Thanks to whoever it was who suggested it!

Discussion in 'Recording/Live Sound' started by decay-o-caster, Oct 14, 2008.

  1. decay-o-caster

    decay-o-caster Member

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    Mic'ing cabs by putting on headphones and listening to the sound of an unplugged guitar cable while moving mics around, I mean. So obvious when someone with a brain suggests it, but it had never occurred to me before. But with that technique it took more time to find the mic cables (the third bedroom - er, the studio - isn't as orderly as it might be) than it did to place the mics.

    So thanks again!

    Any other tips for the slower members of the audience would also be greatly appreciated! :phones
     
  2. KillerV

    KillerV Member

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    Yup, that trick works like a charm. Instead of just leaving an open guitar-cable, I turn the gain way up so that it's still a lot of noise coming out of the cab. If someone touches the jack on the guitar-cable and it makes the speaker pop it can damage the speaker and your ears, so it's just a little safer IMO.

    I also get any cab I record off the floor. Decoupling it from the room just makes the sound much more accurate, even if you're close-mic'ing.

    I've not tried this myself, but I've heard of guys putting down a piece of plywood or plexiglass in front of the cab if they're struggling with a sound that's too dull.

    Although it's not always the case, I've found that I sometimes need to setup my amp differently (gain, EQ, etc.) when I'm recording to what I use for playing live. I'll setup everything as I would usually, then mic the cab and get back into the control-room and check the sound coming through the monitors and make any changes to my settings based on that.
     
  3. Ed Alvarado

    Ed Alvarado Member

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    Wow man I feel realy dumb cause I don't get it. "listening to the sound of an unplugged guitar cable "? Sorry for the density!
     
  4. decay-o-caster

    decay-o-caster Member

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    Sorry for the shorthand! It's hard to hear mic placement when you're strumming chords or what have you, moving the mic, strumming, moving,and hearing the amp and the monitors at the same time, which is confusing. So the idea I stole was to plug the guitar cable into the amp but not into the guitar. It makes a humming sound. So put on headphones, solo the mic track, and just move the mic across the face of the speaker until you hear the hum the loudest and most clearly through the phones. That's the spot to mic the cab. Much easier than play/move/compare/play/move/compare, etc.

    What KillerV pointed out is the risk to your speakers (and ears!) if someone touches the end of the cable, but I work alone and just set it aside where I won't touch it myself. But his trick of upping the gain and micing that hum is probably smarter/safer anyway.

    But the idea is to have a continuous, non-distracting sound to compare, and move the mic around until it's "best". If it's good on hum, it'll (theoretically) be good on music too. Theoretically... :)
     
  5. Scott Auld

    Scott Auld Staff Member

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  6. fr8_trane

    fr8_trane Member

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    Yup. This is a great trick but as someone suggested its easier and safer just to turn the gain/volume up 'til the amp hisses.

    I like the pink noise idea but how do you run it into the amp?
     
  7. Scott Auld

    Scott Auld Staff Member

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    iPod Headphone out to an adapter (Radio Shack) that converts to 1/4" mono ... run that into the amp's guitar input. Start w/ the iPod volume waay low.
     
  8. fr8_trane

    fr8_trane Member

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    Ok cool. I figured it was some kind of RS adapter scenario. Not exactly hi fi (the impedance mismatch is going to give you a skewed pink noise with the treble and bass reduced- or maybe its the reverse - I can never keep this straight) but its should work reasonably well.
     
  9. DreamTheaterRules

    DreamTheaterRules Former Lyricist for Calhoun Tubbs Silver Supporting Member

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    Decay,

    ok... so, when you did this, where did the mic end up?
     
  10. decay-o-caster

    decay-o-caster Member

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    Almost exactly halfway between the center and the edge of the cone, about an inch off the fabric. But it was amazing how different it was just an inch or less either way.
     
