Thanks bro for telling my guitar tones is real/fake?

Acoustic pickup technology.

Ever wonder how an acoustic pickup work. I asked myself the same question too when I joined the retail industry years ago.

Let’s look at some acoustic pickups.

Type A - Piezo element (Under saddle placement).

A piezo element is placed under the saddle. This piezo is some sort crystal element. The two type that I know so far. A single line and 6 piece in line (wired in series). The entire tone capturing ability depends on the coupling contact between saddle and piezo. Added output is further help by the string tuning and string break angle on the saddle. This is important to transfer vibrations through the saddle to the piezo. It involves mechanical figuring out for the best results. 

The downside is, the piezo cares only for the strings tension vibrations, it cannot and does not captures the true resonance of the whole body. Its capturing perimeter is best only under the saddle and limited to the surrounding of the bridge. 

This creates a theory that several guitars with the same Piezo and Pre amp may produce  similar superb or bad amplified tones. Though the electrified tones are artificial almost real but still, the under saddle piezo remains to be the number one choice for manufacturers and consumers. It’s the loudest, safest and hassle free too. I'm blunt to say more emphasize is put into the preamp than the guitar acoustic's itself. Nevertheless, it is what it is. 

True acoustic capture verdict? 

Early piezo pioneers Ovation and Takamine.

Type B - Microphone (Internal placement)

The mic works by capturing air frequency waves generated in and around the guitar body. A good spot for mic placement is near the sound hole rim. In my opinion, good result depended on how much cubic air being moved. The guitar construction does matter here. In short, a guitar needs to be loud or the mic need to highly sensitive

Footnote: - I've seen some preamp unit that with an electret mic attached serving as primary or secondary support (mix with piezo).

True acoustic tone capture verdict?

Credits to electret mic inventor, Dr James E West.

Type C - Microphone (External placement)

The mic is place outside and possibly in front of the acoustic and most likely in a dedicated room. I think this method is able to capture 95% of the good or bad acoustic tone as how we should hear it. The 5% lost are from the guitarist stomach growl, his heartbeat and his brain waves. My theory supported by Along Exist (guitarist, composer and studio engineer) and Tam (Session musician).  According to both, external mic is still the best as its able capture every acoustic nuances. The downside of this system are it needs a proper room e.g. studio, good mics, good preamp etc. Since a good mic alone could cost a hand grenade if not an RPG, they only linger in the professionals’ realm if not serious hobbyists. 

True acoustic tone capture verdict?

Type D - Transducer element (Stick-on placement)

This is similar to the piezo system except for the placement. I'm still in the dark whether this system is a family of Type A or if it’s a different system entirely. The Transducer is stick to the guitar top inside or outside. The location is around or at the bridge. Finding a sweet spot is much tougher as there can be more than one. It is not surprising to see some manufacturer stick-on more than one just for safe measure but still the best spot is likely at the bridge.

True acoustic tone capture verdict?

Credits to Inventor, Barcus Berry Company.

Type E - Electromagnetic coil (Near or in the fingerboard)

I think this system involve finding the sweet spot at the strings scale length itself where the optimum strings oscillation (or loudest and longest decay) is.  I seen one evidence in my past repair post (I hope I can find it). This primitive system said to had been extinct, so I thought. Taylor guitars brought back this system in 2002/03. It’s called the K3 series (I will write more about Taylor K3 in another entry). However despite the single coil having to deal with its own proprietary ratio (magnet + turns + wire gauge), it has to depend on three crucial factors, which are external. 

The placement, say at the 12^th fret (never seen this done before) or anywhere close enough. The core iron content in the strings (to disturb the magnetic fields). By the way, do you remember the high E and B of the acoustic string was phosphor bronze prior 2003/04? Maybe phosphor bronze do not tickle the magnetic field as much as nickel steel? Lastly is the pickup height itself.

True acoustic tone capture verdict?

Credits to inventor George Beauchamp

Type F - Electromagnetic coil (Sound hole attachment).

This the most obvious thing to do post electric guitar era. The system works similar to Type E by converting the magnetic field disturbance into signal. The magnetic coil does not capture the actual acoustic resonance.

True acoustic tone capture verdict?

Credits to inventor Lloyd Loar                    

Type G - Modelling

Of course, how could we deny the existence of such devices? One does not need to buy an actual acoustic in order sound like one.

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Although there are many variants of acoustic pickup out there, I believe their operation originates from one or more of the above. I’m not saying any system is better than the other. Be aware of the trade-off. Know what you’re buying because you have understood it not because it’s being told by someone else e.g. me.

So do I now know how acoustic pickup work already? Hmm. Thanks for visiting reading this entry.

Thank you

Yustech