Posted by Rick Denney on July 31, 2001 at 09:27:23:
In Reply to: Re: Re: Dumb question posted by French Horn question on July 31, 2001 at 07:30:06:
A French horn uses the same length of tubing as a euphonium on the Bb side, and the same length as an F tuba on the F side. With the tiny mouthpiece and bore, it just plays much higher in the harmonic series.
A compensating euphonium is not the same as a double horn. A double horn effectively has two separate valve systems, and the thumb trigger routes the air through one or the other. A compensating euphonium has an extra set of tubes, and when the fourth valve is use, the air passes through both the regular set of valve tubes and the extra set. So, in a double horn, the air only passes through one set of tubes, and with a compensating euphonium, the air passes through two sets when the fourth valve is pressed. From a practical standpoint, though, the fourth valve of a euphonium has a similar function to the thumb trigger on a double horn, converting the instrument from Bb to F.
Back to the original question. There have been several systems for denoting octaves using lower case, upper case, and doubled letters. Other systems use primes (') and other symbols. The common use of "BBb" comes from one of the earlier systems, where BB-flat was an octave below B-flat, which was an octave below b-flat, which was an octave below bb-flat, and so on. Now, it really means no more than a convenient way to designate a contrabass tuba as opposed to a tenor or bass tuba, as described by others. BBb and CC: Contrabass tubas of 18 and 16 feet tubing length, respectively. Then there are Eb and F Bass tubas of around 13 and 12 feet; and Bb and C tenor tubas of 9 feet and 8 feet tubing length. The term "EEb" is an anomaly used as a marketing trick to align the Eb bass tuba with the contrabass sound and application rather than the euphonium or F tuba sound and application.
Rick "who owns six tubas, one of which is a euphonium and another of which is a baritone" Denney