Main Forums => Technical Discussion => Topic started by: yellowesty on April 17, 2016, 07:49:19 PM

Title: Pick Guard Damping?
Post by: yellowesty on April 17, 2016, 07:49:19 PM
I'm a new (and delighted) Larrivee owner (L-03Z) and have now spent many hours reading postings on the Larrivee Guitar Forum (and many more playing my new guitar).  Being the former owner of a "plywood" guitar, I recognize the unfortunate sonic effects of damping in guitar construction -- particularly damping of the soundboard.  So, as a player who doesn't use a pick, I wondered if my pick guard was dampening the sound of my Larrivee.  All of the posts that I found suggested that removal of the pick guard had visual effects (good in that it exposed more wood, bad in that it risked tan lines and a damaged finish), but no one seemed to think the effect on sound was significant.

This seems remarkable.  People note the effects on sound from ivory vs. bone vs. tusk saddles and even from plastic vs. ivory vs. wooden bridge pins, yet the consensus seems to be that gluing a sheet of stiff plastic to more than 15 square inches of the soundboard can't be heard.  One poster (on a Martin forum) suggested that the lack of pick guard damping was due to the pick guard being in a highly braced area of the soundboard, so that area didn't contribute much to sonic output.  I laid my Larrivee on it's back and plucked the strings while lightly touching the soundboard in various places.  The soundboard in the upper bout was fairly still, but adjacent to the sound hole and across the lower bout, the soundboard was very active, so I'm not convinced that interior bracing is what makes the pick guard irrelevant to sound.

I'm not disputing the conclusion that the pick guard has negligible sonic impact, but I do wonder why.  Can anyone explain this?

Thanks.  :donut  :donut  :coffee

Title: Re: Pick Guard Damping?
Post by: rockstar_not on April 17, 2016, 09:01:34 PM
yellowesty

1.  Most of the claimed differences between x vs. y item are very difficult, if not impossible to prove without an expensive automated picking/playing device and sophisticated sound measurement & analysis equipment.  Nearly all of these comparisons are also done by swapping out a used set for new set of strings in addition to pin swaps, saddle swaps, etc.  Most the claimants don't blow through two sets of new and identical strings to try this saddle vs. that saddle, or these bridge pins vs. those, these strings vs. those even, etc.  Acoustic memory function is highly temporary as it pertains to precise recollection over even a few minutes - we can really only detect fairly noticeable changes over periods of weeks or months, or dead old strings vs. sparkly new ones - with reliable, blind repeatable results.

2.  There are some great physics and engineering videos on acoustic guitar top behavior and your observation is well founded, but the thing to keep in mind is that our ability to detect vibrations in the audible range (up to 20kHz) through our fingertips is quite frequency limited - our fingertips can do detection up to perhaps a few hundred Hz.  When you feel a top vibrating, for the most part you are feeling only the vibrations of a quite small part of the character of an acoustic guitar sound.  Where a pickguard would have an appreciable effect on top vibration would be quite a bit higher than that in frequency, unless it was a particularly heavy pickguard.  At the frequencies that you can feel with your fingertips, it's really not the right frequency range to consider, and those that have claimed that the top is relatively stiff and doesn't move much near the bracing by the soundhole are actually correct, at the frequency range where the pickguard (a somewhat smaller one and low mass one at that) could make a difference, the top doesn't radiate much in that frequency range.  This would be a guy that could talk about it more eloquently:
https://youtu.be/o0FT2nsg0sQ

FWIW, my masters concentrated on sound & vibration and for a good 25 years of my career I've been doing sound & vibration measurement and analysis for the automotive and hearing health care industries.  A good deal of that time was conducting scientifically conducted experiments on subjective comparisons between sounds.

All of that said, I won't lie that one of the things that attracted me to Larrivée guitars in the late 90's was the relatively thin clear pickguard that were on the guitars at the time.

On top of that, my L-03 was made with the cheapest tone woods in the Larrivée lineup at the time, and a couple years after purchase, I had the privilege of John Standefer (2 time Winfield winner) playing my L-03 back-to-back with him playing a really fancy custom L-body that he won at Winfield in a nice and quiet environment (John is a Larrivée artist - though they have misspelled his name on the site for years as Standefor).  I intentionally kept my eyes closed while he swapped.  Listened at a distance of about 10 feet.

