Intonation Big Bore = Less Forgiving Intonation & Tone

[rhysonsax]

@turf3 As someone with a very limited technical or mathematical background, I have never been able to understand how to read M.Postma's graph. Can you provide an explanation?

In Marten Postma's own words:

Bore profiles illustrate the way in which a saxophone is conical. Bore profiles are best illustrated in a graph where the length of the instruments (in centimetres horizontally) is depicted short in relation to the width (in millimetres vertically).​

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Several instruments are stacked in a graph, each time placing the zero of the vertical scale a step upward. Thus a quick comparison between the different types of cone is possible. Already at a first glance it is clear that a saxophone is lot more complicated than just a cone. Especially the necks show various deviations from the cone shape and there is great variety in form in the way in which this narrowing is shaped. Its aim is to keep intonation at bay in the upper end of the second register. Only in a few instruments, this narrowing is visible to the naked eye. Bottom bows also show deviations from the cone. A few more observatisons based on these graphs are to be found in the newly written History-section.​

It might have been more useful to others if Marten had provided the raw data but I can't find the actual measurements. He presents two versions for measurements of each sample instrument, which he describes as "Profiles in full" and "Profiles compared to the average main conicity of 20th century instruments [in green]."

The graphs of bore measurements are shown to the right of a thick black vertical line. To the left of that line is a sloping straight line that is either an extrapolation of the main body tube conicity (slope) (shown in black) or an extrapolation of the average main tube conicity (shown in green.

As Marten says, one of the key findings is that the main body tube of instruments measured seems very close to a perfect cone and that the neck, bow and bell diverge quite a long way from that, with significant variations between different makes and models.

The Postma Graph is of his measurements of selected alto saxophones.

He has separate graphs for soprano, alto, tenor and baritone. The example given by @turf3 was for tenor.

Rhys

 

[Dr G]

I would like to see the variability within any model. I measured neck IDs of a handful of Selmer Ref 36 and Ref 54 tenor necks, and recall the range was at least 0.497“ to 0.510”.

Regarding the Bueschers: I would very much like to see data for same year Aristocrat (Big B) vs TH&C. I had one of each for a while, and found them to blow very differently - the TH&C has a larger bell flare and larger bow radius.

Regarding Borgani Jubilee tenors: I have had several of the “J” models and a few of the OBT. I thought the OBT was a smaller bore because the bell flare was smaller and the J neck tenon was substantially larger that the OBT. When I wrote to Borgani to ask about it, I was told that the bore geometry remains the same, but the tenon receiver was changed (hence my observation that the necks were not interchangeable).

 

[turf3]

I find the comparison to average more useful because you can compare instruments against each other more easily.

 

[Yansalis]

Although this information is as apocryphal as general discussion of bore size tends to be, and although this has already been mentioned, it is worth underscoring that Keilwerth bores "are said" to have changed in the late 20th c., so referring to them as a monolithic type is probably blurring an important distinction.

 

[spike]

He has separate graphs for soprano, alto, tenor and baritone. The example given by @turf3 was for tenor.

There appear to be discrepancies in all his charts with regards to sax type.

 

[rhysonsax]

There appear to be discrepancies in all his charts with regards to sax type.

Can you explain what these discrepancies are ? (In addition to the YAS appearing in the tenor charts where YTS is presumably intended).

Rhys

 

[spike]

Hi Rhys - have to admit I seem to have confused myself, I had three browser windows open in an attempt to compare and seem to have got perplexed. Yesterday was a funeral day with heavy fog and freezing temperatures. I should perhaps have refrained from any mental exercise.

 

[turf3]

I will say that my impression is that bore characteristics don't always seem constant across all voices of a particular sax model - baritone XYZ might have a visibly different characteristic than tenor or alto XYZ. Also, some really popular models weren't measured - or alternately, certain important ones. For example, I don't think there are any Selmer Super/New Large Bore measurements, yet we talk a lot about how the bore was supposedly changed between those and the Balanced Action.
I think we're talking about one person's individual effort here and if you think about it you can easily see that just taking this many measurements on one instrument is a significant undertaking; to secure the use of this many horns and take all the measurements that were taken is a huge job. So I don't have any criticism of the project, but by its very nature it's not going to be able to answer all possible questions. Dr G's point about variability of individuals within a given model is excellent as well, but again it appears out of scope of the actual project that was done.

