Low/mid feedback issue - help?

[mwalk]

I'm having an issue with my Fishman Matrix equipped D-18. I use a Fishman Aura DI.

F# in the 4th fret / 4th string range - I believe that's the 160 range - just takes off feeding back. I'll get the guitar dialed in where it sounds excellent otherwise, but that frequency just goes nuts. Happens through my Bose L1 and also through venue PAs with sound techs.

Any advice? Is an EQ device the way to go?

[lkingston]

Get an RTA app for your phone and you'll exactly where your problem is.

Sent from my SM-N910T using Tapatalk

[mwalk]

Originally Posted by lkingston

Get an RTA app for your phone and you'll exactly where your problem is.

Sent from my SM-N910T using Tapatalk

Well like I said I already know where the problem is - middle F#, 160. I'm wanting suggestions on a possible solution that won't cause the guitar to sound thin.

[fazool]

Originally Posted by lkingston

Get an RTA app for your phone and you'll exactly where your problem is.

Sent from my SM-N910T using Tapatalk

What is an RTA app? The only RTA apps listed on Google Play are for Cleveland Regional Transit Authority

[fazool]

Originally Posted by mwalk

...

F# in the 4th fret / 4th string range - I believe that's the 160 range...

184.997Hz




(.)

[jseth]

Are you using the L1 Model II with the T1 mixer? If so, use the parametric on your guitar channel and tweak that frequency back a bit... be sure your tone controls on the guitar are set to "flat", as well as the T1, before you start tweaking things...

Obviously, if you are attempting to "tame" an unruly note in the lower range, it is cross-purpose to have that range "boosted" by increasing bass on your tone controls...

One thing that has worked well for me with my Bose and my AER Compact is to have it behind me and slightly on the diagonal over my left shoulder, so any bass response is furthest away from the body of my guitar (I play right-handed)... also, try to put a bit of distance between yourself and the source of amplification; not only will your amp/Bose sound better to you, it will reduce the proximity effect in those lower registers...

If you have a sub (B1) cabinet, try moving that cabinet an inch or three off-axis (not vertically)... this was a tip I received from the Bose User's Forum from one of the moderators (who all work for Bose), and it was astounding how much difference a couple of inches can make on those "trouble" frequencies on acoustic guitars!

Although I know use the Baggs Anthem SL in my "stage" guitars, I used a Fishman Matrix for over a decade prior to the Baggs units, and I found them to be very manageable, and generally good sounding, with very little eq'ing needed (especially through my Bose Classic L1).

If none of this stuff helps, it could very well be a function of playing a dreadnought bodied guitar... they do put out a lot of bass... it's kind of the point of a dread, don't you think?

Hope this helps you... feedback issues can be particularly troublesome with an acoustic guitar...

[leew3]

Originally Posted by fazool

What is an RTA app? The only RTA apps listed on Google Play are for Cleveland Regional Transit Authority

yep, that's it. once you board the Cleveland metro system your worries about your guitar will disappear!

[mwalk]

Originally Posted by jseth

Are you using the L1 Model II with the T1 mixer? If so, use the parametric on your guitar channel and tweak that frequency back a bit... be sure your tone controls on the guitar are set to "flat", as well as the T1, before you start tweaking things...

Obviously, if you are attempting to "tame" an unruly note in the lower range, it is cross-purpose to have that range "boosted" by increasing bass on your tone controls...

One thing that has worked well for me with my Bose and my AER Compact is to have it behind me and slightly on the diagonal over my left shoulder, so any bass response is furthest away from the body of my guitar (I play right-handed)... also, try to put a bit of distance between yourself and the source of amplification; not only will your amp/Bose sound better to you, it will reduce the proximity effect in those lower registers...

If you have a sub (B1) cabinet, try moving that cabinet an inch or three off-axis (not vertically)... this was a tip I received from the Bose User's Forum from one of the moderators (who all work for Bose), and it was astounding how much difference a couple of inches can make on those "trouble" frequencies on acoustic guitars!

Although I know use the Baggs Anthem SL in my "stage" guitars, I used a Fishman Matrix for over a decade prior to the Baggs units, and I found them to be very manageable, and generally good sounding, with very little eq'ing needed (especially through my Bose Classic L1).

If none of this stuff helps, it could very well be a function of playing a dreadnought bodied guitar... they do put out a lot of bass... it's kind of the point of a dread, don't you think?

