Hi I was just wondering about the opinions of you trombonists out there, which is the better wrap. I was looking at a Conn 88H but couldnt decide which wrap is better. I hear open wrap sounds more 'natural', but does this compare to the nicer look of closed wrap?

As other trombonists don't seem to have any opinions, I thought I would comment from the side, as it were.

I presume the effect of closed wrap is to give you sharper bends (or does it give you more of them; I'm not familiar with the various layouts possible with plug tubing). Horns, and tubas have many bends, some of them quite sharp, though the designs of better quality horns have more open bends, where the length of the tube allows. At a guess (somewhat educated, as I have read quite a bit about the acoustics of musical instruments) bends detune the resonances. This is not necessarily a bad thing, because the resonances of a typical brass instrument are not exactly harmonic, being nearest the exact harmonic ratios for some intermediate amount of parallel tubing, too close together for shorter amounts and too spread out for longer ones.* Detuning the resonances helps in two respects: it allows you to vary the pitch with the lip, to blow the note into correct tuning; and when the lowest harmonic of the lip motion is locked to a particular resonance, it allows some of the higher resonances to support the higher harmonics of the lip motion, giving a richer sound.

* note that the "ideal" shape of a brass instrument is like an alpenhorn or an oboe: a straight tube of conical bore, with the mouthpiece end much smaller than the bell. This gives a close approximation to harmonic resonances, which I would expect to be very peaky (high Q, in the terminology of an electronic engineer), so that any attempt to vary the pitch would be likely to cause a jump to the next frequency.

Open Wrap all the way

There is less resistance when using the F attachment and it feels more natural

I go for closed wrap!

Why?

I don't know! My trombone is closed wrap therefore I, obviously, prefer closed wrap!

If playing a trombone with only 1 valve then closed wrap but if using a trombone with 2 valves then open wrap. When playing a single valve and you need a low b then the slide will pull far enough out on a closed wrap.