Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Tuning the bass

I have been reading an article by Rick Baldassin on tuning the bass.

Some excerpts,

“Tuning aurally, the object is to try, as much as possible, to eliminate beats in the loudest set of partials, while at the same time minimizing beats in the neighbouring sets of partials. Once this is achieved, then the progression of parallel intervals, such as 10ths or 17ths, is tested. If everything checks out, then fine. If not, then a decision must be made either to favour the octave sound, or progression of intervals.”

Rick goes on to say that the beats one hears in the low bass is made up of the partial pairs, 2:1, 4:2, 6:3, etc...

“As tuners we try to eliminate the loudest beats, while at the same time minimizing the other beats. Sometimes, this means that none of the pairs are tuned beatless, but all are beating very slowly, almost not noticeably.”

With regard to the low bass of the Yamaha C3 that he was tuning with a bunch of other tuners, it was agreed upon that the C2-C1 octave did not sound good anywhere, but found a place that was least objectionable. It turned out to be tuned between 8:4 and 10:5.

“This excess inharmonicity made it impossible to eliminate any beats and still minimise the others, so the octave sounded bad no matter where it was placed.”

“From the above, we can see that partial matching, or elimination of the loudest set of beats, is the main criteria used to determine the best octave. Sometimes the beats cannot be entirely eliminated, but are then minimised as much as possible. When there are several loud and incompatible beats present, there can be no placement which sounds good, tuning by ear or with a machine.”

The article was written in July 1989

In the low bass there are often octaves that begin to make a noticeable beat and the best thing I think is to regulate that beat progressiveness.
It is not noisy as with too large 10th or 17th in basses. it is lively, in fact.

I like to use the 7th (+2 or 3 octaves) beat progression as proofs of even progression in the low basses..

It is a good attitude IMO to work with beats, not trying to fight them. That way they are not as disturbing.

Best regards

On partial matching, Mark, these plots from C1 and C2 on my upright illustrate the challenge.


C1


C2

The iPhone program was showing that D# and E were the most prominent partials at the instants when I captured the images. The most prominent ones fluctuated as the sound decayed.

I have found that voicing the bass makes a big difference in how it is tuned. Hammers need to be really soft, because if the hammer bounces off the string too fast, it is like whipping the end of a jump rope really fast, so that the rope goes into one of the higher modes of vibration. The higher the mode of vibration, the less fundamental there is.

After I voice the lowest bass hammers softer, the lowest strings may have to be lowered in pitch by quite a bit, and given how close the frequencies of the fundamentals of adjacent notes are, it could be more than a quarter tone.

As an ear tuner, the bass has always been the easiest part of the tuning. Strive for perfect octaves in the low register, but test with double octaves and thirds, and thirds plus an actave.

What, no minor 7ths plus an octave
No augmented 4ths You can tell I'm guilty of reading the book he wrote

All joking aside, this is exactly why I think it's silly to get hung up on octave types when a compromise is what's needed. Of course I'm willing to have my mind changed if anybody has another opinion.

What's your guys take on tuning with strict octave types? I was always taught to tune as wide as possible within the barriers of the ear checks set out for me, limit being how much the double octave beats among the obvious other intervals. There were never any numbers like octave types thrown around. The piano seems to set its own perimeters well enough.

Thanks Isaac and BDB

Regards,

Sometimes as wide as possible can mean almost narrow if the piano dictates that the resulting M3's, 10ths and 17ths are too fast, intense or otherwise objectionable that they can create a comic effect in the middle of a serious piece of music. A few models from some very fine major manufacturers produce tenor registers that are very full in tone quality where great care must be taken in this respect as their company concert tuners would have told you.

Tuners, when listening to isolated M3 compounds fall in love with the vibrato they create in isolation and sometimes increase its speed but it can be disastrous in context to hear a sudden drunken warble that draws attention to itself and sounds simply put of tune in the middle of an otherwise still passage.
If a string or other ensemble played similar intervals, we could quite justifiably proclaim them to be out of tune.

This, for me is the blessing and the curse of UT's. Equal beating doesn't completely ameliorate it and, in context, the interval where the equal beating takes place is entirely missing most of the time Even if a knowledgeable musician could include it, it would very likely be in the wrong key. Contrast and variety are beautiful things in the right place.

5ths don't have to be as pristine clean as we often fondly imagine that string players prefer them (up to a point). That's something the UT movement has reminded us of.

I find it interesting that ancient tuning departments with many generations of experience teach no flattening of the tenor and bass. When I lived in places where most tuners and/or their teachers were virtually self taught and theory tops experience, most tuners were self employed loose cannon and the habit of excessive stretching was predominant.

I think it was in Alfred Howe's book that I read " there shall be no flattening of the bass to create a deep effect". I merely repeat it for what it's worth.

I wouldn't sacrifice a still and satisfying octave that I could quite happily finish a piece of music on merely to satisfy the demands of a perfectly smooth progression of other intervals that nobody but tuners ever listens to in that way, provided the above conditions are met. That would be taking the concept of ET too far.

I tend to listen to lots of intervals when tuning the bichords to get the progressions right, and to balance the octaves and double octaves etc, but as I get lower in the bass I start concentrating more on the octaves and double octaves in isolation. The partial structures are so unpredictable that picking out any compound intervals becomes counterproductive for me. I tune from flat and raise it until the octave becomes reinforced by the 2nd partial of the bass note, and starts to bloom rather than beat. Sometimes I use my leg against the casework to feel this effect. I check the 12th and 17th to make sure I'm not narrow, then move on.

