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Other Stuff => Other Topics => Topic started by: Bassmanster on August 20, 2009, 10:31:29 am

Title: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on August 20, 2009, 10:31:29 am
Having tried an SM57 and a LD condenser, this is the mic I have settled on.  It sounds the best for slight breakup sounds.  I use an attenuator to keep the amp level down.  I just put it right in front of the speaker a few inches back (to reduce proximity effect).

I've never seen anyone recommend this.  Am I crazy?  (Don't answer that).
Title: Re: Small diaphragm condenser on guitar amp?
Post by: tubesornothing on August 20, 2009, 11:57:47 am
Fascinating - I will have to give it a try.  Are you using this for recording or live work?  What type of amp and attenuator?
Title: Re: Small diaphragm condenser on guitar amp?
Post by: tubesornothing on August 20, 2009, 11:58:19 am
Oh, and most importantly is your Avatar from the original Star Trek series?
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on August 20, 2009, 12:20:32 pm
Recording, MASS, homebrew 10W single-ended, Tele, 1x10.

Yes, I am a Gorn.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: G._Hoffman on August 22, 2009, 12:33:39 am
Sure, go for it.  And you aren't going to hurt a condenser mic by opening up a 10W amp.  Or, for that matter, a 100W amp.  They aren't nearly as delicate as some people think.  You have to be a little careful with a ribbon mic, and if you're dealing with a vintage tube mic you might want to be a little careful, but you don't really have to worry about most condensers until you start dealing with drums, where the transients cause a lot more problems than anything that ever comes out of a guitar amp.  And it is important to crank it, because until you start to get the speaker to break up and get the cabinet really moving, you will never really get a great recording.

If you really want to explore recording guitars, you should check out THIS (http://badmuckingfastard.com/sound/slipperman.html).  It was a thread on a board that kind of disappeared when a bunch of us left, but it was saved for posterity by a bunch of folks all over the internet.  Slippy frames the discussion in terms of Nu Metal guitar sounds, because that is what the OP asked about, but really the concepts are the same no matter what kind of guitar sound you are after.  You have to move some air if you want things to sound great.


Gabriel
Title: Re: Small diaphragm condenser on guitar amp?
Post by: P Batty on August 23, 2009, 07:43:09 pm
 FWIW I always had the best sounding results using small diaphragm condensers when recording guitar amps live - even using Rat Shack Electrets on one gig, but for the tape feed only, not for house PA. In the studio, whatever works- Check out the link from Hoffman to get a grasp of what recording for multi-track can entail. Slippy is some kind of Zen poet when it comes to audio engineering. Great stuff, what you won't get in books...
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on August 24, 2009, 08:33:14 am
LOL.  That is awesome stuff, thanks Gabriel.

When I get around to it I'll post clips of SM57, SD, and LD on my amp (if they sound different at all).
Title: Re: Small diaphragm condenser on guitar amp?
Post by: G._Hoffman on August 24, 2009, 02:32:42 pm
LOL.  That is awesome stuff, thanks Gabriel.

When I get around to it I'll post clips of SM57, SD, and LD on my amp (if they sound different at all).


Just remember, if you want it to sound good, you NEED to move some air!


Gabriel
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on August 26, 2009, 08:49:08 am
First one attenuated a lot, second one with the attenuator up.
SD condenser taped next to SM57.  Condenser on the R channel.  6 in
off the grille.  You can hear that it's more full range.

http://www.el34world.com/Misc/Music/xspf_player_slim.swf?
song_url=http://www.barrierislandgraphics.com/forumfiles/atten.mp3

http://www.el34world.com/Misc/Music/xspf_player_slim.swf?
song_url=http://www.barrierislandgraphics.com/forumfiles/crank.mp3

Makes me understand why the proximity effect helps the SM but is not
good for condensers.  I.e., if I moved the SM closer it should be fuller, I think.

If flash ain't working:

http://www.barrierislandgraphics.com/forumfiles/atten.mp3 (http://www.barrierislandgraphics.com/forumfiles/atten.mp3)
http://www.barrierislandgraphics.com/forumfiles/crank.mp3 (http://www.barrierislandgraphics.com/forumfiles/crank.mp3)

Both sounds are usable for my stuff (add reverb and drop into a mix).
They may not be Record Factory good, but I like these sounds.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on October 02, 2009, 10:03:52 am
Well with lots more tests over time, I've decided close-miking on moderate overdrive sounds is for the birds.  Even Shure's manual recommends 6 - 12 inches for a full balanced sound on a cab with an SM.  I tried 12 dead center and it sounds much better.  That is, if you want your track to sound somewhat like the amp.

Adding more mics should be all gravy.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: PRR on October 02, 2009, 06:13:36 pm
FWIW: some of these differences are not about the mike's electric principle, or really about size.

A small omni can be "flat" at any distance.

The basic Directional (cardioid or fig-8) principle is elegant and valid for "distant" sources, but gives bass-rise on "small near" sources.

