Archtop "Jazz" Guitars - what's so special?

I have always been fascinated by this classy but rather enigmatic branch of guitar design.  They are often used by jazz guitarists but are extremely versatile instruments for any style of playing.  Arguably, more by accident than design, archtops became one of the main forerunners of the electric guitar in all its current diversity, but archtop guitars are also very fine instruments in their own right.

History

The archtop guitar has roots in classical string instruments such as the ‘cello and violin. These fine bowed instruments gradually evolved to their current shape after hundreds of years of experimentation and improvement. It was discovered that a domed carved top and back, together with a floating bridge and f holes each side of the bridge gave superior tone and sound projection.  Tone woods that were readily available in Europe meant spruce was generally used for the top and figured sycamore for the sides.  It’s important to remember that these instruments were all mainly bowed, not plucked, so the design emphasis was on note fundamentals, sound projection and tone, the sustain came from the bow.  Strings vibrate in a very different way when they are bowed than when they are plucked.  Listening to a violin played pizzicato shows some of the limitations of this design of instrument for plucking, with very little sustain or time for the note to bloom, the sound is quite percussive.  For more detailed information on all of this some academic research can be found here https://royalsocietypublishing.org/doi/full/10.1098/rspa.2014.0905 

The development of the guitar meanwhile took a different route.  Strings were gut strings under less tension than steel strings.  The acoustic development of the guitar came out of the need to increase sustain and tone on an instrument that would mainly be plucked and strummed.  Influence came from centuries of Middle Eastern and North African development of plucked instruments along with the lessons of years of lute making in the European tradition.  A flat and braced  board of spruce was usually used rather than an arched top, and frets were used to help the fingering of multiple strings for chordal work and for sustain. If the top was bowed it tended to be a single angled bend to give the bridge some extra height. The bracing was discovered to add greatly to the overall tone and different systems were developed to enhance the tonal range.  The sound was pleasing and rich, but it was relatively difficult to achieve the volume that an instrument from the violin family or woodwind family could manage.  This rather restricted the use of the guitar as an ensemble instrument.  Instruments that had a greater projection such as mandolins and banjos were favoured in accompanying larger groups.

Development of the archtop guitar

The introduction of steel and bronze/steel strings to the guitar gave the possibility of greater sound projection, but also the headache of how to build an instrument which could cope with the greater pressures on the top induced by these strings. One solution was to strengthen the top of the traditional form of guitar, and to develop new bracing and voicing to handle the heavier string pressure. Another solution was to explore the link that the mandolin has always had with the violin family of instruments and see if the traditional archtop style of instrument  building would work for the guitar.  

The archtop guitar gradually evolved out of this experimentation.

Advantages and disadvantages of playing an archtop guitar

The advantage of the emerging archtop design of guitar was a much greater sound projection.   A flat top guitar often seems to compress the sound, meaning that after a certain level, the energy put into playing a doesn’t seem to increase the sound levels.  An archtop guitar appears to respond in a more linear way to harder playing, more in = more out.  However this comes at the cost of tone and sustain.  

An archtop guitar can sound quite “boxy” with an emphasis on mid range tones.  These can be perceived as less pleasing in direct comparison with a flat top guitar (though these are generalisations as each individual guitar has a unique tone of its own).  While this can be less desirable when you are playing alone at home or solo, in an ensemble situation it has certain advantages as it seems to “cut through“ the mix more effectively, and projects far better for solo lines.  An archtop does seem to have a very pleasing natural “reverb”, and this works well for solo lines when played acoustically.  It was discovered that to a certain degree the bigger the body of the archtop guitar the more projection and the better the tone, which lead to some absolutely huge guitars being made.  This of course made them rather hard to play.  It is argued that the f hole design projects sound outward more effectively than the traditional o hole of an acoustic guitar so the audience hear a very different tone to the player.  That’s why when you are buying one it is good to take someone else along to play so you can listen from a distance.  

There were other attempts to develop loud acoustic guitars.  Notably the Maccaferri guitars in France/Italy, which used a sound box inside the guitar (not generally a great success), although the clever construction of these guitars gave a very loud instrument even without the extra sound box inside.  These instruments used more traditional guitar building techniques to produce a similar projection to an archtop, utilising high action, long scale lengths and slightly bent tops.  Again these guitars respond well to energetic playing and focus around the mid ranges of tones.

Another route of design was that of the resonator guitar which is seriously loud, but has a distinctive tone all of its own.

We should also say something about the bracing of arch top guitars here. An advantage of a domed carved instrument is that it is structurally quite strong, so needs minimal bracing compared to a flat top instrument.  Bracing in acoustic instruments serves two purposes.  One is to provide extra strength and rigidity but the other is to allow sound waves to pass more effectively across the soundboard.   Arch top guitars usually come either with parallel or x bracing.  Each of of these has rather different tonal properties.  The x brace in general gives a richer tonal palette, where the parallel bracing seems to produce a more focused tone.  Sometimes a luthier will add a sound post which connects the front and back plate of the guitar as in a violin, this also serves both tonal and structural functions.  