Hope this helps you... feedback issues can be particularly troublesome with an acoustic guitar...

Very helpful! I'll try this stuff. Thanks!

I'm not currently using the Tonematch mixer. But I've been wondering if getting one would help.

[guitaniac]

Originally Posted by mwalk

I'm having an issue with my Fishman Matrix equipped D-18. I use a Fishman Aura DI.

F# in the 4th fret / 4th string range - I believe that's the 160 range - just takes off feeding back. I'll get the guitar dialed in where it sounds excellent otherwise, but that frequency just goes nuts. Happens through my Bose L1 and also through venue PAs with sound techs.

Any advice? Is an EQ device the way to go?

That particular pitch is called F#3 and would be 185 Hz (presuming A = 440Hz), according to the chart.

http://www.phy.mtu.edu/~suits/notefreqs.html


You should at least try a phase inversion to see if that helps, if you haven't done so already. I believe they call it a "global" phase control with the Spectrum. If memory serves correctly, the Spectrum also has a control for adjusting the phase relationship between the dry signal and the sound image. You'll also want to try both of those phase positions to assure the best results.

If experimenting with the phase relationships doesn't help, a simple Boss GE-7 graphic equalizer (with one of the bands centered at 200 Hz) will scratch that 185 Hz "itch" a lot better than just rolling off the bass with the Spectrum's three band tone control.

My Zoom A3 also has EQ controls which could come closer to your problem frequency. (A graphic EQ with one band centered at 160Hz, and a semi-parametric EQ with an adjustable bandwidth and selectable center frequencies at 160Hz and 200Hz.) The A3 also has an automatic feedback zapper which identifies the offending frequency and provides three adjustable options for the notch depth. If it doesn't stop the feedback problem entirely, it can at least point the user in the direction of where to make a wider cut with the graphic EQ or parametric EQ.


If you like the Aura, you'll want to consider the Audio Sprockets ToneDexter processor. Its similar in concept, except that it goes a step further and enables the user to create his/her own WaveMap(s) for his/her own specific guitar/pickup rig.

Its also very relevant to your situation that ToneDexter senses the body resonance frequency of the guitar and lowers the level of that frequency to avoid feedback and boominess problems (according to the manual). Hopefully, user observations on ToneDexter will be available soon as the first production batch is supposed to ship this month. In the meantime, you can find the manual here:

http://audiosprockets.com/documentation/

[mwalk]

Originally Posted by guitaniac

That particular pitch is called F#3 and would be 185 Hz (presuming A = 440Hz), according to the chart.

http://www.phy.mtu.edu/~suits/notefreqs.html


You should at least try a phase inversion to see if that helps, if you haven't done so already. I believe they call it a "global" phase control with the Spectrum. If memory serves correctly, the Spectrum also has a control for adjusting the phase relationship between the dry signal and the sound image. You'll also want to try both of those phase positions to assure the best results.

If experimenting with the phase relationships doesn't help, a simple Boss GE-7 graphic equalizer (with one of the bands centered at 200 Hz) will scratch that 185 Hz "itch" a lot better than just rolling off the bass with the Spectrum's three band tone control.

My Zoom A3 also has EQ controls which could come closer to your problem frequency. (A graphic EQ with one band centered at 160Hz, and a semi-parametric EQ with an adjustable bandwidth and selectable center frequencies at 160Hz and 200Hz.) The A3 also has an automatic feedback zapper which identifies the offending frequency and provides three adjustable options for the notch depth. If it doesn't stop the feedback problem entirely, it can at least point the user in the direction of where to make a wider cut with the graphic EQ or parametric EQ.


If you like the Aura, you'll want to consider the Audio Sprockets ToneDexter processor. Its similar in concept, except that it goes a step further and enables the user to create his/her own WaveMap(s) for his/her own specific guitar/pickup rig.

Its also very relevant to your situation that ToneDexter senses the body resonance frequency of the guitar and lowers the level of that frequency to avoid feedback and boominess problems (according to the manual). Hopefully, user observations on ToneDexter will be available soon as the first production batch is supposed to ship this month. In the meantime, you can find the manual here:

http://audiosprockets.com/documentation/

Very cool, thanks. I will look into all of that. Had forgotten about the "global" thing on the Aura.