I had asked because my acoustic would just roar with feedback if I was directly in front of the amp. It scared the crap out of me the first time it happened. I was curious whether that would happen with a hollow body.
This is what I’ve done or just turning my back to it.
@John_E I’ll be very interested in your take on that book. Some of the “Dummies” books are quite good, but many are total failures. I hope this book you just got is among the good ones.
The way to eliminate feedback is to reduce the level of the ringing frequency being picked up by a mic or pickup. Rotating your body or your cabinet is both lowering the overall direct sound level and changing the color of your tone a bit. It will reduce the higher frequencies more than the lower ones and the lowest ones won’t be reduced at all.
It’s also possible to reduce feedback by not rotating the cabinet or yourself, but rather turning down the master level on the amp or by standing farther away until it doesn’t ring.
It’s also possible just to turn down the frequency that’s ringing. You could put a frequency analyzer as a DAW plugin and watch which frequency number goes through the roof. You could then use an EQ knob someplace in your rig if you have one that can address the needed frequency without taking too much out of the tone you want. I’m guessing it’s one of the higher frequencies you may not care about losing if rotating your body works.
If a bunch of frequencies are all ringing at the same time, it’s master level job.
My friend’s biggest complaint about his hollow body is often it is difficult to use live because of the feedback.
I generally keep the Master level pretty low anyway, which does eliminate the feedback. However, as I stated in my original post, it’s an issue of recording.
In another thread I had asked about how to best set the levels for recording, and one of the bits of advice I got was to increase the master volume on the amp. This is the main cause of the feedback.
Would it help if I covered the front of the amp with a heavy blanket or something when recording?
Why does the volume on your amp matter for recording? That would be the input gain on your DAI more than anything.
I never thought it did either until I posted my question about setting levels for recording, and got that answer from someone. I think it was in the Reaper Questions thread.
What you should shoot for is avoiding clipping in your DAI, but you can turn the input gain up pretty high if you want.
Recording into the DAW, any level over -18dB or so is fine, then you can normalize it in the DAW up to -4dB. I learned recently that -12dB or so is the sweet signal to noise ratio spot for most consumer DAIs.
It is good to have a strong signal going in to the DAI from the recording source but you’re running a line level DI out into the thing so that shouldn’t be an issue.
You can also check your DI out, good ones have a separate output level knob by the DI. Probably won’t on an amp but who knows?
Pam, some of these may help (I know you have tried some, but perhaps a combo of some of them will work in your setup).
Thanks, I already read that article and none of them applied or helped.
yes. maybe just turn a bit and avoid having the holes of the bass body facing the speaker.
Sorry, I haven’t read the whole thread, and I am not as knowledgable as the others when it comes to these things, but AFAIK you should be able to EQ the feedback away…
Here is what the feature set of the amp that I really want includes:
Variable Feedback filter: Adjustable from off to -6dB to -12dB in 1 dB increments. Frequency >>range from E1 (41Hz) to G3 (196Hz) in half step increments
I don’t know if this could be done with software filters/EQ’ing as well!?
As a quick demo (sort of): here is Dave Swift with a fully acoustic bass (the “demo” is really in the first ten seconds… from feedback to no feedback using that variable feedback filter)
I looked at the manual for the Rumble and yes the master level knob does indeed change the DI output level. This is different than what I have on my amp head where the DI is picked off the signal chain before the master level knob.
Any solution that works. If moving away from the amp or turning your body or turning the cabinet is stopping your feedback problems, then good and good.
If for some reason you still do need to turn your master gain down, it may not be a problem for recording. If you turn it down and then turn up the input on your DAI to compensate does your recording get noisy? If not, there’s really no practical issue. It’s good practice to record a nice strong signal, but if it’s your only option given your situation you can make exceptions if they aren’t causing a different problem.
Oh wow really? I was also looking into the 500 manual and the only thing I could find was this: “The level and tone of the LINE OUT signal are affected by all preamp controls, including GAIN.” Does this include the MASTER volume as well? I would think that the GAIN is used for the output volume of the line out and the master for your stage volume.
I read somewhere on TalkBass that it’s pretty rare to have an amp’s master volume impacting the volume of your DI. Apparently there are rare amps (like some of the Mesa’s) who have that design.
If this is actually the case I think an alternative fix is using a DI box? And if you want the rumble preamp in your signal then you could place the DI box in the fx loop?
it’s kinda strange not to have a dedicated level pot for the DI. it seems so obvious to me.
Apparently you are right @DaveT. I was looking at the schematics of the 500 and the 800 (which I own) to see the differences.
Rumble 500:
Rumble 800:
yeah, this difference is very strange actually. a master should not be placed before the tone shaping / EQ, that’s really weird.
/Pam watches as this topic sails way over her head
Yeah. Basically all the good ones do. Even my Battalion did. Weird that the amp doesn’t. Maybe few amps do? No idea.
indeed
I hear ya! It’s basically for the purpose of monitoring. If you are recording from your amps DI the volume of the recording should be controlled by the gain knob while the volume of the sound coming from the speaker/cab adjusted By the master volume knob. In most cases adjusting the master volume knob will NOT affect the recording signal, just the volume you hear from the speaker.
