Author Topic: Close miking with condenser mics (Read 11055 times)

Peterku · « **on:** October 30, 2005, 09:52:31 PM »

Some large diaphragm condenser mics have a -10 dB or -15 dB button so that their electronics can handle SPL's of even 145-150 dB's in the 1kHz range. Most dynamic mics, like the SM58, can handle up to 150 dB in the 100Hz range, and 160 dB in the 1kHz range, where the form of the membrane starts to get distorted due to the high SPL.

Is 10-15 dB a large difference? I know by doubling the distance between the mic and the speaker the SPL decreases by 6 dB. So it seems that placing the condenser 4 times further than a dynamic, the condenser will be able to handle as high SPL's as a dynamic would right on the speaker.

Let's say I have a 40W amp cranked running a Celestion Classic Lead speaker with an average sensitivity of 99 dB -- that's the SPL measured with 1 W power across the frequency range, 1 meter far from the speaker. Doubling the power results in +3 dB of SPL. That will give roughly 115 dB of SPL at 1 meter in front of the speaker. To reach the limit (145 dB) with the condenser mic, I can put it roughly 32 times closer (30 dB difference / 6 dB = 5, that means 2^5 = 32 smaller distance) : 32 mm's. With an SM58 it'd be a headroom of approximately 45 dB, so I can get like 2^7=128 times closer, closer than 8 mm's, which is impossible, of course. So having the SM58 32 mm far from the speaker I should have at least 12 dB before distortion even with the 40W amp cranked, which means that I can still safely mic a cranked 120W amp with an SM58, it'd only start distorting with a 460W amp. :twisted:

Could you please review the counting? I'm not familiar with technical issues, I just wanted to count how close I could get to my amp with a studio condenser mic. If the counting's right, I can't get closer than approximately 4 cm's, but that can already be considered close miking. However, I've read in some places that condensers can't be used for close miking.

Ratrod · « **Reply #1 on:** October 30, 2005, 09:56:55 PM »

I think we need Ben in here.

Joe Dorcia · « **Reply #2 on:** October 31, 2005, 01:28:57 AM »

y dont you just place it closer and closer till u get the right sound, or use an SM 57 close miked (better for guitar recording than a 58) and a condensor somewhere in the room and blend the sound to get exactly your tone. It works for me. Try messing with you placement never stick with one till ur completelly happy, it all depends on what you want to capture on the recording.

Peterku · « **Reply #3 on:** October 31, 2005, 09:36:20 AM »

Thanks. Yes, I know that's the classic method: a vocal mic for close miking and a condenser for ambient miking. The problem is that I can't decide what kind of mic to get. I was hoping that by buying a large diaphragm condenser I'll be able to mike my amp and my acoustic with the same mic. I wouldn't mike an acoustic with a dynamic, it just doesn't have the quick transient response of a condenser. I think I'd be fine with just one mic because I have some very nice reverb plugins and stereo imagers on my computer, and I can easily create any kind of nice ambient track to put next to the direct track.

Or maybe I could get a cheaper dynamic for amp miking and a pair of small diaphragm condensers for my acoustic? Large diaphragm condensers are expensive compared to the other two, I might be able to get multiple cheaper mics for the same price.

Skybone · « **Reply #4 on:** October 31, 2005, 11:27:04 AM »

Dependant upon where you are (home/studio/stage/wherever) I'm sure you can use a "pad" input that shouldn't colour the tone you get on tape. Like on amps, you have a high & low gain input, and I'm sure that most modern mixing desk's have a pad switch where you can lower the input from your source (your amp). The pads are usually marked as +4dB & -10dB, but if you use something like an SM57/58, they're pretty robust mics.

I think.

HJM · « **Reply #5 on:** October 31, 2005, 11:32:39 AM »

A U87 needs nearly killing with level before it starts to sound good on guitar, otherwise the old SM57 takes some beating. I've just picked up a Blue Ball mic after hearing about it from Ben, and it's a very good mic for guitar, flater response than a SM57, more like a Sennheiser MD421. For £40 it was a bargain!

