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Going back to this:

Here's the Charles Fox blurb regarding the adjustable sound port on his $15000 Ergo model

Adjustable sound port - The optional adjustable sound port allows users to vary the Ergo's sound field by selectively opening or closing this second opening into the air chamber. The sound port can be opened to surround the player with sound when playing for pleasure or closed to focus the sound for full projection when performing and recording.



If would seem that marketing blind testing would have revealed that the sound port is more than just a personal monitor -- but the ad specifically states you close it to focus the sound for performance and recording.

Accurate testing of subjective elements is a science.

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Ken Cierp

http://www.kennethmichaelguitars.com/

My $.02 on the subject...
I've built 67 guitars with soundports. I obviously believe in them. Tim McKnight and I have done a good deal of study on them, mostly independently, then comparing some of our results. Most have come out to be pretty similar.
What is happening in the soundbox is that a slight vacuum is being created by the "pumping" action of the top. Punching a hole in the side vents that vacuum and allows the air to escape more easily. I like to compare it to those old cans of fruit punch that you poked two holes in to pour. If you poked only one hole in it, you get "glug, glug, glug" but as soon as you vent that vacuum, you get a nice even pour.
What this equates to is that the guitar is indeed LOUDER out front than it is with the port covered (or not ported at all). Tim ran tests with crazy sciency instruments but his numbers confirmed my extremely scientific "ear" test.
They have become what make my guitars sound like my guitars. Are they for you? Only you can determine that. Do they work? Yes, it is a FACT that something changes. It is my opinion that it changes for the better. Plus, it makes it much easier to get your pick out when you drop it in the soundhole.

Again there is real science to testing for subjective elements results -- the first (I think) is that the testers have "no dog in the hunt" and usually the testers don't even know what they are looking for -- helps eliminates bias. As an example -- how was the strumming action controlled for the McKnight's tests? Hope upon hope was that the ported models were louder. Human nature and variable physical actions cannot be a control points -- I am not suggesting anything nefarious.

Here's the test:

http://www.mcknightguitars.com/soundports.html

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Ken Cierp

http://www.kennethmichaelguitars.com/

I have built around 20 guitars with sound ports and love them. For me, I notice an increase in volume, sustain, and bass response. Most of this is to the players advantage, but can still be subtly perceived from in front of the guitar. I built a guitar with a sliding sounport door ("the control freak"). Everyone who has played it has preferred the sound with the door open- including Andy Mckee.

The guitars I build are almost exclusively built for players who play for their own enjoyment. So I consider the benefits of a soundport to be very much worth what little effort it takes to build one in.

It has already been said that they make pick retreival easier. Here is another one: they make installing the battery in a battery pouch that is by the neck block a ton easier!

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Anthony Z wrote:
" A few years ago I attended a clinic put on by Grit Laskin. The audience all noted a noticeable increase in projection and volume when the port was open."

Was it a 'blind' test? People expect to hear a difference when you open a port, and generally do. If it didn't help, why would anybody drill a hole in the side of a perfectly good guitar? That's why the only reliable tests are blind ones.

Of course, a lot will depend on the size and location of the port, too. A large enough port in the right place might well produce a noticeable difference in the sound out front, and may not do as much for the player. A port at the base of the neck, or in the tail block, will have a disproportionate effect on the 'main air' pitch, and will also 'hear' several modes well that the standard sound hole can't. Back before I did any work on ports I noticed the change in tone of a guitar when the end pin jack was removed and the hole was not plugged, and that's about a half inch hole.

The effect of the port will vary depending on what the guitar sounds like in the first place. Opening a hole does what it does, and the effects are at least reasonably predictable in a qualitative sense as I described them above. Whether the change is an improvement is another matter. If the guitar starts out with a 'main air' resonance that's a bit on the low pitched and weak side then opening a port will almost certainly help. If the 'air' pitch is high, it could be a detriment.

Finally, I'll note that all of the senses are set up to detect change. Things that just sit there are likely to be inedible, and won't eat you, so you don't pay much attention to them. In my first port experiments I noticed that people would open up a hole, play the guitar, and say: "Wow"! Then, after a few minutes they would not be so sure it was all that much better. Even if you don't get a lot of power from the port it changes resonant frequencies, and you are likely to notice that. This could very well be what people detected in my blind port tests; maybe the instrument was not any easier to hear, but just the fact that it sounded different would clue them in to the change.

