A Test Rig for Assessing Tonal Properties of Solid Body Electric Guitar Construction

[mistermikev]

18 minutes ago, curtisa said:

This wasn't meant to turn into a hotly contested argument, and I'm sorry if it's ended up that way.

Sustain vs bloom: I'm perhaps using the technically-incorrect version of 'sustain' (I'm thinking of an old 70s analogue synthesiser and its Attack/Decay/Sustain/Release envelope), and probably lumping the 'DSR' bit of the 'ADSR' in together as one complete thing. Maybe that's right or wrong in this scenario, I dunno? 'Bloom' I would have interpreted as the way the harmonic content evolves as the note decays (or DSR's? ), which again could be an interesting angle to explore with the recordings obtained thus far. But maybe my understanding of the word is different to somebody else's and leaves things open to confusion?

afai go... same here.  If I ever come off as more than just "considering out loud"... that's not how I meant it.

afa bloom, i agree.  there are a lot of things that could go into that (freq resp, level, attack, etc...) but was just narrowing to level as that would seem like the easiest to measure.  all of this is just really interesting - pondering conclusions not drawing them.

[Bizman62]

54 minutes ago, curtisa said:

This wasn't meant to turn into a hotly contested argument, and I'm sorry if it's ended up that way.

IMO we've so far just tried to understand how each one of us understands the terms used. For my part I don't know the meaning of Decay or Release, Attack and Sustain being more understandable, and the only effect I own is a delay...

"Bloom" sounds nice and flowery, is there a simple explanation how it sounds?

[Crusader]

1 hour ago, Bizman62 said:

"Bloom" sounds nice and flowery, is there a simple explanation how it sounds?

If I have the right understanding of it, I think the best way is when you play a note on a piano and hold it. You hear the note seem to change tone like "Bwwwwwoooooowwww" LOL if there's a better way to spell it! On a guitar its quicker due to shorter strings

[mistermikev]

17 hours ago, Bizman62 said:

IMO we've so far just tried to understand how each one of us understands the terms used. For my part I don't know the meaning of Decay or Release, Attack and Sustain being more understandable, and the only effect I own is a delay...

"Bloom" sounds nice and flowery, is there a simple explanation how it sounds?

simply put it's just any changes that happen to the sound as it fades out.  

edit, on second thought perhaps crusader's descrip is better!!

[Andyjr1515]

I'm away from my headphones at the moment, but I'll feedback as soon as I am able.  I like the rig you've set up @curtisa - especially the pick mechanism!

[Andyjr1515]

Listened to most of all categories.  Fascinating.  Will report back when I have a moment

[Andyjr1515]

OK - great set of experiments.  And some expected results and some surprising ones to me.

I listened to the clips through decent quality ear buds and away from external noise.

Consistency Check  I could hear no difference at all.  Credit to the quality and design of the rig @curtisa.  I still think that plucking mechanism is more than a touch of genius

Floating vs Fixed  Hmmm....well, I thought I could discern an attack difference between these.  The first one sounded more strident in each case...but then when you sneakily mixed then around I'm pretty sure it was all in my imagination.  I couldn't discern the differences

Through the Marshall, definitely couldn't discern a difference

Scale Length  Here, I could hear a difference.  It was particularly in the decay.  The decays sounded different on both strings.

Wood differences when heard through pickups - Two woods  I could hear no difference whatsoever

Wood differences when hear through pickups - multiple woods I could hear no difference whatsoever

Wood differences when recorded acoustically  Here was the BIG surprise.  Yes, I could discern some differences.  Wood 4 especially, but Wood 5 also.  But when I heard the tap tone differences between the woods WOW.  Having done a number of acoustics using tap tone tuning, I am amazed just how little difference there was transmitted through the vibrating string

Through body vs Top stringing  Yes - especially the top E where the decay pitch variation was different.  

