Cut bells one or two piece

[Chatname]

When cutting a bell, will a two piece or one piece bell retain its character, or play, better? Or does it not matter? My intuition would say that a two piece should be the best option, however my intuition is usually useless. Successful detachable bells like for instance the Sauer bell are actually one piece. Any insights?
Or, to expand the question : let’s say you cut two bells that have the same bell taper but one is a two piece, the other a one piece. You now have four potential combinations of flares and stems, including a two piece flare with a one piece stem and vice versa. Would they all work fine, or only some combinations?
These are questions that keep me awake at night…

[BGuttman]

Go to sleep. It really doesn't matter (unless you want it to ).

[Matt K]

The sauer bell is supposedly a type 7 bell, which is a two piece bell. I’ve been told it’s in the ball park of a 7RM.

Problem with your example is the shape of the bells have to match and the tech has to use the same threads and then the cut has to go in exactly the same spot. So you likely can’t get say a Bach 36 and a King 5B bell (as extremes) and just swap them around. (I’d love to be incorrect about that).

I think in a hypothetical scenario where you managed to get to identical bells (which I’m under the impression is a little tricky for one piece bells, but I don’t know if it’s totally relevant)… it would be as simple as it sounds. The stem is responsible for the part of the sound that the stem is and the flare likewise. Given that the flare makes up a smaller portion of the overall surface area, I would expect it to be less influential on the overall sound. Given that the flare is the last thing that the sound touches and is responsible in some ways for blocking the sound from directly reaching our ears and projection… but would expect the sound to be influenced thusly.

In all honesty though, if you had two identically shaped bells regardless if they were one piece or two I would expect them to play pretty close to one another.

[Dsbones]

Go to sleep. It really doesn't matter (unless you want it to ).

[sstelmack]

The Shires website says that the Sauer bell is one piece construction.

"RS Bell: 8.5 inch, one-piece construction, screw bell (removable flare), hand-hammered, in balanced lightweight red brass with traditionally brazed seam and soldered bead"

[Chatname]

I got some sleep, thank you Bruce!

My main question was really whether one or two pieces is best for cutting. Considering there being new models coming out regularly, maybe there is a trend in the instrument maker’s or industry’s choice of bell type?

About mixing the bells and flares, that was just a crazy nighttime thought. “What if…” I was thinking along the lines for example Shires TII 5VNYDF and TII 7YMDF, they would have the same shape and come with the same rings, right? This isn’t something I would do, just curious!

[BGuttman]

Two piece bells are welded or fused and then worked to finish the shape. Cut bells are always made from completed bell sections since it's almost impossible to place the cut line right at the seam (it's a function of the design of the rings). That's why I said what I did. By the time the bell cut is made, it really doesn't matter if the bell was originally one piece or two.

Lawlor makes instruments with cut bells and offers several flares so you can change the flare to tune the instrument to the application. In this case you can put different metals and different bell widths (usually a choice between 7.5, 8, and 8.5 inches) depending on what you need.

Conn made an instrument for Gardell Simons with several flares to go on one stem. I believe that instrument is in Steve Dillon's collection. Simons used different bell flares for solo and section work. Given the technology of the day, the Simons trombone probably started out as a 2 piece bell.

[Burgerbob]

I think it probably matters a bit, but you're also cutting the bell up and putting a bunch of mass on it. My cut Bach 50 bell is different than my uncut 50 bell, but, well... it's cut and has a bunch of mass on it.

I'd say cutting a lighter bell, and perhaps choosing one that's not your absolute favorite are a bit more important.

[hornbuilder]

In my experience, a bell retains it's sonic characteristics after being cut, with a degree of added focus and center with the addition of the bell ring.

Meaning, a 2 piece bell will still sound like a 2 piece bell, and a 1 piece bell will still sound like a 1 piece bell, even though now it is, essentially, a 2 piece bell.

The method of construction, including the use of hammering (essential on a 1 piece design) or not (generally not part of a 2 piece bell fabrication) is a big part of why that bell plays the way it does.

So, if you like the way a bell sounds, it will still sound similar after being cut, but may feel to have increased "focus", "center" and/or projection. I have noticed that 2 piece bells tend to change less in that regard, than 1 piece bells do.

[Matt K]

That's interesting. The Archive.org doesn't seem to have archived that page and that contradicts what I've heard elsewhere about the Sauer bell. I wonder if that language is a mistake, if they've changed their process, or where I got that info was wrong in the first place.

In either case, another avenue for you to search for would be to check out Shires dual material bells like the 7GYMT7. I can't remember what they called them and they don't market them, I do remember when they first made one maybe a decade ish ago? The gold and yellow brass look sort of similar when unpolished and someone spinning the bells accidentally put a yellow stem with a gold flare and played differently enough that they at least used to have a couple in stock on showroom floor for ITF and whatnot. It would be similar to what your question asks - obviously not the same as one piece vs two piece, but similar material/wight for the two parts.

[hornbuilder]

PS.

Most horn makers use a specific mandrel to make bell flares, and do not use complete bells to make cut versions of their instruments. Some trombone makers may, too. I know I (M&W) use complete bells, but may invest in some flare mandrels if the demand for screw bells increases.

