Advantages/disadvantages of dual bore?

[Reedman1]

I’m curious: what effect does a dual bore have? I know bell size and shape, materials, and mouthpiece all play roles in timbre, clarity of articulation, volume, etc. so the slide configuration is just one piece of the puzzle, but how does that piece work? PS my daily player is a 2B with a Peppy bell and a Butler CF outer slide.

[Doug Elliott]

I think a traditional description of dual bore horns which is pretty accurate, is that they play with the ease of the smaller bore but the openness and sound of the larger bore. Or something like that. I usually don't really like the feel of dual bores, it seems a bit uneven to me, and almost too open. At one time I had a Bach 16 for a short time and I sold it for that reason.

[tbonesullivan]

IMHO, whether it works FOR YOU depends on you and the design of the horn. The 2B has always been dual bore, and many people have loved it for decades.

[Vegasbound]

Ralph Sauer used a 525/547 on his conn I think especially on first or solo rep it is a great set up

[LeTromboniste]

I haven't had enough experience comparing horns that are otherwise the same to really get a feel for the difference it makes.

But I find it very interesting that dual bore is such an old concept. Surviving trombones from the 16th to 18th centuries typically have dual bore slides, and the Germans never stopped making them that way until today. As far as I know it's only with French trombones of the 19th century that single bore becomes really a thing before these influenced English and then American instruments and they became the majority. Clearly there was something to dual bore slides very early on that made it the preferred design.

[whitbey]

Except for bass I need dual bore. For me single bore makes me either blow the MP off my face or makes me use too much pressure. I have some neurological things going on that I do not feel my face that well. Dual bore lets me just blow.
I use a 547/562 for big groups and 525/547 for small. 500/508 for jazz. The Conn alto is dual bore to.

Before I bought a dual bore slide I had a neck pipe opened up about .004". It helped, but was not a good choice.

[hyperbolica]

I've owned 6 dual bores that I really liked. One was the 32h, 495/522. The only thing I didn't like about the horn was the width of the slide. These are really nice horns with a great sound. I could listen to that horn all day long. Next was the 30h, which is similar, but smaller (maybe 485/508), but also with a (too) narrow slide. You get the faster, clearer articulations like a small bore, but the mellower sound and comfort of a medium bore. Very nice compromise horns if you can't fully commit to two competing sizes.

The third and fourth I've owned were Holtons, the 156 and 159. They were both 547/562, but the 156 was a straight tenor-leaning instrument. It was incredibly powerful for big orchestral stuff. Think Jay Friedman and Chicago Symphony. The 159 had a single trigger, but leaned toward the bass side of things. Really amazingly big sound, without feeling like a bass trombone.

The 5tth was an Olds single trigger bass (S-20), with a 555/565 bore. It saves a lot of air to have a smaller top slide, plus articulations and just moving around on the horn are so much easier with the smaller tube.

The last one, which I still own, is an Olds Recording (495/510). I don't notice any systematic weirdness (and haven't) with this horn. If it's there, it's hidden behind other characteristic features.

If there is one common characteristic of all dual bores I've owned, it might be either the power or the sound. I like the grainy, organic sound that comes especially from the Conns and small Olds. The potential power of the Holtons and Olds was really noticeable.

For me, the 2b was always just too small to feel comfortable on. And I never really played the Bach 16, although I owned a 16m, which is a straight 508 bore.

I agree with Doug's characterization. You get the better articulation, nimbleness, and air savings from the top slide, and the sound of the bottom slide.

Dual bore can work against you too, though. With a bass bone, if you've got 562/578, for some people, that's just too much air to blow and too woofy a sound. And of course it's a bit heavier.

EDIT: I need to add a couple of Yamahas, a 350C and a 455g, both 500/525. The 350C is a bit of an oddball with the C/Bb valve and short overall configuration. i do really like the 455, though, as it's nimble, and plays very nicely where ever you don't want a 547 bore. The 456 model (500/525 w/F valve) might be a really nice light duty horn, although I've never owned one.

[harrisonreed]

It works well on altos

[Reedman1]

Very interesting. As an amateur who started trombone at 60, I find all the various configurations and nuances fascinating, but also puzzling. I haven't played many types or sizes of trombone; I do listen, and I can tell whether I like the sound of a given make/model or not. But I can't listen with my eyes closed and say, "Oh, that has to be a dual bore," or "That's definitely a single bore." I can pretty much tell large bore from small bore by listening. Medium bore is a wash. And the bell and the mouthpiece change everything, too...

