Mic placement for guitar amps?

SeanHurley · 08-05-2009 12:27pm #1

Ok guys I know it is a very broad subject but I am interested to hear how you guys approach recording guitar amps. I have heard of some guys using test-tones or working with guitar hiss to get the most natural guitar tone they can. Does any one here have any cool trick tips?

I am off to the studio for the weekend and I want to try something different. Thanks guys.

fitz · 08-05-2009 12:32pm

Mick from Trackmix showed us a great trick during the recent MP Cover Song recording session.

Sent pink noise through the cab, and then with headphones on moved the mic around, until he found the sweet spot between the centre of the cone and the edge. Really simple, but really effective.

ogy · 08-05-2009 12:41pm

that sounds interesting? but i don't get how do you tell the sweet spot of pink noise? i would usually move the mic around with headphones on while someone plays the guitar. moving the mic a little off axis can be nice too for certain guitar tones.

SeanHurley · 08-05-2009 12:43pm

cool this is the sort of thing I am interested in.

Forgive my ignorance here but how was the sweet spot evaluated? Was it based on level or frequency balance (like using a PAZ analyser)?

ZV Yoda · 08-05-2009 12:56pm

ogy wrote: »

that sounds interesting? but i don't get how do you tell the sweet spot of pink noise? i would usually move the mic around with headphones on while someone plays the guitar. moving the mic a little off axis can be nice too for certain guitar tones.

We asked Mick the same question at the session & he said (adopts a wise Jedi master voice)..... "you just know". :cool:

To be fair, he did give us a very clear demonstration & you really can tell... it's when the pink noise stops being phasey & neither too harsh nor too dull... that's when you've hit the sweet spot.

That's not to say some applications might need a slighter harsher or softer sound, but if that is the case, then at least you have the "sweet spot" as your reference point. That's what I took away from it. Then again, I'm sure Mick will be along to tell me I'm talking out my hole!

PaulBrewer · 08-05-2009 1:20pm

SeanHurley wrote: »

cool this is the sort of thing I am interested in.

Forgive my ignorance here but how was the sweet spot evaluated? Was it based on level or frequency balance (like using a PAZ analyser)?

Base it on your lugs is my advice ! I would use mic placement as tone control , once I'm happy with the amp output in the room I'd move the mic to match to the track i.e if it needs to be brighter and less bottom move towards the centre of the cone and vice versa.

In my opinion there isn't a 'sweet spot' per se that's perfect for everything (though there can be a superior sounding speaker in a cab) but 'sweetspot' in relation to what's around it musically i.e the optimum tone for a part.

Another important tone tool is the cabinet in relation to the room. Stick it in the corner and it will couple to walls and increase bass.

Similarly, raising the cabinet off the ground will decouple that, in this example reducing bass.

That's a whole heap of tone control before you go near a console etc and if your eq isn't the May West will probably result in a better final product.

And that's not even looking at mics ...

Another thing we've started doing recently is on a track that is being overdubbed individually (as opposed to an ensemble recording) is record the densest rhythm parts first as a tonal and tuning centre even before the final bass track.

Virtually every track we get to mix the bass tuning causes problems. Sometimes that manifests itself as making it appear something else is out of tune or 'lumpy' sonically. In those cases we use Auto-Tune to sweeten things up. 9 times out of 10 it makes the rest of the track sound better.

On stuff we record ourselves I've found that if you're doing the bass by itself it's only afterwards you may be aware of slight tuning discrepancies - say an F note on the E string which invariably will be pulled sharp, however little.

Having a Tuning centre , (the guitars) which is internally referencing itself, will flag that up quick enough to fix it.

Like a lot in recording there aren't any special secrets just the application of kop-on, science and taste.

old gregg · 08-05-2009 1:38pm

fitz wrote: »

Mick from Trackmix showed us a great trick during the recent MP Cover Song recording session.

Sent pink noise through the cab, and then with headphones on moved the mic around, until he found the sweet spot between the centre of the cone and the edge. Really simple, but really effective.

Personally I know nothing about this topic but the above technique is the one described in the most excellent 'Mixing with your Mind' book that sometimes comes up here during discussions of this type. I've also never met Mick from Trackmix (yet anyway) but my gut feeling as an internationally renowned psychic detective tells me that maybe Mick read the book?

PaulBrewer · 08-05-2009 1:42pm

old gregg wrote: »

Personally I know nothing about this topic but the above technique is the one described in the most excellent 'Mixing with your Mind' book that sometimes comes up here during discussions of this type. I've also never met Mick from Trackmix (yet anyway) but my gut feeling as an internationally renowned psychic detective tells me that maybe Mick read the book?

It's an old 'trick' that I heard about as a boy !

