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Anyone use hemlock for necks ?

Found a source for nicely quartered hemlock in 2" and 4" thickness. Came home with a 2x6 blank 4' long for a very reasonable price.

-jd

I can't say anything about it's use but it would be great if it could be used for something now that all the trees are dead

It's been used for guitar tops before so it might be analogous to using spruce for a neck.

not a good neck material very splintery

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

So match it with a Wenge body ?

Lots of living hemlock trees in my neck of the woods, so they aren't all dead.

Unfortunately the wood isn't much good IMO, basically because it splits so easily.

I've used it for outbuilding construction and such but only when economy is of the essence.

I wouldn't consider it an instrument grade wood but I'd bet it has been used for that successfully somewhere along the line.

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Brian R, Wood Mechanic
N8ZED

Hemlock for a neck? might as well pick a nice 2X4 at home depot IMHO.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Message received, good thing it was not expensive.

I will find another use for this plank.

Thank you.

I have used it a quite a bit in cabinetry and a lot of firewood. It varies from tree to tree and region it grows. I have lumber in my shop and chunks in the woodpile that would absolutely make a good neck wood. As would old growth Fir. It's very stable and have never found it overly splintery. Go for it if the density is good! It varies a lot.

As Danny says, there are three types of Hemlock, Mountain, Eastern, and Western. The one that splinters is Eastern. If yours is Mountain or Western (Westen is by far the most commercial of the bunch) you should be able to use it for a neck, although it is considerably softer than Mahogany

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Joe Beaver
Maker of Sawdust

Density is on the high side, which is why I got it. No scale in the shop, but compared to other planks, I would say denser than the Honduran I have, about the same as sapele, and less dense than walnut or white oak.

Comes from a West coast Sawyer. Found it while visiting family in the la area.

I used to make waterbed frames from kd 2x10 western hemlock back in the '70s. Flatsawn it had interesting grain patterns. Finished them with Watco black walnut. There's still some boards up in the rack. I'll have to take them down and look at them again with a new eye.

The Tongass National Forest is about 60% Western Hemlock. But also grows the finest old growth sitka spruce in the world. Alaska Specialty woods has done some research on the properties pf WH, mainly because we had found some logs that made one wonder about use for a soundboard. It is quite surprizing what the properties of this specie is. Strength... the stuff is strong. Density, not too much different than most of the sitka. Anyway, most western hemlock is not suitable for soundboards because the specie is shade tolerant and is able to survive with very little sun. It grows under a canopy of shade[unlike sitka] Anyway WH often has un-sightly dark pitch sipes scattered though out the log. And since appearance is so important so sellable guitars it won’t work to produce in large quantity. 80% would get thrown away for looks. Al Carruth did some testing with some WH top sets he purchased from us at an ASIA show about 20 yrs ago, and reported that it hade better tonal properties than the Sitka he had at the time[ which was not from us At ASW.] Also according to the USFS wood lab in Wisconsin, WH is 12% stronger than sitka. But it does not have the elasticity. We have WH tops in our online store.

Since it is nicely quartered you could saw it up for parlor guitar or dulcimer tops. Waste not, want not.

You could build a squareneck with it.
Alan

I remember that WH. It was pretty dense, and would work well for a smaller guitar, where the density is not so much of an issue, or for one where 'headroom' is important. Of course, a sample of only two is not necessarily 'representative', but it's a start.

Can you expand on that headroom comment a bit?

Trying to reason through this : A denser top, being heavier for any given geometry, takes more energy to "drive", so is suitable for people who like to bash chords with enthusiasm, like me?

I have one of those WH tops. It is rather dense compared to the spruce I've compared it to.

As with much of guitar acoustics, the subject of 'headroom' is vexed. At some point somebody needs to do some pretty detailed experiments to illuminate it, but that would take a fair amount of effort and time, and if my experience to date is any guide, we'd still end up wishing we knew more.

One of the assumptions that we use when we talk about the way the guitar works is that the ends of the string are 'fixed'. It's a useful fiction that makes it possible to describe the way the strings vibrate fairly easily (if you've got the math chops), but we all know it's not true. For one thing, if the bridge and top are not moving the guitar won't be making any sound. For the most part we can ignore the motion of the bridge; it's 'small', but once in a while it gets big enough to be a problem. We call those occasions 'wolf notes'.

'Wolf' notes happen at the pitches of strong resonances, particularly of the top, or the air in the box when that can push on the top. A resonance is just a pitch where it's easy to move something, or, to put in another way, a frequency where the 'impedance' is low. Strings themselves have low impedance, and when the string impedance matches that of the top closely it's easy for energy to flow from one to the other. Note that goes both ways: the string can drive the top, and top can drive the string. The feedback means that wolf notes tend to be associated with problems both of sustain and also intonation.

Acoustic impedance is the measure of how hard it is to move something at a particular frequency: it's the ratio of Force/Velocity at a given frequency. It's determined by three things; mass, stiffness, and loss. Adding mass raises the impedance of the system and tends to drop the resonant pitches if the stiffness stays the same. Adding stiffness raises the resonant pitches as well as increasing impedance. Increasing the losses doesn't change the resonant pitches but does increase impedance.