One further thing to mention is that the back plate of an arch top guitar is much more essential to the overall tone than is the case on a flat top guitar.  You can experiment with this.  A few years ago some academics at my local University did some research together with with Fylde guitars into the difference the tone wood of the side and back of a traditional guitar make to the sound.  It appears from that careful research, that they make very little difference at all, with the huge environmental benefit of saving rare hardwood species.  This research was done by Lancaster University in liaison with the amazing Fylde guitars, link here http://www.psych.lancs.ac.uk/hearing/the-guitar-experiment/   

However with an archtop it's slightly different - if you hold the guitar against your body while you play you will notice the sound is muted. Strum a chord and feel the back plate of the guitar and you will notice it vibrates.  I believe part of the sound and projection of the archtop guitar comes from the sympathetic vibrations of the front and back plates and the “bellows” effect produces literally pushing the sound waves out of the f holes.  Of course this means you lose a lot if you play an acoustic arch top standing up, and when sitting down it is best to adopt something like the Freddie Green style of playing for maximum effect, where the guitar is angled away from the body of the player so the back can vibrate freely.  I guess the instruments of the violin family are all designed to vibrate in this way too and are designed to be played away from restriction or damping on any of the boards.  It would be really interesting to see some careful scientific research into this, let me know if you are aware of any.

The electric guitar - amplifying an archtop guitar

The world changed when the electric guitar was born and a massive revolution in popular music was started, along with huge increases in available volume levels.  Archtops were a key part of this.  Arguably the ingenious and technically simple magnetic pickup system that was developed in effect created a whole new instrument related to the acoustic guitar.  New techniques of playing and totally new sounds were quickly adopted.  Sadly a lot of lovely old beautifully crafted instruments were butchered as tops were riddled with holes to fit large magnetic pickups and wiring looms.  Electrification certainly offered the opportunity to turn the guitar into an effective solo instrument that could hold its own in volume against anything in an ensemble.  The tones many of those early players achieved with electric instruments were hauntingly beautiful and many of us try to replicate that sound to this day.

Sadly the innovation was eventually lead to the demise of the very instrument in which it had been developed.  There is an inherent and deep seated conflict in pairing a large highly resonant and expensive acoustic box, higher volume levels and a magnetic pickup.  

Although superior in feedback rejection compared with using a standard microphone, a big acoustic box is still a great way to generate feedback when paired with a magnetic pickup, making playing at any volume a real challenge and source of annoyance to other band members and the sound engineer.  The sound box of an acoustic guitar is susceptible both to the unwanted vibration from the sound waves of other instruments and speakers, but also to the infinite loop of certain feedback frequencies. Dialling these things out ruins the tone.  The guitarist and their monitor all have to be carefully positioned to minimise this, but it is still very hit and miss especially in live performances, where ideal positioning may not be achievable.  

Another issue is that a magnetic pickup requires steel or nickel wound strings to work at its best.  The problem with these is that they are simply not in the same league acoustically as bronze strings and do not drive the arched top of the guitar in the same way.  It is of questionable value to spend thousands having a luthier carve and tap tune a guitar to then string it up with acoustically dead strings, reproducing the sound through what is in reality a very lo-fi pickup solution.  I know there is a whole industry based around hand winding bespoke magnetic pickups but this at best only changes the voicing.  Magnetic pickups really pick up little more than the vibration of the strings, not the individual sound DNA imprint of a sophisticated acoustic instrument.

There’s a significant crowd out there who work within these constraints, trying to achieve a “holy grail” of sounds, rooted in the history of the instrument, good luck to them.  Many who do this I notice have back up instruments for tricky situations.  After all that’s why the solid body guitar was developed.

The immediate solution to keep the archtop alive in an era of amplification was to develop an instrument that was much less lively acoustically, and voiced specifically for amplification, yet still true to its hollow body archtop roots.  Importantly these instruments retained “the” look which only an archtop possesses.  Some of these were specially carved to create less feedback so the top was more dead acoustically.  More often pressed laminates were employed with less tendency to vibrate.  For the manufacturers this also has the benefit of reducing production costs (though not necessarily cost to the consumer).  These laminated instruments are still considerably more prone to feedback than a solid body guitar, and can still pose significant problems at higher volumes or with certain frequencies of sound.  The semi acoustic archtop was developed to counter this, normally coming with a slimmer body and a having the benefit of a solid block of wood under the pickups that vastly reduces the feedback problem.

It’s amazing with all the issues that hollow archtops with magnetic pickups are still so popular with guitarists.  I have to admit that I love them, despite all the issues.  I like the look, and although it’s highly debatable how much of the body sound of the guitar gets reproduced under amplification, they do appear to respond and play differently to a solid bodied guitar.