 

 

[curtisa]

Thanks for partaking in the madness, @Andyjr1515

2 hours ago, Andyjr1515 said:

Scale Length 

...

Through body vs Top stringing

To me it makes the most logical sense that these two resulted in the most obvious differences, as you seem to have experienced as well. They're effectively changing the properties of the strings themselves - tension, downward pressure on the saddles, 'speaking' length of the strings etc. The change in tone due to the other variables tested thus far seem to be a lot more subtle, if even detectable at all.

I haven't forgotten about these tests, I've just been snowed under with work and haven't had the time to devote to further experiments. I hope to get back into the swing of things in the near future.

[curtisa]

Currently in the pipeline:

• stainless steel frets vs nickle silver
• string distance behind the nut, long vs short.

Back soon...

[curtisa]

Finally had some time to sit down and run another few willing victims through the meat grinder,

Length of the string behind the nut

The plank used to test string-thru/top loading has been modified slightly and a new headstock attached with a conventional scarf joint to give a back angle of 14 degrees. This helps make the downward angle behind the nut more or less consistent when switching between the two tuning machines. With the earlier flat/stepdown headstock the string angle and subseqeunt downward pressure at the nut would vary with the string anchor point which may affect the results. The two posts are spaced 30mm and 150mm from the nut respectively, which should give a good spread for covering most situations such as reverse or 3-a-side headstocks. The string has a clear run between nut and post, whichever tuner has the string fitted. Because of the angled headstock I've had to rest the plank on a thick block of wood to raise it up and to stop it touching the table, but the rubber bumpers are positioned between the plank and riser as usual:

 

Stainless steel frets vs nickel silver

For this test two short pieces of nickel silver and stainless steel fret wire have been pressed into a short length of rosewood to act as a reversible fretboard. The two drill holes at either end allow the fretboard to be rotated around 180 degrees on the plank so that the closest fret to the bridge always sits at the same position, which is the equivalent of the 5th fret on a standard guitar. The wire used is the same dimensions and profile for each sample (Stewmac jumbo #0150), and were polished up to 2000 grit and buffed on the Dremel before the tests. Crowning was not performed, but shouldn't be necessary in this case as there are no other frets on the 'neck'. Avoiding crowning also helps maintain the shape of the top of the two test fret wires which may help aid consistency. Rather than construct yet another mechanical aid to depress the string to the fret, for simplicity I'm just fretting the string with my finger. The robo-picker does the rest:

 

Two sets of files are attached, plus the same two files passed through a clean amp sim. A fresh set of 46-10 strings was used.

For the 'string length behind the nut' tests three paired plucks of a low-E, D and high-E string are performed. The first pluck in each pair is with the string fitted to the post furthest away from the nut, the second is with the string fitted closest.

For the 'stainless steel vs nickel silver' tests, three paired plucks of a low-E, D and high-E string are performed with the string fretted at the pseudo-5th fret, giving pitches of A2, G3 and A4. The first pluck in each pair is with the string fretted with stainless steel, the second pluck is the nickel silver.

10 Stainless Steel vs Nickel Silver + Amp.wav 10 Stainless Steel vs Nickel Silver.wav 11 String Length Behind Nut Long vs Short + Amp.wav 11 String Length Behind Nut Long vs Short.wav

[Bizman62]

I couldn't hear any difference between the fret materials. Before having read the entire chapter I was thinking about the flesh effect which you then explained and proceeded "in flesh", the most natural way.

The 'string length behind the nut' test seemed to have a bit more difference, the second notes in each pair sounded more accurate right from the start. The long slack had more 'twang' if I'm using the right term here - the sound seems to gather speed before getting to the right pitch. To me it sounds richer which may work well for a solo player but the tighter sound may be better in a band.

[Andyjr1515]

I couldn't hear any difference in either the fret material (which I wasn't expecting anyway) or the string length to the tuners (which was a bit of a surprise until I thought about it).

