Sound Port: How Big is your Hole?

[Kim]

I have been procrastinating (something I am remarkable good at) for some time over how big to make my sound port.

After drawing up lots of designs over the last week or two I had settled on an Ankh to fit in with the "Eye of Horus" design that I inlaid on my headstock.



The eye of Horus supposedly represents all of the human senses.







This is an Ankh, you would have seen them before, it is the ancient Egyptian symbol for life.









Something a tad larger than the above image to the external edge represents the size design I was about to cut in the side of my guitar. I say about to cut because I chickened out thinking it may look tacky.





I ended up going with the all too common egg.










I did have things a little more elegant than this being that my hole had been more slender and pointed toward the ends, but upon discovering a little separation in the dyed black maple veneer to the rosewood, (that stuff just does not seem to like titebond, especially when bonding to EIR, anyone else had issues with it?) I had to chase it out by reshaping a bit.



Prior to cutting, the area between the side braces was reinforced with .10 black dyed maple + .20 cheesewood + .10 black dyed maple + .50 tassi blackwood and this sandwich was glued into place using a carefully shaped internal caul which was clamped in place with the sides supported by the external mold.



Here is the inside, probably should have used apposing grain for the blackwood, not only would it conform to shape easier, but it would offer more strength like a ply. But I chose instead to use what was at hand and bent this bit to fit.







The hole was cut with a drill, a coping saw and a dremel with a sanding drum thingy on it. The sanding drum cut very quickly, much faster than you would expect and was quite easy to control. I found around 1/2 to 2/3 speed is plenty as too fast and you burn the wood.



Anyhow, I have seen sound ports much bigger, and a little smaller than this one. Do any of you have a preference toward size? If so, why?

Cheers

Kim

[Allen]

I would have gone with the Ankh first Kim. Then if you didn't care for it then you could have reshaped it to an oval.

I've been drawing out all kinds of different shapes too, but can't come to anything that I love yet....maybe that's why there are so many egg shaped ones.

My sizing had nothing more scientific to it than that is what looked about right in the place that I was going to put it. I've only put one in and haven't heard any other guitar with one installed, so I'm really bugger all help to you.

[Craig]

G'day Kim,

I took note of Alan Carruth , when he said they needn't be large .Some of the holes in his "corker " guitar were only 5/8" . (, Alan once made a test guitar and cut holes all over it ,which were then plugged with corks. He was then able to test and compare differing soundport placements and sizes etc. He's kind of an authority on the subject.)

I made my round one 7/8 " and haven't considered enlarging it as it works so well ( I have it positioned heel side of the upper bout shoulder.

Even at 7/8 " diameter , it raises the main resonance a semi tone when opened ( I made a stopper for it ) , so I'm probably going to stick with soundports on the smaller side. I made my soundhole about 1/16 " smaller than my planned size to compensate , which is around the same surface area as the soundport.

I did like you Kim , and glued veneers to the inside . The caul is fairly important to avoid exposing glue lines when you cut your soundport. I made a caul from MDF and roughly shaped it to the inside of the soundport section.I then buttered the caul with Bondo and clamped it against that inside area ( don't forget the wax paper between ). When it dryed and I trimmed off the excess , it made a great caul.


Hey mate , you're holding out on us with your progress. Looks like your getting a whole lot closer to stringing up. Looks to be going great buddy

Cheers , Craig

[joel]

And a nice self portrait too! (in the peghead for those that didn't notice)

[Bob Connor]

Kim - The soundports that we stuck in some OM's a while back were roughly that same dimensions as yours.

They worked fine.

Funnily enough some of the musos around Melbourne who played those guitars had never seen a soundport before and didn't like them because they thought it may affect the structural integrity of the instrument.

After using one I reckon they really add to what the player hears.

I guess these guys were pub musos and the soundhole would be useless in that sort of situation apart from having somewhere to discreetly chunder on stage if they over did it on the drinks rider.

Bob

[Hesh1956]

Only my urologist knows for sure........

Kim my friend it is GREAT to see you building and your guitar is looking fantastic!!!!!!

[Dennis Leahy]

Kim,

I too am excited to see another tantalizing glimpse of your guitar. I really want to see the "whole enchilada"! Please don't make me wait until it is all done...

OK, as for sound ports - size and shape:

I think the ankh (especially without the keyhole in the top) would have been misidentified by many as a Christian cross. There is, of course, nothing wrong with that if you are declaring your faith or trying to break into the lucrative world of Christians that like to buy stuff that identifies them as Christian.

I have seen a couple of clever designs (one that comes to mind is the dog footprint, though I can't remember which OLF member that is), but I have not thought of a cool shape yet either.

I am, however, thinking very seriously of including 2 sound ports: one in the upper bout (typical) and one in the lower bout. The idea being a sound port dedicated to each of the player's ears - stereo. What made me think of that was when I played a guitar (in a relatively small room) with a typical sound port opened and closed, and surprisingly did not note much difference. I figured it must be at least partially the dynamics of the room you're playing in (or no room), thinking that the smaller the room, the less noticeable the port would be, and maybe my left ear is not as keen as my right ear. (My eyes are like that.) Anyway, I'm gonna try it.

Then, that big copycat, Kevin Ryan, sort of stole my thunder by releasing this:


Well, Ryan's sound ports face more forward (audience) than sideways (player), so maybe my idea is different.

I have noticed that when I play outdoors with no reflective walls, the sound of the guitar is swallowed up by the universe, so I am convinced that the ports will make a bigger difference when the room is large (or missing.) So, Kim, if you get a chance to audition a guitar that has a port, go to a big room or step outside and try it, cover some of the port and try it, cover all of the port and try it. That might be a valid way to hear what the port size difference is really giving to the player.

There may also be another effect at play: the engineering/design of the guitar as a more locally vibrating, intimate soundfield (flexible guitar back, supposedly), and a guitar engineered to project (stiff back, supposedly.) So, it might also be true that the more a guitar is engineered to project, the more the player will hear the sound emanating from an included sound port.

Dennis

[Dave White]

Kevin Ryan is a very clever guy, but I'm really struggling to see why you would put soundports in an arm bevel - which are pretty much completely covered by the playing arm. Are you supposed to lift your forearm at suitable points in the music or try for some arm-farts sort of sound?

[Lillian]

Wow Kim, you've been busy. From the little bits you are showing, its going to be beautiful. Nice job on the inlay.

How about some more pictures so we can have a real look see?

[Allen]

I don't know if Kevin Ryan's sound flutes are effective or not, but I think that has got to be one of the most striking instruments that I've ever seen. If I ever get to the point that I think I can pull off a bevel like that I'm going to give it a go.

Then, perhaps he has found out that there is just too much sound port area, and expects some of them to be plugged by the players are.