The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > General Acoustic Guitar Discussion

Reply
 
Thread Tools
  #1  
Old 12-22-2007, 05:59 AM
guitarcatmiami guitarcatmiami is offline
Registered User
 
Join Date: Nov 2004
Location: Miami - actually Homestead - Florida
Posts: 71
Question Homemade Sound Port[s]

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.
Reply With Quote
  #2  
Old 12-22-2007, 06:09 AM
jmagill jmagill is offline
Registered User
 
Join Date: Aug 2006
Location: Asheville, NC
Posts: 539
Default

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.
__________________
Jim Magill
Director, The Swannanoa Gathering

'07 Circa OM, '09 Bashkin 00-12 fret, '10 Circa 00-12 fret, '17 Buendia Jumbo, '17 Robbins R.1, '09 Heiden Heritage F5 mandolin, '85 Sobell cittern,
'08 Poe F5 mandolin, '80 Monteleone Grand Artist mandolin, '83 Monteleone Grand Artist mandolin (oval hole)
Reply With Quote
  #3  
Old 12-22-2007, 06:40 AM
Tim McKnight's Avatar
Tim McKnight Tim McKnight is offline
AGF Sponsor
 
Join Date: Oct 2005
Location: Morral, Ohio
Posts: 5,195
Default

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…
__________________
tim...
www.mcknightguitars.com
Reply With Quote
  #4  
Old 12-22-2007, 06:46 AM
jmagill jmagill is offline
Registered User
 
Join Date: Aug 2006
Location: Asheville, NC
Posts: 539
Default

I'd follow Tim's advice.
__________________
Jim Magill
Director, The Swannanoa Gathering

'07 Circa OM, '09 Bashkin 00-12 fret, '10 Circa 00-12 fret, '17 Buendia Jumbo, '17 Robbins R.1, '09 Heiden Heritage F5 mandolin, '85 Sobell cittern,
'08 Poe F5 mandolin, '80 Monteleone Grand Artist mandolin, '83 Monteleone Grand Artist mandolin (oval hole)
Reply With Quote
  #5  
Old 12-22-2007, 10:11 AM
ljguitar's Avatar
ljguitar ljguitar is offline
Charter Member
 
Join Date: Mar 2005
Location: wyoming
Posts: 38,149
Default

Quote:
Originally Posted by guitarcatmiami View Post
...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.
__________________
Larry J

Baby #01
Baby #02
Baby #03
Baby #04
Full-size Full-Scale Baby #4

Larry's songs...

…Just because you've argued till a discussion turns silent doesn't mean you have convinced anyone…
Reply With Quote
  #6  
Old 12-24-2007, 02:50 AM
guitarcatmiami guitarcatmiami is offline
Registered User
 
Join Date: Nov 2004
Location: Miami - actually Homestead - Florida
Posts: 71
Thumbs up Thanks for Info!

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
Reply With Quote
  #7  
Old 12-24-2007, 05:36 AM
TBman's Avatar
TBman TBman is offline
Charter Member
 
Join Date: Jul 2005
Location: Northern NJ
Posts: 24,466
Default

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.


__________________
Barry

Originals:
Textures

Four to Three

Touched By Light

Covers:
Star of the County Down
{Arr. Stephen Wake}

The Foggy Dew
{Arr. Jim Tozier}

My tunes and videos on Reverbnation

Avalon L2-320C, Larrivee OM-05, Guild D-120c, Gibson, Martin
Reply With Quote
  #8  
Old 12-24-2007, 07:35 AM
ljguitar's Avatar
ljguitar ljguitar is offline
Charter Member
 
Join Date: Mar 2005
Location: wyoming
Posts: 38,149
Default

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.
__________________
Larry J

Baby #01
Baby #02
Baby #03
Baby #04
Full-size Full-Scale Baby #4

Larry's songs...

…Just because you've argued till a discussion turns silent doesn't mean you have convinced anyone…
Reply With Quote
  #9  
Old 12-24-2007, 09:12 AM
Guitarpix Guitarpix is offline
Registered User
 
Join Date: Sep 2007
Location: southeastern NC
Posts: 397
Default

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...
__________________

'79 Yairi Limited edition DY-50 #031 of 900
Yairi Dy74, Dy75, DY77
S & P Showcase Rosewood AER
S & P Pro Curly Maple
S & P Pro rosewood
'64 Martin Baritone Ukulele
Kala LE Spruce & Spalted/Flamed Maple Baritone
Lanikai Mahogany Tenor
Lots of percussion stuff


Life is like music; it must be composed by ear, feeling, and instinct, not by rule
Reply With Quote
  #10  
Old 12-24-2007, 05:13 PM
ljguitar's Avatar
ljguitar ljguitar is offline
Charter Member
 
Join Date: Mar 2005
Location: wyoming
Posts: 38,149
Default

Quote:
Originally Posted by Guitarpix View Post
...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.
__________________
Larry J

Baby #01
Baby #02
Baby #03
Baby #04
Full-size Full-Scale Baby #4

Larry's songs...

…Just because you've argued till a discussion turns silent doesn't mean you have convinced anyone…
Reply With Quote
  #11  
Old 12-24-2007, 07:41 PM
Simon Fay Simon Fay is offline
Registered User
 
Join Date: May 2003
Location: New Smyrna Beach, FL
Posts: 1,485
Default

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
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > General Acoustic Guitar Discussion

Thread Tools



All times are GMT -6. The time now is 05:10 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright ©2000 - 2018, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=