Rainsong CH-OM soundboard's flexibility under strings tension.

[gerardo1000]

I got a beautiful CH-OM from Ted at LA Sales. Unidirectional carbon fiber top, no electronics. I really love this guitar. I noticed that with strings under tension there is a light dip (1-2 mm) on the top in the area that goes from the end of the sound hole and the bridge, and there are two light ripples/bumps (one on each side of the sound hole) that are around 1 inch long. The ripples are at the border of the sound hole, where the top is very thin. All this is visible only under the right light angle, and, if I loose the strings, the sound board becomes flat, no more dip and no more sound hole bumps. I guess that the new unidirectional top is a bit thinner than the old woven striped top, and therefore a bit more flexible and sensitive to strings tension... Dave from Rainsong customer service reassured me that it is not an issue and it is normal to have a light deep, and also some sound board ripples, when strings are under tension.
I am curious to know if other owners of Composite Hybrid Rainsong models noticed the same effect caused by strings tension, and if it has remained stable under time without getting worst ? Thanks !

[jonfields45]

Completely normal for this series of RainSongs and I've got a CH-PA and had a CH-WS that do the same thing.

The RainSong top has no braces and will deflect under string tension (if it didn't there would be dramatically less sound). The 12 fret models with the bridge in the center of the lower bout will deflect a bit more than a 14 fret as the bridge is further from the waist of the guitar. The soundhole is supported asymmetrically by the cut-away on one side which causes what you are seeing.

For an X-braced guitar there are massive braces around the soundhole so we are used to seeing the hump behind the bridge (and expect it to be static as some of it is the intentional radius, some is wood creep, and some is deflection which gets hard to notice). Expectations set by living with wooden guitars don't really apply to RainSong's very unique truly flat top brace-less design.

CF will not creep over time like wood, so what you see is what you (will always) get :~).

Some pictures of mine:

https://drive.google.com/file/d/1NV_...ew?usp=sharing
https://drive.google.com/file/d/10il...ew?usp=sharing

[gerardo1000]

Jon, thank you SO much for your detailed explanation !

[gerardo1000]

[SpruceTop]

Originally Posted by gerardo1000

I got a beautiful CH-OM from Ted at LA Sales. Unidirectional carbon fiber top, no electronics. I really love this guitar. I noticed that with strings under tension there is a light dip (1-2 mm) on the top in the area that goes from the end of the sound hole and the bridge, and there are two light ripples/bumps (one on each side of the sound hole) that are around 1 inch long. The ripples are at the border of the sound hole, where the top is very thin. All this is visible only under the right light angle, and, if I loose the strings, the sound board becomes flat, no more dip and no more sound hole bumps. I guess that the new unidirectional top is a bit thinner than the old woven striped top, and therefore a bit more flexible and sensitive to strings tension... Dave from Rainsong customer service reassured me that it is not an issue and it is normal to have a light deep, and also some sound board ripples, when strings are under tension.
I am curious to know if other owners of Composite Hybrid Rainsong models noticed the same effect caused by strings tension, and if it has remained stable under time without getting worst ? Thanks !

It's normal but as a previous dozen or so RainSong owner, I don't like the dished-in top and this is noticeable on all models or at least the all-carbon-fiber ones. I wish RainSong would make the top more convex so that when under string pressure it won't dish-in. This dishing is noticeable even when there are no strings on the guitars.

[Earl49]

Short answer: If Dave from Rainsong says it is OK and normal, then it is. No need to worry. Jonfield explained it well.

I owned my WS-1000 for 17 years without noticing any dip until someone mentioned it here on the forum. Looked, and there is some dip like yours but not enough to notice until I actually went looking for it.

I'm not even going to look. I have been playing my Parlor for several years now and the play hasn't changed, it still sounds great, and it doesn't feel any different. And it's still beautiful.

If I did look, and I'm not going to, and I saw a curvature, I would not look again. I suspect that about covers my perspective on the matter.

[gerardo1000]

I trust Dave's answer that a flexed top does not affect the integrity of the guitar, but today I stopped by Huber and Breese in Fraser, Michigan, which is an official Rainsong dealer, and they had on display a
CH-OM 1000NS, a CH-WS1000NS, and a CH-PA 1100NS. All three are part of the same series of my guitar: Composite Hybrid. All three have the same unidirectional gloss carbon fiber top. And all three have the 12 fret to the body neck.
Well, I guarantee you that NONE of these three guitars had ANY bump or ripple at the sound hole, and they were all tuned to pitch. The tops looked flat and I carefully inspected all three guitars under different light angles. No bumps, no ripples on the sound holes at all. That is not to say that my guitar is defective, but the fact that mine shows this distortion at the sound hole and that three others that I inspected do not, bugs me.
On the positive side: the neck angle of my guitar looks perfect, at least if measured with the same parameters of a wooden guitar. The neck angles of the three guitars that I tested at Huber and Breeze were all three on the "low" side, i.e. if you run a flat bar over the fretboard, it touches the bridge.
In conclusion: one should think that carbon fiber guitars are very consistent, but in the case of Rainsong it does not look so.

