Neck Strap hook analysis results

  Several weeks ago I posted here and on SOTW that my new Just Joe's neck strap (with a large brass hook) noticeably changed the timbre and volume of the sound of my saxophone. This kicked off a long debate on SOTW in which many people scoffed and said I was crazy (or that my ears were deceiving me). Most of those SOTW members who believed my claims had not even bothered to try the large brass hook test themselves. Some of these players were well respected saxophonists and authors and many of them were weekend warriors. I was totally convinced that the large brass hook on the neck strap brings out certain overtones, on some notes more than others. It was perfectly clear to my own ears, which at this point in my life I tend to believe. About 80% of the saxophonists who tried the hook comparison test also believed that it made a difference. The 20% who did not hear any difference were usually either very inexperienced players or experienced players who were totally convinced before they even tried the test that it was impossible that a brass strap hook could change the sound of the horn. There were admittedly a few serious players who didn't notice a difference and seemed to have an open mind about the idea, like Ellery Elskelin. My theory is that the different makes of saxophones have the strap hook in different places, which causes different degrees of effect because the hooks may not be sitting right at a vibrational node. This means a large brass hook may have a greater effect on a Selmer than on a Conn.

  My testing with different saxophonists wasn't very scientific, so I turned it over to some pros. I have a saxophone student named Randal LeNeve who is an engineer at Rodgers Instrument corporation (which manufactures organs and is a division of Roland) and has a Masters degree in physics. Randy noticed a significant difference in the brass strap and was just as puzzled as I was about why a hook could make a difference in the sound. One theory that Tom Garcia and Sammy Epstein (who taught acoustics at Berklee) had at first was that the difference in timbre was more noticeable to the player because of the increased vibrations traveling up the strap to the players jaw and ears. This theory was shot down by Randy because of the fact that neck strap cord is a poor acoustical conductor. One of Randy's theories was that the large brass hook acts as what he called a 'resonating antenea'. This means that the hook itself puts off extra higher frequency overtones when the horn is played. Randy also thought that the point on the horn where the strap ring sits could be right at a critical vibrational node of vibration, which could explain the greater difference of change to particular notes on the horn. One thing that Randy really stressed was just how acoustically complicated the saxophone is. Just the driver (mouthpiece & reed) alone is highly complex and unpredictable. The instrument is actually quite mysterious and even scientists are not totally clear on some of the details of its workings.

  Randy took the Just Joe's strap into the Rodgers labs, enlisted the help of his colleague John Pospisil and they did some testing. John also heard a noticeable difference between the Joe's strap and a strap with a plastic hook and, being a saxophonist himself, was intrigued enough to join the project. They tested the Just Joe's strap against a strap with a plastic hook and one with a small thin steel hook. Randy played alto and soprano and John was the recording engineer. Randy tried his best to play as close to the same volume on all of the tests and they recorded eight different notes on each horn. John used the Roland R09 recorder, sampling at 24-bit, 48kHz and analyzed the frequencies using Sony Sound Forge, using a Blackman-Harris algorithm with 65,536 sampling points.

They found that the Just Joe's strap amplified some of the higher partials. It also appeared as if the strap eliminated a small amount of the frequencies between the overtones, which might account for a 'clearer sound' (this is my theory). Their conclusion was this:

"Certain notes on the Alto showed higher peaks on frequencies above 6 kHz which implies that the harmonic ratios of sound pressure levels are being altered i.e. a change in the timber of the sound, not the frequency distribution. Also G# on the Alto showed considerable added frequency content starting at about 200 Hz. The Soprano shows considerably more frequency content above 10 kHz for some, but not all notes.  It is perceivable that the Just Joe's Saxophone Gel Strap has an impact on the frequencies at or above 10 kHz for the Soprano sax setup used in this experiment and on certain notes on the Alto sax on frequencies above 6 kHz and in one case for G# starting as low as 200 Hz."

Randy added:

 "So in the case of Joe's Neck Strap the report shows that certain harmonics of the fundamental frequency were amplified. This means that those notes are LOUDER and the TIMBRE of the note was altered. That is, the horn still sounds like a saxophone but has 'brighter' and 'louder' harmonics. The LOUDER is pretty obviously a good thing. The TIMBRE being brighter can depend on what a player wants." 

Here is one of the screenshots from the analysis. It is middle A on the alto:

click on above graphic for a larger view

 They also felt that further testing would help to make these results more concrete and that these tests might include:

1. Recording several takes of each note using each strap and averaging the frequency response of the resulting recordings.
2. Using several straps to compare the differences in frequency response between each strap.
3. Recording in a more acoustically "dead" environment.
4. Using several microphones for recording including contact microphones on the saxophone body.
5. Determination of the fundamental frequency and harmonic distribution of the metal piece(s) on the strap itself when not attached to the saxophone.

 So although this question should be investigated more thoroughly to discover exactly what is causing the difference in timbre between the Just Joe's strap and a typical strap (with a plastic or small steel) hook I feel like I have been vindicated by the testing that was done in the Rodgers labs. No amount of scientific testing be enough to convince some who are convinced that a strap hook cannot change timbre, so I fully expect that this post will set off another 20 page thread on SOTW. Fortunately I will save myself the aggravation and not be reading that thread. I had the wisdom to have my SOTW membership suspended indefinitely.

If anyone is interested in reading the full report from the Rodgers labs email me and I'll send you a copy.


I can say this will a fair amount of certainty though......

There is a difference in timbre!


Just Joe's Neckstrap