A discussion in another group on adding Soundports to guitars started me thinking about altering my Seagull S-6 Cedar - which is a Pawn Shop Rescue and my RV guitar. I'd like to be able to practice when my wife takes her turns driving in the RV, and roads can be noisy.

Chatted via e-mail with Tim McKnight (a luthier who frequently builds sound ports on his acoustic guitars) yesterday a bit, and this morning a student cancelled so I dug in. I play in a neck up position so I sat down and held the guitar before beginning, and determined where the additional ''port'' would reach my ear(s) best.

Didn't have the cutting bit Tim specified, so I double masked the area, marked the approximate shape, drilled out the corners, and then drilled smaller holes to ''connect the dots''. I played it and decided to enlarge it twice during the process - which was better than going too big first and trying to fill the hole.

Sanded it to size with my dremmel tool, and vacuumed it out. Hand sanded it smooth, and polished the raw edges with superglue. Then I ''stained'' it with a Brown Sharpie pen.

Results...
It is louder for the player. It doesn't affect the tone, or bass anyway, in any adverse manner. I feel (rather than hear) a slight shift of volume or maybe direction of sound when covered and uncovered from the audience position. I hear volume increase big time as a player.

Here are some pics which include some familiar objects for scale...

This is the first soundport I've played that I hear well (because of my playing neck up).

Fun project...once is enough (the Olson, Bashkin and Kronbauer are a safe distance from my tools.)

Larry J

I think Grit Laskin (Canadian luthier) makes a guitar with a soundport that has a little door you can open and close.

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Originally posted by Jack Cook:
Holy Moley. The thought of it scares me! Looks good, though. I've seen guitars with soundports like that but never played one. Does it affect the sound at all for the listener? That is, is the overall tone of the guitar the same, or changed? And what about dynamics on the listener's side also?

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Hi Jack...
Actually it makes a difference to the player, and barely at all for the listners.

On mine, and this was purely for fun and hearing a bit better when I'm practicing in the RV during my wife's turns to drive, it really gives a volume boost to the person playing it without taking any volume away from the guitar.

It didn't affect the tone. Tim McKnight had told me the closer the hole is situated to the neck, the less the bass is likely to be affected. I really took my time, and made sure I understood the process before beginning. I had e-mailed Tim McKnight and we had discussed where to locate it for my style.

Tim's website - click

He put a great detail sheet out on how to do this a few weeks back in a group I frequent (I'll put them at the end of this post). It and his advice helped me immensely. I really went slow and made sure I paid attention. Took less than 45 minutes total.

You asked about the listeners perspective several times, and I doubt the listeners will ever notice it at all. Volume, dynamics, projection and sustain are unaffected.

Here are Tim's instructions...(as if you are going to carve holes in your objects of affection!).

Larry J

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Sound port installation instructions:

List of material:
Dremel with router base
1/8" Downcut spiral bit (Stewmac)
1/2" dia Dremel sanding drum
180, 220, 320 sand paper
Brush on super glue (Stew Mac)
2" masking tape

Tape the area off with two layers of masking tape. Be generous so you don't risk scratching the surrounding finished area around the port.

Look inside your guitar and see if there are any internal side braces. If so, transfer the brace locations onto the outside on the masking tape. This is the area that your sound hole must be located as you don't want to sever a brace. Stay well below the top and back kerfed linings too.

Draw out the port shape on the masking tape. Smooth designs seem to produce a better tone. I use a port roughly the size of a Large Egg.

Use the Dremmel , router base and down cut spiral cutting bit. Stay 1/16" inside of the line and cut the hole out.

Put the sanding drum in the Dremmel and now sand to the finished shape outline.

Use 180 sandpaper and round over the internal and external edges of the hole. Progress to 220 and finish with 320. Be very careful NOT to sand the finish on the exterior of the guitar.

Coat the edge of the hole with superglue. It will dry hard and shiny. Use the edge of the brush to apply the glue and make a circle around the freshly sanded edge.

Remove masking tape. If the glue is rough (usually it isn't) you can smooth with 600 wet or dry sandpaper and then buff.

Get a glass of iced tea, kick back on the couch and let me know how big your smile is when you first hear the port.

Tim…

©Tim McKnight 2005

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Originally posted by FretMonkey:
That is wicked - in the last week or two I have been thinking of doing that to my Seagull Artist! I'm inspired! Nice job!

FM

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Hi FM...
Look at this thread...another Seagull with a bite out of it.

Side Port with pics

Larry J

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Originally posted by John B:
I can tell you that my wife usually sits to the left of me in the living room - unless I'm playing this guitar.

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Origianlly posted by Eskimo:
Elderly has had a lot of very recent Seagull's on their "used, As-IS" list lately however, w/ a whole lot of things wrong w/ them like neck sets ! Ouch. Look 'em over good before ya buy...

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Hi E...
Mine was a pawn shop rescue. So far I recemented the bridge, cut the sound port, and next I'll install a compensated bone saddle, and cut string slots for slotless Ebony bridge pins. Still, not bad for a $200 solid topped guitar.

Larry J

In theory, it would seem that a side port would result in some low/mid tone reduction coming out of the front. Working in reverse, I know that if you completely block the soundhole, the treble sounds pretty much the same, the mids are reduced and the bass is downright muffled sounding. Assuming the sound generated inside the guitar is consistent, additional soundholes would seem to allow that fixed amount of sound more exit points. Which would seem to imply that adding one would result in less coming out the other.

You're onto something (not "on something").

Keep in mind the Vivi-Tones were designed with the backs as soundboards as well (carved spruce back) - so both the top and the back would be working in concert to produce sound. A nice discussion and great pictures are here; one for sale is on this page (page down to item VT-00023).