"Given the technology of the day". ?? One piece bells have been around since the time of the Pharaohs. Conn traditionally made a choice to make their bells 2 piece, for the sonic properties those bell have. They could have made 1 piece bells, had they chosen to, and were certainly not restricted in their choice by any technology.

[BGuttman]

A one-piece sackbut bell is not difficult to make, but a 1 piece flared bell as would be made in the mid 19th century and onwards generally requires the flare be a different piece from the stem. Cutting a piece of brass for a 1 piece bell with a flare of 7.5" (220 mm) or larger is a bit of a challenge.

Bach was making 1 piece bells based on his trumpet designs (scaled up).

[hornbuilder]

There are plenty of old (pre WWII) 1 piece french horn bells with 11"+ diameters. Not to mention all those German trombones from 100 or more years ago with 1 piece bells and huge flares.

Bell construction is a choice the manufacturer makes. A choice which has never been based on "technology limits."

[OneTon]

I have a Bach LT42G with a one piece bell. Taking a sawzall to it would be a first degree felony. I would be reluctant to put the one piece bell on a 42B. I don’t think my LT42AG would benefit by it. Shires rep Alexis Smith recommended against cutting one piece bells on a YouTube video with Samantha Lane that may have been taken down. The bang for the Buck for one piece trombone bells occurs with straight uncut trombones.

Which is not to deny that “everything” makes a difference. In a blindfold test a player might prefer a one-off flare. Or not. In a YouTube video Thomas Lubitz claims cornets are better with two piece bells but a trumpet player may prefer the brighter response of a one piece bell trumpet. It quickly becomes a Holy Grail horn. The point of diminishing returns resides comfortably in the rear view mirror.

[whitbey]

Maybe
Not sure
but just for fun.
If a bell is one or two piece, it is brazed together so it is just one piece.
Maybe the metal spins thinner at the edge of rim on a one piece.
I notice my 1960' built Bach bass is thicker on the stem compared to the rim then my Edwards bells are.
After the bell is made, many parts connect the horn together, so it is pretty much one piece.
Then you cut off a piece and reconnect it so was half a piece and now it is two pieces that make one piece.
So if it sounds funny, the cutting did not go well.
Several years ago I was playing with a copper ring and a brass ring that were about 2-1/2 inches around made with a strong 1/4 inch think round material. I could take off the Edwards bell and put one or the other of these rings on the throat of the bell. It really sounded pretty good. Better then the Lindbergh wrap thing. But if they got loose (when) they rattled and it was bad. It was a fun game showing everything can change the horn. Those rings sound pretty dead now as they were cut, put on the ends of a utility belt and are now case shoulder straps.
I would think that if you could place the ring on the bell it would give you a pretty good idea of the change in sound you would get when fully assembled.
That would be thinking the ring would be more change to the sound then the cutting would because the parts would be fully connected when you played. The same setup in a trombone case made for a cut bell will probably sound muffled.
Time to cut and run.

[LeTromboniste]

A one-piece sackbut bell is not difficult to make, but a 1 piece flared bell as would be made in the mid 19th century and onwards generally requires the flare be a different piece from the stem. Cutting a piece of brass for a 1 piece bell with a flare of 7.5" (220 mm) or larger is a bit of a challenge.

Bach was making 1 piece bells based on his trumpet designs (scaled up).

Romantic German trombones, which typically have larger flares than modern .547 bore tenors, were made from one piece, with the seam running straight down to the rim.

Conversely my Courtois' bell, which is much smaller (and much less flared), is in 2 parts. But it's not a stem and a flare forming a T seam, but rather a 1-piece style construction with an added gusset, so it has a Y seam, like is more commonly seen on horns. There is at least one bass sackbut that even has 2 gussets, with a ψ-shaped seam.

[Blabberbucket]

Cut bell (detach flare) and one piece/two piece bells are entirely different discussions, though the two may interact.

There are some posters here saying that mixing/matching stems and flares is not possible, which is entirely false. As long as the bell rings are the same and fit properly, any bell component using that ring will match up. The internal diameter of the ring is what dictates the placement of the ring. There could be some whackiness in overall length of the bell if you mix components from bells with wildly different tapers but in my experience there's no problem mixing components from reasonably similar bells. I did play with this a little when I was working at Shìres and found it really amazing the difference that changing the flare could make.

As for the impact of the ring itself,who really knows? It will add mass to the bell which will effect balance, the feel of the horn in your hands, the response and resonance behind the bell, and possibly in front of the bell. I can't speak to exactly what impact that may have.

As for the one-piece vs. two-piece bell, the difference is really in the movement of the metal and where it is thinned during the spinning process. It's my understanding that, typically, one-piece bells will be thinner through the area close to the bead, while a two-piece bell will be thinner where the flare is brazed onto the stem.

However! That really all depends on how the bell blanks are designed and cut by the manufacturer - the amount of material stretch and thickness of metal can be controlled by the shape of the sheet metal blank before the bell is created. Bells are typically sanded and buffed rather heavily to create the typical mirror finish, which is another uncontrolled variable in the mix. Short story long: who really knows?