Brass tubing length

[BflatBass]

I hope this is in the right section.
I have a question about the length of tubing used for the key of a brass instrument as well as it's intended range.

If a BBb tuba (contrabass) is 18' long, is an instrument half that length (9') in the same key and, relative to the tuba, what would be the intended range? Would it then be a baritone horn or euphonium? And so on down the line as far as length of tubing? Like what would the intended range of a horn 4.5' long be? Trumpet?

I'm seeing conflicting information online that a french horn is anywhere from 12 to 20 feet long which doesn't follow the logic of the statement above. So I guess the length of tubing doesn't determine the intended range? Though I know it determines the key of the instrument. So why are tubas long and trumpets short?

So I'm just wondering where the length of tubing comes in when determining the intended range and does the numeric multiple of the length have an affect on that? Like 16' vs 8' or 18' vs 9' and so on...

Cheers,
Robert

[JohnL]

A BBb tuba is roughly 18' long.
At 9' you have the typical Bb tenor trombone, euphonium, baritone, etc. This is also the length of the Bb side of a double French horn.
At 4.5, you've got Bb trumpet, cornet, flugel horn, etc.

A single French horn in F is 12' long. The other common alto register brass instruments (alto trombone, mellophone, alto/tenor horn) are only 6' long (F) or 6.75' long (Eb).

Part of what gives the French horn its characteristic sound is that it is normally played much higher in its overtone series than other brass instruments, and that its bore is smaller in relation to its length when compared to other brass instruments.

[Mikebmiller]

I have never taken a tape measure to a trombone. Is 9' the length in 1st position?

[JohnL]

I have never taken a tape measure to a trombone. Is 9' the length in 1st position?

Yes. It's a nominal dimension rather than an exact measurement - there are things that will cause it to vary slightly.

[Basbasun]

"I'm seeing conflicting information online that a french horn is anywhere from 12 to 20 feet long"
French horn players are funny. 20 is the lenght using all the tubing including valve tubing.
If we messured a BBb that it could be 38 feet long, a basstrombone 20 feet long.

[LeTromboniste]

Also because you mentioned it, 16' and 8' and 4' are also terms used to describe the octave on which something is played, and comes from organ registers which in turn are derived from pipe lengths for C. An 8' organ register (and by analogy any instrument playing "in 8ft") sounds the written pitch. 16' equals 8vb and 4' equals 8va.