Planet Waves O port - Page 3

hyenik · #31 09-14-2015, 09:47 AM

after some time, small continuation, now with small nylon Cort CEC7

Silly Moustache · #32 09-14-2015, 10:51 AM

Dunno about this gizmo, but it does occur to me that if you feel the need to spend on things like this, then, maybe, you don't have the right instrument?

jimmy bookout · #33 09-14-2015, 11:19 AM

Quote:

Originally Posted by Silly Moustache

Dunno about this gizmo, but it does occur to me that if you feel the need to spend on things like this, then, maybe, you don't have the right instrument?

Hey, I'm impressed that a 42 month old thread was brought back to life!

Jimmy

baimo · #34 09-14-2015, 12:23 PM

Never saw this before but some of the people took their smart pills that morning and some are very committed.

Marteenie · #35 09-14-2015, 01:09 PM

My daughter gave me an O-Port for Christmas last year as I was thinking it might tone down the brightness on my Taylor 150e 12 string. Unfortunately the ES system circuit board protrudes too far into the guitar so the O-Port could not fit properly into the sound hole. I ended up putting it in my Seagull Maritime but can't say I've noticed a difference. I really only leave it in there because it was a gift from her.

Tekadum · #36 09-14-2015, 01:53 PM

I put an O-Port in my Washburn laminate koa dreadnaught to see if I could reduce the boomy A-string. It did that. I also think that it increased volume and projection and made the strings more balanced. The difference is not dramatic, so someone else might have a different opinion, but I feel it was worth it and have been playing this guitar with the O-Port for a couple years now.

hyenik · #37 09-14-2015, 01:53 PM

Quote:

Originally Posted by Silly Moustache

Dunno about this gizmo, but it does occur to me that if you feel the need to spend on things like this, then, maybe, you don't have the right instrument?

definitely good point, but for me is nylon only small part of sound pallete, I dont need and I dont want to spend more money for perfect instrument.
btw in historic times Torres recomended this gizmo too, but....

JackH · #38 06-02-2018, 11:54 PM

This seems to be one of those things I need to try for myself to know if I like it or not. The characteristics of my guitar and personal taste may have more of an impact on my opinion than anything else. Right now I like the way my guitar sounds unamplified. If the o-port would make it louder that would be nice.

I value the benefit of electronic equipment to give a visual indication of sound. However, I don't know enough about it to know what the displays are going to translate to when I hear it.

If I ever get one I'll post my opinion. I may add the o-port to an order of strings or something I'll be getting anyway.

Here's a benefit I haven't heard of yet. When I drop a pick and it goes inside my guitar I get it out by shaking the guitar to position the pick(s) on the back of the guitar and resting against a brace that runs along the middle of the back wood. Then turning the guitar over quickly results in the picks falling out the sound hole. The shape of the o-port should make the picks fall out easier as it would create a funnel guiding the pick to the sound hole. I doubt this will increase sales though.

Jack

Alan Carruth · #39 06-03-2018, 05:07 PM

Just saw this thread.

I put an O-Port in a Mahogany/Red spruce OM size guitar that I made as one of a pair a year ago, and ran an 'impulse spectrum' test on it. Basically, this is a sort of 'snapshot' of what the guitar does: it shows the output of the instrument out in front when the bridge has been tapped lightly on the saddle. The guitar 'rings' like a bell, although, of course, it sounds more like 'thud' since it's wood and not metal. By feeding the thud through a Fourier Transform program you can get a look at how much sound the instrument will produce for a given input power at any particular frequency. The resonant frequencies that send out sound toward the microphone show up as peaks, and there will be valleys in the response where the box is less effective at turning vibration at the bridge into sound, or where the sound is, perhaps, going off in some other direction that the mic won't pick up.

As Jan said at some length, in the low range the guitar acts something like a 'bass reflex' speaker cabinet. Adding in a 'neck' or 'sleeve' in the port of such a speaker cab will drop the pitch of the 'Helmholtz' resonance. In a speaker you want that pitch to match the 'free air' resonance of the speaker cone itself pretty closely. This gives a strong 'couple'. Both the cone and the cab itself are highly damped: their resonant peaks are spread out in pitch. The combination in the assembly gives a response spectrum that is nearly 'flat': the two output peaks that are generated by the 'air' and 'speaker' are not more than about 3dB higher than the 'dip' in between, which, to your hearing, is only just noticeable as a change in 'loudness'. The setup is more efficient than a speaker alone, since it captures some of the energy off the back of the speaker via the air in the box, and gives a decent approximation of a 'flat' response.

On guitars the isolated 'top' resonance is usually somewhere near a musical fifth higher than the isolated 'air' resonance. The coupling is not as strong as it is on a speaker. The back often gets into the act as well in this range, and, of course, not being made of heavy plywood or other 'rigid' material, there are other resonances of the 'wood' at higher frequencies. The guitar shape also introduces some 'air' resonances, although, again, these are not usually influential in the 'bass reflex' range. On a guitar this range generally runs from about G on the low E string to a bit above the pitch of the open G string an octave higher.

Added 'sleeves' have been used for a long time on guitars. The Classical maker Torres seems to have been a fan of a configuration called a 'tornavoz'. His were usually copper or brass, and slightly conic, wider at the soundhole end than toward the back of the guitar, so that had to be built in. Some of them went almost the entire depth of the box, and many, if not all, had a pattern of small holes punched in near the bottom end. Most of them (tellingly, IMO), have been removed over the years. I tried out a version of this, made of card stock that I could scrunch up and put into an existing guitar. I saw pretty much what Jan described: the 'air' resonant pitch dropped. The added drag of the tube also reduced the amplitude of the peak to practically nothing. In essence, it was nearly equivalent to simply making a guitar with no hole.