If I could have figured out how to swing either one, I would have.

Here's a Boaz Elkayam "Flamenca Negra" with a side soundhole/soundport and no soundhole in the top. Page down on this page to the 6th guitar down to see how much it costs.

P.S. If you ever get the urge, take a look at Lloyd Loar's patents related to the Vivi-Tone guitars. They're listed on this page, courtesy Roger Siminoff. I ordered electronic copies of three of them from the USPTO.

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Originally posted by Duke:
...In theory, it would seem that a side port would result in some low/mid tone reduction coming out of the front. Working in reverse, I know that if you completely block the soundhole, the treble sounds pretty much the same, the mids are reduced and the bass is downright muffled sounding. Assuming the sound generated inside the guitar is consistent, additional soundholes would seem to allow that fixed amount of sound more exit points. Which would seem to imply that adding one would result in less coming out the other.

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Hi Duke,
Thanks for the ideas. Actually theory is only that, and in reality there is no localized sound, ''split up'' as it were, by adding the soundport. It operates more ''omni directionally'' around the guitar.

We are having fun walking around while the player plays and listening etc.

It's an amazing thing.

Larry J

http://www.acousticguitar.com/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=1;t=021455#000008

http://www.acousticguitar.com/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=1;t=022440#000004

Charleston Guitar

I hope I did that link right. If not search for auction number 7393790786. This is a Charleston Guitar that was built by a luthier named Magnus Charleston that worked on this concept from the late 20's until he died in the early 80's. That big old vent on the back actually gives the player a totally different perspective on the sound that the guitar is making.

[This message has been edited by DiegoMoon (edited 02-28-2006).]

Okay, so it was a joke. Tuned ports make sense, high end hi-fi speaker design sure makes use the concept. I just wouldn't have the guts to experiment on my guitars. Thanks for the details.

-Dave

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Originally posted by DiegoMoon:
I think the tuned port concept on speaker design is a little different, although it might be interesting to build a bass using the same concept as a Klipsch corner horn.

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Hi DMoon...
You are correct, that is a different principle, with perhaps only a few overlapping similarities between the two.

Similar
A person can measure the square inches of port on a tuned/ported speaker cabinet or a guitar and split it up between several smaller holes which total the same surface area of port and it will technically port the same amount of air/sound. Both have resonant frequency requirements, and the amount of port helps determine the resonant frequency. And you can move the ports around to different parts of a speaker cabinet or face/side of a guitar.

Different
A guitar that was totally sealed would not tear itself apart, and the instrument could still make nice sound, just not as much of it. Whereas a speaker that was sealed in a cabinet subject to sufficient power to be useful would eventually kill itself off with backpressure, or phase cancel part of it's sound.

A traditional speaker housing has 6 rigid planes to channel sound while the cone is flexible. An acoustic guitar has three planes...front (top), back, side (a continuous single plane). In a speaker, all sides are rigid. On a guitar, two are flexible - top and back. And one is sympathetic to the opposite.

When the guitar's top vibrates, the soundwaves travel inward to the back which sympathetically vibrates and resonates (in solid guitars better than laminate) and reflects - and part of the sound travels out the back of the guitar. So sound is produced partly by reflection and partly by vibration. The guitar has to be built with sustain in mind. So the guitar's ''enclosure'' has to withstand the tension from the strings, pressure of strumming or picking, and transfer it into reflection, projection, vibration, sustain, and tone.

Quite a different set of capabilities than we ask of a speaker enclosure. There are structural issues with cutting additional ports into instruments as well. Some of the tone is produced by active surfaces, so cutting holes in the top or back will affect tone more than cutting them in the side - which is rigid and doesn't contribute much to the ''resonating'' sound reproducing parts of the guitar.

Just some thoughts...

Larry J

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Originally posted by paulm:
wow, I think I would have bought a quieter rv. You must have a gasser. try a diesel pusher and save your guitars.
good job though

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HI paulm...
It is a gasser, and it is more road noise than engine noise (we drive 50 mph everywhere).

It is a fun project, and after the first road trip I'll know how much it helped. Thanks for responding.

Larry J

Buscarino Cabaret

I was thinking about removing my Fishman board out of my guitar are replacing it with a port. The guitar sound really nice with the Fishman flipped open in the battery changing position. I would reshape the hole so that is is more oval then make some nice pieces of wood to lay around the hole and finish it out. I have a Highlander ready to go it.

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Originally posted by tordoc:
My wife has this port on her Buscarino Grand Cabaret. It makes a major difference to the player. Looks right purty too...

[img]http://www.buscarino.com/cabaret.asp]Buscarino Cabaret[/img]

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Simply beautiful...

Thanks for posting the pic.

Larry J

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Originally posted by ~(,o)===::::
...I was thinking about removing my Fishman board out of my guitar are replacing it with a port. The guitar sound really nice with the Fishman flipped open in the battery changing position. I would reshape the hole so that is is more oval then make some nice pieces of wood to lay around the hole and finish it out. I have a Highlander ready to go it.

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Hi Jim...
My gigging partner has a Taylor 714CE which has the Fishman prefix which he will replace with a K&K this year, and he is making plans to fashion a wooden ''plate'' to cover the hole, and he plans to put a port into it. He got excited by my experiment as well.

According to Tim McKnight, the hole would be so large as to create tone issues if left the size it is without electronics. We routinely joke about cup holders, pick pouches and other things which could be stored there. He even contemplated a leather sliding door. He finally settled on the idea of a wooden plate...I think.

Larry J