Re: [Harp-L] Which harp mic is most feedback resistant?

[Rick Davis <bluesharpamps@xxxxxxxxx>]

On Sun, Oct 11, 2009 at 1:33 PM, Greg Heumann <greg@xxxxxxxxxxx> wrote:



> Man there's a lot of B.S. floating around on this subject. Some truths too,
> but a lot of misinformation.
>
> Greg, you've provided a bit of B.S on this subject.  You said that
microphone gain is the top "priority" for feedback, and you later said that
amp gain is "the biggest variable by far."

Not really.  If the gain of a specific frequency in the loop (harp mic to
amp to speaker and back to harp mic) is equal to 1 then feedback will
occur.  It matters not a whit if the gain occurred at the mic or at the
amp.  The gain may come from mic, amp, speaker resonance, room resonance, or
just the gremlins that hide out in the music.  One component of the loop may
produce zero (or negative) gain, while others bump it up.  If the closed
loop achieves a total gain of 1 at a specific frequency you will get
feedback at that frequency, no matter what amp you have or how many speakers
it uses.

When I asked the question, "What harp mic is most feedback resistant," I was
looking for anecdotal reports of the characteristics of each mic
configuration with respect to feedback.  I got lots of fascinating replies,
none of which I considered to be B.S.

-Rick Davis
The Blues Harp Amps Blog
www.bluesharpamps.blogspot.com