We may never see again such an effort, as it isn't something any company would fund (or if they did, they would keep all the information as proprietary); I think you'd have trouble getting university funding for a PhD thesis that involved this much work; and it'll take a specific kind of dedicated individual to do the work on their own time and budget.

 

[jbtsax]

The only other work along these lines I am aware of is the table of measurements of various saxophones done by Nederveen on page 106 of his book acoustic aspects of woodwind instruments. Unfortunately the instruments measured included a Shenkelaars tenor, a Rasco tenor, a Shenkelaars alto, a Selmer soprano, a Shenkelaars soprano, and a Solotone soprano---which are common in the Netherlands but not in the U.S.

 

[Ivan]

... the range was at least 0.497“ to 0.510”

My Imperial thinking is a tad rusty

Is that feets or inches?

 

[lydian]

My Imperial thinking is a tad rusty

Is that feets or inches?

That's feets. We're talking REALLY big bore. Almost impossible to control intonation.

 

[Dr G]

My Imperial thinking is a tad rusty

Is that feets or inches?

Well, let's try a napkin approximation to make a guess...

0.5 x 1 foot = 6 inches = approximately 15cm

That's more like the size of a bell flare, so it's not that one.

0.5 x 2.54 cm/in = 1.27cm

That's more like the small end of a crook (neck).

 

[Ivan]

That's feets. We're talking REALLY big bore. Almost impossible to control intonation.

Thunk so

I'm into brewing beer and I realise the US gallon is not as big as the UK version

Wouldn't surprise if miles were miles apart

So when it comes to measuring a brass cone, you might as well use rods and chains

 

[turf3]

Well, what do you think the unit "foot" might possibly be named after?

I'll give you a hint: all my shoes are just about 30 cm long...

 

[Ivan]

0.5 x 2.54 cm/in = 1.27cm

My rule or thumb is 1.25

Over here the old imperial conventions live on... sheet material is 2440 x 1220mm (eight foot by four)

And you can ask for timber by the mm dimensions or simply say, "four b two", or "three b two"

 

[Dr G]

My rule or thumb is 1.25

Over here the old imperial conventions live on... sheet material is 2440 x 1220mm (eight foot by four)

And you can ask for timber by the mm dimensions or simply say, "four b two", or "three b two"

So you would concur that there exists no measurable difference between various saxophones?

Close enough for beer!

 

[EdJ]

I must be bored to have finally opened a thread entitled “big bore”

From what I’ve experienced as a listener, people that suck on one horn are equally likely to suck at least as much on another.

Better to blow in my experience but not that of Jackson Jeffrey Jackson

View: https://m.youtube.com/watch?v=DGbEXCq-Ybw

 

[Campbell]

Here's a weird, and probably contentious 😉, question that has arisen due to a comment another sax player made on Facebook.

Their comment regarded how large bore saxes, such as Keilwerths, are less forgiving regarding intonation and tone production compared to Selmer-based horns. The question is, is this actually true?

I've got an old Conn tenor, and I had intonation problems with it until I got a modern plastic Conn mouthpiece. It sorted out the intonation problems, and gives a soft, dark tone like '20s and 30s players. I had been trying to get a hard edgy sound, so I was using metal mouthpieces with baffles. It went so sharp, the crook was too short - I would have had to have pulled the mouthpiece off the crook. I think the aspect of the Conn mouthpiece which improved the situation was the size and shape of its barrel.

 

[turf3]

Yes, this is well known. You need a medium or large chamber mouthpiece (chamber about the same diameter as the cork bore, or larger) to get good tuning on Conn tenors and baritones. There are high baffle pieces that work, as in Dukoff (at least for tenor, the reports are that they don't tune well on bari) and some Jody Jazz pieces, because their chambers are larger - there are also some fairly low baffle pieces that won't work due to small chamber size - I have a couple of these.

To get the essential Conn-ness, though, more middle of the road pieces like Links and Meyers really bring out the character of the horn. And you don't need a duck call highbaffle grass cutter to be heard playing a Conn; if you can't be heard once you learn how to blow a Meyer or Link on a Conn, you need a microphone.