The gooseneck

[Elow]

Id like to start a thread about the role of the tapered tubing right after the valve, or slide receiver on straight horns. How important is the gooseneck to the overall design? On bass trombones with large valves, Axials/Lindberg valve, there is not much room and some makers don't include a gooseneck on their designs (Conn/Bach). Shires and Edwards build their axial basses with a gooseneck, much shorter albeit, and I imagine that contributes to a better overall horn. I feel like ever part of tapered tubing on a trombone really impacts the build design, and to not have that on some designs must impact that design, maybe negatively. My current bass trombone was built by the guys at J Landress Brass in NYC, without a gooseneck. I really enjoy my trombone, but if i cant stop thinking about that extra 5% playability.
Has anyone experimented with building bass trombones and spent time with different gooseneck options? Mathew Walker? Brad Close, building that replica Conn contrabass must've taken some trial and error.

[Burgerbob]

Yup, that's why my horn with Olsens has reverse tuning slide with a special tapered piece after the valves. It matters.

[Matt K]

That's why dependent basses still exist. Like Aidan, I have a little bit of tapered tubing past my valves, only very slightly more than if I had Axials (Long Island Brass made mine and had to machine a bit for the part past the rotors that goes into the tuning slide). IMO, some of the basses I've played wth Thayers like the Getzen 3062 or the Bach 50T3 can work really well even though there isn't much taper by pairing with a leadpipe that has a little bit more focus, like the Bach 50 pipe, Shires 1 or 1.5, Getzen 1, etc. But then, there are still dependent models like I mentioned, such as the Doug Yeo model that have almost as much tapered tubing as a large bore tenor.

That all said, more tapered tubing doesn't always mean better. I've played straight neckpipes that played way worse for me than a rotor... and there are certainly dependent basses that don't play as well as my independent bass for me. Everything has to match up and swapping things out may lead to a tradeoff where one aspect of your playing might be better but worse in another respect.

[ithinknot]

not much room

Tapered tuning slide inners are an option too.

Everything matters - but conicity≠perfection by default...

After all, TIS remains a minority interest. Lightweight TIS setups like the Kanstuls don't weigh significantly more than some standard-weight slides, and with carbon fiber one could go even further in that direction if slide weight was the only thing standing between the J-bend and universal popularity... But you have to judge the design as a whole. Take the opera wheel and sleeves off a 70H and things get pretty splashy. Without some interesting taper interruptions, you have to put resistance back in somewhere.

[elmsandr]

Random opinion without real data or theory to back it up: I tend to think that discontinuities matter more than taper. But having a nice taper is a good way to get rid of discontinuities.

This is one reason why I want to re-do the valves on my inline. Get this small section of the horn a little more sorted out. I was meaning to convert to dependent a long time ago, but I’m now thinking that might not be the way I want to go. Lack of a firm plan is why I stay where I’m at.

Cheers,
Andy

[tbonesullivan]

Most of the Inline Axial instruments I have seen have a gooseneck that looks to be in the order or 3/4" long, probably less. Bach's doesn't have any.

Looking at most Thein inline bass trombones, they don't seem to have any gooseneck, and on their dependent horn, the outer for the tuning slide goes right up to the valve. It doesn't look tapered, but I guess it could be.

[Matt K]

Can you see the taper from the outside? I was under the impression the inside taper could be quite aggressive with the external appearance being even completely uniform from one end to the other. Looking at the "Universal Dependent" one they have:

https://thein-brass.de/en/instrument/un ... dependent/

There does appear to be plenty of space for taper and that assumes that the Hagmanns don't have a taper built into them either, which some do. I'm a little surprised you don't see the "progressive bore" idea copied to other configurations to be honest. Like having the first valve be .578 and the 2nd valve being the typical .593. Maybe with some taper between them even. I guess there's probably a reason why not but that's a little surprising to me.

[timothy42b]

There does appear to be plenty of space for taper and that assumes that the Hagmanns don't have a taper built into them either, which some do.

Apparently to a sound wave, a bend appears as an expansion of bore. So arguably the valve does have a taper built in.

