What exactly is Feedback?

So, when I crank the sound system in the church, or put a mic in front of a monitor I get feedback. It's a sound loop that amplifies itself until you shut it off or break something.

When I teach a college course I conclude with a "Feedback Survey" and get feedback on the highs and lows of the course.

When I tune a carburetor the rpms, smell, and throttle response give me feedback allowing me to find that sweet spot where she runs smooth, efficient, and responsive.

When I hone I use tests like shave tests, magnification, "hair popping" etc. to get feedback on where the edge is on its journey toward shave-vana.

When I read honing threads or articles, or watch Lynn, Glen, or Sham hone I find this word "Feedback" popping up time and time again, but I've yet to find a clear answer on what is meant by this term. At one point it seems to be a feel, or a suction, at another point it seems to be a sound, then again at other points the term seems to be referring to the composite of information gleaned from various tests.

Right now I'm in the midst of a "no shave" experiment, but as I near the end of this experiment I'm honing up my razors and getting ready for all the glories of my daily straight routines. Refreshing myself after some time off I'm coming up against this term again.

Anybody have a clear definition on this term?

Thanks,
Jim

This is a good question.

I wondered for a long time.

Then I decided that it didn't really matter how other people used it, cause I don't talk to other people about honing feedback.

But for me, feedback is any sensation I receive from the razor on the stone, as a result of honing. This can be sound, feel, sight or touch. Good feedback, is feedback that I can interpret in a meaningful way. While poor feedback is a lack of any identifiable sensations I can interpret. This means I might get great feedback from my Norton stones, while the feedback from my coticule is poor. Why? Because I know what a properly set bevel feels and sounds like on a Norton stone. But on a coticule, each one is unique, and none of them like me. So..they don't talk to me. :p

JMHO, YMMV, and several other acronyms I'm sure.

The term can mean whatever you'd like and might have some basis in different hones. To me, in it's most simple terms, it's the drag caused by honing when the edge starts getting sharper. As the bevel becomes smoother it sucks and drags more. As the stone dries, or is re-wetted the feedback might change. It's all about the stone and what it does. Once you realize each stone does something when it's sharpening an edge that information becomes a critical aspect in honing.

For example the feedback while honing on Shapton is very good, feels like the razor is stuck to the stone once it reach its max potential on one stone, then move to a finer stone till that suction shows up again. Sound is a big part as well you get to know what sound comes for a particular stone, if it doesnt sound right something is out of wack, maybe more water or lapping or you moved from one stone to the other to fast, all part of feedback to acheive your goal.
Another good feedback is watching the water in front of the blade while honing, it will definately point out if there is dirt on your stone or grit.

There also feedback on ebay! :)

Hey There

So this is a good question, and one which is going to cause an angle to lose her wings :(

Ok ...

When I am honing I have an understanding of which hones are going to do what to the razor in my hand. We all know that we move from setting a bevel, to refining the bevel (some call this sharpening), next we move onto polishing the bevel. There are a number of interesting things going on throughout these processes.

Bevel setting -

When we are setting a bevel we are going to remove steel and have the two edges of the blade converge at a small point. When they converge at an acceptable angle, we can shave with the edge. We generally use stones around 1000 grit to bevel set. This stone is going to remove a moderate amount of steel, as such there are going to be certain things you can feel, hear, and see to use as feedback so that you know everything is going well.

First you are going to see steel being removed from the razor. You aren't going to see it happening but you are going to see evidence of it. You will see grey being deposited on your stone, and the lubricant you are using will become darker, and darker as it holds more and more steel. You will be able to see the lubricant moving in front of your razor, it will move more and more uniformly as the bevel becomes set and more uniform in nature. If your stone isn't flat, or the bevel isn't completely in contact with the stone the lubricant won't move in a smooth, wave form along your hone. If it isn't uniform then there is something wrong and you should fix it.

You will be able to hear a small amount of noise, the noise will get smaller and smaller as you go on with the honing, and the bevel becomes set. This is IMO because the surface of the bevel is reflecting the surface of the stone with it's scratch pattern and how "straight"/flat it is.

You will feel some vibration, these vibrations are minimal but important. The less vibration you feel, the closer to having a set bevel you are. Also as the bevel becomes set there will be less resistance along the line of the stone, but as you come to turn/roll the blade over the spine to come back in the opposite direction the set bevel with provide resistance, as it sucks to the stone.