[CRM]

I just checked my Smoky Hybrid and it appears flat with no deflection......Maybe the fiberglass weave helps.....On a side note the finish was looking a little dry like the life had been sucked out of it so I gave it a coat of Meguiar's DeepCrystal Carnauba wax while I had the strings off for a change and man it did the trick and made it look new again....

[SpruceTop]

Originally Posted by gerardo1000

I trust Dave's answer that a flexed top does not affect the integrity of the guitar, but today I stopped by Huber and Breese in Fraser, Michigan, which is an official Rainsong dealer, and they had on display a
CH-OM 1000NS, a CH-WS1000NS, and a CH-PA 1100NS. All three are part of the same series of my guitar: Composite Hybrid. All three have the same unidirectional gloss carbon fiber top. And all three have the 12 fret to the body neck.
Well, I guarantee you that NONE of these three guitars had ANY bump or ripple at the sound hole, and they were all tuned to pitch. The tops looked flat and I carefully inspected all three guitars under different light angles. No bumps, no ripples on the sound holes at all. That is not to say that my guitar is defective, but the fact that mine shows this distortion at the sound hole and that three others that I inspected do not, bugs me.
On the positive side: the neck angle of my guitar looks perfect, at least if measured with the same parameters of a wooden guitar. The neck angles of the three guitars that I tested at Huber and Breeze were all three on the "low" side, i.e. if you run a flat bar over the fretboard, it touches the bridge.
In conclusion: one should think that carbon fiber guitars are very consistent, but in the case of Rainsong it does not look so.

The amount of dishing varies but, from my experience, it's most pronounced on the Unidirectional-topped models. A few years ago, I raised the top-dishing issue with RainSong, suggesting they change their process to ensure a slight convex contour to their tops, but if dishing is still out there, then they haven't done anything about my suggestion--as if they'd listen to me anyway. At any rate, although I love RainSong guitars, I haven't owned one in about three years and will first consider Emerald for my next carbon-guitar purchase.

[jdinco]

These guitars are too expensive to settle for something that bothers you. I'd return it. If you ever decided to sell it, the ripples could cause an issue with that buyer too.

[gerardo1000]

Can't return it. Ted at La Guitar Sales has a 3 days return time frame. I've had the guitar for ten days.

[SpruceTop]

Originally Posted by gerardo1000

Can't return it. Ted at La Guitar Sales has a 3 days return time frame. I've had the guitar for ten days.

Geraldo, enjoy your RainSong and don't let the dishing bother you--it's part of the brand. To hear the wonderfulness of tone that a RainSong offers, retune to play Nick Drake's "Pink Moon" and figure out the piano solo within the song's rhythm and prepare to be amazed at the upper-mid-range/treble that your RainSong will impart to the tone! RainSong IS carbon guitar! Enjoy!

[jdinco]

Originally Posted by gerardo1000

Can't return it. Ted at La Guitar Sales has a 3 days return time frame. I've had the guitar for ten days.

The ripples you speak of is what bothers me, not sure if they would consider that a defect and cover it under warranty or not. Rainsong is a great company so it may be worth a try. Maybe Ted would help you with this?? I've owned a number of Rainsongs, never seen any ripples on them. Good luck with whatever you decide.

[jonfields45]

Originally Posted by gerardo1000

I trust Dave's answer that a flexed top does not affect the integrity of the guitar, but today I stopped by Huber and Breese in Fraser, Michigan, which is an official Rainsong dealer, and they had on display a
CH-OM 1000NS, a CH-WS1000NS, and a CH-PA 1100NS. All three are part of the same series of my guitar: Composite Hybrid. All three have the same unidirectional gloss carbon fiber top. And all three have the 12 fret to the body neck.
Well, I guarantee you that NONE of these three guitars had ANY bump or ripple at the sound hole, and they were all tuned to pitch. The tops looked flat and I carefully inspected all three guitars under different light angles. No bumps, no ripples on the sound holes at all. That is not to say that my guitar is defective, but the fact that mine shows this distortion at the sound hole and that three others that I inspected do not, bugs me.
On the positive side: the neck angle of my guitar looks perfect, at least if measured with the same parameters of a wooden guitar. The neck angles of the three guitars that I tested at Huber and Breeze were all three on the "low" side, i.e. if you run a flat bar over the fretboard, it touches the bridge.
In conclusion: one should think that carbon fiber guitars are very consistent, but in the case of Rainsong it does not look so.

A taller saddle means more torque and more deflection of the guitar's top. I think if we obsess on what we think makes sense for a wooden guitar and apply those standards to CF we are going to be disappointed. A tall saddle is a good thing for a wood guitar that is going to creep over time.

If I was buying a new guitar with a spruce top, I would never buy it sight unseen because I have all sorts of prejudices about the grain spacing, evenness, how vertical it is at the sound hole, run out, and the amount of silking. Now I've read that things I can't see, like the total weight of the top and deflection under a known load are much more important (and that most current red/Adirondack spruce is actually far from the best stuff of guitar construction). We should learn to listen with our ears, not our eyes.