“Dead” fretted bass note

[davenumber2]

Originally Posted by Jimi2

Well I just got the Daddario O port and installed it:



https://www.amazon.com/Planet-Waves-...s%2C101&sr=8-1



It’s pretty unobtrusive and now the “thud” is gone. I don’t think it affects the tone too much otherwise, but which is good, but I didn’t really do an A/B test on that. Just happy to have the sustain back on that G.

I’ve tried the O-port on a couple guitars. It enhanced the bass and treble. Be careful if you take it in and out. Mine broke in half after doing it several times.

[printer2]

Originally Posted by davenumber2

I’ve tried the O-port on a couple guitars. It enhanced the bass and treble. Be careful if you take it in and out. Mine broke in half after doing it several times.

This is interesting. The video says that there is increased bass, I thought I might try to equalize the levels and jumped back and forth between with and without. With it is louder but when adjusting the volume the balance between the bass and treble did not seem to change.

[davenumber2]

Originally Posted by printer2

This is interesting. The video says that there is increased bass, I thought I might try to equalize the levels and jumped back and forth between with and without. With it is louder but when adjusting the volume the balance between the bass and treble did not seem to change.

I should also say one guitar I tried it on I didn’t really notice any difference. The others were noticeable. The cone shape projects the sound outward so it seems louder.

[Jimi2]

Originally Posted by davenumber2

I should also say one guitar I tried it on I didn’t really notice any difference. The others were noticeable. The cone shape projects the sound outward so it seems louder.

Yeah, Im not noticing much of an overall tone difference. Which is good, as this is a nice sounding (though a little beat up) Lowden. I should have played for a while before installing it, to get a better before and after comparison, but I had just gotten home and didn’t pause to play before installing it.

[Jimi2]

Originally Posted by PointlessPicks

It could also be a very bad fit of such a large diameter string to the nut. Please check it's sound after applying a capo an any fret.

Cheers, Doug

I didn’t think to try a capo; just assumed it was a resonance thing as it always stays at that G. When I take the O port out, I’ll try that though. I did get the impression that it was a little better going from. .060 to .056 originally.

[Alan Carruth]

I made 'impulse spectrum' measurements of the same guitar with and without an O-Port a few years ago. It's difficult to control the input energy exactly in this test, so I can't say for sure whether it had a major effect on the output power all else equal. I suspect it reduced it, though.


What surprised me was that it had almost the opposite effect on the output that one would see with a more normal 'tornavoz': a simple pipe with little taper. In that case you usually see the 'main air' resonance drop significantly in both power and pitch, without much change in the 'top' resonance. With the O-Port the pitch of the 'air' resonance did drop some, from 100 Hz ( a little above G) to 92 Hz (F), with little relative change in the amplitude, so far as I could tell. What really changed was the pitch and activity of the 'main top' resonance. From having a tall and well defined peak at 201 Hz it was chopped off in height relative to the 'air' pitch by about 2/3 in amplitude, with a drop in pitch of about 8 Hz. Frequencies higher than about 250 Hz were affected far less.

I was not impressed with the sound quality with the O-Port in place, although it's hard at this remove (7 years) to be specific about the changes. The guitar was one of a matched pair of mahogany/spruce OMs that came out well, and the change did not improve it in a direct comparison.

[Jimi2]

Originally Posted by Alan Carruth

I made 'impulse spectrum' measurements of the same guitar with and without an O-Port a few years ago. It's difficult to control the input energy exactly in this test, so I can't say for sure whether it had a major effect on the output power all else equal. I suspect it reduced it, though.


What surprised me was that it had almost the opposite effect on the output that one would see with a more normal 'tornavoz': a simple pipe with little taper. In that case you usually see the 'main air' resonance drop significantly in both power and pitch, without much change in the 'top' resonance. With the O-Port the pitch of the 'air' resonance did drop some, from 100 Hz ( a little above G) to 92 Hz (F), with little relative change in the amplitude, so far as I could tell. What really changed was the pitch and activity of the 'main top' resonance. From having a tall and well defined peak at 201 Hz it was chopped off in height relative to the 'air' pitch by about 2/3 in amplitude, with a drop in pitch of about 8 Hz. Frequencies higher than about 250 Hz were affected far less.

I was not impressed with the sound quality with the O-Port in place, although it's hard at this remove (7 years) to be specific about the changes. The guitar was one of a matched pair of mahogany/spruce OMs that came out well, and the change did not improve it in a direct comparison.

Interesting- I’d try the sort of sleeve you describe, but I’m not sure how I’d attach it without tape showing. The o port is at least unobtrusive. Did you find it negatively affected the sound or did it just not improve?

[Alan Carruth]

As I said, I was not impressed with the sound I got from that guitar with the O-Port, although at this point it's hard to remember exactly what the change was.