I simply could not tell the difference in the hands of that master.  Listening for differences in sounds was what I did for a living, every day.  His had much more fancy tonewoods and spangle; glossy finish, etc.  John's ability to play the same form guitar, with a repeated play through on both axes was amazing and it also demonstrated to me just how great Larrivée acoustic guitars were.

You could remove the pickguard if it's a real concern.  It will be very difficult to tell the difference, but you would have the benefit of not having to wonder if it's making a detrimental effect for all of your years of ownership.

-Scott



Title: Re: Pick Guard Damping?
Post by: yellowesty on April 17, 2016, 09:24:34 PM
Scott:

Thanks for the thorough and thoughtful response.

I'll keep the pick guard -- my Larrivee sounds great as it is.

On the general topic of physical changes and sonic perceptions, a few months ago, to accommodate a lower tuning I wanted to raise the action of a non-Larrivee guitar with a low bridge and I didn't have any suitable plastic or bone material so I made new, compensated saddles from what I had on hand -- steel and aluminum.  From the first touch, the steel saddle was harsh, almost shrill, and unpleasant.  But the aluminum one was not bad, maybe a bit brighter than the tusk it replaced, but not objectionable.  Surprise.

In any case, thanks for the perspectives.   :donut :donut :coffee
Title: Re: Pick Guard Damping?
Post by: Paraclete on April 19, 2016, 12:00:45 AM
I took the pickguard off my Seagull, and yes, had both a tan line problem and top damage (cedar satin finished tops are somewhat fragile). No, I don't have before and after proof.  But the sound difference was very noticeable....the difference between tight and muted and far more resonant.  I had really mixed feelings about the guitar and its sound up until that point, but couldn't afford a new guitar.  Keep in mind that the guitar did not come with a pickguard, but I had one put on when I first got the guitar. It was on there for about 15 years.  Despite the damage, I don't regret taking it off. (Do regret putting it on in the first place, though).  It's a interesting thing.  I wanted the pickguard off because it was ugly and because I had stopped playing with a pick anyway.  Did not expect the sound to change as much as it did.
Title: Re: Pick Guard Damping?
Post by: skyline on April 20, 2016, 09:23:49 PM
You don't need any fancy high tech grar.

Find yourself another pickguard or similar piece of plastic.

Lay your guitar on its back somewhere safe, strum and pluck.

Now just rest the other pickguard opposite the existing one (as if it were for a "lefty"). Uncle Rob could probably point you to a safe adhesive to temporarily hold it in place, if you really want to go whole hog

Strum and pluck again / remove second guard / rinse and repeat.

I'll be surprised if you don't notice a difference.

Whether or not you care about the differnce is a different question.

Title: Re: Pick Guard Damping?
Post by: rockstar_not on April 21, 2016, 02:45:01 PM
Quote from: skyline on April 20, 2016, 09:23:49 PM
You don't need any fancy high tech grar.

Find yourself another pickguard or similar piece of plastic.

Lay your guitar on its back somewhere safe, strum and pluck.

Now just rest the other pickguard opposite the existing one (as if it were for a "lefty"). Uncle Rob could probably point you to a safe adhesive to temporarily hold it in place, if you really want to go whole hog

Strum and pluck again / remove second guard / rinse and repeat.

I'll be surprised if you don't notice a difference.

Whether or not you care about the differnce is a different question.



I would also be surprised if this laying on a pickguard didn't show a difference - but it's not the difference that you would experience by adding/removing an actual pickguard.  Fundamentally different physics involved between an actually applied pickguard, one put on with some removable tape, and one just laid on the surface.

Even Larrivee's old clear pickguard would change the local stiffness of the wood through the shear limiting that would result across the surface of the top.

Just laying a non-tape pickguard down on the top only adds the mass of the pickguard to the surface, it doesn't mimic what happens in shear and in fact could just sit there and buzz on a top that is pretty active at low frequencies.  Taping it on with some removable 2-sided tape would be closer to trying to hear the effect, but even then it's not the same shear strength as what gluing on or using non-removable 2-sided tape would do.



