyzed and sweep the tine position through the full range of motion while repeatedly striking a note with the same dynamics (within the limits of my ability). Strikes at the beginning are in the position shown at left, and the adjustment screw was turned to advance toward a position as shown at right. That procedure was recorded and normalized.

You can listen to the change in timbre:
http://music.linear1.org/mp3/timbre-test.mp3

Visualizing this as a waveform is useful to observe how the overall amplitude changes as well with the position of the tine.

(click to enlarge this diagram)

It's important, because psychoacoustics research has shown that people prefer a louder sound in A/B tests (speaker salesmen have used this for years to their advantage). You need to be aware of that tendency as you make your voicing adjustments--you can get suckered into a false preference just because one position is louder relative to another (and you may prefer the other if volume were equalized).

Now let's look at the spectrum changes with tine position.

(click to enlarge this diagram)

I can equate the descriptive terms in the service manual to reasonably empirical measurements in the spectrum graph. "Pure fundamental (deep)" is represented by a lack of harmonics and presence of the fundamental. The first three strikes or so fit this description well. "More overtone (ideal)" is represented by a strong fundamental together with noticeable overtones. The 10th through 15th strikes fit this description well. "Pure overtone (shallow)" is represented by the lack of fundamental, and strong presence of the first harmonic. The 21st through 24th strikes fit this description well.




But, you can see and hear that the "quality" or overtone profile is continuously variable--there's not a well-defined transition point between these tones, although you'll know them when you hear them. As the tine advances past the centerline of the pickup, the tone changes back toward a fundamental sound.

Observations:
1. "ideal" turns out to be the loudest too, luckily for us. That makes you most likely to land there if you "trust your ears" while doing voicing. The strikes from around 6-7 seconds were loudest, and most ideal from an overtone perspective.
2. "ideal" is probably actually ideal if you consider what we previously discussed, that it's easy to take overtones out with EQ, but hard to put them in.
3. The overtones we're hunting for are concentrated in the attack, so you should repeatedly strike a note while you adjust timbre, not sustain. (You can still perceive a difference if you do sustain.)
4. If no tine position sounds good, you may need to adjust strike line or conduct some repair procedure.
5. It's probably better to do voicing with a straight-off-the-harp signal, but at least try to minimize any coloring from EQ as you work.

Let me know if you like this kind of thing and I'll work on some more topics.

[tnelson]

Rob,
Many thanks! This is wonderful!  As you say, your ears need to be the guide when actually making the adjustments, but your plots of what we're hearing are so revealing.  Quite true what you say about needing to avoid being misled by volume and sustain when listening for harmonic character.  I've learned that the hard way.  There's a big psychoacoustic factor in getting a Rhodes set up by ear, though. Ear fatigue, room ambience, context (what I listened to most recently, or who I'm playing with), and some Factor X about the sonic content of Rhodes output can make a particular set up "sound" completely different to me each time I play it, even though the settings of the piano and amp are the same.  I'm sure we all experience that---my ear/brain interpretation of a live Rhodes sound seems not as stable as for other instruments.

[BJT3]

my ear/brain interpretation of a live Rhodes sound seems not as stable as for other instruments.

I could definitely relate to that. I've been pretty pleased with my Rhodes setup/tone for a while now, but before that, shew, it seemed I'd find a spot that sounded good that I thought I could live with one day, then the next day It'd sound completely different and I'd try tweaking the whole thing all over again. Adjusting strike line really helped me eventually find a sound that I am happy with. It's a very subtle adjustment, but once you find that sweet spot, it can make a world of difference.

5. It's probably better to do voicing with a straight-off-the-harp signal, but at least try to minimize any coloring from EQ as you work.

This is a tough one. Kinda like the chicken or the egg scenario. Do I dial in my Rhodes while listening to it as uncolored as possible (i.e. off the harp direct into an active DI or pre that does not color), or do I run it into my rig (i.e. Fender Twin, Pre with EQ, etc...)
I've tried it both ways. For me, I got a better result having it hooked up to what I'd be playing it through, (in my case, the Twin). This way I could get it sounding as good as possible and working with the coloration of the amp. It is a bit tricky deciding where to set the EQ etc on the amp... I've found that the legendary "6-6-6" setting actually works pretty good for guitar, Rhodes, and clav on my particular amp. This is where you set the volume on 6, treble on 6, middle on 3, and Bass on 2 (3x2=6). My amp is a blackfaced 100 watt, so not sure how well this setting works on the 135 watt Twins.

[Rob A]

Do you then mic your amp on stage?

I think it's a valid approach if you consider the amp a part of the instrument, similar to a guitar player approach. I always thought I got a better sound by carrying a direct box. No one really heard my amp tone unless they were on stage with me, and my amp was just insurance against the sound guy not having a monitor mix for me.

I think it's just a different point of view as to whether you consider the amp an integral part of tone production or not. That will be decided by your individual preferences I suppose.

[keysandslots]

I agree with Rob regarding voicing the piano off the harp or at least with the EQ flat.  That way, I can get as close as possible and then use EQ later to fix potential overall differences.  I currently have mine running off the harp into a Tube MP preamp, a BOSS CE-3 chorus and then stereo into an old Tascam 24 channel board.

This is probably obvious but don't forget to play the piano a bit as you're voicing it.  Start voicing at middle C and work your way up an octave or so, and then work your way down an octave or so.   You won't get as much ear fatigue this way.  Once you have a couple of octaves done, play a few chords and lines and things and see how it sounds.  A voicing that sounds fine as individual notes may not sound as good when you start playing harmonies.

I have a small .mp3 of my piano but I'm not sure how to attach it or where to host it.  Is there a "Photobucket for sound files" out there somewhere?

Randy

[BJT3]

In my case, i would mic the Twin. Since I have the 100 watt Blackfaced, it doesn't go to ear bleeding levels when used with the Rhodes. When I've tried dialing in the Rhodes direct, I find the result doesn't always translate the way I'd think when plugged into the Twin. The Twin amp does change the EQ and the way some of the harmonics shine through (or not). Personally, I like the change. One thing I like about going into the Twin is how it affects the response and feel of the Rhodes. I mean it affects how a note sounds when struck soft compared to hard while at the same time kinda fattening it up. Anyway, I'd recommend trying it both ways, but in my experience, I had a better go of it having it plugged into the amp I play it through mostly while dialing it in. BTW, thanks for all the work you've done with the Timbre graphs, always nice to see it in a different light.

-Ben-

[shmuelyosef]

I like to use a compressor with a fast attack and slow release to remove the volume effect when voicing. I run off the harp into the compressor...use lots of compression, but just shy of distortion, and then turn the volume down for the feed to studio-grade headphones or studio monitors to minimize ear fatigue from using an amplifier.