Official Luthiers Forum!

I have started building my first acoustic (under the amazing supervision of Lance-though I spend a great deal of time removing glue ) and am really tossing around the idea of a soundport. This is primarily for another personal design element, but I do not want to sacrfice tonality and performance for aesthetics. As such, can someone lay out the rules of soundports? What's the general "ported" area? What should I expect tonally? Are there negative affects to certain frequency ranges?

I do so greatly appreciate your help and input!
Stephen

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www.ziegenfussguitars.com

So many variables to assign given rules. So may post related to this. Your best informed bet is search the archive and read everything you can that Alan C. has written on this subject. That said if you keep the port in the upper bout and around a 1"-1 1/2" dia. opening you are not going to loose tone. your going to hear more things than you ever have in the past.

I believe that a recent issue of GAL has interviews with a number of top builders regarding sound ports.

I believe that the common "sound port" as we see in the majority of instruments does nothing for tone quality and in fact may even contribute to loss of projection. I do believe that the player will have an "enhanced" experience as sound is now being released in a direction in which the player is better able to hear. In our quest to build a better "matchbox" we see many "inovations" come about. I do not believe in this one. Perhaps one of our Master Luthiers who often visit will chime in and explain further. I simply can't, logically, understand how a loss of energy thru the side is beneficial...especially to the audience (I assume most of my customers are using their instruments for performance). I do understand that some players who play for themselves only would enjoy it.

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Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

Michael's correct and I think that Al even built a guitar with plugable sound ports and did some measurements. Hopefully he will weigh-in here.

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Hesh
Ann Arbor, MI USA
http://www.heshtone.com

I have spent a good bit of time reading things over in the archives, and have also read what Alan Carruth has to say on his website as well as what Tim McKnight says. While much of what is presented is useful in concept - it doesn't touch much on the application (size, location, geometry) of the soundport; which is what prompted my question. I greatly respect the work of all the veterans here and elsewhere, and respect the lessons they have learned on their own time and money. I am merely trying to skip over some of the beginners mistakes.

thanks for your input so far guys. Again, I greatly appreciate it.
Stephen

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www.ziegenfussguitars.com

There again this would be hard to simply quantify but I will say this. The best results I have had to my ear on a grand concert sized guitar and smaller has been a 1 1/4" long by 3/4" wide ellipse pretty much centered on the apex of the upper bout. on larger guitar 1 1/2" long by 1" wide. But I have done several custom shaped ports like crosses and clovers that placed in the tangent flat between the waist radius and the upper bout radius with no problems. you have to under stand that the play will hear a slightly different sound than is project from the main sound hole.

Michael,

In your experience, do the more decorative design ports have any different affect than the standard ovals?

Thank you so mcuh for your help.
Stephen

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www.ziegenfussguitars.com

I would chime in, having used side ports for the past six years on almost all my guitars, but I don't want to dub myself a Master Luthier. I'm a guitar maker. I just cut away everything that doesn't look like the guitar I'm thinking of.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

The size will affect the sound heard by the player I don't feel the shape has a lot of affect. I notice more highs the larger the port and always keep in mind that we hear a lot of what we want to hear so take mine as just one opinion. Once again I will bow to Al as the best authority around here on this topic. But the guild lines I posted earlier are working for me.

Dave I respectfully disagree with you on soundports "may even contribute to loss of projection". Last year I attended a talk by Grit Laskin who demonstrated the effect of a soundport to the listener. He played one of his guitars with and without the soundport covered. Everyone in the audience heard the loss of projection when the port was covered. No doubt a soundport could lead to a loss of projection if not sized correctly. As for the player, this time I strongly disagree as my experience playing a number of ported guitars is the contrary. Not only is the volume enhanced to the player but I have found the player gets a better flavour for the tone that the audience hears.

I concur with the others, hopefully Al Carruth will weigh in on this thread as to sizing.

Michael, thank you for sharing your dimensions. No doubt a useful starting point.

As a player, I really like a sound port. I can't think of a good reason not to have one.

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

You're too modest Howard. I believe that's also how Michaelangelo sculpted his David.

Al has chimed in here on this in depth. Please don't forget the archives here. There's no reason for anyone to have to repeat themselves on this or any other subject.

Very strange There are two post with quote with in a quote that has a quote associated to me. I did not write it. David wrote it. some sort of glitch or Howard edited the text of the quote and that some how associated that paragraph to me.

This could be deadly

I have another thought on this subject. Some people say that the audiance can not tell a difference in tone but the player hears a big difference. If you are a player and hear more sonority coming from the instrument it is a big help as you try to play with feeling etc. Does this not translate into a better performance that the audience can hear?

This is assuming that the musician is good to begin with...

My experience has been the same when talking about projection.

My personal feeling is yes. A player playing a guitar with a sound port will be much more aware of his or her attack and technique shortcomings during practice or performance. Therefore will invariably lead to better performance as well. To me this is the biggest benifit of a sound port.

If indeed that loss of projection is the largest detractor when criticizing soundports, then its easily remedied with sliding doors or plugs to close the ports when in performance,,,
This way a player can refine the nuances of his playing... soundport exposed while practicing, and then close the soundpost in a performance situation...
Cheers
Charlie

That is where I get confused...Amid the literature that I have read, it is said that there can either be a slight decibal gain in output (.2 dB presented by Mr. McKnight) or a slight decibal loss overall and only in certain frequency ranges (Alan Carruth). Obviously, I am very much oversimplifiying the issue and comparing data resulting from two very different tests. So to make matters simple, I will say this - I am a bass player and not an acoustic player. I am making this acoustic for a friend who I care very deeply about who I also believe may end up doing well in the music business (Thomas Mack). I want it to be the best I can possibly make it with "features" that can facilitate his growth in tone as a musician. Should I put one in?

Thanks
Stephen

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www.ziegenfussguitars.com

Considering your last post Maybe you should study the physics of the sound port for about ummm lets say some 10 15 years then you will know for sure in you own mind if you want one, what size and shape to use. by then you will think you know exactly what the outcome will be, only to be surprised but what actually happened.

Or you can take a leap of faith a pick a starting point and build one to a given spec and learn form the process and carry the new knowledge into your next build

My point is you can read and read and ask and ask. but saw dust sweat and glue are the real teachers around here.

Yeah Michael,

At the end of the day I very much agree with you - and that is how I have lived my life thus far. I am just uncharacteristically hesitant on this one becuase I want every choice and detail to be as perfect and well done and as well thought through as possible. But sometimes you just need to pick it and go...

Thanks for the kick

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www.ziegenfussguitars.com