The best way to record a guitar amplifier

Factual Questions
1

Hey guys… my band is in the process of recording our EP, which has proven to be a lot more tedious and tiresome than the fun and carefree image we’d all had in mind beforehand. Things take forever, there’s a lot of stuff to deal with… but that’s not the point of this post.

When recording my amp (a 250watt Marshall 2x12), the clean sounds I get from it sound fantastic when we play them back on Pro Tools. But attempting to mic an overdriven/distorted sound (the bulk of our guitar sound) has proven nearly impossible. It ends up sounding thin like a practice amp! The sound played back through the studio’s monitors sounds like there’s a blanket over the speakers… it doesn’t “push any air”, so to speak.

We’ve tried direct input AND miking the cabinet, and got disgustingly similar results. We tried double tracking the rhythm, which just made it sound even more harsh.

So, if any of you can help me get a decent overdriven guitar sound to Pro Tools, it would be greatly appreciated… how the hell can I get a fat distorted sound? Especially since I can get awesome clean sounds down? Help please!

2

I’m no expert, but why use such a powerful amp for recording? This might be your problem.

3

I might be way off base here, but the following worked for me. I was doing a project for work and the sound from the raw video was way too low and I couldn’t re-shoot the video. I fed the sound through my stereo receiver and ran a patch cord from the headphone jack to the dubbing VCR. I was able to increase the volume to a usable level without it sounding too crappy.

Does your amp have a headphone jack? If so, you might try this. Start out at a low level and increase until you get the level you want.

4

I don’t understand why you can’t pull the same sound using line input. How are you sourcing this? The amp may be causing clipping because a 250 watt stack, while sounding great live, is producing lots of volume to be loud enough to get good distortion. Compression can overcome this as well as adding back some of the attack you are losing.

You could be fluking some phasing problem with the mic - a reflective surface behind the mic could be reflecting the sound slightly out of phase. This can be overcome by placing any kind of baffle behind the mic, even towels draped over a chair.

5

Is the EP called Opiate by any chance?

Regarding your question, all I can suggest is putting up baffles around the amp/mic. That’ll create a dead space and all you’ll be getting is the output of the amp, not reflections from the room.

And good luck with the EP. It may be a pain in the ass now, but when you’re done it’s a wonderful thing. Just slightly less of a rush than actually standing on stage playing for a crowd.

6

Tried this, actually… it made the thin, nasty sound get louder. It was like amplified deadness :wink:

don’t ask - This sounds feasible. I’m writing this down and will try tomorrow morning when we start recording again. The amp sound was definitely clipping on the Pro Tools EQ when I tried to get it loud enough to push air. Thanks for the suggestions.

Eegba - :smiley: I think you’re the first person to understand the username reference! Regarding your suggestion, I was under the impression somehow that the reverb from the room, etc, might fill out the sound a bit. But I’ll try deadening it as well.

Thanks also for the words of encouragement… the recording is just a way to get us more opportunities to play onstage for a crowd… we’re just now starting to headline shows and it feels good that the work pays off, especially since we are trying to marry pop-rock and prog. We kinda sound like the bastard child of AC/DC and Rush :wink:

7

How loud are you playing your amp when you’re recording? It may be that the recording situation is forcing you to have the amp operating at a lower level than normal, in which case you need a smaller amp that you can drive hard at reasonable volumes.

8

From recording websites I have read, here are some suggestions:
Use 2 mics, one close up on the speaker cone and one further away. Have someone move them around until you get a great sound comming fom your monitors. Make sure they are mics made for the purpose of recording amps.
Double track rythm guitars (with different eqs) and pan them left and right. Fool with the eq of each track until it sounds good.
If you ask your question on a recording website, you will get better answers.
I doubt you will ever get the “moving air” feeling of being in a room with an amp, you have to think differently --spectral balance of the song. Here are some general guitar and other eq hints I have collected (it may prove different for your individual song):

"Rolloff at 80 hz., cut at 800 hz. to remove “cheap” sound, and edge
is around 2.5 k. "

"I was looking at the spectrum for a Steve Vai tune (I am into guitar instrumental style) and noticed a dip at 1000Hz. So I applied about -4dB cut at 1000Hz to my entire mix and it sounds so much better. The annoying nasal quality has gone away largely. "

             "50HZ
                    1. Increase to add more fullness to lowest frequency
                    instruments like foot, floor tom, and the bass.
                    2. Reduce to decrease the "boom" of the bass and will
                    increase overtones and the recognition of bass line in      
                    the mix. This is most often used on loud bass lines like      
                    rock.
         100Hz
                    1. Increase to add a harder bass sound to lowest                                                
                    frequency  instruments.
                    2. Increase to add fullness to guitars, snare.
                    3. Increase to add warmth to piano and horns.
                    4. Reduce to remove boom on guitars & increase clarity.

         200Hz
                    1. Increase to add fullness to vocals.
                    2. Increase to add fullness to snare and guitar ( harder       
                    sound ).
                    3. Reduce to decrease muddiness of vocals or                   
                     mid-range instruments.
                    4. Reduce to decrease gong sound of cymbals.