Sharpening -

This is generally very similar to bevel setting with you using less pressure so the feedback becomes less, this is why as you hone more this feedback becomes easier to notice.

Polishing -

For me this feedback is more about the feel of the suction between the razor and the stone, and how the lubricant/slurry looks.
There should be more suction at this stage because the stone is harder (my stones are all natural), and the bevel is much smoother. You need to take care not to allow the edge push into the stone, as the suction could allow you to lift the razor from the stone. If this happens you will feel a horrible scratching in your fingers and you may see it.

My experience of the slurry is that a slurry forms more and more as I polish the blade. This is going to vary depending on who you ask BUT everybody's experiences with this are important (providing they end with an excellent shaver). My slurry get's whiter and whiter as I polish more. This is significant to me because I am done once I can't see the certain colors on my stone. For you, this could be different but you will gain your feedback with experience.

I HATE the following acronym but YMMV. I use it here because your fingers may be less/more sensitive than mine, your eyesight better/worse, and the same with your ears. You will have different hones, may use a different lubricant (as I make my own), and you may or may not have kids screaming at you as you hone lol.

I hope this helps

When you talk feedback in a sound system that is a specific thing and in fact is an engineering term and it can be defined and studied and seen on test instruments and acoustic engineers can quantify that. However with many other things it's just a term with no real definition except in the mind of the individual. With razors it's like that. it's all relative. Ten folks might hone the same razor on the same hone in the same condition and you might get ten descriptions of the feedback they perceive and some may feel nothing at all.

For me feedback is the feel of the razor on the stone.
Different stones can feel different on the same razor.Some stones feel similar on majority of razors, the ones that provide the most consistent feed back are the ones preferred by honers.

For me, feedback in relation to honing, is the result from the first shave of a just honed razor. It tells me all I need to know about the honing of that particular razor.

After a certain number of blades I developed an ability to sense feedback from the stones to help guide the progress.

Draw, grittiness feeling in the stroke, sound, and perhaps other less tangible perceptions I get through my fingers.

Predominantly, this is all relative and possibly unique to blade itself. Ideally all these perceived qualities diminish to a lesser state, but MOST importantly, they are consistent from heel to toe.

Often I find that the heel or toe need more attention than the interior of the blade. The feedback from the strokes on the stone are usually my first tip off

I suspect there is no definitive answer as we all key on different things, have different expectations of "sharp", and we all potentially have more/less acute senses. Some have great eyes, some have fantastic hearing, others have a sensitive touch....I have even heard some talk about taste as a sense that gets used (dull blades taste like steel, and sharp ones taste like blood :D)

To date, I have not talked to anyone that relies much in smell feed back at the honing/stropping level:)

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Originally Posted by unit

To date, I have not talked to anyone that relies much in smell feed back at the honing/stropping level:)

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Some naturals, after being slurried have a very distinct smell, for example the earthy smell of a coticule, the escher/thuri as well.

Something that I failed to mention is the negative feedback from grit on your finishing stones. If I feel grit on the stone through the razor I begin to feel a little sick and stop immediately. I go and rinse the stone under the tap and the razor too. Feeling these negative things on polishing stones is important because they could ruin all your hard work!

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Originally Posted by Martin103

Some naturals, after being slurried have a very distinct smell, for example the earthy smell of a coticule, the escher/thuri as well.

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Touché.

While I suppose this is a feedback of sorts from the stone...is it useful or necessary, or simply an observation? (honest question, as I have not used these types of stones/hones).

In honesty, I have noted smells during grinding (even by hand on hones) that involved removal of significant (carbon) steel. I have never used this observation as any sort of guidance or feedback...just a realization, and a thought of "wow":)

In the world of knives, I guess I would have to claim to have used smell as feedback. Carbon steel often has a slight "rusty" smell to it that I have used to differentiate it from stainless steels...but it only works with fairly aged or worn pieces. Hard to celebrate this too much though because there is usually an accompanying patina or bloom that can be identified on sight.

When I use the term "feedback", in the context of honing, it refers to the feel of the razor on the stone.

