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Multible micing, on guitar cabinets??

Discussion in 'Guitars' started by golli, Dec 19, 2003.

  1. golli

    golli Active Member

    Apr 17, 2003
    I've been reading a lot lately :roll: , about micing guitar cabinets.
    And when the pros talk of their favorite micing techniqes, it involves finding the best speaker and put their favorite mics on it and deal with the phase issues. Is'nt it more logical to put the mics on separate speaker cones, to honor the 3-1 rule and be free from phase problems???
    I even read somewhere that Steve Vai crams many mics on the same speaker cone.
    Is there such a difference in speaker quality on the same cabinet, in your opinion??
  2. freaky

    freaky Guest

    Personally, I don't find the difference in speakers to be the issue. What makes the guitar sound better to me is the phase issues between the mics. Works pretty well for a metal type sound. Phase isn't allways the enemy, think about a good drum mix with all the bleed, sometimes it just works. Keep in mind that I'm no pro, however and I have yet to capture an amazing guitar tone...
  3. AudioGaff

    AudioGaff Distinguished Member

    Feb 23, 2001
    Silicon Valley
    Well just because there may be several mics on the speaker and/or cabinet, that doesn't mean they will all get used in mixdown. This is just a better way to cover your ass to make sure that any perfomance using that cabinet is captured in several different ways. Which one or ones makes it to the final mix will be decided and further processed later.
    Sure, Not all speakers are equal. The speakers age, how worn/fatigued a speaker is compared to another. Where it is in the cabinet and how the cabinet interacts with the room could make one speaker position better than another. Some cabinets don't have the same speakers but have different types of speakers in them.
  4. Sometimes more than one cabinet is used, to get a variety of sounds. Sometimes a mic is placed away from the cab to get the ambience of the room. Always check for phase, because you might end up using all of the tracks recorded.
    I usually record multiple tracks when ODing, and when I am mixing it gives me the opportunity to find the right tone balance for the mix. Before I reach for the eq, I try to get the tone balance right just through the relative volumes of the various tracks.
    Sometimes less is more!
    Happy Holidays to all the good folks here at RO,
  5. golli

    golli Active Member

    Apr 17, 2003
    WOW I did'nt know that. I've allways belived that a cabinet, with speakers the same size, would be like matched pairs (if you get my drift).
  6. AudioGaff

    AudioGaff Distinguished Member

    Feb 23, 2001
    Silicon Valley
    This of course is dependant on who made the cabinet and installed the speakers, and who owns the cabinet and what the have done to modify or enhance it. But I've been told by many guitar players that when they have checked out what was inside some cabinets they were very surprised at the speaker mis match in manufacturer, ohms, power ratings, magnet size.

    I've also known those who choose to have a specific speaker different than the rest in a specific location to be used as the recording speaker for mics.

    And I could see how a manufacturer might install different speakers in pairs for the higher or lower position in a cabinet to obtain it's unique sound, but this may be more rare than normal.
  7. Screws

    Screws Active Member

    Feb 16, 2001
    Home Page:
    I had a nice conversation with Eric Rachel about this. On the ETID "Hot Damn" CD, he used two amps with two mics on each amp. A 57 dead center and a 414 in figure 8 on the same speaker, halfway between the center and the edge.

    On the first guitarist he used a Mesa Rectifier for tone and a 5150 for distortion. On the second he kept the Mesa but used a JCM800 for the crunch.
  8. coysoundnyc

