Mic'ing A Cab, With A Condensor?!?

[Adji]

I was always told this was more or less illegal in the music production world?
A few months ago i bought an Red5 RV6 Condensor (pretty cheap at around 70 pounds) so that i didnt have to rely on vocalists to bring there own mics and also so i could record acoustic instruments better also.
One day i just couldnt get a good sound mic'ing up my Hughes and Kettner Trilogy with the Sm57, i tried everything i could, on axis, off axis, close mic'ed, further away etcetc, but it just sounded really crap. I figured it was probably because i record in my room and cannot turn the amp up loud enough to get a good sound.
So i htought, ah what the hell, ill whack a condensor in front of it.
Ive never looked back! For me it seems to give a fatter sound to my recordings, even though my amp is on relativly low volumes. The bass seems more present but tighter and i just allround prefer the sound.
If i went to one of you pro studio guys and suggested this, would i get punched?? haha.

[Mike Hillier]

Not at all. We use condensers in front of cab's all the time. Just because you'd never do it live doesn't mean you wouldn't do it in the studio. I wouldn't even worry about blasting that amp up a bit more, the RV6 should be able to handle it, and if you do sense you might be overloading it whack the 10dB pad on.

Mike

[EOSPete]

You ever tried combining both mic types Adji?
You can balance them out later on.
I am considering trying to put my synths through some guitar amps at some stage. Wondered about the little AC30 headphone amp.

P

[Escape Velocity]

Pete,

Running synths through a guitar amp can be a good way to schrack the guitar amp. The spread of frequencies coming out of a synth is far broader than what you'd put through with a guitar and you can literally shake the speaker cone to pieces with the LF signals a synth can pump out. If the AC30 has a good bass roll-off filter then it might sound okay, but only when you're playing the synth in the same frequency range as your guitar. As much as I'm wary of recommending Behringer kit, they have a few synth amps which are quite good and I haven't heard too many complaints about from a reliability perspective - and they're quite good value for money.

Cheers


Jez

[Adji]

Never tried combining both mics, but after reading this months feature on mic'ing up cabs im going to try that on my next recording. Maybe with the 57 close mic'ed and just off axis, and the condensor a little further back for some ambience.

[Escape Velocity]

The only thing to worry about in this situation is the SPL that your condensor can handle. Most capacitor mics are fairly fragile in comparison to their dynamic brethren. From memory, an SM57 has about 10-15 dB SPL more volume tolerance than a Rode M3 (nice capacitor mic for the price) - which is one of the more rugged condensor's around. As long as you're using gain - not volume - to get your nice even-harmonic distortion then you're in a good place, as you don't need to move heaps of air to get the same result from the speaker. Then again, if the amp has a post-gain line-out, you're not going to get that much more out of a mic than you will from speaker other than the colouration the speaker adds to the tone.

Keep in mind that if you're recording your cab in a smallish room, some of that extra warmth might be a result of room ambience, early reflections, etc. The SM57 is highly directional. If your condensor is an omni, then you'll get an entirely different result. Also keep in mind that with a more directional mic, the positioning of the cabinet in the room might have more of an impact on the sound. i.e. It's not simply enough to move the mic around the cab, you might need to move the cab around the room to find a position where the 57 sounds good.

With all that said... if I was tracking a single guitar amp without having to worry about other musos creating spill into the mic on the guitar cabinet..? I'd use my M3, AND a large diaphragm omni condensor set 6-10 feet from the amp, AND I'd take a line-out from the head, AND I'd take a DI'd signal from the guitar itself before any other amplification. This would give me the ability to blend the signals from each to get an optimal sound.

Ultimately the SM57 is a live microphone. It has some characteristics that are useful during recording if used selectively and with care, but you want to know what those are before you start using it in a recording situation, with perhaps the exception of drums (particularly snares and toms), for which it's close to an industry standard. It's not the world's most accurate microphone though - it doesn't have the dynamic range of a condensor, and that's by design. It's also got hot and cold spots in its frequency range which are designed around live performance rather than recording. These can be compensated to some degree with EQ, but you want to make sure your EQ doesn't add much phasing to your signal path. (i.e. use a good EQ).

If you had a drummer and a bass player both playing in the same room as your guitar cab when you record, I'd use the 57 every day of the week. But when rejection of other sound sources is not an issue I'd go with a condensor (carefully though - remember the SPL tolerance).

Cheers


Jez

[Adji]

Hey man thanks for lengthy reply. First off, i have no idea what SPL tolerance is, im gonna go read up on that now.
And secondly, thaks for confirming what i thought to be more or less true, the 57 is a live mic but has its uses in the studio in the right situation. Like as you say because it is direcitonal it is good at blocking out other sound sources in the room. Also, moving my cab is not an option as my room is now pretty packed with gear its impossible to move my self, let alone a huge cab!! haha.

[Escape Velocity]

*grin* All good. SPL = Sound Pressure Level. I'll dig up a chart for you that gives you an idea of what sort of sound source is capable of pumping out what levels.

SPL tolerance is basically the maximum level of SPL that your mic can withstand before you start damaging the capsule.

Cheers

Jez

[Adji]

okay cool, ill take a look at that chart when you find it, thanks man.

[Escape Velocity]

Check out this WikiPedia article... it has a good table towards the bottom showing relative sound intensities. The Krakatoa one is amazing considering the distance...

Cheers


Jez

[Brian Caulfield]

One thing I learned in a sound engineering course I was doing is use any mic on anything just to see how it sounds. The worst that can happen is u decide you dont like the sound and use something else. There aint no rules when it comes to mics. Guidelines at best

[Kashif Ejaz]

Hi Adji,

Everybody have said enough. I would like you to check my blog here http://www.mtmstudionet.com/profiles/blogs/mixing-rock and listen to the radio add on my page.

Let me know what you think :)


Cheers,
Kashif

[wanabeme308]

I think the last resuft is the most important, don't care what you used, if the last sound recorded good, you did it well.
I always use condenser mike for Bass Amp ( with -20Db cut). My SM 57 sound really good with guitar, but never work with Bass.
I also tried balancing 2 mikes. With guitar we can use a close - on asix SM57, and a far - off asix Condenser ( -10 or -20Db cut).
Normally I like more Lo tone from the L and Hi tone from the rite, so the condenser mike I pan it hard rite, the other sould be panned hard left.
The problem is, although you get the Condenser in off asix and -20Db cut, the signal is still overload sometimes. I solve it by getting it about 60cm far. And it works.
My mike is C414 B-TL II ( try a Tube Solid Tube before and received the same resuft).