This article was in response to questions concerning bell sizes and alloys from the horn mailing list.

Alloys:

Alloys used for brass instruments range from very hard (nickel silver) to extremely soft (ambronze).  Red (rose/gold) brass is softer than yellow brass.  What this means is that the harder the metal, the more "bright" the instrument is perceived.  In actuality the harder metal allows more presence of the higher overtones within the musical spectrum.  Likewise, the softer the metal, the more the lower overtones in the harmonic spectrum are enhanced, thus sounding "darker."  As a caveat, each listener may have their own special qualifiers for the qualities of sound.

The softer the alloy, there is a greater tendency for the tone to "edge out" at high intensity levels.  Those hornists who prefer to play with more "color" to the sound will go to a softer metal instrument while those musicians that wish to strive for tonal and color consistency will choose nickel silver.  One isn't inherently better than the other, it is just different and is strictly a matter of personal taste.  For instance, I prefer the sound of a brass horn.  I've owned nickel silver instruments in the past, and after switching to brass, I find that the timbre variances and shadings are greater.  Being that I perform with many various groups in a myriad of venues, this affords me the flexibility I desire.  Again, this is just me.

While brass instruments tend to sound "warmer," silver instrument tend to give greater projection.  Also the start-up time to the attack is quicker.  Ambronze instruments, to me, respond to the attack very slowly.  Thus, I need to articulate much more deliberately and with more energy to get the tone to speak readily in the hall.

Bell sizes:

Bell throats help projection and also will help modify the tone of an instrument.  They will also equalize the difference between a brass instrument and a silver instrument.  Let me illustrate.

A large bell throat makes the tone of the instrument more diffuse; allowing the tone to radiate in the hall less concentrated.  When this occurs, the resulting sound of the instrument is perceived as a "darker" sound.

A smaller bell throat helps compact the sound of the instrument, thus helping concentrate the resulting tone, aiding projection.  This is why we traditionally see the following configurations: large bell silver horns and small bell brass horns.  Using the above information, it is easy to see how both designs are two avenues to get to the same goal. This being the production of the type of quality of sound the instrumentalist wishes to achieve and the effective projection of that sound into the performance venue.

Thus, a silver instrument that would normal sound very bright is tempered significantly by a large bell throat.  Conversely a brass instrument that would normally be quite dark is aided by a smaller bell throat that helps compact the tone and aid in projection.

Coda:

New wrinkles have appeared in horn design with the introduction of silver horns with smaller bell throats (Conn 9D, Holton 177).  These horns are very efficient  in projecting tone, but have a tendency to be very "hot" (brittle).  Large bell brass horns (Yamaha 668, Holton 180, 181, 105, Conn 8DY, 8DR, and the Paxman 25 A in yellow and gold brass)  Are decidedly more dark and require greater care in articulation and energy to get the tone to project in a large venue with clarity.

Again, let me underscore that these qualifiers to which I refer are totally subjective.  There are undoubtedly will be readers that will vehemently disagree with many of these statements.  However, they will perceive distinct differences in various metals and bell throats when trying out instruments.

What this means for the average hornist is that we have a variety of factors that will weigh our decision when previewing an instrument.  Instrument companies have done much research in the last several years.  This has translated into many more quality products from which to choose.  All of us should be grateful to the research done my private designers, as well those designers at the major instrument companies.