Hello Steffan,
I never responded to your email, r.e. the Bridge Doctor. My comments about these things can be found in the archive, but I love them! The first one I had installed on a Taylor guitar nearly 10 years ago at the advice of my guitar tech. It not only fixed the bridge pull, but the guitar sounded dramatically better. Not just louder, but it increased the guitar's bass growliness. I did some research on them and discovered that Taylor and other makers use them routinely in their repair shops to correct behind-the-bridge bulge.
Also that sound tests show that they often increase the volume of a guitar by transmitting vibration from the bridge plate to the end block and thus to the sides and back. Now, I'm pretty skeptical of laboratory sound test claims -- I usually can't discern any difference when using products that claim to make guitars sound better.
But two things do make an audible difference: replacing a plastic saddle with bone, and installing a Bridge Doctor.
On 12-strings the BD not only corrects any bridge pull (something that's more likely to occur on 12-strings because of the additional pull of the strings), they also prevent it from happening in the first place.
I've had them installed on all my good 12-strings, which means all my Guilds, and the improvement in sound has run the gamut from slight to dramatic. My Guild JF-30 12, my first good 12-string and one I've owned for years, was a completely different beast with the BD on it.
However, I can't bring myself to put them on six-sting guitars that don't have bridge pull. It feels like I'm having non-essential surgery performed on them!
Glenn//.