If you're using a softwood for the top, and build to a certain stiffness, it turns out that the denser the wood is the heavier the top will be. All else equal it will have a bit lower resonant pitch than a less dense top built to the same stiffness and other specs, and it will have higher impedance. Its less likely to move enough to cause problems with the energy flow from the string, so you can push it harder. You can also get some headroom by changing the brace profile: 'scalloped' bracing tends to be less stiff at the bridge location than 'tapered' bracing, or even 'straight', so the scalloped brace profile can cost some headroom. Another way to increase headroom is to use a heavy bridge: go with ebony at 30 grams instead of rosewood at 25. Each choice you make has an effect on the final sound, and you have to balance things to get what you want.

This is, as far as I can tell, part of the 'standard model' of how headroom works. It's actually more complicated than that, as most stuff on guitars tends to be. That useful fiction of the 'fixed' bridge is part of the larger useful fiction of 'linearity'. Guitars are pretty close to being 'linear' systems, but not quite, and it's those departures from linearity that make things 'interesting' when they're not too large, and 'troublesome' when they are. The boundaries can be fuzzy.

Alan: I've followed and enjoyed your posts for several years. You provide a rational and thoughtful perspective in a domain that, being as complex as it is, is fraught with tradition, folklore, and presumptions. The experiments that you've conducted seem among the few substantive guideposts in the field. Thanks.

I'm intrigued by your comment that "guitars are pretty close to being 'linear' systems, but not quite." I've always presumed (note the word choice) that guitars were, in fact, linear systems -- complex linear systems, but, nonetheless, linear. That would suggest that no sonic frequencies will be radiated that are not initially present following excitation of the string. I recognize that the ends of the string in a flat-top guitar, and particularly at the saddle/bridge, are not fixed so the vibration modes of the string are not those that can be simply calculated. (Archtops, with the strings terminated by a tailpiece, seem a more idealized construct.) But I don't understand the non-linear mechanism unless, with very aggressive input, the elastic response of the guitar structure may not follow Hooke's law. That would read on the "overdriving" issue, but I find it unintuitive that even the hardest strumming will flex any of the guitar's wood to non-linear deformation. Maybe I just need to refine my intuition.

Your thoughts?

What Hans said.

I really appreciate your willingness to share & educate, and the time it takes to write up the thoughtful responses.

So, in a nutshell, a high headroom guitar gives you the facility to hit it harder rather than play it louder?

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

You can hit it harder and play it louder without things becoming unmusical and dissonant. Obviously you can hit them equally hard and they may be equally loud but the one that lacks headroom won't sound good.

" . . . the one that lacks headroom won't sound good."

Alan, Trevor: It's been a LONG time since I was in school, so please check me/correct me if I'm off in the weeds on this, but it seems that, If a guitar changes tone as it's driven harder, that means that the spectrum produced by the soundboard has changed. That means either that the excursion of the some portion of soundboard has moved into a non-linear region (no longer following Hooke's Law) and is producing non-musical harmonics or that some part of the system is displaying hysteresis when driven hard (but not when driven softly). If these are, in fact, the possible causes of limited headroom, they would derive from different structural limitations, so knowing which is operative would be useful in dealing with the issue.

Repeating a thought I shared in an earlier post, positing that the wood of the soundboard is deformed sufficiently by hard playing to develop non-linear response seems remarkable. Hysteresis in the guitar could have a number of sources, possibly related to damping in the wood or at wood/wood joints, depending on glue properties, or at the wood surface, depending on characteristics of the finish. Or it could be due to movement at the bridge between bridge and saddle or bridge and pins/string ends or strings and saddle. The range of possible causes seems worthy of investigation.

That's the way I've always thought of it.

_________________
Steve Smith
"Music is what feelings sound like"

You might be able to model "headroom" using rate dependent hysteresis formulas since it can deal with sinusoidal inputs to linear systems.

Trevor Gore (ever on the critical point) wrote:
"So, in a nutshell, a high headroom guitar gives you the facility to hit it harder rather than play it louder?"

Well, that's the question, is it not? We need to figure out just what really is going on here.

Hans Mattes wrote:
" I've always presumed (note the word choice) that guitars were, in fact, linear systems -- complex linear systems, but, nonetheless, linear."

Complex; yes.

My problem is that I'm not strong in mathematics; it's why I do experiments. I keep wondering at what point a stack of linear responses acting on each other becomes non-linear? Basic string vibration theory says that the tension on the string must be constant to provide a true sinusoidal response, but we know that's not the case. The change in tension with displacement follows linear rules but can alter the response of the string in ways that 'shouldn't' happen. Pluck a short, heavy plain steel G string hard and listen to it 'wow'. Is that non-linear? Seems so to me. When I spent time measuring the forces that a plucked string puts on the saddle top I found all sorts of unexpected things, some of which did introduce 'new' frequencies into the signal. We know that string stiffness introduces dispersion into the frequency response: the higher partials travel faster along the string and are shifted upward in pitch. That's a liner cause producing, what? Seems non-linear to me. I spent a lot of time a few years ago tracking down the source of the longitudinal 'zip tone' vibration of the plucked string. There's a linear model that can describe it, but the effects can be pretty odd.

I'm not saying the model I gave for 'headroom' is strictly correct: since I don't have the data I can't. It does seem consistent with observations and suggests experimental approaches. Now we need to do the experiments.

My own opinion is that the high headroom guitar could very well end up producing more sound than one with less headroom, but it takes a lot more input to get there. I also think it's plausible that you reach a point of diminishing returns with any guitar. It will take a lot of hard work to resolve this all.