Emerald Soundboard Prep (Beware)
 

Some of you may remember seeing this pic on my NGD post:

[IMG]https://i.imgur.com/qoab1L0.jpg?2[/IMG]

Besides the sloppy job the questions I've been asking myself the last few days is: what is this prep material? and does it affect the tone of the guitar? If you tap your finger close to the area on top of the soundboard it sounds dead (hard as a rock).

I've been struggling the last few days to get the sound from a pickup that I'm used to and after exhausting all options I finally looked at the soundboard prep and you can probably guess what happened next. 60 grit sand paper made quick work of it. I can't say exactly what it is but it's some form of carbon compound. I followed up with 400 grit to smooth out the surface afterwards. The guitar sounds totally different now (unplugged). Not that I had an issue with how the guitar sounded before but now it sounds a lot clearer overall.

I'll reinstall the pickup when I get time but I really don't recommend people to get the soundboard prep if it had that much of an impact.

Did you sand through all the way to the weave? Or, just the excess glop?

This makes me wonder - if the carbon construction is identical between guitars (seems it would be), the different styles of prep could account for some of the otherwise inexplicable differences between guitars. E.g. - Puerto Player's bad-sounding X20 when he has others that are great. I've now seen on this forum at least 3 different styles of factory Emerald soundboard prep, all of which could have different effects on the sound of the guitar. This one looks the thickest for sure, not to mention just plain sloppy.

Yes I sanded all the way to the weave and probably a small bit into the weave as well. I agree with everything else you said. Put it this way I wish I did a before and after clip. Most people who post about the X20 tone report it as a bright guitar. Mine from the factory was warm. Not that it was a bad thing I like all sorts of tone. After sanding off that crap my X20 is bright sounding (not Taylor bright) but bright and with better clarity. My only question is do Emerald realize this? Who knows. All I can say is I'm a lot happier right now.

This interests me because I'm starting to stare at a lot of X20 pics and like the specs on that model. However, I don't care at all for the electronics options offered by Emerald. What kind of pickup are you planning on installing?

Emerald has used a number of electronic options and I've been through most of them (with nylon string guitars). I think the constant change is due, in part, to the evolution of electronics. So far my favorite pickup is the active Barbera in my thin-bodied X7 nylon electric. It's really clean and reflects the tonal qualities of the guitar. It is also a pickup used by Kirt Sand in his marvelous $6,000 guitars.

I have a Barbera Soloist pickup (passive steel string version). For fingerpicking it's fine. However, as soon as you take a pick to it it's quack central for strumming and flatpicking. It is a minimally invasive install though.

Schatten HFN. I already had it installed and did a demo of it in the amplification section of the forum. Here's a link to the thread if you're interested (https://www.acousticguitarforum.com/...d.php?t=545966)

The Anthem is a bright sounding pickup due to the tru-mic and requires serious EQ. This is my 3rd Schatten install and the only one I wasn't happy with. My other installs required no EQ and sounded like the guitar mic'd up. I'm not 100% yet but I'm willing to bet it was due to that soundboard prep. You can also get an idea of how warm sounding my X20 is in that video. Judging by how much brighter it is now I'm willing to bet the pickup will sound much better. I'm hoping to reinstall the pickup today and I will more than likely do an updated comparison video in a week or 2.

Excellent. I appreciate your work!

Thanks Steel. I also prefer to install my own pickups. Most companies seem to favor the LR Baggs element and Anthem systems these days. There's nothing wrong with them just not my first choice.

I personally don't think the looks of it matter much, since it's so hidden...if it functions without affecting tone.
What you can see by peering in the soundhole of Emeralds is much neater than many CF guitars' insides. (See: CA, Rainsong's hybrids...esp the inside of the Super OM, though all other Blackbird interiors I've seen have been far neater.)

Anyway, I wonder why they don't just use a sanding block, as their tops seem thick enough to handle it. But I'd expect that to look rougher.
I actually used a sanding block to prep one of my Emeralds for a K&K (though I didn't inspect it for visual attractiveness)...that held just fine. But when I attempted the same method with another Emeralds and a Lyric, it only stuck about a week before falling off. :/

Looks like they use a putty knife to wipe some epoxy in there and then sand it smooth. I wonder if they've noticed the tonal difference from doing that? The placebo effect can be strong...then again, in my experience, CF seems very sensitive to little changes like that. Surely gluing in a plate would affect tone even more, besides adding a glued-in part to an otherwise seamless one-peice build.

Guess I'm back to "why not just sand it?"

A typical CF buildup is very thin outer layers of CF with a thicker light weight spacer. You can not sand CF like it was solid wood. Imagine sanding a double topped wood guitar. They are essentially two veneers separated by Nomex. Sand through the veneer and you've damaged the guitar.

If the build-up for a pickup was really epoxy it would not sand very easily. I am guessing it is something closer to spackling compound. Hopefully those who have sanded have not taken out much of the actual CF.

Tommy it's most definitely not epoxy. I'm aware that's what they used in the past but I'm very familiar with epoxy I use it a lot at work. You're right it is out of sight but that doesn't compensate for the sloppy work and the impact it had on the soundboard. It's like a NGD again for me.

Jon is right its similar to a spackling compound like drywall compound only a little tougher. Its definitely carbon based I could tell when it was all over my hand. 60 grit sandpaper made quick work of it.

When I was in the process of changing the pickup in my X20, I bought some epoxy goop used to repair epoxy boat hulls. But after sanding with a sanding block, I decided it was not needed. There was black sanding dust created, which I cleaned out with a damp paper towel. Yes, I was a bit nervous about doing this sanding and the whole process.

And it may be my imagination, but the guitar seems more responsive when played without amplification now (it now has a K&K Mini pickup). When amplified, I use a preamp, to cut the lows and extreme highs. I like the amplified sound much better now, but I am still searching for the elusive perfect sound.

Guitarluva OK, bear with me here. I have a very dull custom build X20. Nothing like my other two. You sanded between the bridge and the neck, not behind the bridge, and that opened up the tone of the guitar? Unfortunately, my guitar is on it's way back to Ireland, but I wonder if that was what was wrong with it. It's like the tone is there, but can't get out. No highs or clean mids at all.

I assume it's heading back to Emerald? If so, I'd love hear their verdict on it, if you (and they) are ok with sharing it here.

This doesn't surprise me at all. So long as you just gently sand the outer layer you should be fine but like Jon said you don't wanna sand too much. Under the saddle is a very sensitive area on an acoustic guitar, it's where the vibrations are transferred from the saddle to the soundboard.

Puerto did you have the soundboard prep done on that guitar? The prep work is located under the saddle between the bridge and the neck yes. I never had another X20 to compare to like you just an X30 which is a whole different animal. My X20 from the factory was warm sounding, not that that was a bad thing. If you strum chords you wouldn't notice anything off. If you flatpick than you could hear some mudiness on certain notes. It wasn't until I went to install my pickup that I could tell something was not right. I could EQ the pickup to make it sound better. There was a lot of variables to consider, and the soundboard prep was the last one and one I nearly overlooked.

So yes sanding it off changed the voice of the guitar (unplugged). Made it brighter and clearer. I did reinstall the pickup again later last night, and while this install still does require a little EQ, it sounds amazing.

The whole purpose of this thread is I don't recommend the soundboard prep work. I love the X20 it is an amazing instrument. I enjoyed it up until the pickup install, had a few days of misery and scratching my head, now it's enjoyment again. I'm not mad at Emerald, but whoever did that prep work needs to up their game. I don't claim to be an Einstein, but I am brave and stubborn, and glad I figured this out on my own where others might've shipped their guitar back to Ireland.