electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
 Forum index » DIY Hardware and Software » ChucK programming language
Guitar Feedback Enhancement
Post new topic   Reply to topic Moderators: Kassen
Page 1 of 1 [4 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
Inventor
Stream Operator


Joined: Oct 13, 2007
Posts: 6221
Location: near Austin, Tx, USA
Audio files: 267

PostPosted: Wed Aug 06, 2008 4:08 pm    Post subject: Guitar Feedback Enhancement
Subject description: Jimmi Hendrix meets ChucK
Reply with quote  Mark this post and the followings unread

I just played around with feedback using my guitar + amp, and I want to do ChucK-enhanced feedback. I ordered the adapter jacks that I need to establish the hardware loop through ChucK, so I have a few days to code up an effect. It seemed like a good topic for discussion here, so I thought I'd post for your comments as well.

What I found with the feedback was that if I put my amp on heavy distortion and cranked up the volume, feedback would occur. I could take the guitar from 10 feet away with no feedback, push it into the speaker's proximity to get a feedback squeal, then back off and sustain that feedback in a controlled way. I want to enhance this phenomenon.

One enhancement is anti-squeal. It would be great if the output signal were somehow attenuated particularly at the squealing frequencies when it got too large.

Another enhancement is harmonic amplification, using either distortion or some other effect to increase the harmonics.

A final enhancement would be range control, limiting the distance that the feedback was maintained so that the performer could do this without backing a full 10 feet away.

I figure a good algorithm for this will be FFT/IFFT with little routines that detect the RMS and adjust various spectrum amplitudes upper or lower as required. But I have just some general ideas and a lot of time to do this, so I thought I would post for comments before jumping into the coding. Besides, I thought it would be fun to think about. Comments?

_________________
"Let's make noise for peace." - Kijjaz
Back to top
View user's profile Send private message Send e-mail
kijjaz



Joined: Sep 20, 2004
Posts: 765
Location: bangkok, thailand
Audio files: 4

PostPosted: Thu Aug 07, 2008 3:48 am    Post subject: Reply with quote  Mark this post and the followings unread

Hmm.. for limiting feedback on some frequencies,
one easy way I might try to implement first is Multi-band Compressing..
but it's gonna be quite basic, so i guess fft would help create much more sophisticated system for use with guitar & amp feedback.
Back to top
View user's profile Send private message Send e-mail Visit poster's website Yahoo Messenger MSN Messenger
Inventor
Stream Operator


Joined: Oct 13, 2007
Posts: 6221
Location: near Austin, Tx, USA
Audio files: 267

PostPosted: Thu Aug 07, 2008 5:16 am    Post subject: Reply with quote  Mark this post and the followings unread

kijjaz wrote:
Hmm.. for limiting feedback on some frequencies,
one easy way I might try to implement first is Multi-band Compressing..
but it's gonna be quite basic, so i guess fft would help create much more sophisticated system for use with guitar & amp feedback.


Well, I figure the squeal has got to happen when one of the fundamentals or harmonics gets larger than a certain amount, so If the algorithm simply checks the magnitude of each harmonic and shrinks each one to some specified limit, then squeal can be eliminated.

In that case, the squeal event would produce a strong hum result as each of the harmonics filled to the maximum. So you press your guitar into the speaker and you get HUMMMMM, then you withdraw it and the hum persists but decays with distance.

Could be cool, eh?

_________________
"Let's make noise for peace." - Kijjaz
Back to top
View user's profile Send private message Send e-mail
Inventor
Stream Operator


Joined: Oct 13, 2007
Posts: 6221
Location: near Austin, Tx, USA
Audio files: 267

PostPosted: Thu Aug 07, 2008 3:40 pm    Post subject: Reply with quote  Mark this post and the followings unread

the attached mp3 file records a guitar feedback session on my setup. This is normal, non-ChucK enhanced. Notice the squeals mixed in with the pleasant sounds. Basically I want to remove the squeals and enhance the good stuff.


feedback1.mp3
 Description:
Regular Guitar Feedback

Download
 Filename:  feedback1.mp3
 Filesize:  787.35 KB
 Downloaded:  1219 Time(s)


_________________
"Let's make noise for peace." - Kijjaz
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic Moderators: Kassen
Page 1 of 1 [4 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » ChucK programming language
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use