    coysoundnyc Guest

    I think pretty much all of the rock and more hard than rock produced now days is done with multiple cabinets and multiple mics.
    it really makes a huge difference to me, slim vs. fat (at the least for rhythm parts,rifs and chung stuff).
    if you use a splitter and say 3 cabinets with 3 mics on each cabinet you probably will have to committ and print multiple mics to one or 2 tracks just because is not fun (even if you have 128 track available) to go back and edit and choose among few takes of a 9 tracks guitar line.
    if thats the case one trick I know is:
    1.get your first mic set up in a "sweet spot" that gives you a good tone.
    2.get your second mic up.
    3.crank the mic pres on those 2 mics and send them to a pair of headphones you had set up nearby the cabinet (out of the same mono aux send
    and do not cranck that send).
    4.invert phase on your second mic (on the console phase invert button).
    5 both faders to 0.
    6.go there get the headphones on and start playing with your second mic until you hear cancellation.
    7. go back and flip phase back to normal and see how it sounds.
    BE AWARE you will be listening to noise in the headphones, you will be checking the phase of those 2 mics with the noise of the cabinet it self amplified real good with your mic pres.
    be sure nobody is near the guitar because if they
    play a note you may die right there or at least you'll loose your ears for good! :D
    only a starting point sounds complicated but it is not, you'll understand something about phase, noise and cabinets.

    As far as phase goes I have a question for Gaff.
    what is the difference between a device like Little's IBP and moving the tracks on your DAW back or forward by samples?
    That's what I usually do, I take the tracks and juggle them untill I got the best phase possible, and that doesn't mean I just go by eyes couse sometimes they are not aligned but they just sound great.
    Of course this is only for guitars, could not make it work for drums.
  9. AudioGaff

    AudioGaff Distinguished Member

    Feb 23, 2001
    Silicon Valley
    Well, the biggest difference is that with the IBP you have a continious variable realtime adjustment that just makes it so much easier. You may find the perfect setting while listening just for all the guitar mics together, but prefer something a little different when the whole mix is going on. The manual method of slipping tracks with a mouse to get it right and do the same kind of thing is very time consuming and is zero fun to do.

    If there is any bleed into any of those mics, then you will have to live with it and compromise to get the best overall sound.
  10. coysoundnyc

    coysoundnyc Guest

    thanks gaff. have you tried the IBP?
    I do like moving tracks around :s: and it doesn't really take me that much, I see it as a good tool for getting guitar tones that you wouldn't get otherwise (or better, you would but than you're stuck with that one, right?)
    IBP sounds cool for when the client is paying and also when you have to track other instruments.
    bytheway is it the only box that does that?
  11. Doublehelix

    Doublehelix Distinguished Member

    Oct 7, 2001
    When using multiple mics on guitars, I have been using a good dynamic close-mic'ed (SM57, MD421, MD441), and then a LDC from about 3-6' away, preferable an Omni model (414, NT2). Mic placement is critical, both for the close-mic'ed dynamic, and the room LDC. With the heavier punk and metal sounds, the proximitry effect of the dynamic can be used effectively, so I try to keep the mic within an 1" or so of the grill.

    Blend to taste...
  12. AudioGaff

    AudioGaff Distinguished Member

    Feb 23, 2001
    Silicon Valley
    No, no yet. But it is a perfect tool that is long past due in the market place. I do have two of them on my must have list.

    As for time slipping tracks, your right about having the ability to be able to do that rather than being stuck with what you have. You get a few other features in the IBP as well like using it as a direct box and reamping.
  13. coysoundnyc

    coysoundnyc Guest

    yes I find it effective...
    sometimes I set 3 mics up listening to individual tones out of them, than I track with the band listening only to the one mic usually the 57 and than I mix later.
    however, I was curious about the theory:
    phase, for the way I see it, is more like a rotation thing. like when you have something 180 out of phase and you can see the wave as the negetive of itself. when you slip tracks you cannot get that negative "effect". so, is that to be still considered phase related or is more like a delay?
    I know it doesn't matter its just me being a freak over nothing.
  14. clintrubber

    clintrubber Guest

    Must admit I still don't see the difference between the IBP and shifting tracks w.r.t. each other in a DAW. Could image there's a difference in convenience though.

    But in sound ? Please tell if someone has tried both methods.




    There's a recent review of the IBP in SOS-mag., but it still left me with a few open questions. Actually, imho they're pretty vague in this review here ! :)

  15. AudioGaff

    AudioGaff Distinguished Member

    Feb 23, 2001
    Silicon Valley
    Sure you can, in software you should be able to slip tracks as well as invert the whole track.

