Posted by Tim Cary on May 19, 1999 at 09:30:31:
In Reply to: 5 valve help posted by Todd on May 17, 1999 at 20:13:33:
I won't go into a lot of detail, as fifth valves are primarily used to correct pitch in the lower register of the horn, and each model of tuba has its unique characteristics at the bottom end. There are two types of fifth valves available, low whole step and two step. Low whole step is basically an over flat first valve, usually pitched 1-1/4 lower than the fundamental of the horn. Thus pitches such as EEb, which are sharp on CC tubas with a 1-3-4 combination can be played 5-3-4, and so on.
Two step fifth valves are two steps below the fundamental, or basically the same as a 2-3 combination. On CC tubas, the Db tends to match poorly with its BBb brethren (those of us who play in large concert bands have experienced this), and the 1-2-3 or the 2-4 combination sometimes just don't match (especially if the person next to you has a YBB-321 or something along those lines), so a 5-1 combination can be used. Also, the low EE tends to be poor with 2-3-4, so a two step fifth fingering of 5-4 can be used.
Hope this helps.