         400Hz
                    1. Increase to add clarity to bass lines especially when
                    speakers are at low volume.
                    2. Reduce to decrease "cardboard" sound of lower 
                    drums (foot and toms).
                    3. Reduce to decrease ambiance on cymbals.

         800Hz
                    1. Increase for clarity and "punch" of bass.
                    2. Reduce to remove "cheap" sound of guitars.

         1.5KHz
                    1. Increase for "clarity" and "pluck" of bass.
                    2. Reduce to remove dullness of guitars.

         3KHz
                    1. Increase for more "pluck" of bass.
                    2. Increase for more attack of electric / acoustic guitar.
                    3. Increase for more attack on low piano parts.
                    4. Increase for more clarity / hardness on voice.
                    5. Reduce to increase breathy, soft sound on 
                    background vocals.
                    6. Reduce to disguise out-of-tune vocals / guitars.

         5KHz
                    1. Increase for vocal presence.
                    2. Increase low frequency drum attack ( foot / toms).
                    3. Increase for more "finger sound" on bass.
                    4. Increase attack of piano, acoustic guitar and 
                    brightness on guitars (especially rock guitars).
                    5. Reduce to make background parts more distant.
                    6. Reduce to soften "thin" guitar.

         7KHz
                    1. Increase to add attack on low frequency drums ( more
                    metallic sound ).
                    2. Increase to add attack to percussion instruments.
                    3. Increase on dull singer.
                    4. Increase for more "finger sound" on acoustic bass.
                    5. Reduce to decrease "s" sound on singers.
                    6. Increase to add sharpness to synthesizers, rock 
                    guitars, acoustic guitar and piano.

          10KHz
                    1. Increase to brighten vocals.
                    2. Increase for "light brightness" in acoustic guitar and
                    piano.
                    3. Increase for hardness on cymbals.
                    4. Reduce to decrease "s" sound on singers.

         15KHz
                    1. Increase to brighten vocals (breath sound).
                    2. Increase to brighten cymbals, string instruments and
                     flutes.
                    3. Increase to make sampled synthesizer sound more                  
                     real"

“With guitars, watch those boost that are below around 250Hz. Anything below that is not worth boosting on a guitar
The lower-frequency sounds (250 Hz and
below) are the Bass Frequencies”

“The human chest resonates around 80hz.”

“Take out a bit at around 300hz on guitar tracks to cut the mud - not too much though or it will start to sound thin!”

Goodluck!

9

I’m not an expert, but I’ve run across a couple ideas magazines.

A Shure SM57 mic is the standard for recording guitar amps.

I don’t think you’re supposed to point the mic directly at the center of the speaker cone. It supposedly makes the sound “brittle.” Experiment with pointing the mic sideways and with moving the mic off to the edge of the speaker cone.

I agree with the EQ recommendations, especially cutting in the range between about 600 - 1200 HZ. Maybe you could experiment with some natural EQ. Can you stick the amp and mic in a tiled bathroom, close the door, and crank it up?

If you don’t get enough help here, try asking on the forums at http://www.harmonycentral.com.

10

Hmmmm… seeing as how you’re trying to get a cool axe sound, I went into one of our isolation booths today and set up one of my VOX AC30’s with a Neumann U87 mic.

The little 1:15 second mp3 I’ve included for you here is a guitar only example of a totally neutral (non eq’d) classic British Crunch guitar sound.

I used a Gibson Cherry Red 1968 ES335 through a 1971 VOX AC30 to record this little demo bit for you. I chose the ES335 and the VOX combination because it’s Dave Grohl’s signature sound and that makes it easier for you to get a reference point. No pedals. No stomp boxes. Just the VOX set at 7 out of 10 and the Gibson was on the treble selector position.

I placed the Neumann U87 precisely 12 inches in front of the amp. The mic height was in line with the speaker cones, and the mic was placed directly in between the 12" speakers. If I was dealing with a 4 x 12" cabinet, I’d probably do the same thing with the bottom row of speakers as well.

The Neumann U87 was set to it’s -10db position because, well, the VOX was on the verge of feedback and it was very, VERY loud.

I applied a 75Hz low cut on the SSL mixing desk, and the signal went straight into one of our Pro Tools HD3 systems.

This mp3 has been encoded at 192 kbps to give you a pretty good sense of quality but it also means it’s 950kb in size sorry.

But it’s pretty easy to get a good gnarly sound through Pro Tools - it’s really in the mic placement in my opinion. Aim for the edges of your speaker cones. You can’t go wrong with a Shure SM57, but I used the Neumann U87 in this instance because, well, they’re the best. Also, if you can, it’s probably best if you can isolate your guitar amp in an isolation booth and actually play your guitar from the control room. If you do it this way, you get to hear your axe through the control room monitors - and it’s a very honest way to ensure your recorded sound is just what you’re looking for.

You’ll note in this mp3 that the guitar sound has HEAPS of big rich bottom end. A lot of it has to do with your playing style actually. Which is why I include a number of quick little styles just to give you a quick run through.
VOX AC30 Demo Recording with Neumann U87 mic