The only way you'd know if worked better would be to do another test to find out how well they actually hear it in different cases. You could, for example, have players do some sight reading, and set it up so that they would have a hard time seeing the guitar. The only way they'd know they were making mistakes would be if they heard them. Then you pipe in some noise, and chart the number of mistakes they make as a function of noise level. If the guitar is really easier for the player to hear with a port they should make fewer mistakes at any given noise level. This sort of thing takes a fair amount of effort to do, and there's not a lot of payoff, so it's not likely to happen any time soon. As James Randi noted, it's easier to come up with new 'miracle cures' than it is for scientists to show that they don't work, so those of us trying to establish what's actually happening are always likely to be trying to catch up.

I do make guitars with ports, by the way. They have their uses, and can be worthwhile. I just don't think they're miraculous.

Steve I've always layed my ear on the upper bout. I love the tones you receive. Still do it to although much harder to do


Sent from my iPhone using Tapatalk

Not sure I'm going to add anything if value here. I'm a new builder, almost done with #4. All have sound ports. Something I've noticed that is interesting is that if my hand is over the port I feel an immediate suction after I strum. Maybe that is happening through the sound hole too? From a players perspective I can't say I notice much unless my head is 6" away. What I hear I like a lot and the guitars have been loud and have great sustain. How much is the port affecting this, I don't know but I'm thinking the port is helping move the top and back. Also noticed a drop in tuning when the port is opened. Perhaps this is helpful when fine tuning the box.

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The players that play my guitar which includes a sound port all say that they can hear the guitar better. Both players and nonplayers almost always remark, without being asked, that the aesthetics are improved and more interesting.



Over time, I believe that players may well motivate the industry to include them. But this would take years.

Ed

Thanks for all the opinions

Here's my personally summary:

I think for obvious reasons its marketing component, by offering a customized feature as standard fare -- (nothing wrong with that) to help set their product apart from the others. Lets be realistic, pick up any issue of Acoustic Guitar Magazine -- every single maker and or manufacturer advertisement has claims of the best looking and best sounding guitar -- you'd think somebody is making something up -- right?

There's no current science that would indicate with or with out port is better -- those that like them hear something the rest of do not. Do we tend to hear what we want to hear, I think Bob touched on that above.

Still most compelling to me is that on his $15000 Ergo model -- there are no claims except that it is a nice feature as a personal monitor this also leads me to believe its best to have one that can be closed ---- in my mind that's the logic and is where I'll leave it.

Thanks again

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Ken Cierp

http://www.kennethmichaelguitars.com/

Ken Cierp wrote:
"There's no current science that would indicate with or with out port is better -- those that like them hear something the rest of do not."

All of what I posted is based on 'science': measurements I made of guitars with and without ports, and careful testing of what they do. It may not be totally correct: science is better at telling you what's not true than what is. I do stand behind the work, though.

'Better' is, of course, a matter of opinion. My opinion is that a port id likely top work out best for somebody playing in noisy or dead spaces, as I said. In the end, though, only the player can tell you what they like, and no amount of science is likely to predict that perfectly.

Alan -- I am not challenging your tests or your science or yours or the opinions of anybody else. The summary is me sort of me thinking out loud, I am not looking for any sort of validation of those thoughts. If you would like me to remove the post I would be more than happy to do that for you.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Ken,

I find your apparent tone and comments very interesting. There's no science of which I'm aware that indicates that anything is better or worse on an acoustic guitar when it comes to listening. Its subjective (beauty in ear of the beholder). There's no science of which I'm aware that indicates that anything is better or worse on an acoustic guitar when it comes to aesthetics. Its subjective (beauty is in the eye of the beholder). Sound ports are about listening and aesthetics IMHO. There's no science logic that will give one the "right" choice IMHO.

Plastic vs wood binding, hide glue vs PVA, rosette vs no rosette, binding vs no binding, shell vs plastic, plywood vs solid wood, double sides vs single sides, tuss rod vs no truss rod, double top vs singe top, varnish vs lacquer, etc. etc. on and on. Can one choice over another be proved "better"?