Title: Re: Pick Guard Damping?
Post by: skyline on April 21, 2016, 08:22:24 PM
Quote from: rockstar_not on April 21, 2016, 02:45:01 PMFundamentally different physics involved between an actually applied pickguard, one put on with some removable tape, and one just laid on the surface.

For sure, but the difference is nothing unimaginable.

And as I said, if the experimenter is having trouble I'm sure someone here could direct them to a harmless way to temporarily attach the pick-guard. Either way, it's a simple process that shows how pick-guards dampen vibrations. Of course you might like those vibrations to be dampened, helps to get that "vintage" sound  :wink:
Title: Re: Pick Guard Damping?
Post by: George on April 22, 2016, 09:04:55 AM
I believe just about anything other than the bridge itself will have some dampening effect on the top soundboard.  Some of my very favorite acoustic guitars have satin tops/backs/sides/neck, no pickguard, real wood rosette inlays, etc. and they just ring and ring.  If I were certain I would never sell the guitar, I would take the pickguard off...  The rub for many is not damaging the instrument during removal, getting all the old adhesive off cleanly, and being ok with any color change present on the top after the fact...
Title: Re: Pick Guard Damping?
Post by: skyline on April 22, 2016, 11:31:53 AM
Quote from: georbro3 on April 22, 2016, 09:04:55 AMThe rub for many is not damaging the instrument during removal, getting all the old adhesive off cleanly, and being ok with any color change present on the top after the fact...

My OM-03 had the old clear guard and it was lifting at a couple of corners - I impulsively pulled it off myself - slowly, but not slowly enough, caused a little tiny nick - doh@*&!
I had a pro take the guard off of my SD-03.

After about two years, the OM showed nothing of where the guard was. After one year the SD is evening out nicely.

Title: Re: Pick Guard Damping?
Post by: yellowesty on April 22, 2016, 01:30:28 PM
Is there any chance we could get a Larrivee factory perspective on possible sonic effects of the pick guard?   :donut :donut :coffee
Title: Re: Pick Guard Damping?
Post by: George on April 22, 2016, 04:40:27 PM
Quote from: skyline on April 22, 2016, 11:31:53 AM
My OM-03 had the old clear guard and it was lifting at a couple of corners - I impulsively pulled it off myself - slowly, but not slowly enough, caused a little tiny nick - doh@*&!
I had a pro take the guard off of my SD-03.

After about two years, the OM showed nothing of where the guard was. After one year the SD is evening out nicely.



Any tips about how to Properly Remove one?  I have heard of blow drying while carefully peeling.  I wonder what kind of Goo remover works the best?  Is it any more difficult on a gloss top vs. a satin top?  I have a couple of very nice tops that I am certain would sound better without the original pickguard...
Title: Re: Pick Guard Damping?
Post by: rockstar_not on April 27, 2016, 08:41:34 PM
Quote from: yellowesty on April 22, 2016, 01:30:28 PM
Is there any chance we could get a Larrivee factory perspective on possible sonic effects of the pick guard?   :donut :donut :coffee

Here is an educated guess at their reply, should there be one:  If there was a possibly noticeable effect on tone, pickguard would have been a customer selection option at time of ordering.
Title: Re: Pick Guard Damping?
Post by: skyline on April 28, 2016, 09:42:38 AM
Quote from: rockstar_not on April 27, 2016, 08:41:34 PMIf there was a possibly noticeable effect on tone, pickguard would have been a customer selection option at time of ordering.

If you're custom ordering it's certainly an option. Didn't the Forum acoustics ship with the pickguards in the case?

Does JCL spends as much time picking out plastics for pick-guards as searching out wood for tops?

Sure -  some folks like the look of faux tortoise shell but if you really don't think a pick-guard affects the guitar - consider this:
Title: Re: Pick Guard Damping?
Post by: skyline on April 28, 2016, 09:09:04 PM
Does anyone have higher res photos of Larrivée bracings?

It's interesting to look at where pick guards sit in relation to braces.