I'd go for a dynamic for electric and a pair of small diaphragm condensers for acoustic, they'd be more useful as acoustics almost always sound better recorded with more mics.

Don't get too hung up on SPL.....U87s can survive drum kits...

Peterku · « **Reply #6 on:** October 31, 2005, 02:03:17 PM »

I think I'll rather focus on miking my amp. Later I might get a pair of nice condensers for my acoustic.

I'll buy an Electro-Voice N/D 468. I've noticed Electro-Voice has really good prices here. It costs $160 in Hungary, has a neodymium mag structure thus increased sensitivity, clarity and wider response (I want cleans to really shine), and it has a pivoting head, which is a nice feature IMO. It also has some kind of bass compensation to counteract proximity effect (it's a supercardiodid mic).

Thanks for the responses.

TwilightOdyssey · « **Reply #7 on:** October 31, 2005, 02:39:41 PM »

Okay, from my experience, this is what I've learned ... sorry if this is too basic, Peterku!

I've used dynamic, large and small diaphaphragm condenser, ribbon, and other mics on electric guitar amps. The ribbon is by far the most delicate: too close, and you will destroy it. A really vintage condenser might be the same; I remember PJ clipped a 1940s Telefunken in the studio once from about 3' away -- that girl's got a powerful voice!

Now, in terms of level, 10dB is the equivilent to a 100% increase in perceived volume. In other words, 60dB is perceived as being twice as loud as 50dB. A -10, -15, or -20dB pad on a mic should bring the level down so that the mic is safely operating.

The SM57 is great for hi gain guitars, but I find it lacking for clean stuff, which is what you play.

What I've found to be a great all-around mic is the phantom-powered dynamic mic from Blue; best of both worlds.

An expensive condenser mic (+$500), imo, is a waste if you're going to be recording at home - you simply don't have a room that can do the mic justice. Worse than this is a cheap condenser mic, tho. Cheap condenser mics sound thin and raspy.

Ratrod · « **Reply #8 on:** October 31, 2005, 02:58:32 PM »

I've heard of gitarists blowing up amps, drummers bashing through their skins etc.

This is the first time I heard of a singer blowing up a microphone. Rock n' roll!

(OK, it was clipping but you get the idea)

Peterku · « **Reply #9 on:** October 31, 2005, 04:30:40 PM »

Quote from: TwilightOdyssey

Okay, from my experience, this is what I've learned ... sorry if this is too basic, Peterku!

What I've found to be a great all-around mic is the phantom-powered dynamic mic from Blue; best of both worlds.

Thanks very much, it was very useful to read your post, it wasn't basic at all. I'm quite a beginner with mics.

Brow also recommended me the Ball, and I started searching. So far it seems Sweetw@ter.com's the only place where I might be able to buy it for a reasonable price, I'll have to call them for a quote on shipping first, though. (Music123.com charges an insane $65 for shipping a small mic...)

Thanks for your response.

HJM · « **Reply #10 on:** October 31, 2005, 06:17:12 PM »

I had one of those EV mics and it broke.....

Peterku · « **Reply #11 on:** October 31, 2005, 07:54:59 PM »

Quote from: HJM

I had one of those EV mics and it broke.....

:lol: Ok but did it sound good?

HJM · « **Reply #12 on:** October 31, 2005, 10:01:43 PM »

Not bad, similar to the Blue Ball, but not quite as flat. Not so much in the bottom and and less bite than a 57

Brow · « **Reply #13 on:** October 31, 2005, 10:57:20 PM »

Quote from: Peterku

Brow also recommended me the Ball, and I started searching. So far it seems Sweetw@ter.com's the only place where I might be able to buy it for a reasonable price, I'll have to call them for a quote on shipping first, though. (Music123.com charges an insane $65 for shipping a small mic...)

Thanks for your response.

I recommended the baby Bottle, but the Blue Ball is good too :)

Peterku · « **Reply #14 on:** October 31, 2005, 11:36:02 PM »

Quote from: Brow

I recommended the baby Bottle, but the Blue Ball is good too :)

Oooooops... and I can't even say I'm getting old. My memory sucks... :lol: