740x300 Lab Slide

Songwriter Series VAOM-04 as tested


D.P. Hess
Mechanical Engineering
University of South Florida
Tampa, Florida

November 2012

Vibration tests are performed to assess the transmission of vibration from the bridge to the headstock for a Voyage-Air VAOM-04 guitar shown in Figure 1. This guitar features a unique hinged-neck for convenient transportation. Vibration measurements are taken with the guitar neck extended and secured following manufacturer specifications.

Figure 1 Voyage-Air VAOM-04 guitar

The test set-up is shown in Figures 2 and 3. The guitar is placed on a pad with the neck supported on foam between the nut and ninth fret to level the instrument horizontally. The strings are damped with foam at the seventh fret.

Figure 2 Test set-up

Figure 3 Angle view of test set-up

 A small piezoelectric impact hammer is used to apply an impact force to the center of the flat on the bass or left side of the bridge as shown in Figures 4 and 5.

Figure 4 Impact hammer and top plate accelerometer

Figure 5 Impact hammer and top plate accelerometer closeup

Two miniature accelerometers attached with wax are used to measure the vibration response from the impact hammer. One is attached 1 cm in front of the bridge at the sixth string as shown in Figures 4 and 5. The other one is attached between the third and fourth string tuning pegs on front of the headstock as shown in Figures 6 and 7.

Figure 6 Headstock accelerometer

Figure 7 Top view of headstock accelerometer

A dynamic signal analyzer is used to record the force input and acceleration responses as well as to calculate the frequency responses for each acceleration response and the force input. The frequency response data is presented in Figure 8. The blue curve is the frequency response of the top plate acceleration and hammer force input. The green curve is the frequency response of the headstock acceleration and hammer force input.
The top plate frequency response (blue curve) clearly reveals the two dominant low frequency modes with peaks at 105 and 203.5 Hz as well as the Helmholtz resonance at the valley at 132.5 Hz. The magnitude of the top plate response is higher than the headstock response over most of the frequency range shown. The difference between these response magnitudes provides an indication of the amount of vibration (between 70 and 270 Hz) transmitted to the headstock compared to the top plate.

Figure 8 Frequency response data from the Voyage-Air VAOM-04 hinged neck guitar

Two common designs used today to attach the neck to the body of an acoustic guitar are the dovetail joint design and the bolt-on design. Frequency response data has been collected from guitars with both designs. Sample data are shown in Figures 9 and 10.

The frequency response data in Figures 8, 9 and 10 show some similarities common to acoustic guitars, namely, two dominant low-frequency modes identified by the peaks in the top plate frequency response curves.

The difference between the top plate and headstock frequency responses is comparable for the hinged, dovetail and bolt-on designs. This data suggests the Voyage-Air hinge neck design transmits low-frequency vibration at least as well as the sample dovetail and bolt-on neck designs.

Figure 9 Frequency response data from a 000 size guitar with a dovetail joint neck


Figure 10 Frequency response data from a dreadnaught guitar with a bolt-on neck





Stories From The Road

Owner Testimonials

  • 5star-100
    I received my VAOM-1C and boy does it sing!  I am the proud and happy owner of several top-notch Martins: a D35 Johnny Cash, a HD28e, a solid DCPA4R as well as a 1973 00-18. I also had a 2003 D18 which I sold because it wasn't so good. I was expecting the VAOM-1C to sound ok but not more. "Can't have the best of both worlds" I thought. Well, now I do. It is just exquisite, so melodic and yet with a surprising sustain and expressivity. It is a true jewel at a more than decent price! All the Best and THANK YOU!
    Jean-Dominique Michel, Switzerland - VAOM-1C
  • 5star-100
    My wife and I travel a lot and in the past have had issues with taking a guitar with me......they're either too bulky for the overhead compartment, or I have to let the luggage handlers toss around my guitars like they're a bag of beans. I recently purchased one of your VAOM-04 guitars, and I'm totally impressed with the sound and the playability of this instrument. My first choice is my Martins, but since I received the VAOM-O4 I haven't put it down. I would recommend this guitar to any player, even if you don't travel that much. I'm looking forward to my next trip. I may just spend most of the trip playing this guitar.
    Great Job Voyage-Air.
    - Tony H. - VAOM-04
  • 5star-100
    It’s considered a “travel guitar,” and it truly is a remarkably portable instrument; however, that label does it a disservice, because honestly, it’s a damn nice guitar. It just happens to have a nifty set of hinges that allow the neck to fold over on the top, making it far more compact and transport friendly. I love my Telair!
    - Anthony K. Sandy, UT - VET-2SBB
  • 5star-100
    I am pleasantly surprised at the quality and genius behind this amazingly compact, but great sounding guitar!! I work in the movie industry and travel quite a bit, and being able to bring my guitar as a carry-on wherever I go is just what I've been looking for! The overall sound is amazingly rich for its size, and the folding mechanics work like a dream! If you’re wondering if it's worth getting, the answer is a big YES!!
    - Nancy F. Santa Monica, CA - VAMD-04
  • 5star-100
    I bought a VAD-04 strictly for travel and light use. The day I bought it I paid a visit to United Airlines. As I was walking up to the counter the clerk said that he had seen these before and that there was no problem taking it on as carry-on. .I think that this is a great value and a nice sounding piece All in all it is a winner in my book. I’ve heard less sound from much more expensive instruments. I may mike it because I think it compares to my Taylor 814ce and Breedlove it surprised me!
    -  Michael, Columbus, NE - VAD-04
  • 5star-100 
    I travel a lot, and for years, I schlepped my heavy Goodall Jumbo, always worried about it getting damaged and stolen.  I recently purchased a Voyage Air guitar and love it.  Its light, gets on planes, and sounds terrific. It has made travelling with a guitar a no-brainer.  Even after closing and opening, it stays very close to being in tune. I recommend this guitar to anyone who likes to play wherever they go.
    - Stewart, Santa Fe, NM - VAOM-02