In those days it was a detuned radio used as a sound source :pac:

The flaw in the idea to my mind is that it's a bleedin guitar that you're recording not pink noise .... and as I mentioned in my previous post, that technique doesn't allow for what the sound recorded is to 'do' in the track either.

It also doesn't allow for tonal differences for the Key a song is in.

Psuedo - Scientific - Mumbo - Jumbo is my official line ...

i57dwun4yb1pt8 · 08-05-2009 1:56pm

thanks for the advice paul, i have noticed that probelm with bass alright .

artvandulet · 08-05-2009 2:14pm

Speaking of pink noise, here's a handy generator:
http://www.nch.com.au/tonegen/index.html

SeanHurley · 08-05-2009 2:31pm

Paul thanks for the advice -as always the voice of reason;)

I suppose the theory with these kinda of tricks to capture the sound of the speaker faithfully. You can then sculpt the sound using the amp and eq.

Lately when we've been recording guitars we have the head in the control room and tha cab in the live room which allows tweaking of the amp to make things fit, so maybe capturing the sound of the speaker could be useful in that respect.

However, I fully agree that there is no better eq than mic placement. I am just interested in how other do things sonce guitars are such a big part of what we do.

PaulBrewer · 08-05-2009 2:42pm

SeanHurley wrote: »

Paul thanks for the advice -as always the voice of reason;)

I suppose the theory with these kinda of tricks to capture the sound of the speaker faithfully. You can then sculpt the sound using the amp and eq.

Lately when we've been recording guitars we have the head in the control room and tha cab in the live room which allows tweaking of the amp to make things fit, so maybe capturing the sound of the speaker could be useful in that respect.

However, I fully agree that there is no better eq than mic placement. I am just interested in how other do things sonce guitars are such a big part of what we do.

Aye, I love the amp in control room.

My overall point is that everything is a variable all the time .... it might be handy in your head to say to yourself ' well that's definitely the best place for the mic, I can worry about FX (or whatever) now' but all other elements have a say in the final outcome.

Everyone, especially those with limited experience, want to travel on a mapped out road of 'bestness' , at least theoretically until the price comes up!

It's those who'll start a journey on a road that isn't there yet are the ones who make the magic music.

If your guitarist is bursting with magic now , phuck the tone and the technology around it, it matters not a jot to the listener.

If it did Samboras flat bends, Keef's rubbish timing and Slashes sloppyness would never have made it to record!

SeanHurley · 08-05-2009 2:49pm

And you are talking to one of those with limited expereince here

As you say all the variables can be daunting but given that we aren't looking at a clock anymore I think I might spend a little more time exploring all the variables.

Seziertisch · 08-05-2009 3:00pm

Experiment with the room (particularly if you are using an open back cab) Work on the positioning both in relation to the walls as well as up or down from the floor. Try hanging stuff up (blankets, duvets, sheets etc.) You'd be surprised what even a 57 directly on the speaker can pick up. You may find the a sheet hung in the right place might take a sizzle off the top end that you would otherwise be eqing to get rid of (and with than might not even be able to get rid of).

I know for example that the SE Reflexion Filter comes recommended for using on cab mics as well as on vocals or whatever. I am getting one on loan from a friend so I'll let ye know what my experiences are. It should work pretty well seeing that a dry signal (to which you can add ambience later) is always preferrable to a signal with a less than optimum ambience (with which very little can be done).

PaulBrewer · 08-05-2009 3:00pm

SeanHurley wrote: »

And you are talking to one of those with limited expereince here

As you say all the variables can be daunting but given that we aren't looking at a clock anymore I think I might spend a little more time exploring all the variables.

Indeed ! That's the plan! Make your own rules !!

You have the tools to do so now anywus ...

SeanHurley · 08-05-2009 3:07pm

Seziertisch wrote: »

I know for example that the SE Reflexion Filter comes recommended for using on cab mics as well as on vocals or whatever.

I have one of them and they work quite well. They are especially good if using smoething like a ribbon that is in figure-8, you can kill the rear of the mic quite well which is useful as you say if the room is less than great.

woodsdenis · 08-05-2009 3:07pm

SeanHurley wrote: »

And you are talking to one of those with limited expereince here

As you say all the variables can be daunting but given that we aren't looking at a clock anymore I think I might spend a little more time exploring all the variables.

Always independently of whatever mic positioning you use, record a guitar
DI simultaneously. You can then reamp/use gtr amp sim etc, If you need to.
If you never use it so what, disk space is cheap.
It has saved my bacon many times.

fitz · 08-05-2009 3:13pm

woodsdenis wrote: »

Always independently of whatever mic positioning you use, record a guitar
DI simultaneously. You can then reamp/use gtr amp sim etc, If you need to.
If you never use it so what, disk space is cheap.
It has saved my bacon many times.