[tbonesullivan]

Can you see the taper from the outside? I was under the impression the inside taper could be quite aggressive with the external appearance being even completely uniform from one end to the other. Looking at the "Universal Dependent" one they have:

https://thein-brass.de/en/instrument/un ... dependent/

There does appear to be plenty of space for taper and that assumes that the Hagmanns don't have a taper built into them either, which some do. I'm a little surprised you don't see the "progressive bore" idea copied to other configurations to be honest. Like having the first valve be .578 and the 2nd valve being the typical .593. Maybe with some taper between them even. I guess there's probably a reason why not but that's a little surprising to me.

I would assume they would need to machine it if they wanted a constant external diameter with an increasing internal diameter. I don't know if that type of thing would be possible to draw, and having a constant outer diameter just seems like overkill.

On the other hand, never underestimate German craftsmanship and engineering. I still remember the story of a Japanese company (I think?) developing the worlds smallest drill bit, and by the time they premiered it at an engineering conference, a Germany company had drill bit that could drill a hole through the Japanese drill bit.

[Blabberbucket]

You could certainly draw a tube over a tapered mandrel with a fixed washer to get an internally tapered tube with a constant outer diameter. Dimensions would need to be carefully considered. I have also seen that Hagmann produces "progressive bore" valve sections where the first valve is a smaller bore than the second. Which, even though maybe not an even taper, would mimic the acoustical effects of a tapered tube.

To the best of my knowledge believe Edwards/Getzen uses a short tapered neckpipe after the valve sets on their bass valve sections, and a straight tube in the tuning slide lower leg. I believe Bach horns are built in the same way. Shìres uses a single straight tube that functions as both a non-tapered neckpipe and also as the tuning slide lower leg which adds some rigidity to that area of a bass valve set.

As for the acoustical properties of a short tapered tube in that area, I'd wager that it would not make a huge difference over the small space between the end of the valve set and the beginning of the tuning slide. Perhaps a tapered tube and an internally tapered tuning slide leg would have an impact.

[boneagain]

... I don't know if that type of thing would be possible to draw, and having a constant outer diameter just seems like overkill....

... You could certainly draw a tube over a tapered mandrel with a fixed washer to get an internally tapered tube with a constant outer diameter...

On my King Duo Gravis the bell end of each tuning slide pipe measures larger than the other end. King did, indeed, draw a fixed OD over a tapered mandrel. That not only maintains SOME overall taper, but reduces the discontinuity at the end of the tuning slide tube.

[Elow]

The thing that throws me off about the progressive bore haagman valves is that each of the valves will have a different feel. Unless i’m misunderstanding the concept. I feel like the bore should only change on the open side of the horn, not the actual valve tubing. That way there is still a taper through the open side of the horn.

[ithinknot]

Unless i’m misunderstanding the concept.

You are - just read their website. Hagmann cores have three passages; the Bb route is independent

[Burgerbob]

Unless i’m misunderstanding the concept.

You are - just read their website. Hagmann cores have three passages; the Bb route is independent

Wow. I always wondered about that, that makes so much more sense

[Kbiggs]

One of the disadvantages—yes, you read that correctly—of Thayers and other large valves (Hagmanns, CL valves, etc.) is they take up a lot of space on the “gooseneck” or neckpipe. That is, they they DON’T allow much room for a taper from the valve to the t-slide. There is such a thing as too open.

When there is little to/no taper to a horn, it can sometimes create negative feedback: instead of feeling more open, it will feel less open or more constricted. (Don’t ask me why. That’s a physics/acoustics question. It’s just my experience and what I’ve observed and heard from others. I’m just a stupid trombone player after all. ) I don’t think tapered/untapered neck pipes is about resistance: we’re talking about sound waves after all, not air flow.

I believe (and I’m not sure about this) but some makers have designed and engineered various ways to build some resistance into horns with oversize valves (compared to older stock valves) so that the soundwave doesn’t create that negative feedback. There are several places to put a taper in a trombone: the leadpipe, the slide bow, the neckpipe, the tuning slide legs, etc. I’m sure Christian Griego or Matthew Walker could say something about this, but that would probably be like giving you their secret sauce recipe.

Think, for example, of the old Conn 62H. It had a continuous taper from the port of the F-valve to the rim of the bell. The design wasn’t about finding “the most open horn” out there; it was to create a horn that had an even response over the range of the horn. The continuous taper, I believe, helped achieve that.