    Phase is like a rotation. One complete sine wave represents 360 degress rotation. In your example, slipping one track compared to the others that are in phase to out of phase would be considered a microdelay. 180 degrees out phase is not really negative, it is one half waveform delayed from the other where both start at exactly zero degress. Phase as a term often gets used incorrectly to describe polarity.

    If two audio signals of equal amplitude and opposite polarity are combined, any signal common to both of them is cancelled out and are said to be electrically out of phase by 180 degrees.

    If two mics are positioned in such a way that one receives a postive sound wave at the same time the other receives a negative sound wave, this is said to be acousticly out of phase by 180 degrees.

    Slightly out of phase acousticly would be much less than 180 degrees, and usually much less than 90 degrees to almost none when the 3:1 rule is applied. So when there is a slight path length difference between two or more mics, (as in when you ignore or do not conform to the 3:1 rule) acoustic phase cancellations can be expected and will vary by frequency.
  16. Davedog

    Davedog Distinguished Member

    Dec 10, 2001
    Pacific NW
    Excellent physics lesson AG.I'd like to add something to it.While at times this acoustic 'phasing' can cause degredation of a signal, there are other times when it adds a flavour unattainable through any other method.So, at times,phase can be your friend and not something to fear.

    As far as multiple micing on guitar cabinets,I dont know if its been mentioned, but this is usually only very effective on your closed back kinda cabs.Although a nice LDC in figure of 8 set a foot from the back of a twin/deluxe type amp and oriented so the null is pointed at the amp,plus a close mic in the front, makes for an interesting soundscape to play with. I have the use of a very original and old Dallas-Arbitter 4-12 cabinet.The thing is all birch ply and very musical(if you tap the cab it makes a distinct note)The speaks are all marked with a metal adhesive tag and each has its power handling,impedence, and magnetic flux(gauss) marked on it.They're all 22 watt speakers and have that mid 60's english tone to em.I really like running this with my little Fender Blues Jr.which wants to see an 8ohm load.The output character changes dramatically with the 15ohm load of this cab and the results are stunning.The clean sound is so in-yer-face and the driven sound is a big stack as good as I've ever heard.And while each speaker is similar, there are minute differences that really show up with a close mic on it. In the 'old' studio, we had a slant marshall cab that was loaded with a pair of greenback 25's and a 70 watt celestion and a vintage 30.Each wired out separately.This gave us a lot of options with the several amp heads there to chose from.The coolest guitar sounds ,though, came from the old Ampeg B18 amphead and the single 18 cabinet.Talk about HUGE!!We had a Jazz guy in for 3 song demo...he loved that amp and wanted it..not for sale.....two weeks later I see him 'lounging 'in the driveway when no one was around...he wanted to 'check on more time'........uh hhuh.....
  17. teleharmonic

    teleharmonic Guest

    Dave, anyone,

    What do you find happening with open back cabs that makes mult mic techniques less effective on them? Something to do with how the sound projects out of closed back cabs?

  18. sammyg

    sammyg Active Member

    Dec 12, 2003
    Hey Guys,

    One thing i think a lot of people forget about is their ears. Many times people get a killer tone from their amp, then walk up to it and stick a mic in front of it, forgetting that the tone they are happy with is located wherever their head and ears were at the time.

    I used to do this a lot, with a low success rate of a good tone. Now I get on the floor in front of a cab,with my left ear pointed at the cab (please note when using sammy's dodgy recording techniques please swap between ears, this will ensure an even loss of hearing!)...anyway, i move my head around, once i hear the tone im after i stick a mic as close to my ear as possible.(pointed at the cab of course to kinda replace my ear)

    This may sound dumb but my success rate has gone up.

    well, its just a suggestion!

    Merry Christmas!

  19. nugget

    nugget Guest

    i often will mike the cab with several different mikes and positions then having them feeding up to the mixer ;maybe three to six different angles/mikes.
    Then i just sit in the control room and choose the best one.i don't want to know which one it is because it will bias me and besides setting up the same next time won't necessarily duplicate the sound.A lot depends on the weather.
    If at least one '57 through a good pre doesn't get it, try a different player.
  20. golli

    golli Active Member

    Apr 17, 2003
    Have a great new year guys :tu:

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