Homemade Sound Port[s]

[guitarcatmiami]

OK, I've been inspired by all I've read here, and I'm ready to do my own soundport on a decent sounding but not rare old Kay, so if I botch it, it's no great loss. I got some good feedback on this topic last time I posted, but now my Q. is more specific. Where, exactly, is the prime spot on the upper bout to drill such a port, so that I, as the player, get the best sound ? Specifically, I am thinking about drilling, in some sort of pattern, a series of 1/4 inch holes, until I get good sound projection. But where is the maximally effecive spot to do so? I hold the guitar in an average tilt position.

I am an OK woodworker, and besides, this isn't fine luthiery, but are there any specifics I should keep in mind? Thanx in advance to all you experienced soundporters.

[jmagill]

Assuming that you can put the soundport anywhere you like without cutting through some structural component that would weaken it, then take note of where you hold the guitar in your normal playing position, AND where you hold your head when you normally play, so that the soundport will point directly at your ear. If you turn your head toward the neck when you play, it may make more sense to put the soundport in the waist than at the upper bout, or you can cover your bases by soundports in both locations, an option I've seen on several guitars.

[Tim McKnight]

Be VERY careful using a drill. If you have experience drilling holes in wood then you know that if you do not back up the underside then the wood will splinter out. These splinters will travel a long ways and will become stress risors which could lead to or possibly propogate a crack [if the sides are one piece, soild sides].

Here is a tutorial I wrote a few years ago that may be of some help to you:

Sound port installation instructions:

List of materials:
Dremel with router base
1/8" Downcut spiral bit (StewMac)
1/2" dia Dremel sanding drum
180, 220, 320 sand papers
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 so they are visible from the outside. This is the area that your sound hole must be located [between] 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 small egg. Remember the larger the sound port the higher pitch your guitar will be. Start out smaller and you can always make it larger.

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 the 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 your ported guitar.

Warning [read the fine print >] Even though this may seem like a simple modification please remember there is no way to reverse it once the port is cut. It took me about 9 months of continuous R&D to work out the ideal shape and location for my sound ports. I tune my sound box to a certain frequency and if the port is cut too large it will raise the Helmholz Hz or main air resonance of the body. The result will be a loss of power and projection. If the port is cut to the correct size the sound port will actually produce an increase in forward and 360* projection.

Tim…

[jmagill]

I'd follow Tim's advice.

[ljguitar]

Originally Posted by guitarcatmiami

...Where, exactly, is the prime spot on the upper bout to drill such a port, so that I, as the player, get the best sound ?
...I am an OK woodworker, and besides, this isn't fine luthiery, but are there any specifics I should keep in mind? Thanx in advance to all you experienced soundporters.

Hi g-cat-miami...
Even though I had altered my Seagull S-6 with Tim's instructions, I didn't trust myself to do this to my Kronbauer, and a luthier friend did this for me. Boy am I glad - you can see the obvious difference in the finished edge.

The luthier who did this for me followed Tim McKnight's instructions to the letter...and used Tim's precise measurements for his default ''egg''.

I sat down and held the guitar and played it for a minute to set up the correct position, and he marked it accordingly.

He had built a template based on Tim's default ''egg'' and used it...here are some pics of the process ''Tim style''...

















It is obvious I'm a neck up player from the placement.

[guitarcatmiami]

To Tim McKnight, ljguitar and jmacgill - thanks guys for the incredibly helpful info. Esp to Tim .... so much I had not considered... now I'm a little bit hesitant on my DIY approach. Maybe I will go ljguitar's route and get someone who actually knows what they are doing. - Cat

[TBman]

I did one in my Washburn. I just drilled around a shape - the sides are laminate. And then used crazy glue to seal the edge after I sanded it a bit.

[ljguitar]

Forgot to post the picture of my Seagull S-6 with sideport I did with Tim's instructions (not his size of default hole though). The placement is for my left ear...I play with the headstock up both when sitting and with guitar straps.



Kind of a pick shaped thing. It started as an oval, then I enlarged it a bit more with the thought of not getting it too big, and felt I'd gone far enough with enlarging only one side, so I smoothed, darkened it with a Sharpie, and coated it with super glue.

It is quite effective actually though not as pretty as the luthier created ones.

[Guitarpix]

I have a few questions to add to this... I've been told that to do this you need to add a support plate (inside the guitar, of course) where the soundhole is going to be to reinforce the area and prevent possible future cracks in the side from the soundport. Is this true and is there a diffrence in doing this to a instruement with laminate sides versus solid sides as far as recommended procedure? If all goes well, will this still effect the resale value? Not meaning to steal the thread just add to it. Thanks!

I've got a cheapo that I plan to try it on first...

[ljguitar]

Originally Posted by Guitarpix

...If all goes well, will this still effect the resale value? Not meaning to steal the thread just add to it.

Hi Gpix...
I've never bought a guitar with the intent to do other than play it. Resale has not been my goal, and if it were, I'd have it setup and put away till sold and guard it and protect it.

I'd think if you are in the investment business with instruments, a sideport is not a good idea. If you are in the playing market, it's a toss up. Are you willing to take a hit of a few bucks to enjoy an improved instrument?

What is a turn-off to some, is a plus with others, so your future marketing would be a factor as well. I had a sideport put in my Kronbauer, and were I to decide to sell it (I am not), I'd not knock off a cent because of it, and would present it unapologetically as a feature, and not a drawback.

All one has to do is play the guitar with it, and then cover it while they are playing, and it sells itself.

[Simon Fay]

GuitarPix,
Adding a soundport may or may not affect the value depending upon how it is done. If the results look pleasing and professionally done - then I would say resale value won't take much of a hit. If the job looks bad then you will absolutely take a loss on your instrument.

However, if it is an inexpensive instrument - I don't think knocking a little of the value is much concern.

Merry Christmas,
Simon