You can just enjoy it.

The mike designer may optimize midrange, let the far-bass fall-off, so that bass-rise on near sources is not excessive, and distance becomes a useful balancing tool. This works well on Dynamics.

The designer can tune for "flat", and give you bass-cut switches for close-in work. A condenser naturally wants to be flat, so this is what you usually get.

E-V had the "Variable-D" principle, with a more complicated back-path, which gives much less bass-boost on close sounds. Good when you don't want the "Sinatra balls" come and go as the talker sways back and forth. (However many professional talkers, such as O'Bama, learn to use an SM's bass effects to emphasize their speech.)

And any of these effects can be done/un-done with a flexible bass control on the recording system.

> close-miking on moderate overdrive sounds is for the birds.  Even Shure's manual recommends 6 - 12 inches for a full balanced sound on a cab with an SM.

Cones have significant proximity effect too. If you get the mike less than an inch from the cone, you get a very-near-field sound that you never get in the room. From there out to about half-diameter (say 6" on a 12" cone) there is a near-field sound which varies from place to place, still "not normal". Out beyond about 4 feet you get Room-Sound, the basic balance heard when you play.

Close-miking is over-used. If you do not have other sources in the room, and your source is loud, you really should try 3 feet and 8 feet out. True, if you have other amps or a drummer, you "need" to be close for isolation.... or actually listen to what is happening in the room and adjust placement for good blend.

> I tried 12 dead center and it sounds much better.

Sure. But you may find that "dead center" has strong focus points, and a small change of mike placement gives a large change of sound. Conventional wisdom is to set 1"-2" OFF-center.... you don't get hot-spots that come and go when the stand gets bumped.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on October 03, 2009, 08:59:51 am
Thanks, Mr. PRR.  I'll keep all that in mind.  That much more informative than the other crap I have read.

I figured close-miking is used for historical reasons.  And maybe it works on raging Marshalls, but all the Fender recordings that I like (Anson Funderburgh, Dick Dale) don't sound like it at all.

It's probably all in the room for those kind of recordings.  Homes have bad rooms (mine are terrible) so everybody wants to avoid room sound.  But I don't think I'm getting much of that at a foot.

 :coffee:
Title: Re: Small diaphragm condenser on guitar amp?
Post by: G._Hoffman on October 04, 2009, 05:16:25 pm
Three points:

On-axis with the speaker is rarely a good idea.  Put the mic at some degree of angle to the front of the cabinet, and point it at the cone rather than the dust cap.

With anything that isn't right up to the mic, room sound is EVERYTHING in getting a good sound.  With close micing, it is only almost everything.  The single best thing you can do to improve your recordings (aside from improving your skill set) is to improve your room.  Far more important than any piece of equipment you can buy.

Finally, if you want your electric guitar to sound good, IT MUST BE LOUD.  Move some air, or go home.


Gabriel
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on October 05, 2009, 01:14:13 pm
I think what I have learned since I started this thread is that mic placement is more important than mic type (or electrical principal, as PRR would say).  Now that I seem to have more knowledge about single mic for cleaner sounds, I can move on to two mics to try to get a fuller picture of the sound.

Second seems to be my touch on guitar.  That really comes through in the recording.  Still working on that.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: G._Hoffman on October 06, 2009, 12:04:05 am
Two mics is fine, but it's pretty tricky to do without causing phase issues.  Keep the 6:1 rule in mind - the distance between the two mics should be six times the distance between the source and the mic closest to the source.

Personally, I always prefer to just use one mic - I think it usually sounds better.


Gabriel
Title: Re: Small diaphragm condenser on guitar amp?
Post by: birt on November 12, 2009, 12:54:58 pm
in a live setup where close micing is used i put the mic on the speaker like i would on a snare. close to the rim, pointed to the dust cap. i haven't tried this in a recording setup yet.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on November 12, 2009, 01:21:32 pm
Thanks.  I've settled on an SM57 four inches from the grille on axis at the center and a LD a few feet back.  I can mix them and pan them to get a bit more space and to fill in the midrange if I need that.

It doesn't sound all that much like the amp to me, but it's passable.  I figure at four inches, 60 degrees of cardiod (just a rough guess) will get all the 10 inch speaker, so I'm getting most of the sound.  Since the sound is in there, I feel justified in using some EQ to clean things up if needed.  Whenever I go back to close miking, even when angling the mic to get a balanced sound (kill the mud), it sounds really artificial to me.  I'm guessing I would prefer a foot or two in a good room, but I don't have one of those...yet.

I'm also learning to not compare a raw track to a track with some EQ and compression.  Those make a world of difference.

Your mileage WILL vary.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: G._Hoffman on November 12, 2009, 02:45:31 pm
Thanks.  I've settled on an SM57 four inches from the grille on axis at the center and a LD a few feet back.  I can mix them and pan them to get a bit more space and to fill in the midrange if I need that.

