Mic'ed Amp woes!

[Alexbt]

Hi all,

I had posted some of this in my topic in the Mic forum, but I'm hoping that I may be able to get more help here as well, if some don't frequent in there.

I just got back from a session on some modern rock for a play production.

Mics I have to work with:
2 x MXL 990
2 x MXL 991
1 x Shure Beta 58
1 x Audio Technica DR-VX1 (Dynamic, like SM58)
1 x Fender (Dynamic, cheap, not sure of model)

[It had been suggested to take the pop screen/windscreens off the dynamics when micing cabs.]

For acoustic guitar, we used a MXL 990 and a DI line. This worked out well.
When it came time to use the electric, we had some problems.
Basically, it was just some light distortion from the amp that we were trying to capture.
The volume on the amp was set very low, and even so, we had some big problems.

I set up the Beta 58 in the center of the amp, pointed at the cone. At first we noticed that the Beta was picking up a lot of air, but this is what comes from the amp itself. When actually playing, it sounded as though it were clipping, which was not on the preamp side. I had it plugged into Line 1 (XLR) on my Delta. The signal was not anywhere near the red. (Peaking in yellow) Basically it is more distorted than what the amp is putting out.

It sounded like the mic was being overloaded from 4 inches to a foot away from the amp, always the same, just less clear. The further away, the more room noise we would get, anyways. (By room noise, I mean physical movement, the guitar being picked, etc.)

I tried with my AT mic--similar situation.

Instead of the Delta in, I tried going through the mixer's preamp. The results were a bit more favorable, but not good enough. These pres are also a tad noisy, which only adds to the air from the amp.

For the hell of it, I put a MXL 991 on it. These results were the most favorable, after adjusting the amp and turning way down (the 991 is VERY hot compared to both dynamics).

Is there anything I'm doing that sounds majorly wrong, or is it something in the signal chain that could be the problem?

When we did a different project 2 years ago, the same Beta was used, but into a Tascam US-122. I did not engineer most of the project, though I was present at the sessions for piano. I can't imagine how it was done much differently...

BTW, I have no reason to believe the amp is at fault. I was able to stick my right ear about 2-3 inches from the amp and it sounded fine... to my left was the mic, which was probably around a foot away getting more distortion.

Any suggestions are much appreciatied. We're going to do a second session tomorrow evening. I don't think I can dig up any other mics by then, so we've gotta work with what we've got.

 

[scrubs]

There is no magic fix. Lots of trial and error until you find the right spot for the mic are in order. I would start with the AT dynamic (or go to a music store that rents live equipment and rent an SM57 or MD421 for the session). Put the mic very close to the speaker (say 1-2 inches from the cone) and angle it so it is parallel with the inside of the cone. Placing it near the center of the speaker will tend to give you more high end (which can be harsh). Moving it out toward the edge wil give you a mellower tone. Wear headphones while placing the mic, so you can hear exactly what the mic is hearing. Have the guitarist play something while you move the mic around to find the "sweet spot."

You can also add one of the MXL condensers a foot or two out in the room (or even behind the amp, if it has an open back -- you may need to reverse the phase of this mic if you do that).

In general, less distortion is needed for recording, compared to what would be used in a live situation. Also, start with all the EQ knobs in the middle (not scooped mids -- which will give you a fizzy sound with no meat) and tweak.

 

[Scottgman]

Sounds like a gain staging problem. If you can't hear the distortion when your ear is next to the amp, then the problem is coming from the recording signal chain. What Delta do you have? Does it have a button for -10/+4 operation? If so, try switching that into the other position.

Also, what kind of mixer are you using? Depending on the mixer, you might be able to tap a channel on the mixer (bypassing the main circuits) and get more control over the input gain (and better sound).

 

[Alexbt]

I have the Delta 1010LT, and yes it does have -10/+4 operation.
Channel 1/2 had been set to +4 and Channel 3/4 had been set to -10.
I'll make sure to check these tonight. I realized later that this is one thing I hadn't tried.

The mixer I was using was a SoundTech ST-122 (I think--it's sitting there). I was using the Insert jack as an output, as I get less overall noise than through the board's other outputs. The only controls I get are the gain knob and 20db Pad button.


Scrubs--perhaps I did not understand correctly where to place the mic.
When you say the cone of the speaker, you are talking about the very center, correct?
Is the inside of the cone just to any side of the cone, being slightly offcenter?

In any case, I don't know if we kept or even tracked any of the electric guitar problems. I'll look through and see what we got.

 

[scrubs]

Scrubs--perhaps I did not understand correctly where to place the mic.
When you say the cone of the speaker, you are talking about the very center, correct?
Is the inside of the cone just to any side of the cone, being slightly offcenter?

No, I actually meant the wall of the cone. If you aim right at the center of the speaker, you will generally get a harsh, treble-heavy sound. As you move out toward the edge of the speaker, the sound gets mellower and more bass-heavy. Try to find a happy medium for your particular speaker by starting at the center and moving out toward the edge until it sounds good.

Here's a terrible illustration.

 

[Farview]

It does sound like a gain staging problem. On the delta control panel, do you have the input levels all the way up? If you have these turned down, you will turn up the preamp to get the right signal level, clipping the preamp/converters in the process.
I have miked screamingly loud guitar rigs with a beta 58 and never distorted one.

 

[Alexbt]

I do have the faders all the way up in the CP, but I had the VSL set to +4 on the XLR in.

-10 when coming from the preamp. I'll experiment with different signal level settings and mic placement.

I'll also take a DI line from the amp to compare with. Expect samples tonight!

PS., Thanks for the illustration, scrubs, as crude as it is, very helpful, thanks.

 

[Dogman]

I don't know if this will help at all, but here is my part of a collab....one guitar, dry, one bass, same and drums. It is mic'd with a Shure SM 58, into an M-Audio Buddy, into a Delta 44. The mic was placed about how scrubs described...slightly off center of the cone, pointed directly at the speaker grill. No eq, or anything....

Same with the bass....
Ed

 

[amt7565]

Hate to digress-
But I was wondering from everyone here who has experience mic'n:

If you have a Mesa Solo-50-Watt rectifier, what is the minimum setting you would need in order to get a good signal through the Mic? I live in an apartment, so I like to know if this is feasible.
Consider channel-2 (distortion). Gain all the way up.
master=?
Volume=?

Thanks in advance.

 

[Alexbt]

Today's session went very well. The problem seemed to be more with the Delta's gain or 'preamps' because the Beta worked fine going through the mixer with the gain reduced.

Thanks for the help, all.