I bought an dynamic element from harpmicshop.com, and installed into my mic shell. The tone is good (very vintage, but it seems like a new element), but I have an issue.
When I cup the mic, It start to feedback, when I loose the cup, is OK. This is a big problem for me because I use a very tight cup, and every time that I cup, I hear the feedback coming.
I can get more volume whit my Akai DM13 before feedback standing closer to the amp because of the shorter cable (and the akai has more output than the dynamic element)
The amp is a Pro Junior III, jensen C10q, V1-12AX7 V2-12AT7
So, my question:
Some mics have a natural tendency to feedback when cuped? if so, they are useless for harp?
When talking about feedback from a mic plugged into an amp, it's important to specify the type of feedback, because there are two very different types: high frequency and low frequency. My own mic/amp combos almost never feedback; when they do, it's low frequency feedback. I've deliberately induced such feedback, in fact, as a way of making sure that the pair of amps I play through are in phase. I'll turn one amp up all the way with the other on zero, then turn up the second amp while keeping the mic fairly close to the area directly in front of both amps. If they're in phase, a low frequency sound will boil up--thanks to both amps reinforcing the bottom end coming from the other amp. If the opposite happens, I know that the amps are out of phase and are nullifying each others bass.
My subjective impression, though, and my experience with bad amps and bad mics (and bad amp/mic combos) in days gone by, is that the great majority of complaints are about high frequency feedback or "squeal." I'm not sure why, but it's easy to produce this with, for example, Green Bullet mics and amps that have master volumes that let you turn up the preamp.
I have no technical vocabulary to talk about this stuff, so I'll leave it to those who do to do so.
Remember, feedback can't be caused by the mic alone. It is interaction between the amp and the mic. Perhaps your other mic is less sensitive, or perhaps this one is hyper-sensitive. Cupping can be just like a satellite dish and "focus" sound onto the mic; it can also create a resonant chamber at just the "wrong" frequency - one that the new mic is sensitive to and the old one isn't. You CAN adjust this out with an EQ pedal - but it won't be a panacea - feedback will simply find the next most resonant frequency to grab onto.
If you aren't setting the volume on your amp specifically for this mic - then the comparison is flawed. You can't assume that both mics have the same output level - therefore you shouldn't expect the same performance at the same amp volume setting. If the new mic is simply a little hotter, and the amp was near the feedback threshold where you normally set it with the other mic - then feedback would be expected.
And with all that said - some mics are just nasty. It usually is NOT all mics of the same brand and model. I've had a few Green Bullets that were awful while most were "normal".
+1 Greg. That's especially pertinent to consider the mic sensitivity, not just the position of the amp volume knob. Is it actually louder with the akai, or can you just turn the volume higher? And what type of shell? 3-4 on the volume doesn't seem too bad to me, for this amp with a 12ax7 pre, but you might find greater control with a less gainy tube.
This is the element: http://www.harpmicshop.com/servlet/Detail?no=80
This is the shell: https://dl.dropboxusercontent.com/u/59246420/IMG_1423.JPG
This element is not as hot as the Akai. Whit the Akai y put the Volume on 2 and te walls shake!! Whit the element in question, I can get the volume on 2 1/2 whitout feedback, and in 3-4 whit cup-feedback (no feedback whit the element is in free air) but is not as loud as whit the akai on 2 (no wall shaking).
The problem (for me) is the feedback start when I move the mic closer to my mouth, so I cant play whit a mic like that.
On wensday I have a Gig (yes, I am in a band!) and I am going to test the mic live, maybe it work, and maybe not.
Some mics definitely seem more prone to feedback. I find CM's the most feedback resistant (they were designed to be used in noisy environments). I've got a fair collection of vintage mics, some of them have awesome tone and volume and sound fantastic in my woodshed, but are useless when I play with our (loud) band due to feedback issues. ---------- Lucky Lester
Mics and feedback are a very elusive subject. Mics respond differently to their environment. The room acoustics have a great influence on feedback. My 664 responds as the OP's does. I simply reposition myself with regard to the amp. Another thing that harp players are notorious for is , standing in front of their own amp. We are not guitar players holding a 6 lb. hunk of wood. Our old mics pick up everything. I find that having my amp off to the side or in front of me, at my feet, will increase the volume before FB level.
There is the possibility that the element in question is a clunker. It may work great in a different rig also. So many variables. Good luck...BN
rogonzab, I think that Universal shell you have is one of the coolest looking bullets out there. A little to much meat on the bottom for an ideal cup but still a great shell. I hope you find the perfect element for it. I'm pretty sure that some have installed CMs in those but I think it requires some machining (or dremel grinding) to get there.
@rogonzab There a few things you can do. First the Akia mic of yours is not an omni directional mic like the green bullet so it will be less likely to feed back. That's one of the things I like about it! When using your bullet mic try standing 4 or 5 infront and about 2 or 3 feet to the side. That should help. Also you could put a lower gain tube in the first socket. That might help?
I open up my mic and put another piece of fabric betwen the inside grill and the outside grill/shell (I use those tissues that came whit glases) that mod did help whit the feedback, is not the solution but now is a little better.
In my next gig I am going to try the mic in a big space, and I am going to use a 20ft cable and stand far from the amp.