Take guitars with few (measured) overtones, little (measured) sustain, little (measured) volume, old dead strings, paint finish, no bindings and even pegs for tuners. You'll find people that love them and call them "blues" guitars - all that the blues originators could afford I guess. Is there something absolutely better than this? No, not really. Its subjective. But to my ears there is something far better. And to my eyes there is something far better. But I don't think I can support my view with science logic. Am I just hearing and seeing what I want to?

If you don't "get it" regarding sound ports, then you are right for you. If you do "get it", then you are still right for you. If I were you, I certainly would not sell or "market" something to someone that I thought had no merit. It sounds like you found no merit which is perfectly fine.

Some do not hear nor see a postive difference because they do not want to hear nor see a postitve difference. And vice versa. I certainly agree with you there. But I do not think that ALL people are hearing and seeing "what they want to".

Ed -- I am not even sure what the the heck you are talking about? My opinion on this is topic meaningless -- remember I asked for sound port logic. So those that have an opinion, experience or what ever could post it - remember one of the elders said "an ash tray". And I am not asking validation on my personal conclusions they are mine and mine alone, I will gladly delete my posts for you too just let me know.

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Ken Cierp

http://www.kennethmichaelguitars.com/

So based on the passion shown by some regarding the "Sound Port" option. I thought maybe I should play one for myself. My go to guitar shop is Elderly's here in MI. So I called and the conversation went like this --me "how many guitars do you have in stock that have sound ports" sales person -- "gosh I've never seen a guitar in here with a sound port -- a couple of ukeleles. Let me check the inventories" sp "nope nothing. me "how many flattops do you have in stock?" sp "about 700 new and used" me "to bad I wanted to stop by and play one" sp Sorry we just don't get asked about guitars with sound ports"

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Ken Cierp

http://www.kennethmichaelguitars.com/

Great idea to evaluate sound ports by listening; after a certain point, words will only take you so far. Elderly is my go-to guitar shop as well--been going to it since it opened when I was 19. (I'm 61 now; still hopelessly preoccupied with guitars.) It's a great guitar shop. However, Stan mainly carries factory-made guitars, old and new, including excellent new instruments by smaller workshops such as Collings and Bourgeois. Of those 700 guitars, probably less than ten are built by hand by individual luthiers. As mentioned earlier in this thread, sound ports have yet to be adopted by factories. I think most buyers interested in sound ports wouldn't be asking Elderly about them—they'll be going to stores emphasizing hand builders, or festivals where luthiers display their work. I'd suggest visiting one of the festivals. Happy listening!

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Tim Allen
"Never hurry, never rest."

I called Elderly and asked if they had any guitars with figured wooden rosettes. No, they don't have any said the sales person. I guess, like the sound ports, there is no call for them either. I'm not sure exactly what that tells me about the logic of sound ports or the logic of wooden rosettes or the value of either item. They have a huge supply of plastic rosettes. It seems to tell me that factories are doing what they have mostly done for years.

Yeah Tim -- Elderly is great fun, I go there to pick off dimensions to make sure our KMG kits are pretty close to spec. I've played a Charles Fox there and was hoping Collings and Bourgeos might have something with a port. I know they also take consignments from boutiques makers too, I think Ken Casper has/had a few there now -- maybe not. John Greven had indicated that out at the Healdsburg Festival there were plenty of ported guitars.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Ken:
When you asked about the 'logic' of sound ports, I assumed you were looking for whatever factual information there was about them rather than opinions. I've done a lot more work on them than I originally meant to, in part as a way to counter some of the hype that seems to often be put out by folks who have an interest in promoting them. Selling a new idea or product is, of course, perfectly legitimate, but sometimes the claims that are made seem to me to pass the bounds of physics as we know it, so I set out to find out what was really happening. My post was an attempt to set out, in brief, what I've found: what happens when you put in a port, and the circumstances where it may be handy to have one. Your statement that "There's no current science that would indicate with or with out port is better " gave me the impression that you simply had bypassed my post. It was a long one, and may have been confusing if you're not used to that sort of stuff, but it was a bit galling. I've been playing catch-up for a few weeks, and was sort of irritable. Sorry to pop off.