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Originally Posted by thebigspendur

When you talk feedback in a sound system that is a specific thing and in fact is an engineering term and it can be defined and studied and seen on test instruments and acoustic engineers can quantify that. However with many other things it's just a term with no real definition except in the mind of the individual.

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This appears to be the overwhelming response. For a term that is thrown about so much you'd think there'd be a clearer definition of it.

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Originally Posted by unit

...I have even heard some talk about taste as a sense that gets used (dull blades taste like steel, and sharp ones taste like blood :D)
...

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:p

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Originally Posted by HNSB

When I use the term "feedback", in the context of honing, it refers to the feel of the razor on the stone.

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It appears that feedback is the collective body of evidence gathered through the honing process to determine the effectiveness of the honing work. It may consist of sight, feel, sound, (taste,) and/or performance in various tests (TNT, TPT, HHT, etc.)

Anybody want to add to the wiki? ;)

I use Nortons (1-8k) and Barbers (Swaty & Keen Kutter) for my honing. Maybe someday I'll get a "real" finisher, but I obtain satisfactory results with these stones. The Nortons definitely have a different feel than the Barbers, and the Barbers have different feels from each other and coarse vs. smooth sides. But when you read/hear about someone doing rolling X's until they get good feedback--unless that term is previously defined--the ambiguity makes the comment less than helpful.

Thanks for the replies guys,
Jim

For me it was something I knew when it happened. For a long time I wondered the same thing. Then one day as my balance, pressure, draw, and steady handedness improved I felt what everyone was talking about. It was a constant almost suction type feel of the blade to the stone. I could feel the stone give even resistance on the blade throughout my entire stroke. I have only felt it on my Naniwas. I am going to try my Nortons today and see what the feedback feels like from them. Anyway for me it was something that just happened after practicing and experience.

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Originally Posted by ccase39

For me it was something I knew when it happened. For a long time I wondered the same thing. Then one day as my balance, pressure, draw, and steady handedness improved I felt what everyone was talking about. It was a constant almost suction type feel of the blade to the stone. I could feel the stone give even resistance on the blade throughout my entire stroke. I have only felt it on my Naniwas. I am going to try my Nortons today and see what the feedback feels like from them. Anyway for me it was something that just happened after practicing and experience.

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That's how it happened with me also. I use Shapton glass. Same as with the draw and noise of stropping, I translated it to honing ( noise in only during bevel setting). Double O

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Originally Posted by ccase39

For me it was something I knew when it happened. For a long time I wondered the same thing. Then one day as my balance, pressure, draw, and steady handedness improved I felt what everyone was talking about. It was a constant almost suction type feel of the blade to the stone. I could feel the stone give even resistance on the blade throughout my entire stroke. I have only felt it on my Naniwas. I am going to try my Nortons today and see what the feedback feels like from them. Anyway for me it was something that just happened after practicing and experience.

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I was finishing a razor on my Zulu yesterday, and I got some incredible feedback from the stone. I began with a milky slurry & did 20 or so x-strokes, then diluted, and repeated the process. Then, after my 4th or 5th dilution (by dipping the blade in water), I started getting a pronounced resistance that I can only describe as "stiction" to the stone. This, to me, was the stone letting me know that the razor was ready to be stropped.

And the stone was right!! I got a perfect HHT right off the stone (before stropping) and the subsequent shave was amazing. So yeah, this feedback phenomenon really is the stone communicating to you..

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Originally Posted by BigJim

It appears that feedback is the collective body of evidence gathered through the honing process to determine the effectiveness of the honing work. It may consist of sight, feel, sound, (taste,) and/or performance in various tests (TNT, TPT, HHT, etc.)

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The problem is, I think, that the term has never really been defined formally. This thread is probably the closest thing as there is to a "definition".
I'll continue to use the term the way I use it, since my use is the one that's correct. ;)

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Originally Posted by Martin103

For example the feedback while honing on Shapton is very good, feels like the razor is stuck to the stone once it reach its max potential on one stone, then move to a finer stone till that suction shows up again. Sound is a big part as well you get to know what sound comes for a particular stone, if it doesnt sound right something is out of wack, maybe more water or lapping or you moved from one stone to the other to fast, all part of feedback to acheive your goal.
Another good feedback is watching the water in front of the blade while honing, it will definately point out if there is dirt on your stone or grit.

