Sunday, 19 January 2014

The Mystical World Of Guitar Feedback

Hello all ! I'm so glad to say that I had a freaking fun day learning about Guitar Feedback from my great teacher Az. Not to mention that I spent over an hour post-lesson self-imposing guitar feedback to my ears at loud volumes (that I usually do not play at) in my small bedroom.

Well an analogy that I love from my guitar lesson is, as my teacher said, "If you are afraid of heights, you go bungee jumping to counter that fear", so "If you are afraid of guitar feedback, go and create feedback". Hahaha it was a really eye-opening lesson and from today onwards, I will not see feedback the same way again. Well guitar greats such as Jimi Hendrix have manipulated feedback to their advantage during shows.

Firstly I have to lay out what gear I use and what tone settings I typically use that makes my guitar such a "victim" prone to feedback. I play a red semi-hollow Ibanez guitar that you guys probably seen and heard if you have been stalking my guitar videos. And semi-hollow guitars are just more prone to feedback than their solid body buddies.

Also I love high gain tone settings, I love it when my tone is edgy, fierce and dirty. And as my teacher said, the higher the gain, the more sensitive the pickup is to picking up information channeled from the amp. So the higher the gain, the easier you get feedback.

I use .011 flat-wounds strings on my 'jazz' guitar and that gives it a naturally more bassy sound. I have friends that used to tell me, as a joke, "Wow you can essentially replace the bassist by now" hahaha since when paired with certain settings I am amazed how bassy my guitar can sound. Given that, I tend to increase my treble beyond normal levels to compensate for that.

Essentially, the higher the Gain, Volume & (Treble) EQ, the higher the likely of occurrence of Feedback.

In an experiment today, my teacher took out his EQ pedal and we tried to find out at which frequencies my guitar feedback is occurring at. And so I learnt a new thing, feedback occurs at certain frequencies and if you cut those specific frequencies, you can reduce feedback. The idea is to find out which frequencies are the 'problematic' ones.

The feedback continued even if the 8k frequency range zone was reduced, thus it ain't what we are looking for. Then we found out that when the 4k range is boosted, the feedback became so much more intense, so the idea is to cut the 4k range frequencies which actually corresponds to the treble EQ. 

I do not know (yet) of any such similar smaller parameter breakdowns available in my GT-100, so all we can deal with is to have a "general" cut. Instead of only cutting the 4k range, I had to cut the entire treble range.

The rest of this post I would cover the other learning points from this Guitar Feedback lesson plus some of my past 'mistakes' when dealing with feedback. Today I finally found out WHY just a couple of months ago when I was running around switching to different amps in my music school, the feedback just wouldn't go away. Hahaha and it was definitely enlightening and fun to find out why.

The lesson started as my teacher mentioned that some players actually stuff 'something' into their semi-hollow guitars through the holes in the body in order to reduce feedback. Haha I haven't found out what material is supposed to be used, how effective would it actually be, the extent to which it will affect the tone of the guitar AND is there a technique to even 'stuff' some 'stuff' in the guitar because I suspect there is definitely a whole world of science and technicalities as to why 'it' has to be done 'this' way. Haha well, I don't think I would use this method...

Moving on, the lesson was fun as it was filled with us placing the guitar in various positions, facing the amp, away from the amp, a certain angle away from the amp to find out how the nature of feedback changes.

Before I forget I have to mention this: Today the patch settings had way higher gain than I actually used in school but when the guitar is placed directly in front of the amp, facing away from the amp it did not feedback, and mind you, the volume was put at super loud levels and my treble EQ is at 100 (maximum).

BUT in school, I had lower gain, same guitar and it feedback-ed alot when I sat in front of my amp and played (alright it's a crammed place with tons of people in the band room, so I just settled cosily in front of my amp hahaha !! Pretty amusing and fun now when I think of it since I just found out why I shouldn't sit in front of an amp !). So why did my guitar feedback in my school and not my teacher's place ?