I expected much the same from the O-Port, but that's not what I saw. This device is about an inch, or a bit more, in depth, and flares out sideways about the same amount. The large radius thus could help smooth the air flow, and the rapid flare reduces the effective length of the sleeve. The result in the impulse spectrum was that the 'air' resonant pitch was only lowered by about two semitones; from 100 Hz to 92. It's a little hard with this test to feed in exactly the same amount of power every time, so the fact that the 'air' peak was reduced in height by about 20% with the O-Port in may not be overly significant. I suspect the device introduces some loss, but surprisingly little at that frequency, or so it seems.

What did change, dramatically, was the activity of the 'main top' resonant peak. The pitch of this peak was about a semitone lower, but the amplitude was reduced by almost 60%. Again, the absolute value of the input is hard to control in this rig, but the relative amplitudes of the various peaks is usually reasonably constant between tests. If the input was different you'd expect both the 'air' and 'top' peaks to be reduced by about the same proportion, but they were not.

I'm not sure what caused this. It's important to keep in mind that what we call the 'air' and 'top' resonant peaks actually involve motion, and sound production, from both elements at the same time. The top pumps air in and out of the sound hole, and the air flow causes pressure changes in the box that drive the top, at both frequencies. It's possible that the shape of the O-Port, which seems to smooth the air flow at the 'air' pitch may add drag that impeded movement of the top at the 'top' pitch. It would take some time to work this all out, and I had too many other irons on the fire at that time to do so.

I put this out for what it's worth. As Jan says, it's all physics, but, as is usual with the guitar, it's far from 'simple'. Relating 'what it does' with 'what it sounds like' is even trickier. I suspect that the result with a different guitar would be broadly similar physically, but can't say for sure: it might sound quite a bit different. I still have the O-Port, and may get to play with it again some time.

Beakybird · #40 06-03-2018, 06:11 PM

It's like the big watch my grandpa invented to be worn like a belt. A few liked it. Most called it a waist of time.

tinnitus · #41 01-11-2020, 04:56 PM

Well, that settles it (for now anyway). It won't fit!

I was sufficiently curious to want to try one and keep the receipt just in case. But alas, both of my daily acoustic players have cutaway bodies and long fretboards extending all the way to the sound hole, which would interfere with the lip of the O Port around the hole.

I suppose I can get one for $16 through Amazon Prime, flatten one side of the plastic lip with a Dremel tool (allowing room for the fretboard) and see if it makes any difference. In that case, I'd own it even if it was useless.

One thing holding me back right now is wondering why all the amazing guitar players we idolize aren't already using and endorsing these. I never saw one anywhere, ever, until I picked up a strap at Guitarget yesterday.

Another question... would it make as big of a difference to me (ears 18-24" above the sound hole) as it might to a jam buddy facing my guitar head-on from 4-5 feet away.

TBman · #42 01-11-2020, 06:02 PM

Quote:

Originally Posted by tinnitus

Well, that settles it (for now anyway). It won't fit!

I was sufficiently curious to want to try one and keep the receipt just in case. But alas, both of my daily acoustic players have cutaway bodies and long fretboards extending all the way to the sound hole, which would interfere with the lip of the O Port around the hole.

I suppose I can get one for $16 through Amazon Prime, flatten one side of the plastic lip with a Dremel tool (allowing room for the fretboard) and see if it makes any difference. In that case, I'd own it even if it was useless.

One thing holding me back right now is wondering why all the amazing guitar players we idolize aren't already using and endorsing these. I never saw one anywhere, ever, until I picked up a strap at Guitarget yesterday.

Another question... would it make as big of a difference to me (ears 18-24" above the sound hole) as it might to a jam buddy facing my guitar head-on from 4-5 feet away.

I bought one and right now it is in my Guild D-120, which is more or less cased for the winter. I had put the O-Port in my Larrivee and didn't care for the sound, but in the Guild it seemed to enhance the sound a bit. The Guild is a dread and my Larrivee an OM. Maybe that had something to do with it.

Brucebubs · #43 01-11-2020, 06:52 PM

The used Epiphone EJ-200 I bought in 2018 has one fitted by the previous owner.

I haven't done a comparison simply because the guitar sounds great .. so I'm leaving it in!

tinnitus · #44 01-13-2020, 02:37 PM

Quote:

Originally Posted by TBman

I bought one and right now it is in my Guild D-120, which is more or less cased for the winter. I had put the O-Port in my Larrivee and didn't care for the sound, but in the Guild it seemed to enhance the sound a bit. The Guild is a dread and my Larrivee an OM. Maybe that had something to do with it.

Absolutely what I might expect... certain sizes, shapes, woods, strings, etc., might make it sound incredible in one guitar and not so much in another. Like some here, I'm a little OCD myself. Paid plenty (for me anyhow) for my Larrivee, and I'd hate to think a $16-19 piece of molded plastic might make it sound better. So my other daily strummer might get the mod instead.

Ralph124C41 · #45 01-14-2020, 08:58 AM

Good timing. I changed the strings a couple of days ago on my Alvarez AD30 which has the O Port. I got the strings installed, adjusted the neck tension ... and then thought about taking out the O Port. Lazy as I was I didn't loosen the strings enough so when I tried to take it out I broke it ... it just snapped apart. So I clumsily put it back in shape. So I wonder if I "ruined" it as it still sounds pretty much the same IIRW.

I mean it's in there solidly it's just one of the sides has broken but it's still retained.

Any thoughts? As I wrote elsewhere I put one also in my Esteban and seemed to improve the sound of that "guitar" (to be polite) but I didn't notice any improvement except maybe a little in the AD30. In one guitar, I think the Alvarez jumbo, I think it actually worsened the sound!

So now I own both the O Port (2 of them) and the ToneRite. Call me Gizmo Boy.