Jim Marshall: The other Marshall

Jim Marshall, also known as the “Father of Loud” passed away at the beginning of April.  You don’t need to be a musician to know that the name Marshall is ubiquitous in the field and is a popular music amplifier and loudspeaker combination.

Marshall was born in London, England, on July 29, 1923.  As a child he was struck with tuberculosis of the bone and spent many years in a full body cast.  (Incidentally audiologists see people today, who are typically immigrants from third world countries, who have tuberculosis.  Audiologists are necessary to monitor the status of the higher frequency acuity since the medicines of choice tend to be ototoxic, resulting in a permanent hearing loss.  Also, a “salt shaker” multi-perforation pattern of the eardrums are typically noticed in the more advanced cases).  In Marshall’s case (and era) he had no medication, nor any reported hearing loss from the tuberculosis.  His later life would be different however, but this would be from the more mundane and gradual nature of music induced hearing loss.

While in the full body cast, he taught himself engineering, and by his teens knew his way around a circuit board which would help him immensely in his later years.  This medical history was sufficient to make him ineligible for military service.

He auditioned for a local dance band and became their vocalist.  The war had just broken out and the band’s drummer was called up for active service.  He volunteered to play the drums, never having played before.  After some time of practice and listening to the music of the famous drummer Gene Krupa, he began drumming as his day-job.

If anyone has ever belonged to a musical group, for some reason the drummers and the bass players hang out together.  In some sense these are the real musicians- the drummers need to keep a constant, albeit funky sounding beat, and the bass player is the “listener” in the band who needs to keep everyone together.  The bass player needs to set the key of the music and follow the lead guitarist who may be going off in weird directions.  Typically the bass player is a much better musician than the lead guitarist!

And it was this friendship between Jim Marshall and the bass player that sent Marshall off in a new direction.  Bass players of the time were constantly complaining that they could not be heard over the background of the lead guitarists- their equipment was just too limited.  Having spent many of his formative years in a body cast studying engineering, Marshall was up to the task.

Marshall Chasin wearing his Marshall Amplifier jacket.
Marshall Chasin wearing his Marshall Amplifier jacket.

In his parent’s garage, Marshall build his first amplifier/loudspeaker combination just for bass players.  It was physically much larger than the other systems of the time, and better than the rudimentary “bass reflex” systems (that are even in widespread use today).  Bass reflex uses a volume of air in parallel with the speaker cone and this enhances the lower frequency output of the loudspeaker.  (This is essentially an acoustic inertance for those engineers out there.  Actually it’s still an acoustic inertance, even if you are not an engineer- known to audiologists as a “vent associated resonance” in earmold acoustics.  This is the basis behind the small Bose system that we see frequently being flogged on late night TV).  The drawback of the bass reflex design is that it can only increase the bass slightly.  What Jim Marshall did was to build an amplifier (coupled intimately with the loudspeaker) that could electrically generate a previously unheard of low bass response.  This became known as the “Marshall sound”.

Marshall had a retail drum store but was soon encouraged by people like Pete Townsend of the Who (known as the Whom in Canada) and Jimi Hendrix (known in Canada as Jimi Marshall Hendrix) to build a full line of amplifiers and speakers for guitarists as well, and that is exactly what occurred.

What Marshall was able to do was to create a lot of output between 50 Hz and 2500 Hz (for his bass amps) and a larger bandwidth for his guitar amps.  Initially he was able to accomplish this but with about 25% distortion.  This may sound like a lot, but modern day telephones also have about 25% distortion.  The reason he could get away with that level was that the distortion harmonics were above the bandwidth of the amplifier/loudspeaker, at least for bass amplifiers.  The same is true of the telephone- even modern day telephones are constrained to a bandwidth between 340 Hz – 3400 Hz.   A distorting harmonic or overtone above 3400 Hz is simply not transmitted by the telephone system.  And when he made broader bandwidth amplifier/loudspeaker combinations at the bequest of Pete Townsend and others, this distortion became more audible, and among other innovations, contributed to the Jimmy Hendrix late 1960s sound.

Jim Marshall was known as the “Father of Loud”, but in reality, he should have been called the “Father of a bit more intense” – somehow that name doesn’t sound as great but it is more accurate.  There are marketing tricks which he loved such as the loudspeaker volume control going to volume 11, but he understood that loud doesn’t necessarily mean intense.  By increasing the bass output of his systems, Marshall was able to correct for the ear’s relative inability to perceive bass notes (see for example Fletcher-Munson curves or the calibration of our clinical audiometers).  This elevated the sound level for the left hand side of the piano keyboard (<250 Hz) to a desired audibility.  In many cases the overall sound pressure level (measured with a dBA reading) only increased slightly, but any bass increase was certainly noticed both auditorily as well as vibro-tactally.  A bass increase is a big bang for the buck.  Musicians could now feel the bass as well as hear it.  Rock and Roll needs to be loud- it does not need to be intense.

And from the Marshall Amps company: “While the entire Marshall Amplification family mourns Jim’s passing and will miss him tremendously, we all feel richer for having known him and are happy in the knowledge that he is now in a much better place which has just got a whole lot louder” (but not necessarily more intense).


About Marshall Chasin

Marshall Chasin, AuD, is a clinical and research audiologist who has a special interest in the prevention of hearing loss for musicians, as well as the treatment of those who have hearing loss. I have other special interests such as clarinet and karate, but those may come out in the blog over time.