Hybrid Top on new Jon Gomm signature Lowden

[CoolerKing]

Once again, mods please feel free to move to correct forum. . I wanted to get the pro luthiers opinions on this concept and didn't know where else to put it, and figured it would get a different crowd in the general section. What do you guys think about this?

http://www.musicradar.com/news/guita...-guitar-637824

[LouieAtienza]

Originally Posted by matthewpartrick

Once again, mods please feel free to move to correct forum. . I wanted to get the pro luthiers opinions on this concept and didn't know where else to put it, o figured it would get a different crowd in the general section. What do you guys think about this?

http://www.musicradar.com/news/guita...-guitar-637824

I remember Alain Bieber (who posts on the MIMF) making a guitar top in a similar fashion, with the inside layer positioned on a slight bias. This was about 5 years ago or so. I believe the goal was for a thinner, stiffer top.

[Monsoon1]

so they're saying the two sheets of soundboard would actually be louder?

[JJI]

It'd be odd if Gomm and George L built his Sig Edition as a gimmick.

[theEdwinson]

So, it's basically a plywood top, aimed at people who like to treat their guitars as percussion instruments? Okay, fine. This Gomm fellow says it sounds good. who's to argue?

[westman]

yeah, a percussion performance stringed instrument
Mostly played plugged in / close Mic’d - I have a suspicion it’s the right tool for the job ?.
Is it a double top (with a difference ?.

[CoolerKing]

Originally Posted by theEdwinson

So, it's basically a plywood top, aimed at people who like to treat their guitars as percussion instruments? Okay, fine. This Gomm fellow says it sounds good. who's to argue?

I think it may be a little more to it than this, scientifically, and was hoping that that luthiers that have built with double tops, nomex honeycomb, or even the dovetail redwood/spruce top that Howard Klepper built, might chime in at one point or another.

[Marcus Wong]

I stumbled across this just yesterday and had a similar question. The way they described it sounds more like plywood than a double-top. I too would be interested to hear what the luthiers know about this

It seems as if Jon has not taken possession of or started using it yet. His latest video still features "Wilma" and he hasn't announced anything on media platforms AFAIK.

[nacluth]

Sounds like they're going for a very thin top to provide maximum thump. A plywood sheet in this case can probably hold up around a 1/16" if made with the right glue. Electronics probably take care of any tonal issues.

[mikealpine]

If this works out for Mr. Gromm, that's cool. I'd like to hear samples of it played "traditionally" alongside another solid-topped version.

However, the cynic in me feels as if they are taking what has often been looked at as something somewhat inferior, in this case a laminated top, and repackaging it as an advantageous feature.

Laminated top = not so good

Hybrid top = "insane" (really good)

I'm not saying it doesn't work, and make no judgments against the sound and how well it does what is claimed, just noting as to how it comes across to me.

[Tim McKnight]

Take my response with a grain-O-salt since I have not seen one of these tops in person ...

A true double top is constructed using two thin plies of wood sandwiched around a Nomex honeycomb core. The design goal of such a top is to reduce overall weight yet increase stiffness thus reducing the amount of brace mass required under the soundboard. The end goal is a sound board that weighs less which should equal more efficiency with the widest dynamic range.

Based on the article in the link it appears Lowden is using just two plys of wood, glued directly together with the grain orientation skewed. The article doesn't divulge the thickness of the two wood plys so one can only speculate without having seen one. I have a hunch that Lowden's top might weigh more than a standard one ply top which would explain the increase in bass response noted. When one increases the weight of the top it can result in an increase of low frequency (bass) response. I only speculate because the amount of glue that would be required to join two tops together would weigh significantly more than the amount of glue required for a Nomex top. The additional adhesive would add a significant amount of mass, verses the minimal amount of glue required to glue a Nomex double top.

When one glues a Nomex double top one applies glue to ONLY the Nomex which is akin to applying glue to the edge of a sheet of computer printer paper. Therefore, much less glue is required for the Nomex technique. We typically weigh the amount of glue we use on double tops so we can control the overall weight more accurately. Compare the surface area of Nomex to the surface area of an entire top plate and you would find that Nomex requires a fraction of the glue, which equates to far less mass.