[hyperbolica]

...But I can't listen with my eyes closed and say, "Oh, that has to be a dual bore," ...

I don't think anybody can.
The differences we talk about can be very subtle to hear, but are more apparent when you talk about feel. Being behind the bell is entirely different from being in front of the bell.

[dukesboneman]

I`ve had a couple dual bore horns.
The Conn 32H (I`ve had 3) are amazing instruments. .500/.522 I`ve heard some say here that they are quircky with
intonation. I never found that to be the case. However the bell on a 32H is a little lower than some horns so that might account for the problems.
The Conn 30H, which was Conn`s answer to the 2B, was a (for me) WAY TOO bright an instrument. I played in the loud rock band back in the early 1990`s and it was perfect but for ANYTHING else NO!!
I had a Later Conn 8H with a .525/547. I did not like the dual bore on that horn, but also I just really didn`y care for the horn itself. The person I sold it to LOVES it.
I`ve been toying with the idea of a .508/.525 slide on a Bach 36, but I need gig $$$$ before this can happen

[BurckhardtS]

When comparing instrument makes and styles, you also have to remember that everyone is biased, and thinks that certain features will create certain qualities - and most people if you test equipment back-to-back in front of them will follow that bias. Blind testing is a smart idea.

[Reedman1]

The 32H has a beautiful sound. On the non-dual side, I really like the sound of the Martin 4501 Urbie, the 4H, the 48H, and the .508 horns. Oh, and of course, the Bach 6.

[ChadA]

It really depends on what two bores and what you’re doing with them. I use a 525/547 slide on my 88H quite a bit. It works well in quintet and solo settings, and I’ve used it in orchestra on principal. On bass, I use a 562/578 dual bore and have for years. That’s my preferred setup for orchestral and most solo stuff.

There was a concert where I played both horns, making it a quad bore day.

[Reedman1]

There was a concert where I played both horns, making it a quad bore day.

Too bad there's not a "like" button here...

[Tremozl]

Dual-bores tend to make certain partials hard to center (especially the 3rd partial.) This effect becomes pronounced when playing at the end of the slide, but isn't as bad when in 1st position or near there.
This is because of all the extra small-bore tubing that is also added when playing down further. It seems to make the horns unstable.

The effect is very pronounced on the BBb Contrabass Trombone, which uses a dual-bore double slide; when playing in 6th position the 3rd partials are extremely hard do center since there is so much extra small-bore tubing having been added. When playing with the trigger down instead of using the slide, those same notes tend to be more stable and easier to find.

On more common Trombones the effect will still be there, just less extreme.

[Reedman1]

Dual-bores tend to make certain partials hard to center (especially the 3rd partial.) This effect becomes pronounced when playing at the end of the slide, but isn't as bad when in 1st position or near there.
This is because of all the extra small-bore tubing that is also added when playing down further. It seems to make the horns unstable.

The effect is very pronounced on the BBb Contrabass Trombone, which uses a dual-bore double slide; when playing in 6th position the 3rd partials are extremely hard do center since there is so much extra small-bore tubing having been added. When playing with the trigger down instead of using the slide, those same notes tend to be more stable and easier to find.

On more common Trombones the effect will still be there, just less extreme.

Can anyone else corroborate this?

[Trav1s]

With my 32H, the 3rd and 4th partials just feel off. I have tried many different mouthpieces without luck. The best option is my current DE combo that I also use on my 24H but the horn still just feels odd to me and I can't befriend it after nearly 2 years of ownership. It is looking for a new home.

[Doug Elliott]

Dual bores have always felt a bit odd to me. The "center feel" just isn't the way I want it to be. Maybe it just takes more time or more experimenting with backbores.

Traditional German dual bores are different, but the whole horn is different too. I think a more conical design like dual bore is trying to accomplish needs other adjustments too.

[Tremozl]

Dual-bores tend to make certain partials hard to center (especially the 3rd partial.) This effect becomes pronounced when playing at the end of the slide, but isn't as bad when in 1st position or near there.
This is because of all the extra small-bore tubing that is also added when playing down further. It seems to make the horns unstable.

The effect is very pronounced on the BBb Contrabass Trombone, which uses a dual-bore double slide; when playing in 6th position the 3rd partials are extremely hard do center since there is so much extra small-bore tubing having been added. When playing with the trigger down instead of using the slide, those same notes tend to be more stable and easier to find.

On more common Trombones the effect will still be there, just less extreme.

Can anyone else corroborate this?

I think what Doug Elliot is saying directly above corroborates it? Hopefully?