It doesn't sound all that much like the amp to me, but it's passable.  I figure at four inches, 60 degrees of cardiod (just a rough guess) will get all the 10 inch speaker, so I'm getting most of the sound.  Since the sound is in there, I feel justified in using some EQ to clean things up if needed.  Whenever I go back to close miking, even when angling the mic to get a balanced sound (kill the mud), it sounds really artificial to me.  I'm guessing I would prefer a foot or two in a good room, but I don't have one of those...yet.

I'm also learning to not compare a raw track to a track with some EQ and compression.  Those make a world of difference.

Your mileage WILL vary.


You should always compare between EQ'd and not, to make sure it actually sounds better.  After too much time, your ears will play tricks on you, and you can really mess things up without noticing.  Same with compression. 

Also, I'd move that 57 a little off axis - the beaming from a 10 speaker will really mess with the sound.  If you are used to hearing it from around 6' off the ground, and the mike/amp are down low, the sound will be pretty drastically different.


Gabriel
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on November 15, 2009, 04:40:26 pm
Hold the phone.  I finally tried the front/back mics (phase reverse on one) on an open cab, and that's giving me a LOT more complexity and body.  Hopefully I'll find time to provide some clips within a couple weeks.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: madison on November 17, 2009, 07:15:10 am
Please report back on this subject.
I too am having an obstacle with recording guitars recently.
Seems to be too much cone or too flat.

I have a condenser, which I haven't busted out form recording guitar yet.

But the work horse has been the same SM57 forever.

As of now, placement is back about 18 inches @ around 4 o'clock.
But still not satisfied.
Yes, I can clean it up a bit with compression an EQ but like to stay natural as much as possible without additives.

I am seriously wondering if mic preamps are the key.

You recordings sound wonderful BTW.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on November 17, 2009, 09:11:25 am
Well that Hamptone kit pre I built did help a lot.  I got the idea from tubegeek on here (is that his name?) because he had a killer recording and was using one of those.

But I was still frustrated with getting a clear, big, complex, cleanish lead tone, like a blues guy playing through a turned up Fender would have.  I would hear the amp in the next room, and then through the monitors, and it was much less tone.

Back and front is giving me much more of the tone.  I remembered reading somewhere that that would give a clearer picture of a cab's sound...so I finally tried it.  But I've just started.  I should disclaim that I also suspect that my playing style or tone is not really that "in your face"; that is I can't get as much crazy squawk and squeak and dynamics out of a guitar as some guys, so I might be miking to dig up my own more subtle nuances.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: G._Hoffman on November 18, 2009, 11:36:50 pm

I am seriously wondering if mic preamps are the key.



No, they aren't. 

In rank of importance:

The player
The guitar/amp
The engineer
The room
The mic
everything else.

And all internet crap aside, that is the facts.

Also, if you want to improve the quality of your equipment, be prepared to spend a LOT of money.  A $150 preamp will be no better than the one you have in your sound card, in all likelihood.  An $600 mic pre will probably be better, but not by enough to be worth the effort if you don't have everything else in place. 

The most effective thing you could do (which most people doing home recording never actually do) is to treat your room, which doesn't involve anything from Aurulex.  If you want to spend money on it, go HERE (http://www.realtraps.com/), or if you would rather DIY, go HERE (http://www.ethanwiner.com/acoustics.html), but be prepared to spend a LOT of time learning how to do it, because I'm afraid this stuff isn't simple.


Gabriel
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Frankenamp on November 19, 2009, 12:34:50 am
+1 on Ethan Winer. That's a really good site by someone who knows his stuff.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on December 24, 2009, 03:10:54 pm
Guitar over canned blues backing track.  P-90 melody maker, Vibro Champ into open 2x10 cab.  Fender RI reverb unit.  LD condenser on front, SM57 in back.

http://www.el34world.com/Misc/Music/xspf_player_slim.swf?song_url=http://www.barrierislandgraphics.com/forumfiles/melmakchamp%2Emp3
Title: Re: Small diaphragm condenser on guitar amp?
Post by: terminalgs on December 27, 2009, 01:17:09 pm
if you are recording an amp with two mics, like G._Hoffman mentioned, you will have phase issues.  If you are using digital recording software, look for a plugin that has a 0-180 phase "knob".  alternatively,  you can add delay to one of the two tracks.  a few milliseconds will (sort of) move the mic further away from the speaker and help you get the mic in phase with the other.  let your ears decide when the "delay|phase" knob is tweaked to sound it's best.
Title: Re: Small diaphragm condenser on guitar amp?
Post by: Bassmanster on December 29, 2009, 01:50:17 pm
Well after many listens I've decided I like the recorded tone on that clip I posted.  There is no eq, catsup or mustard on that.  Both mic trax are panned to the same point and at close to the same level.

I can clearly hear the woodiness and snap of the guitar and the protestations of the amp.  I need TONE to cover my other shortcomings.  :)

Amazing how well Champs record.