Nobody can tell you whether you'd like a ported guitar better than a similar one without a port, any more than anybody can say whether you prefer vanilla or chocolate. Whether any other member of this list does or doesn't like ports has no bearing on that either. If you have a specific problem and think a port might help solve it the sort of work I've done can help predict whether it might or not, but even if I recommend a port as the solution, you might not like it when you heard it. It's a drag that it's so hard to find instruments with ports to try out. They're out there, but not in great numbers, and I don't expect the manufacturers will offer them any time soon. Keep looking; you'll find one eventually, and then maybe you can answer your own question.

Alan, I do appreciate your input. Perhaps my topic line could have, should have said why would one of "my customers" buy a guitar kit with a sound port in it? I think most of us want to pay for "better or best", not just different -- a utilitarian feature is good too. I think personal monitor is a good selling point. As one of your comments indicated you really can't define best with conventional sampling -- my hope was that there was indeed a blind test done with a large sample pool, wishful thinking on my part and looking for that was the bases for using broad term "science".

I apologize if I offended you in anyway -- that was/is never my intent.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Duh on me! I have a dozen or so prototypes around here I'll just mod one or two of the those.

How many square inches for a "D" and how many for an OM? Or is it pure guess?

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Ken Cierp

http://www.kennethmichaelguitars.com/

You don't need a very big port to make an effective monitor. My 'corker' test mule had two, 5/8" diameter corks in holes at each of ten port locations along the bass side, and they worked. Bigger holes are more effective, of course, but also change the sound of the guitar more. The test mule I used for the blind testing had a 2" diameter port, which was larger than I would normally use. I was trying to answer the objections about the corker: some folks though those little holes were just too small. I usually make ports 1-1/4" diameter these days, although I've used 1" too, and they're effective.

Generally, when I'm building a ported guitar I'll reduce the diameter of the main sound hole by anywhere from 1/4" to 1/2". This helps keep the 'main air' resonant mode pitch down where I like it. If you work it out you'll see that it's not simply a matter of keeping the total area of the holes the same with or without a port. The further the the port is from the the main sound hole the larger the eefect will be on the 'main air' pitch, and it's a bit hard to predict.

One of my students made a fancy reso. He inlaid a rattle snake on the top, coiled around the pan, and used the tail as the sound hole. I thought it looked a bit small, but he was thinking more about the artistic effect. Sure enough, when he got it done the sound was 'choked'. Eventually what he did was to open up a port in the side. He reinforced the side where the port was going to be with, iirc, a thin cross grained patch epoxied in. Then he used a burr in a handshaft to make a small hole. He kept enlarging it and playing the guitar (which remained strung up throughout). At first the sound got better, then plateaued, and started to get worse. At that point, he neatened up the edges of the hole, and made a surround out of wood that covered the edges, reducing the size of the hole to get back to where it sounded better, and giving it a finished look.

I've only done a sound port once. The reason I did that was because main top and main air were octaves, and the Gore books say that's a no no, and since the books seem to be right about everything else, I chose to believe it. So I punched a hole in the side to raise the main air a half step, making the relationship a major 7th, which I find is nearly always the relationship between main air and main top in all models that I make. Just kinda works out that way...

Didn't notice any real difference, though it was subtly a bit 'cleaner'...

I did get an order for one recently. The customer also wanted a 1/4" deeper body. So we'll see how that goes...

This has been one of the more interesting threads currently running on the OLF for me. And... not because of what you may think.

I don't doubt the claims made about sound ports by those who have done the research Al and others nor do I doubt that there is a real value-add to those who believe in the value received from a guitar with a port. My "ash tray" comment was intended to be a joke.... not an opinion....

What is interesting to me is when the discussion morphed into how many instruments at Meca (Elderly Instruments) have ports. None.

So what if any conclusion might be drawn from what we have read here?

Those who produce instruments with ports obviously believe in them and as such if they are successful in selling instruments with ports they have been able to convey their beliefs and value proposition to clients.

It's also likely that Martin, Collings, Santa Cruz, Gibson, etc. are not feeling the need at least yet to include ports because these are market driven organizations, obviously....