[Reedman1]

Can anyone else corroborate this?

I think what Doug Elliot is saying directly above corroborates it? Hopefully?

Yes, I guess so.

[Doug Elliott]

Yes. I just wanted to add that I've played some really exceptional German style dual bore horns that don't conform to those qualities. When you make the entire instrument more conical, it works, but on a different way.

[Reedman1]

What a puzzle. So American-style dual bore instruments have a biggish sound and clear articulation at the cost of loss of definition in the 3rd and 4th partials, but German dual-bore horns don't? And otherwise, the dual bore doesn't change the timbre - it's still trombony? (I mean, I play a dual-bore 2b - it sounds like a trombone, so I know that one, but it does sound a bit bigger than my .50 bore XO 1632). I don't find much difference between .50 and a dual bore in terms of the 3rd partial, though. Should I?

[BGuttman]

The differences are pretty subtle.

Note that a dual bore 2B is .485/.495, so it's smaller than a .500 XO anyway.

I have a dual bore Olds that plays very nicely. No issues on 3rd or 4th patials. In fact, most Olds trombones were dual bore and they were generally well liked in their day.

Don't make this into more than it is. It's like comparing a Super 20 Tenor Sax to a Mark VI Tenor Sax.

[Reedman1]

I never played either a Super 20 or a Mark VI, for what it's worth. My primary sax was baritone (Selmer), then alto (Martin Committee). I didn't have a special tenor. But we digress.

The 2B sounds bigger to me than the XO, in spite of having a smaller bore. It's probably because the Peppy bell is 8" and rather heavy yellow brass, while the XO bell is 7.5" and lightweight rose brass. But I have approximately the same issues with the 3rd partial on both.

They're both great horns, anyway.

[Doug Elliott]

You really shouldn't ever attribute any one aspect of a horn's construction to its playing qualities. It's a sum of its parts and everything has an effect.

[Reedman1]

I guess what you're collectively saying is that dual bore makes a difference unless it doesn't, and that expert trombonists may detect a difference in response around the 3rd partial or not...

[Doug Elliott]

Exactly. Judge any horn by how it plays, not how you might think it should.

[Reedman1]

Well, OK, that's useful advice. Turning it around, though - if I were a trombone maker and I wanted to make a new trombone that generally produced a certain sound, I would probably go with a small bore and bell for a lighter sound, a big bore and bell for a fuller sound, choose materials to emphasize those characteristics and modify for weight and cost, right? What might I think my design might gain from having a dual bore (or not)? Why would I complicate my design, unless I thought there were a payoff?

[BGuttman]

There was a time when cornets were more popular than trumpets and a more conical sound was desired. The dual bore trombone was an attempt to make the trombone more cornetty. That coupled with TIS and a longer taper from the joint to the bell flare was the intent.

Note that a single slide bore TIS instrument with the longer taper can have as much or more effect than simply having a dual bore slide.

[Crazy4Tbone86]

We should not assume that dual-bore trombones sound a specific way, feel a specific way, center notes differently, or have specific tuning tendencies. The dual-bore slide is just one part of the complicated trombone equation.

I think this topic is very closely related to an article I remember reading over 30 years ago. Four or five top-notch brass players were being asked about the features/dimensions on their prized instruments. They all agreed that their favored instrument had the proper resistance or "back pressure feel" to give them the articulations, tone quality, flexibility, endurance, etc... that they were seeking. All of the artists also agreed that there might be a dozen or more different construction combinations that could potentially result in that perfect "feel" and they felt fortunate that they found one of those combinations that worked. The equation included (but was not limited to): mouthpiece variables (this alone is dozens of options), leadpipe aperture, leadpipe taper, leadpipe length, straight vs. dual bore, cylindrical versus conical, taper of tubing at multiple places on the instrument, etc, etc, etc....

I remember that the trumpet player in the article had one section of his main tuning slide that was oversized by about 10 or 11 thousandths of an inch and then the bore came back to the normal .459 ML bore in the valve cluster. He admitted that it was unique among trumpet players, but it worked for him.

I have a few .547-562 dual-bore tenor slides. I usually use them for 2nd trombone parts on large orchestral works. Most of the time, I prefer to pair the dual-bore slides with the same mouthpiece, leadpipe and bell as my straight .547 slides......it gives me the broader sound I am seeking. However, I am completely able to make the dual-bore slides sound and feel exactly like my straight .547 bore slides. I can do this by using a mouthpiece with different components, changing leadpipes or switching to a more constricted neckpipe. Again, there are multiple ways to create the particular "feel" that a musician is seeking.