Only on the exceptionally good pianos do I put more effort into smoothing out the bass octaves using compound RBIs. On the rest, it isn't worth it. I don't tune many exceptionally good pianos!

Thanks Phil for your input.

I should have named the thread heading, "Tuning the low bass", as this is more the topic I was hoping to provoke some discussion on.

One other thing that Rick said when tuning the C2-C1 octave, remembering that it was a Yamaha C3 grand with high inharmonicity in the bass and that this is all taking place with a group of tuners present to evaluate tuning the bass and low bass and the intricacies and difficulties involved in that,

"The next octave tuned was from C2-C1. After several minutes, the group could not decide where the octave sounded best. When part of the group felt the octave sounded good, another part of the group would say it sounded awful. There seemed to be at least three factions scattered around the room. We finally agreed that it didn't sound good anywhere, but found a place which was least objectionable..."

Mark,

I have limited experience, but I'd like to add to this thread, if I may.

I've battled, and still do, to tune the low bass through octave partial matches or through evenly progressing intervals such as M17 or m21. Rather, I've tried a technique described amongst others by Reblitz, by sounding a major chord together with the note to be tuned, e.g.
For tuning F1, sound F2-C3-F3-A3 (essentially the harmonic series)

I've found that this tends to give quite a narrow window for the note to be tuned, and the resulting stretch and octaves are acceptable (to me) - even though M17s and m21s may not be perfectly progressive.

[Edit: I now use this method, from about G2 (D3-G3-B3) all the way down to A0 (A1-E1-A2-C#3).]

I was wondering whether you or some tuners here are using such a method. If it's too inaccurate, or only a beginner's crutch, feel free to ignore this post.

No growling low octaves allows them to sound more in tune indeed even if the tuber sometime wish to have those
The beats perceived are due to more tight octaves but they are not disturbing.
IH and see tea of basses are all other the place that is a why I like to refer to a progression it helps me to detect things my ears liked but that could be more social.

Hi Mark

Thanks for your post.

Yes, what Reblitz says is one way of getting things to where the low bass is sounding as good as it can.

Usually two passes of the bass, one to get things in the ball park and that by tuning single octaves. The second pass is to refine so that the best sound for the low bass is achieved.

Ghosting is one way of tuning the low bass, whether it is using single partial test to tune a particular octave/interval or a tone cluster. One can either play the tone cluster and then the octave one is tuning, as Reblitz suggests, or hold down the octave you are tuning, with the dampers off the strings and strike the tone cluster a staccato blow and adjust your note you are tuning to where it is quietest.

One can change/increase/decrease the stretch of the octaves/intervals by varying the tone cluster accordingly.

So, for less stretch use the harmonic series of a 4:2, 6:3 and 8:4, eg, tuning C2-C1, use C3, G3, C4 and for a wider stretch, 6:3, 8:4, 10:5, use G3, C4, E4, etc...(A technique that David Love, RPT, recommended to me, though he is strictly an ETD/hybrid tuner today, checking his work by ear).

As I tune many different pianos, in varying conditions, there are obviously other dynamics involved and so one uses varying techniques and combinations to tune the low bass as best as possible. Many of my clients only want a tuning, though I offer other work at the outset, so that is all they get and then I have to move on to my next client.

I hope this helps,

Using multiple notes simultaneously can work. Be aware that it may mask or cancel what is really going on when the harmony is more sparse.

Even adding the 5th inside and octave needs to be checked as seperate intervals because of the cancelling effect that often takes place.

Isaac, can you rewrite your post as to make what you are saying clearer please?

Just to clarify, when I said, "Many of my clients only want a tuning, though I offer other work at the outset, so that is all they get and then I have to move on to my next client".

I often include vacuuming out the piano and pitch adjustments in the tuning, anything from 10 to 20 cents. This is more so for new clients. So, my clients, apart from having their pianos vacuumed out, get a pitch adjustment too, with the tuning. All depending on the piano and how much talk may take place with my client before I begin the tuning, the approximate time taken from beginning to end is, anything from 1 hour to 1.5 hours.

When it does take 1.5 hours, I am running late, and let my other clients know in advance. I usually catch up by the end of the day, but sometimes not, and then I am tuning at 7pm at night.

Dan Levitan, RPT, in one of his articles, says,

"As octaves descend into the low bass, the octaves sound less like unisons, we hear more and more beats which are impossible to silence, and the range of acceptable tunings and methods of tuning them multiplies. The most conservative approach here is to tune all the octaves as pure 6:3 octaves.

Such a tuning will rarely be disputed. In general, octaves in this range should be as beat free as possible, but with so many audibly beating upper partials, the choice of octave size may depend on which upper partials are most prominent. As notes descend into the lowest bass, artistic factors and our sense of relative pitch begin to play a larger and larger role in the ultimate choice of octave size.

As long as the P5's, octaves, P12's, double octaves, P19's and triple octaves are reasonably quiet and consistent, and all the 5th partial intervals whose beat rates can be comfortably heard in this range progress smoothly, almost any size octave for notes in this range may proove to be acceptable"

I admire anyone who can tune the bass with ease. I always found it difficult - requiring great discernment, aurally. There is no greater challenge than a Bosendorfer 225.