Weird Buzz in the Bridge Area (Ibanez BTB Monorail Bridge, BTB705DX Bass)

[biro]

Hello everyone,

I was wondering if any of you tech-savvy gearheads could help me sort this issue out. I have recently bought an Ibanez BTB705DX, which is by far one of the best instruments I ever played in terms of playability and tone--which is hardly surprising, as it is loaded with some EMG goodness. However, I am experiencing an issue that really bothers me.

While the sustain on the treble side is just plain awesome, the same does not appear to apply to the same extent to the bass side. Well, the B string sounds remarkably clear, loud and for a long time. Nevertheless it appears that something is choking the proper vibration of the E and A strings.

The phenomenon appears to mainly affect the E string when I am fretting notes and to result in a buzzing sitar-like sound that seems to originate from the bridge area. I have attached a video in order to avoid splitting hairs.

http://youtu.be/0KBv2_vw0sE

I am not talking about the normal string buzz, which I am used to, and I like to a certain extent. The noise to which I am referring is lower in pitch and has a different nature.

I tend to exclude the truss rods from being potential causes of the noise at issue (hitting the back of the neck results in no noise whatsoever). They also work fine, and I don't think they are responsible for that noise.

I tried removing the bridge springs on the E and A strings and the noise appeared to diminish, but did not disappear. I put on a "fairly new" E string, but it didn't really solve the problem. I took it from another bass, tough, so it may well have been subject to weird torsion and stuff. I also tried to put on an exposed core E string (LaBella Supersteps) but, besides the usual chorus effect, there was little improvement.

I've come to the conclusion that the most likely cause is that horrible bridge, but I am not quite sure about what I should do -- short of buying and fitting new strings on the bass. Any thoughts?

Thank you so much, mateys!

[paul h]

I am in no way an expert but...

...to me that sounds like a string to saddle vibration. Unfortunately I have no experience of that bridge so there is nothing really specific I can say.

If it was me...and a standard Fender'ish type bridge...I would of course make sure there are no loose screws. I would have a look at the slot in the saddle to see if it is cut properly or indeed was working ok with my chosen string gauge. I would also experiment by adjusting the saddle back as far as possible hence increasing the break angle of the string. If that affects the buzzing then at least I would know I was on the right track.

As I say I am pretty sure it's a string vibration noise as it's so similar sounding to the buzz caused my a badly cut nut slot.

Sorry I can't be of more help but hopefully someone more useful will be along soon

[biro]

Thank you very much! I think your comment is spot on, the resulting noise is quite similar to that caused by a nut which has not been cut properly. However, this affects fretted notes and thus cannot be due to the nut. On the other hand, a bass bridge always makes contact with the strings and is the most likely cause. I wonder if there is anything I can do to improve the saddle. The point is: the D and G strings vibrate wonderfully, and the B string ain't bad either. Short of replacing the strings, I think this might have something to do with the size of the strings slots on the bridge.

[paul h]

Try the D and G strings in the offending saddles? Or is it possible to swap the saddles around and see what happens?

I think you are stuck with a process of elimination but I am pretty sure you will find the problem will be where the string meets the saddle. I did some work on a guys Epiphone Rivoli that had some rattle and intonation issues. Turned out it was just shipped with a couple of the saddles in the wrong place.

[biro]

Ok, I think I finally found the culprit. In some monorail bridges such as mine, which looks more or less like this one,

the actual string saddle is enclosed in a somewhat bigger structure. It's a nice design and, if everything is crafted properly, there will be a tight fit between the inner and outer parts of each monorail bridge.

That is exactly what I found to be lacking: the saddle is a tiny bit too narrow and, as a consequence, when the string vibrates, the saddle vibrates too and starts "bouncing" onto the outer part enclosing it. This produces the buzz whereof I have been speaking...

As usual, thank you guys for helping me out with this problem!

Edited September 5, 2013 by biro

[paul h]

Glad you found the problem

(I knew it was going to be those pesky saddles!)