In more recent years huge developments have been made in acoustic guitar amplification. The development of the piezo under saddle transducer provides a reliable, relatively feedback free way of producing a sound more like an acoustic guitar.  However the piezo has significant drawbacks.  My experience has been very mixed.  While it has been great to have a way of playing acoustic guitar along with a band without having to stand by a mic, the piezo doesn’t really reproduce the actual sound of the guitar any more successfully than a magnetic pickup, it just sounds different.  An archtop with an under saddle pickup sounds suspiciously similar to a flat top guitar fitted with with one.  We have got used to the rather harsh quacky piezo sound in live performance and guitarists have developed new techniques and effects to work with the new possibilities, such as the trend for percussive and tapping styles of playing and the use of effects and looping that piezo pickups have opened up.  Many people speak of quickly tiring of the harsh sound a piezo produces.  I was recently helping organise a gig where two of the musicians insisted on playing and singing through a single Ear Trumpet condenser mic for their performance. It was incredible to hear the ‘real’ sound of the instruments, in direct comparison to other acts using pickups and close miced vocals. Of course the piezo pickup and close vocal micing was far louder and more punchy, but much more tiring to listen to.

To get the best sound acoustically a microphone is still the most effective solution.  In a studio setting with no competition from other instruments you can experiment with placing mics in different places to really get that unique sound of the guitar you have carefully chosen for it’s lovely sound.  But what about mixing in a live situation, where you have to stand or sit still by a stand mic?

The option that is just beginning to really take off is to use close micing with small cardioid condensor mics on acoustic instruments. This is not a perfect solution, but even a really cheap clip on mini condenser mic offers a far more faithful reproduction of the sound of an acoustic guitar than the most expensive piezo based system, even when that piezo system comes with an inbuilt mic.  More expensive clip on mics offer better feedback rejection and better quality sound reproduction. Modern digital mixers offer a huge range of eq, compression and feedback rejection which helps enormously with some of the inherent problems of mics like these.  The secret with an archtop guitar is to clip a gooseneck mic onto the handy tailpiece or to the strings behind the bridge (a great advantage over a flat top this!) and direct the mic towards the soundboard between the treble end of the bridge and the treble f hole.  You can mic really close and still achieve a sound far superior to a piezo based system.  There are issues around feedback and sound overspill from other instruments, so this is no silver bullet, but worth a try if tone is critical to you and volume levels not too high to make it workable.  For much more in depth discussion of this please see Jonathan Stout/Campusfive's excellent explanation - he has all this down to a fine art https://www.campusfive.com/swingguitarblog/2017/8/2/rig-rundown-2017

Because each system comes with its own drawbacks some people have success with combining close micing with magnetic or piezo pickups to cope with the unpredictability of different venues, and to help with the greater volume needed for soloing.

Future of the archtop guitar?

I guess archtop guitars are probably going to remain a bit of a niche market. There’s been a bit of a resurgence in recent years with some truly great and reasonably priced guitars coming out of the Far East.  Predictably these have received a mixed reception, as many of them come in at a quality and price point that threatens highly lucrative home markets.  The manufacture of instruments has benefited hugely from computer based automation which, when directed sensibly, can mean that a lot of time consuming tasks can be replicated with more accuracy than a human being and in far less time.  Most guitars whether made in a workshop or in a factory still are largely hand finished. There’s a lot of bargains to be had because of the differing costs of this intensive labour globally.  Don’t get put off by the country of origin snobbery expressed in some guitar forums.

Recently in the acoustic arch top market there’s been a resurgence of the solid top “pressed” archtop.  Instead of painstakingly carving a top out of a substantial piece of timber, a thinner solid wood plate is steam pressed into shape. While these instruments will never reach the dizzy heights of a carefully crafted and tap tuned carved archtop, they can often be a good value and more consistent alternative. They can sound extremely good and provide a really different tonal palette to the standard Martin style flat top for the impoverished working player.

There’s a lot of people doing very well cashing in on the mystique and the ready disposable income some people have for fine instruments. Good historical archtop guitars can be eye wateringly expensive and very high maintenance. This drives the cost of some newer models in its turn, with original historic brand names carrying huge price tags, even if the brand name is really the only remaining shred of continuity with the past, as a totally different company or holding is now building the guitars!

The archtop market as much as any guitar market is definitely prone to bragging rights and oneupmanship.  It is difficult to discern what is mojo and what is reality as you trawl the forums discussing such things.   Carved tops, hand wound pickups, the label, the luthier, and speciality woods and unnecessary bling carry a huge premium.  You definitely don’t necessarily get what you pay for in this market, in many cases, in effect, you pay what the manufacturer or retailer can get away with charging.

Having said that there are some truly wonderful small workshops and luthiers out there making some amazing instruments that rival the best of any ever produced.  I recommend playing as many different examples of archtops as you can so you get a feel for the sounds, playability and variety. However, please always remember that the primary sound is in your fingers not in the guitar, and that great guitarists, jazz and other styles, have successfully made beautiful music on all kinds of different types of guitar.