The reason I was surprised with the string length is that on a couple of my own electrics when the band was playing - and specifically 6 in a row without string trees - the sympathetic harmonies through those top strings harping were so marked, even through the amp, that I had to (not least because the band insisted I did   Admittedly their preference was always that I didn't play at all   ) pop a damper sponge under them or weave a piece of wool in between the string runs. 

The 'until I thought about it' is that, of course they harp in sympathy with their critical frequencies - so it was unlikely that it would happen to be open string of that same string.  It is much more likely that it would have been a fretted note from one of the other strings.

So a question (though I'm not suggesting a full rig test of this!) is whether the after-vibration of that length being plucked is picked up at all through the unplucked main string run...

[Crusader]

3 hours ago, Andyjr1515 said:

So a question (though I'm not suggesting a full rig test of this!) is whether the after-vibration of that length being plucked is picked up at all through the unplucked main string run...

If I understand you correctly the answer is yes. I asked a University Lecturer (who also happened to be a guitarist) about this and he said when you play a fretted note, the vibrations go past your finger as Longitudinal pulses and past the nut and then of course reach the tuning pegs

Edit: I should mention that once the vibrations have got past your finger they return to Transverse waves again

Edited June 13, 2021 by Crusader

[curtisa]

9 hours ago, Andyjr1515 said:

The reason I was surprised with the string length is that on a couple of my own electrics when the band was playing - and specifically 6 in a row without string trees - the sympathetic harmonies through those top strings harping were so marked, even through the amp, that I had to (not least because the band insisted I did   Admittedly their preference was always that I didn't play at all   ) pop a damper sponge under them or weave a piece of wool in between the string runs. 

Yes, Strat players are probably well aware of the natural harping that occurs on the open G string if their guitar doesn't have a string tree fitted on the D/G pair. The distance behind the nut to the tuning peg is pretty close to the 5th harmonic on that one string, which then rings like crazy on open staccato runs. I've seen some players exploit it going back the other way though, plucking the string behind the nut to excite the 5th harmonic back onto the open string and then bend the string behind the nut to get some interesting pedal steel-esque slide runs.

Metal musicians are often aware of the problem of harping too. High gain and staccato runs on open strings don't sit well with certain styles of metal, and you'll often see their guitars fitted with foam stuffed under the strings behind the nut or fluffy hair ties wrapped around the neck.

Personally I could hear the differences between the long and short lengths of string behind the nut, but only on the lower strings. It was most prominent on the low-E long-string-distance example where the resonance as the note started decaying had a descending filter effect, giving an 'eeeeoooowww' after it was plucked (perhaps akin to @Bizman62's 'twang' he described and @mistermikev's 'bloom' characteristic?). The short-string-distance examples didn't have this effect. Whether that was due to the length of string behind the nut causing harping or some other byproduct of the way the string's elasticity differed between the two extremes I don't know.

I did the stainless steel/nickel silver trial as I'd seen mentioned that some people didn't like stainless steel on their guitars as they felt it gave the fretted notes an extra metallic 'zinginess' that disagreed with them. That might still be the case when an instrument is played in a real life situation, but on face value from these tests I'm not hearing it.

[Bizman62]

8 hours ago, curtisa said:

a descending filter effect, giving an 'eeeeoooowww' after it was plucked

Exactly that, I just wasn't sure about the spelling of  'eeeeoooowww' so I typed 'twang' instead.

[curtisa]

I believe the Finnish and English words uttered when accidentally stabbing yourself with the end of a string are pretty similar in both languages

 

[Bizman62]

Pretty much so but the spelling is very different: Auts! v.s. Ouch!

[curtisa]

Next time I stub my toe on the leg of a chair I'll remember to yell, 'TWANG!!!' at the top of my voice.

Or maybe I should use the Finnish word instead..?

[Crusader]

I made a Strat Copy with angle on the headstock so it didn't need string trees, bad idea!