1-What are the benefits of sound hole pickups? and how to choose one ? 2- Does it sound like electric guitar ?! . I'm not sure if i really have to try it .
- A sound hole pickup is temporary and allows an acoustic guitar to be amplified without a microphone and without a potentially expensive and invasive modification to the guitar. It's also cheaper to buy and use a sound hole pickup than to have a pickup installed in an acoustic.
- A sound hole pickup usually sounds very different from a piezo-electric (the most common type) installed pickup or pickup system. Sound hole pickups can sound a little bit like an electric guitar, but the resonating body of the acoustic guitar does affect the string vibrations and is picked up by the pickup. Piezo-electric pickups often sound thin and bright without processing, while sound hole pickups naturally have a fuller sound.
If you have a desire to gain the ability to plug your guitar into and amplifier or PA system so that its sound can be amplified without using a microphone - you have numerous options. One of those options (not the best for everyone) is a sound hole pickup.
I will limit this answer to the discussion of sound hole pickups and the different types and some of the advantages and disadvantages.
First of all, there are many different brands and types of soundhole pickups available. Some are designed to be used temporarily and can be easily and quickly interchanged between guitars - while others are intended to be installed permanently (meaning for use on just one guitar intended to be left in the guitar all the time).
The portable temporary interchangeable designs will have an instrument cable attached directly to the pick up. This cable plugs into your amp or PA and hangs out of the sound hole. This is the least invasive, type to install as no modifications to your guitar are necessary. They also costs less. Below you can see what one of these looks like prior to installing into the guitar. There are two versions shown. One has a cable that plugs directly into your amp. The other has a shorter cable with a female socket that allows you to connect the pickup to the amp with a standard instrument cable of whatever length you choose.
Below is a picture of one of these type installed (temporarily by design) in a guitar.
Some types of sound hole pickups are designed for a more permanent installation. They require drilling a hole in the tail block of your guitar to install the instrument cable end pin jack. There is a small cable connecting the cable jack to the pickup that stays inside the guitar - so you don't have a cable running out of your soundhole. To plug into an amp or PA - you simply plug in your instrument cable like on any electric or acoustic/electric guitar.
Prior to installation, one of these type sound hole pickups (made by LR Baggs) would look like this:
Installed it would look like this (no cable hanging out of the sound hole):
Many sound hole pickups are magnetic - meaning they detect the strings vibration using magnets that react to the metal strings. Because of this - they will only work with steel strings. Also because of this - standard acoustic strings will not respond as well as electric strings because the brass windings on acoustic strings (in contrast to the nickel windings on electric strings) are non magnetic. So the magnet in the pickup is only able to react to the steel core of the wound strings that is shielded to a large degree by the non magnetic windings.
That is why many of these magnetic sound hole pickups have adustable pole pieces (one for each string) which allow you to position the sensors closer to the wound strings to increase the detection of the steel core and adjust the sensitivity for each string to achieve better balance. In the picture below you will see one of these pickups with all the poles for the wound strings adjusted to be closer to the strings.
Some sound hole pickups can detect and respond to the vibration of the guitar's soundboard (top). These will clamp tightly to either side of the soundhole so it can react to the vibration.
Other sound hole pickups (such as the LR Baggs Anthem) have internal microphones as their means of amplifying the guitar. The advantage of a microphone based sound hole pickup is that the true sound of the acoustic guitar is amplified without the artifacts often imparted by magnetic pickups. Magnetic pickups can make your acoustic guitar sound more like an electric guitar than an acoustic.
The other advantage of the vibration detecting and microphone based sound hole pickups is that they can be used with nylon strings.
The think I like least about sound hole pickups is that you might have to adjust your strumming or picking technique to avoid hitting the pickup or the poles with your pick or fingernails. So if your normal comfort zone for strumming falls where the pickup lies (this is not really adjustable on most sound hole pickups) then you may need to change where you strum your guitar. Otherwise you may get an amplified annoying clacking sound everything your pick hits one of the poles on the pickup.
Also - when playing acoustic, I like to vary where I strum or pick to add effects while playing. In other words if I need a more twangy sound I will strum or pick near the bride. strumming in the center of the soundhole imparts a fuller mellow sound while strumming closer to the headstock will reduce volume and be less boomy. With a sound hole pickup with poles close to the strings, I find that I am having to consciously dodge the pickup.
This is why I would not recommend a sound hole pickup for a beginning guitarist. It can hamper and interfere with proper strumming or picking technique and you have enough to worry about without having to try to play around and avoid accidentally touching the pickup in the middle of your sound hole.
Another thing I don't like about sound hole pickups is the way they look. To me, they are not aesthetically pleasing in the least.
But if you want to amplify your guitar without extensive modification and you don't want to try to stand with your soundhole in front of a microphone, any of the many type and brand soundhole pickups would be an option.
But you might also want to look at the portable contact pickups as an alternative. Here is one at Guitar Center for only $34.99 US. Dean Markley Transducer Pickup for Acoustic Guitar
Hope this helps - and good luck.
I agree with the answers above. In addition, an advantage of a soundhole pickup with magnetic pickups is that you can use electric guitar effects. This is especially important when you are using distortion, overdrive and even wah. Using electric guitar effects beyond chorus and reverb on a transducer (piezo) signal is a sure way to get extreme squealing feedback.
A magnetic soundhole pickup tends to make your acoustic guitar sound like a jazz hollow-body guitar with wound strings.