Internal resonator question.

Getting things drawn out for my first build. Decided not to go with the cigar boxes I have. Most are cedar veneer over particle board. Kinda disappointed but they wont go to waste. I do have a couple that are or at least look solid wood. I'll save them for later. Going to make the box out of 1/8 ply savaged from an old dresser I got off the street on trash day. The neck will be 2 piece maple from the same dresser. These folks have cats. The smell will travel farther and faster than the sound....LOL The bottom of the dressers will have to go.

Here's my plan that will lead to my question.

The only structural support for the top of the box will be two long thin bolts imbedded into a small piece of wood going from the bottom of the box to directly under the bridge.

What I'm thinking of doing is using nuts and locking washers to suspend something off this assembly. The sound traveling from the tension under the bridge would travel threw the bolts and into the resonator.

My questions. If I suspend something inside the box will it make it louder? Wood or metal? The inside of the box will be 10 3/4 x 7 3/4. Anyone have a formula or idea as to how big or what shape would create the best sound?

Good idea? bad idea? why?

Thanks again folks!

Look toward real guitars for an understanding of acoustic technology. Notice that the soundboard (top) is free to vibrate. The wave vibrations of the strings move the brigde. The bridge moves the soundboard. This is why the top is made out of cedar or spruce (braced) and the sides are made of harder woods like rose wood. Internally this movement generates waves inside the box developing the tone and volume. Anything restricting soundboard movement will effect your sound.
A resonator is not built like a standard acoustic. The whole box is fixed and stiff forcing the sound out of the resonator cone. There is no soundboard. This is why they are commonly made out of steel. They are definitely two entirely different birds.
I hope this adds some insight. Enjoy.

Replies

A.D.EKER January 14, 2019 at 3:16pm

For the Smell wasch it down whit sopy water,Dry, and poire parfum over it, it wil allso smell but plesantly !
A.D.EKER January 14, 2019 at 3:14pm

Hi, The use of a inner cone ,is there for to bounce the sound back out, so it gets louder, they created (The DOpera Bros; DOBRO,in the big Band era, so they whoed bee loud enough whit the Horn section and the other instruments) the vibrations come out two way's by the cone and from the otherside in the body of the (wood or metal) f slots opening or roster hole's if you have the square neck lapstyle dobro, so sound travels ,& vibrations vibrate what you need is volume inhancement and projection! I say just build the thing and see what happens!!! Greeeeettssszzz And good luck on the Building !!BCB Holland !
Rogheff January 11, 2019 at 4:53am

This is an old thread I know. But you inspired me to experiment with my build. #3 has an internal hip flask double resonator. The large flask is bolted under the small flask and is suspended freely inside the box. The sound is great and it is loud!
nick tyson July 1, 2010 at 3:39pm

never even seen one that big here in the uk, having said that ive only just started to try and get hold of boxes in the last ten day. Biggest so far is a davidoff double R's box.

Mark Werner said:
That Casa Blanca box is a big one, almost 13" long and 8" wide, 2 1/2" deep. Wish I could find more....
Mark Werner June 30, 2010 at 10:39am

That Casa Blanca box is a big one, almost 13" long and 8" wide, 2 1/2" deep. Wish I could find more....
nick tyson June 30, 2010 at 6:53am

Mark what size of box are you using for that?

Mark Werner said:
Here's a pic I took when my resonator was in progress:

http://www.cigarboxnation.com/photo/resonator-build-in-progress?con...

The resonator in this case is an aluminum lid for a girl-scout cooking set... It sits on those two rails in slots, suspended from the back of the guitar by about 1/4". This lets all the air move around...
The bridge sits directly on top of the resonator, and then the cover goes over that; neither it nor the face of the guitar contact the resonator in any way.
That's fairly typical construction.
Paul Stephen Eklund June 29, 2010 at 10:14pm

Thanks again everyone.
Mungo Park, Don't really want the look of a resonator for this guitar. Kinda want to keep the box as simple looking as I can.

Mark Werner, Great shot of your work. And Thank you for the info! I didn't know a resonator assembly shouldn't touch the top of the instrument. Totally cool dude!

Keni Lee Burgess, I have a 1970's Yamaha acoustic. Deep and loud. Hoping to build something that will hold it's own against that kind of volume.

Matt Philip, you and I are on the same page my friend. Great to hear it works! Metal it is!
Matt Philip June 29, 2010 at 1:51pm

http://www.cigarboxnation.com/photo/2592684:Photo:117855?context=user

I did the suspension thing and it worked great
Keni Lee Burgess June 29, 2010 at 12:32pm

Look toward real guitars for an understanding of acoustic technology. Notice that the soundboard (top) is free to vibrate. The wave vibrations of the strings move the brigde. The bridge moves the soundboard. This is why the top is made out of cedar or spruce (braced) and the sides are made of harder woods like rose wood. Internally this movement generates waves inside the box developing the tone and volume. Anything restricting soundboard movement will effect your sound.
A resonator is not built like a standard acoustic. The whole box is fixed and stiff forcing the sound out of the resonator cone. There is no soundboard. This is why they are commonly made out of steel. They are definitely two entirely different birds.
I hope this adds some insight. Enjoy.
Mark Werner June 29, 2010 at 10:47am

Here's a pic I took when my resonator was in progress:

http://www.cigarboxnation.com/photo/resonator-build-in-progress?con...

The resonator in this case is an aluminum lid for a girl-scout cooking set... It sits on those two rails in slots, suspended from the back of the guitar by about 1/4". This lets all the air move around...
The bridge sits directly on top of the resonator, and then the cover goes over that; neither it nor the face of the guitar contact the resonator in any way.
That's fairly typical construction.

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