I don't think trombonists should conclude that dual-bore slides play a particular way. Trombonists should keep an open mind and consider it one of the many options we have in trying to find an instrument that works well for us.

[hyperbolica]

Well, OK, that's useful advice. Turning it around, though - if I were a trombone maker and I wanted to make a new trombone that generally produced a certain sound, I would probably go with a small bore and bell for a lighter sound, a big bore and bell for a fuller sound, choose materials to emphasize those characteristics and modify for weight and cost, right? What might I think my design might gain from having a dual bore (or not)? Why would I complicate my design, unless I thought there were a payoff?

I can't answer that. But as a player, I actively went looking for a dual bore at one point to get something that sounded like a bass, but took less air. That landed me with the Olds S-20, but possibly also a Holton tr159.

Also, as a player, you don't always have the option to try before you buy. Especially if you don't live in NY or LA or DC. So you kind of have to try to get in the neighborhood by reputation and by specs.

You might like the faster articulations of a 500 bore but also the meatier sound of the 522, which would land you in 32h territory if you prefer light horns, or Olds Recording if you prefer heavier horn and sound.

There's a small Yamaha (356?) that does something similar. People who design and build horns have a more detailed, more proprietary, and more empirical view of causality in brass than we mortals. I don't think they always get exactly what they're looking for. Design is not that precise a science in this realm. A lot of horns are built with between a builder and a pro trying options, or trying to copy something that already exists and then tweak it a little.

[Reedman1]

Thanks, everybody, for helping me to think about this question. You've all contributed key pieces of the puzzle - warmer or cornettier sound (Bruce Guttman), bigger sound with easier playing and a different feel (Doug Elliott), history of the design concept (Maximilien Brisson), feel and reasons for trying or buying (Hyperbolica), caveats (Travis B. and Tremozl), details about dual bore in use (Brian Hinkley). You've fleshed out the picture of how to think about dual-bore trombones and why one might choose them or not, and made clear that it's not a hard-and-fast rule. Now let's go bother the violas.

[drbucher]

The Holton 156 and 159 were both 0.547/0.559 (according to a Holton brochure), perhaps to deal with intonation issues herein discussed that would have pertained to the 0.547/0.562 prototypes. Later single- bore versions of the 156 were developed to deal with this issue.

[ithinknot]

The Holton 156 and 159 were both 0.547/0.559 (according to a Holton brochure), perhaps to deal with intonation issues herein discussed that would have pertained to the 0.547/0.562 prototypes. Later single- bore versions of the 156 were developed to deal with this issue.

Hmmm. I'm pretty certain there wouldn't be any deal-breaking tuning quirks that arise specifically from this .003 difference, especially considering that 88H and 36/42 bell sections are commonly used with all kinds of single and dual bore slides between .525 and .562 without the world ending. In any case, dual-bore 156s don't have any particular problems in this regard and - at least in my experience - seem to have better/more consistent high slots and tuning than many other large bores.

(Also, the single-bore .547 versions of the 156 seem to come from the first couple of years of production, *after* which .547/559 became the standard.)

[drbucher]

The Holton 156 is the natural result of customizing a stock prototype trombone, much like the Alessi custom models for Edwards and Shires. An email from Mr. Friedman to me documents that he designed it, along with an advertisement sent to me from the dealer who sold it.

[ithinknot]

Makes sense, I guess. Then, why 547/559 instead of 547/562? Only Jay knows.

Eh, I bet it had nothing to do with JF.

Some mandrels turned out a few thou undersized and they decided to use them anyway? (In case anyone wondered, I've measured a couple of 156s and the lower leg is dead on .559, so they weren't kidding...)

Everything Holton is nuts. You don't even need measurements - just look at the ergonomics. Trigger and straight horns all have completely different receiver/brace/tenon/cork barrel geometries model to model and year to year.

Any normal manufacturer would have a standard basic slide layout - R&D would establish 'averagely comfortable' bell/slide brace and lever positions - and then you'd bore out standard components to fit different slide tubes as needed. With Holton, things seem to have been designed from scratch, for better or worse. It probably explains some cool stuff pursued regardless of commercial demand, like the screw bells... and some other things...

[drbucher]

So, the Holton 156 is the result of poor quality control? Perhaps.

[modelerdc]

I think it's best to play the horn first and ask about the specs later. Good horns have been made with both single and duo bore, I think of duo bore horns as having the resistance and breadth of sound of a horn in between the large and small-bore sizes of the tubes, nothing too complex.