The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Acoustic Amplification

Reply
 
Thread Tools
  #16  
Old 07-26-2021, 10:41 AM
EZYPIKINS EZYPIKINS is offline
Registered User
 
Join Date: May 2020
Posts: 1,403
Default

Quote:
Originally Posted by Cuki79 View Post
You need a Parametric EQ to tame it. Add a sharp cut at 100 Hz.
A decent mixer has a lo cut switch usually at 100 hz for just this problem.

Also a feedback buster will knock this down as well.
Reply With Quote
  #17  
Old 07-26-2021, 11:47 AM
shufflebeat shufflebeat is offline
Registered User
 
Join Date: May 2016
Posts: 820
Default

Quote:
Originally Posted by Odedi View Post
...I have a small soundport on the upper side !
I should try and cover that too,
however I am afraid it will kill the tone.
And also

Quote:
Originally Posted by Odedi View Post
Fishman Presys Blend (mic + ust)
I believe are key to your solution.
__________________
Give a man a fishing rod... and he's got the makings of a rudimentary banjo.
Reply With Quote
  #18  
Old 07-26-2021, 02:01 PM
Odedi Odedi is offline
Registered User
 
Join Date: May 2020
Posts: 82
Default

Quote:
Originally Posted by MarkF_48 View Post
How close is the amp placed near you and is it in front of you, to the side, or behind? Set fairly high in volume?
Have you tried some distance between you and the amp?
Sometimes in front, sometimes behind, sometimes to the side.
And also sometimes its close and sometimea its further away.
It doesnt matter much.

As to volume , I would say it's about medium , maybe a little more
Reply With Quote
  #19  
Old 07-26-2021, 02:03 PM
Odedi Odedi is offline
Registered User
 
Join Date: May 2020
Posts: 82
Default

Quote:
Originally Posted by shufflebeat View Post
And also



I believe are key to your solution.
Hey, what do you suggest regarding the pickup?
Reply With Quote
  #20  
Old 07-26-2021, 03:49 PM
ljguitar's Avatar
ljguitar ljguitar is online now
Charter Member
 
Join Date: Mar 2005
Location: wyoming
Posts: 40,618
Default

Quote:
Originally Posted by Odedi View Post
Oh, that's because I have a small soundport on the upper side !
I should try and cover that too,
however I am afraid it will kill the tone.
Hi Odedi

I've got small side ports on two guitars, and they do not affect feedback that I've ever detected (and I play in bands with the main soundhole covered).





As mentioned, pitch specific, escalating, overpowering frequencies can best be controlled with parametric EQ, or distancing one's self from the source of the guitar hearing itself.

If it's triggered by a stage monitor, the monitor can be turned down or moved. If by a personal stage amplifier, then reposition it to behind yourself so your body shields the guitar from it. I run stage amps knee to waist high and 4-6 feet behind me. My body shields the guitar's body from hearing itself.

If it's being triggered by the mains you may have to move away from the speaker proximity some. If there are subs, sound techs seem to want to run them very hot and pump the bass into the room at decibel levels which trigger feedback in audience members as well as guitars.

This is a major source of feedback for acoustic guitars.

Also depending on the sophistication of one's gear, or the PA board capability, you may be able to deal with it by notching it out.

Most digital boards can produce quite narrow notches, and my ToneDexter with the latest update now identifies and isolates the likely frequencies to 'sing' (howl) and pre-assigns them to the notch filter.

Here is a string by string (1st string-treble) at top going down to the bass. Even though it's not listed, if you are in dropped D, the low D would be around 73Hz (cycles per second).


I have a simpler chart somewhere which lists only the open strings, and if I can find it, I'll post it. They are usually the culprits anyway.

EDIT Found it… EDIT


Added both of these to my 'favorites' in my phone photos just now…

Hope this helps the discussion…




__________________


Baby #01
Baby #02
Baby #03
Baby #04
Baby #05

Larry's songs...

…Just because you've argued someone into silence doesn't mean you have convinced them…

Last edited by ljguitar; 07-26-2021 at 04:05 PM. Reason: found the simpler chart
Reply With Quote
  #21  
Old 07-26-2021, 09:07 PM
shufflebeat shufflebeat is offline
Registered User
 
Join Date: May 2016
Posts: 820
Default

Quote:
Originally Posted by Odedi View Post
Hey, what do you suggest regarding the pickup?
First the soundholes.

The soundhole plug prevents a strong bass resonance building up in the structure of the body. It's similar to the difference between ported speakers/monitors which use escaping (and returning) air to simulate a much bigger cabinet (most cheap monitors) and "infinite baffle" (sealed boxes) which are either small and lacking bass or full range and huge (ye olde Yamaha ns10/Kef 103.2).

In some respects it doesn't matter where the air is flowing in and out of, the plug is not doing it's job as designed. Now, you may be lucky and hit on the perfect balance of killing your problem resonance without sealing the box but I think that's unlikely.

If you seal the small port you will lose some *acoustic* bass but if you don't you'll have to filter it out electronically anyway to avoid feedback so swings/roundabouts. I suspect if you can kill the acoustic resonance you can ramp up the amplified bass to more than compensate...

...except ...for the mic.

I don't know the Presys Blend. Does the EQ work on UST, mic or both after they've been blended? I've seen various combinations over the years.

It would be useful to know if there is one element of the system (UST vs mic) which is responsible for the booming. If it were me I would cover the port with something of significant mass, kill the mic for the time being and see how hard you can push the volume without losing it. It may not sound pretty but knowing the result of this will inform the next step.
__________________
Give a man a fishing rod... and he's got the makings of a rudimentary banjo.

Last edited by shufflebeat; 07-26-2021 at 09:17 PM.
Reply With Quote
  #22  
Old 07-26-2021, 10:01 PM
calvanesebob's Avatar
calvanesebob calvanesebob is offline
OldDude
 
Join Date: Feb 2021
Posts: 176
Default

Quote:
Originally Posted by Odedi View Post
Can you tell me more?
What needs to be checked there?
I'm no expert but maybe if the saddle is not sitting perfectly flat in the bridge, it my have more/less pressure under certain strings making them louder. Same with the nut.

just seems odd that it is louder on certain notes unplugged too.
__________________
Bob

2021 Martin D-28 Standard
Reply With Quote
  #23  
Old 07-27-2021, 04:55 PM
Br1ck Br1ck is offline
Registered User
 
Join Date: Sep 2014
Location: San Jose, Ca
Posts: 4,280
Default

Run into this sort of thing at an open mic I help with. Our mixer has a built in compressor. Dialing in some compression usually smooths the hot spike. This is the quick and dirty on the fly solution.
__________________
2007 Martin D 35 Custom
1970 Guild D 35
1965 Epiphone Texan
2014 Martin 00 15 12 fret custom
Pono OP 30 D parlor
Pono OP12-30
Pono MT uke
Goldtone Paul Beard squareneck resophonic
Fluke tenor ukulele
Boatload of home rolled telecasters

"Shut up and play your guitar" Frank Zappa
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Acoustic Amplification

Thread Tools





All times are GMT -6. The time now is 07:53 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Copyright ©2000 - 2021, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=