Does Your Scroll Vibrate

[mandozilla]

I've never given it any thought before but I was fooling around with the old mando today and found this interesting. I hit the open G string at the end of a piece, and hit it pretty hard. I immediately grabbed the scroll with my left hand to free up my right hand and I was startled by how much the scroll was vibrating.

Like I said, I never paid any attention to this before. My first thought was that my scroll was hollow but I knew it had a solid scroll block (they're all solid right) from peering inside with a mirror before.

My question is twofold, 1.) Have any of you ever noticed this phenomenon before? And, 2.) Does this vibration contribute to tone and volume or is it merely parasitic or sympahtetic vibration?

Weird...:disbelief:

~o):popcorn:

[Mike Bromley]

I have no sympathy for parasites, but my scroll does vibrate......

[Amandalyn]

It's interesting how much a mandolin does vibrate. When applying a Tonerite (a vibrating de-damping device) I have felt the different parts of the instrument and you can feel it resonating throughout. Some areas seem a little stronger, but I do believe all parts vibrate. How much tone comes "out" of the whole instrument? No doubt the sound chamber, top and back project the most sound, but knowing the whole instrument is "alive" adds a dimension to be aware of.

[Ivan Kelsall]

I'm amazed just how much both my Mandolins do vibrate,although thinking about it,i shouldn't be. After all we have basically a hollow wooden box with another piece of wood attached to it.The whole point of the affair is to make the box vibrate as much as possible (within certain constraints),so,anything attached to it will to some extent,also vibrate. What amazed me years back when i first got my Stelling Banjo (my first 'Pro.' instrument), was how much vibration was transfered to the neck when playing,& that's from an instrument, the main vibrating part of which,the 'skin',isn't directly attached to the neck. Personally, i love to feel the instruments i'm playing vibrate,it's as though they're alive in my hands - a great feeling,you know that they're 'joining in',
Ivan:mandosmiley:

[Michael Lewis]

Mark, the scroll of a typical Gibson style F model is hollow and does have a block in part of it. The scroll does vibrate on many mandolins, and will vary depending on how thick and heavy the materials are. Often I hear a chattering squeak when block sanding the scroll area. It is one of those cantilevered situations that can generate a harmonic resonance pushing one way but does it less pushing the other way. How much this can contribute to the sound of the instrument is anybody's guess and probably a bit different for each mandolin.

[Mike Bromley]

Every time I read the title of this thread I am reminded of a scene in the Pink Panther, where Sellers asks "Does your dog bite"....and it sounds like "dez yaw deg bet"

"Dez yaw screll vibbrit?"

[foldedpath]

Sure, it vibrates. Clamp a transducer tuner pickup hooked up to an electronic tuner to any part of the mandolin, including the scroll (if the jaws are wide enough!), and you can tune up.

The trick is to figure out what parts of the vibrating mandolin are the most important.

Spend enough time setting up mics to reinforce a mandolin through a PA system, or (better yet) setting up mics for recording a mandolin, and it soon becomes clear where the important zones are for capturing that vibration. And it's not the scroll. :)

[Chuck Naill]

I noticed two things about this mandolin I am using right now. It was very light and it resonated noticeably when I played and held it against my body.

I did check to see if the scroll vibrated and it did. :disbelief: Like Michael said, its not completely hollow.

chuck:)

[billkilpatrick]

mine as well - no reason why it shouldn't ... but it is a surprise. thanks for that - bill

[sunburst]

The whole instrument "vibrates", and if part of the instrument is a scroll, well then...

There are many vibrational modes; top modes, back modes, air modes, and the ones at work here, whole body "bending" modes. The whole body, including the neck, will vibrate at one, two, or more frequencies, and if you touch the scroll you may feel that vibration. If you grab or touch various places on the mandolin you will feel vibration or not, depending on whether you are at or near a vibrational node (not mode) or in between nodes.
Does the vibration of the scroll (or peghead or tailpiece or whatever part you ar feeling vibrate) contribute to the sound of the mandolin? Maybe, but other than the top, back, and air in and immediately around the mandolin, any vibration can more easilly contribute to the sound through losses because ther string's energy is being used to vibrate thoes parts rather than make sound. Is that bad? Not usually, especially in a well designed and built instrument, the losses are more-or-less filters that "color" the sound.

[mandozilla]

The whole instrument "vibrates", and if part of the instrument is a scroll, well then...

Of course you are correct sir. But I was taken aback at just how much it vibrated (don't know the technical term) versus other solid parts like the headstock and neck...it quite literally startled me. :grin:

~o):popcorn:

[Chris Keth]

I just tried it with my fullerton and I can't find a spot that doesn't vibrate. The endpin area seems tamer than most of the rest of the instrument, but it still noticeably vibrates.

[desaljs]

Mike,

"It's not my dog"......................

Great line in a classic movie! My scroll vibrates too. :)