Well, because my school had bigger amps hahah ! My teacher uses the super mini ZT amps for teaching and probably the information from the amp gets diverted to the sides instead of traveling around me to the front of the guitar and thus to the pickups. Now that's interesting :D (Alright for those of you who are tech geeks or physics experts, it would probably be common sense to you guys, but please pardon me haha as I lack knowledge in this field and totally couldn't figure out why certain things happen when they happened, all my mind was occupied with is the music haha ! Okay, enough of self-entertaining.)

Okay, in this lesson I learnt also that due to their individual construction/nature of certain effect pedals, some pedals are more prone to feedback as well such as the Fuzz Pedal. So, please do not panic when your Fuzz feedbacks, it is normal.

Another interesting concept my teacher pointed out was that "Distortion" used to be a 'problem' in the guitar world. Now that's something that's got to do with understanding the history of how these things came to be. But now "Distortion" has definitely become mainstream and loved by many. Actually tons of people or in fact everyone around me in my music school (including me) really thought that feedback is a 'problem', so I learnt today that it is a problem if you don't understand it, don't know why it occurs and if you don't know how to manipulate it.

Now I'm going to recount what happened when I had my intimate 1++hour session with guitar feedback this evening. I have a big Roland amp at home, plugged through my beloved multi-effects pedal. At the same settings, when my back is against the amp (at a distance) the feedback basically had a more constant quality in that it occurs in surges like tidal waves in the ocean, it swells in volume in a pretty constant manner, it is slower and has that sustain quality to it.

But at the same distance, when my guitar is actually facing the amp directly in front of the amp, oh my gosh ! The feedback becomes very very dynamic, it tells a very complicated story and the pitch of the feedback varies as well.

When less feedback occurs, I realized it tends to exist as "tails" to the existing sound, not invasive but noticeable at the end of the actual sound created from striking the guitar strings.

As I gradually increased my gain or treble, I noticed the feedback becoming a more and more dominant element in the entire sound. Instead of existing only as a 'tail' to the main sound, now it accompanies the entire sound.

Of course as I increased my gain to scary levels I would say, the feedback actually became louder than the actual sound signal generated from picking your guitar strings. And so this is when the sound gets really really disturbing.

As my teacher has shown as well, the nature of feedback actually reacts and corresponds to tampering on the fingerboard. Even with the guitar strings muted with 2 hands, at a feedback-friendly level of gain, treble and volume, the feedback actually assumes the pattern of slapping on the muted guitar strings.

Now on to the big reveal: I finally found out why I've gotten immediate humongous feedback no matter which amp I've tried in school the moment I switched on the amp. It is because I was hanging my guitar on my shoulder with my volume knob on to the fullest and my effect pedal's volume on to its normal level accompanied by high gain. The moment I on the amps, the guitar pickups come no more than a foot away from the amp speakers, thus the close proximity of the pickups and amp actually served as the final ingredient for the "Feedback Disaster" hahaha.

Thus my learning lesson would be that in future, I would have to either minimize the volume levels and then bring them up gradually after every equipment in the chain is on, or even lower the gain and then gradually bringing the gain back up again judging by the nature of the situation and most probably having to settle with a much lower gain level - because volumes are naturally set higher when the entire band is around (& everyone else plays really loud) as compared to solo home practice sessions.

I learnt a new name from my class: Nels Cline, a "pedal-geek" guitarist who plays with feedback a lot.

And here's a youtube video that I've been introduced to, to watch about guitar Feedback Techniques:



Not only so, I've found out that sometimes guitarists do not have to personally manipulate the change of patches during live shows as sound engineers would do the job for them. 

And as my guitar teacher said, the sound engineers could actually help you reduce the right range of frequencies if you encounter feedback (hahaha so if you invest in an awesome sound crew, you probably do not have to learn to control feedback using parameters such as gain, volume, treble EQ etc - Okay, just kidding.)

Alright guys, that's about it for this post.
See you again !

Take care & have fun,
Sapphire Ng



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