There also feedback on ebay! :)

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I think you're referring to stiction: the friction which tends to prevent stationary surfaces from being set in motion? And is quite noticeable on my Ozuku when the potential of the stone is achieved. If I try to push it too far I risk the blade 'skipping' due to the desire of the blade to stay where it is.

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Originally Posted by HNSB

The problem is, I think, that the term has never really been defined formally. This thread is probably the closest thing as there is to a "definition".
I'll continue to use the term the way I use it, since my use is the one that's correct. ;)

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I would like permission to suggest that this is not feedback, at least in the honing sense. The hone provides feedback suggesting that it is sharpening the blade, or that the blade is in fact sharp. Tests provide sensation, or a reaction, or a sound that indicates the condition of the blade. The razor is not getting sharper and providing feedback in the moment, it is providing information post action.

This thread is feedback on feedback about feedback. The information you get from input. If I put too much pressure on a blade going across the hone I get negative feedback. If I do it right I get positive feedback. Smooth is the feedback I am looking for and anything that eventually gets me there is the feedback I try to repeat. If I feel a bump there is a hair or grain on the stone and it needs to be cleaned. If I hear scratching it should decrease as I continue with laps. Anything short of that is telling me something is wrong.

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Originally Posted by AFDavis11

I would like permission to suggest that this is not feedback, at least in the honing sense. The hone provides feedback suggesting that it is sharpening the blade, or that the blade is in fact sharp. Tests provide sensation, or a reaction, or a sound that indicates the condition of the blade. The razor is not getting sharper and providing feedback in the moment, it is providing information post action.

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Close. I'd say feedback is the observation of the result of an action, by the originator of that action.

Audio output getting fed back in an amplifier is feedback.
Doing a survey of customer satisfaction is feedback.
The feeling of a razor moving over a stone is feedback.

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Originally Posted by BigJim

. But when you read/hear about someone doing rolling X's until they get good feedback--unless that term is previously defined--the ambiguity makes the comment less than helpful.

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:) And yet I know exactly what they mean from the term, it is all the same, even with the Feedback from your Stereo, most here understand exactly what you mean because we have experienced it.. But try and explain audio feedback to a person that has never listened to amplified music using only the typed word and I bet it will be a good bit of a chore :p

Experience is all relative, one you experience good feedback, be it Tactile, Visiual, Audio, -vs- bad feedback you will no longer question the term it will be as obvious to you as the Stereo Feedback...

Bruno nailed the Technical definition, it is the

"Observation of the honing Action through any of the 5 senses"..

Speaking of, I have no more razors that need honing. I have dulled and honed all 14 of them several times I don't want to risk over honing and frown it or something. Its a shame because it was just recently I experienced feedback and I would like to practice more.

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Originally Posted by ccase39

Speaking of, I have no more razors that need honing. I have dulled and honed all 14 of them several times I don't want to risk over honing and frown it or something. Its a shame because it was just recently I experienced feedback and I would like to practice more.

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Hah, that sounds way too familiar.
My poor collection was subject to massive exagerations hone-wise for the longest time:)

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Originally Posted by gssixgun

...one you experience good feedback, be it Tactile, Visiual, Audio, -vs- bad feedback you will no longer question the term it will be as obvious to you as the Stereo Feedback...

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I'm not sure if I'm educated or depressed by your comment Glen! On the one hand, if I should "know it" when I experience it, perhaps my honing and shaving experience has been rather lacking. On the other hand, the discussion here has proved fruitful to me; namely that I'm on the right track and not missing some ethereal "it".

I've been around live sound a lot, and over a long period of time. But I can remember several different occasions where feedback reared its head and the person holding the mic (or irreverently jacking with the board) looked up shocked and said something to the effect of "What was that!?!" Experiencing it didn't tell them what it was, but having someone to name it did...but that's also the benefit of learning to hone from someone as opposed to learning as you go.

Bruno's definition is certainly the most concise and clinical. But it also answers the question, as it were, as to what constitutes "feedback."

Peace,
Jim

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Originally Posted by ccase39

Speaking of, I have no more razors that need honing. I have dulled and honed all 14 of them several times I don't want to risk over honing and frown it or something. Its a shame because it was just recently I experienced feedback and I would like to practice more.

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HA! I do the same thing..:o