Its theoretically possible to laminate two thinner plys of wood but the final mass could still weigh more than an equivalent solid one ply top.

Controlling weight of the top "system" is a key design element to a lot of builders. Most of the weight is in the top plate alone and the braces and bridge plate weigh only a fraction of the weight of the top plate. Weight can be the enemy of an efficient top. It takes less energy to drive a light top.

I can see the structural benefits to what Lowden is doing as a plywood top would certainly hold up better and be more crack resistant to the impacts of a percussive player. So I am not dissing what he is doing as it makes perfect sense from an engineering point of view. How would it sound to an acoustic purist? I am sure we will read more after the guitars trickle to market. I congratulate George for addressing the needs of a percussive player and look forward to reading some in depth reviews.

[LouieAtienza]

Firstly, I would think this wouldn't be exactly Lowden's most popular model, or something that can be bought "off the rack" normally. As good as Joe Gomm is, he isn't exactly a household name. And one look at his current Lowden's top would reveal why he and George may collaborate on something different. Not Glenn Hansard bad, but bad nonetheless.

[CoolerKing]

Originally Posted by nacluth

Sounds like they're going for a very thin top to provide maximum thump. A plywood sheet in this case can probably hold up around a 1/16" if made with the right glue. Electronics probably take care of any tonal issues.

To carry this thought forward, "sounds loud with a mic but no natural overtones" ?

[CoolerKing]

Originally Posted by Tim McKnight

Take my response with a grain-O-salt since I have not seen one of these tops in person ...

A true double top is constructed using two thin plies of wood sandwiched around a Nomex honeycomb core. The design goal of such a top is to reduce overall weight yet increase stiffness thus reducing the amount of brace mass required under the soundboard. The end goal is a sound board that weighs less which should equal more efficiency with the widest dynamic range.

Based on the article in the link it appears Lowden is using just two plys of wood, glued directly together with the grain orientation skewed. The article doesn't divulge the thickness of the two wood plys so one can only speculate without having seen one. I have a hunch that Lowden's top might weigh more than a standard one ply top which would explain the increase in bass response noted. When one increases the weight of the top it can result in an increase of low frequency (bass) response. I only speculate because the amount of glue that would be required to join two tops together would weigh significantly more than the amount of glue required for a Nomex top. The additional adhesive would add a significant amount of mass, verses the minimal amount of glue required to glue a Nomex double top.

When one glues a Nomex double top one applies glue to ONLY the Nomex which is akin to applying glue to the edge of a sheet of computer printer paper. Therefore, much less glue is required for the Nomex technique. We typically weigh the amount of glue we use on double tops so we can control the overall weight more accurately. Compare the surface area of Nomex to the surface area of an entire top plate and you would find that Nomex requires a fraction of the glue, which equates to far less mass.

Its theoretically possible to laminate two thinner plys of wood but the final mass could still weigh more than an equivalent solid one ply top.

Controlling weight of the top "system" is a key design element to a lot of builders. Most of the weight is in the top plate alone and the braces and bridge plate weigh only a fraction of the weight of the top plate. Weight can be the enemy of an efficient top. It takes less energy to drive a light top.

I can see the structural benefits to what Lowden is doing as a plywood top would certainly hold up better and be more crack resistant to the impacts of a percussive player. So I am not dissing what he is doing as it makes perfect sense from an engineering point of view. How would it sound to an acoustic purist? I am sure we will read more after the guitars trickle to market. I congratulate George for addressing the needs of a percussive player and look forward to reading some in depth reviews.

Exactly the kind of feedback I was hoping for. Very cool perspective, and thanks for sharing.

[printer2]

My first thought was that it is to have a more dent resistant top. We were talking about something like this on a classical site and the thought was that it would be difficult to glue two thin sheets together using a water based glue. I thought it would be no problem, glue ordinary tops together then send them through the sander a few times taking as much off you want on either side.