  11. KillerV

    KillerV Member

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    I might add that every different speaker I've tried have had a different "sweet spot". Sometimes it's dead-centre, sometimes between the centre and the edge, sometimes with the mic angled a little. I do this whole sweet-spot-check every time I mic an amp. As decay-o-caster mentioned, the sound can differ significantly if you're even an inch or so off.
     
  12. Ulysses

    Ulysses Member

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    I do something similar to find mic placement for two mics to avoid phasing. I'm guessing that's what they are talking about here. Use the sound of the cord hum while wearing headphones for a reference and move the two mics (or at least your second mic after you place the first) to find a spot where the hum is the loudest or the least "phase cancelled".
     
  13. cram

    cram Member

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    I've used these sort of waves to test the acoustics of my room. I've got the room sounding pretty good for 150hz - 1000hz, but I have some issues with lower frequencies that I'll address with bass trapping in the corners.

    Mind you, it's not a computer program to monitor and graphically lay out the frequency response, but a db meter testing for variances with individual waves being put through the speakers.

    I do this at every show we play live. I'll put a two chord riff on a loop and the guys will jam to it. I then stand in various places of the room to hear the mix. Works great.
     
    Last edited: Oct 17, 2008
  14. mrface2112

    mrface2112 Member

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    another way to do this is to record a track DI'd and then 'reamp' it back into the amp while you place the mic and listen via headphones. that actually gives you an idea of what the guitar itself is going to sound like (assuming you've got a clean DI, match impedences right, etc).

    but yeah, the "pink noise technique" is VERY good. :banana


    cheers,
    wade
     
  15. elambo

    elambo Member

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    That's a good way to get the best mic position for pink noise. How does that relate to guitar?
     
  16. Bassomatic

    Bassomatic Silver Supporting Member

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    My thoughts exactly. Also don't see how the unplugged cable noise would really work out.

    A cheap looping pedal sounds like a pretty hip idea, especially if it's got enough memory where one could capture a few different kinds of playing in one fell swoop.

    Better still to have someone else play while you move the mic around.
     
  17. Ed DeGenaro

    Ed DeGenaro Supporting Member

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    The idea is to hav the amp hissing and where the hiss is he loudest is where you put the mic. Courtesy of Fletcher from Mercenary...I posted this about 5 years ago or so.
     
  18. MichaelK

    MichaelK Member

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    I was thinking exactly the same thing as I read this thread. Position affects tone as much as anything; I would not mic up an amp based on the most pleasing 60-cycle hum.

    Another thing... I know that when I mike up an amp on my own, anything coming out of the amp that's loud enough to be heard by a dynamic mic is also loud enough to bleed into the cans. My headphones are closed-back and provide decent isolation, but there's no way I can separate the sound in my cans from the ambient sound of an amp in the same room. Regardless, using noise as an indicator of guitar tone makes no sense to me.

    I think the fastest way to mike up a cab is to dial in the tone you want, then put the mic in a position that you know works well. If you have doubts, record a few bars and play them back.
     
  19. decay-o-caster

    decay-o-caster Member

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    I wondered if I might have stolen this from you, Ed.

    Working alone, and with respect to MichaelK's problem (which I share) of headphone leakage, this seems like the best I'm going to do. When I'm hearing guitar sounds coming out of the amp, they always bleed through the headphones and make it hard for me to hear the ideal spot for the mic. It's easier for me to read the position of the mic via hum. And yeah, if I had the ability to completely isolate the amp sound while moving the mic around to optimize the program instead of the hum, I might come up with a different position for it. But for quick and dirty, this seems to give me the best mic placement for my, um, extremely amateur sounding recordings as I've found by trying to position it by way of playing/moving/playing/moving.

    Theres' not a whole lot of auditory magic coming out of Third Bedroom Studios these days. But I'm trying to make what does come out less leaden sounding, and this has been a good trick for the project studio kinda recorder.
     
  20. Bassomatic

    Bassomatic Silver Supporting Member

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    Still don't get it, Fletcher or no (not that I'm a huge fan - he strikes me as mad attitudinal and snobbish/cultish). I'll have to give it a try some time.

    Is louder necessarily better in this case?
     

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