Around 8 years or so ago there was a lot of differentiation between Luthier built instruments and the run of the mill f*ctory stuff. We were using lots of Koa, African blackwood, Black Limba, etc. and the f*ctories were still pretty much using the big three, EIRW, Hog, and Maple.

Along came R. Taylor and other custom shop entrants and low and behold we started seeing instruments with other body shapes such as SJ's, use of other exotic woods, just like Luthiers used, etc. and this now even includes Martin.

The point - Back then it surprised me that the Luthier world was likely having an impact on the f*ctory world meaning that someone was perceiving that they were losing sales over not having certain features, materials, shapes, etc. But I believe that it indeed happened.

Who wants to take me up on a bet that at some point we will also see ports on f*ctory produced instruments. Some of the earlier Taylors that had pup issues are already equipped for the port when you rip out the electronics...

Seriously though it's likely just a matter of time before everyone has to have one, they may not know why they have to have one, but hey who are we to deny them anything....

Lastly a big thanks to Al for all of his dedicated research including the corker guitar. I remember that thread well when it was in real time and I was also impressed with the small size of the port that seemed to do the trick over some rather larger ones.

As such I think that there is room for ports and the more traditional single sound hole configuration. I also think that we will be seeing more ports and on f*ctory instruments as well.

Which begs the questions who drives who: are Luthiers influencing the f*ctory world of guitars, f*ctories influencing us, or both?

Good thread guys!

Hesh wrote:
"Those who produce instruments with ports obviously believe in them and as such if they are successful in selling instruments with ports they have been able to convey their beliefs and value proposition to clients."

It's getting so you can hardly swing a cat without hitting a luthier, and many of them seem to do really nice work. This brings up the need to differentiate yourself from all the other guys doing nice work. For a while there it seemed that a port was a good way to do that. Since it does, in fact, make a difference in the way the guitar sounds, all you had to do was convince the mark - umm - customer, that different = better. This is relatively easy, since people are so prone to hear what they expect to hear. This lead to a lot of hype: 'makes every guitar better', 'releases pent-up energy'; that sort of thing. Good ad copy, but bad physics in some ways, as far as I can tell.

Now that ports are more common people are getting the opportunity to compare ported and non-ported guitars, and draw their own conclusions. What I'm seeing is a move toward acknowledging reality: that they can help the player in some circumstances, are not miraculous, and may even cut down on projection out front in some cases. People who need hype to pump up their business will need to look elsewhere, and ports will become a standard option, like cutaways.

I suppose it's possible that the manufacturers will, at some point, put out ported models. It's a relatively simple thing to add in and there probably will be a small, but steady, market for it, at least for a while. I could also see an aftermarket product coming out to convert barn-door EQ openings into reasonable sized and attractive ports.

As for who leads in the dance: it's always been hand makers, at least in terms of innovation. C.F. Martin and Orville Gibson were individual luthiers, just like Bob Taylor, before they gave their names to factories, and the real innovations came out of the one-man shops. They may, of course, have always had their eyes on production, but the only recent acoustic guitar design I can think of that was born into a production setting was Ovation's Tupperware. My memory is that it was not a huge success until they started offering it with a built-in pickup: as an acoustic the design has real limitations, IMO. But, again, it was hype-able.

Yes, Hesh, I agree as I said in my previous post above.

I like the port for the 1) clarity of sound (monitor) I receive as a player and 2) the potential for an aesthetic improvement. I say potential since a circle or oval does not achieve that potential aesthetic improvement for my eyes but does achieve the monitor aspect very nicely.

It is interesting that I am not concerned near as much about the audience as I am the player. When plugged in they hear the amplified acoustic anyway. If not amplified, I would be very surpirsed if the audience could consistently (blindly) tell any sound difference with or without the port. However, my audience does consistently remark about the aesthetics of the port in a postive way. I am surprised that they pay enough attention to notice since other aesthetic details often has to be pointed out to them.

Ken,
My port is 1.7 sq. inches and I reduce my sound hole by 1/8" to 3 7/8" (which compensates for about half of the port's opening). Working backwards, I find 1.7 sq inches is about like a 1.5" diameter circle's area. I hope you enjoy your test.

Ed