Great tip.

trackmixstudio · 08-05-2009 3:40pm

The pink noise technique works well for me because I have been doing it forever and know what I am looking for.
If you feed pink noise into the amp and sweep a mic with headphones on you will hear the sound change drastically as you sweep. The point I look for is the point of most clarity. An inexperienced engineer will often mistake this as the brightest signal but it's not. When sweeping from the centre to edge you will pass through several distinct variations in the sound. The centre is very sharp with a predominance of 4-7K. Then, as you move towards the edge, you will hear this harshness disappear and the pink noise will sound full but not harsh then, as you move further towards the edge, you will hear a low mid muddiness coming in. The sound I look for is the middle one. Full with the right balance of highs and lows but none of the harshness or muddiness. The idea of using pink noise is to take the variable of the guitar playing changing as you sweep which makes it much more difficult to gauge the right position. Pink noise has a very similar frequency range to a guitar.
Then I will often get a second mic up and sweep it with the 2 mics coming through the headphones and find a position on the second mic that is in phase and adding depth and punch to go with the clarity of the first mic. Phase problems are very easy to hear when using pink noise.
Normally when you find this position the guitar will sound rich and full when you plug it in. If the sound does not fit the song then I will get the guitarist to play along with the song with the amp low and get in front of it and move the mic(s) while again listening on headphones.

As denis says always take a di so you can reamp later. This is vital with metal bands because they usually want far too much gain when tracking which gives the "wasp in a jam jar" sound.
Less gain gives more clarity and attack and sounds much bigger and clearer than an overly saturated distorted guitar.

I have not read that book. This technique has been used for many years and is nothing new.
Before pink noise generators where easy to come by (in software) the technique was to plug a lead into the amp and hold your thumb on the jack to make the amp buzz when sweeping.

Head in the control room feeding the cab in the live room is the best way to go for sure.
Another life saver is an ibanez ts808 which focuses the guitar in the midrange and drastically improves the clarity of a distorted amp. A killer preamp like an API or Phoenix Audio or Neve will also focus the sound far better than a lesser pre. This is fact and not my opinion ;-). Valve pres loose out big time to "iron" pres on guitar in my experience too.

Please note that I mainly record rock/metal so the point of most clarity and presence may not suit jazz, blues or country etc. Some genres really require more experimentation with mic positioning to get the right sound.

SeanHurley · 08-05-2009 3:48pm

trackmixstudio wrote: »

The pink noise technique works well for me because I have been doing it forever and know what I am looking for.
If you feed pink noise into the amp and sweep a mic with headphones on you will hear the sound change drastically as you sweep. The point I look for is the point of most clarity. An inexperienced engineer will often mistake this as the brightest signal but it's not. When sweeping from the centre to edge you will pass through several distinct variations in the sound. The centre is very sharp with a predominance of 4-7K. Then, as you move towards the edge, you will hear this harshness disappear and the pink noise will sound full but not harsh then, as you move further towards the edge, you will hear a low mid muddiness coming in. The sound I look for is the middle one. Full with the right balance of highs and lows but none of the harshness or muddiness. The idea of using pink noise is to take the variable of the guitar playing changing as you sweep which makes it much more difficult to gauge the right position. Pink noise has a very similar frequency range to a guitar.
Then I will often get a second mic up and sweep it with the 2 mics coming through the headphones and find a position on the second mic that is in phase and adding depth and punch to go with the clarity of the first mic. Phase problems are very easy to hear when using pink noise.
Normally when you find this position the guitar will sound rich and full when you plug it in. If the sound does not fit the song then I will get the guitarist to play along with the song with the amp low and get in front of it and move the mic(s) while again listening on headphones.

As denis says always take a di so you can reamp later. This is vital with metal bands because they usually want far too much gain when tracking which gives the "wasp in a jam jar" sound.
Less gain gives more clarity and attack and sounds much bigger and clearer than an overly saturated distorted guitar.

I have not read that book. This technique has been used for many years and is nothing new.
Before pink noise generators where easy to come by (in software) the technique was to plug a lead into the amp and hold your thumb on the jack to make the amp buzz when sweeping.

Head in the control room feeding the cab in the live room is the best way to go for sure.
Another life saver is an ibanez ts808 which focuses the guitar in the midrange and drastically improves the clarity of a distorted amp. A killer preamp like an API or Phoenix Audio or Neve will also focus the sound far better than a lesser pre. This is fact and not my opinion ;-). Valve pres loose out big time to "iron" pres on guitar in my experience too.

Please note that I mainly record rock/metal so the point of most clarity and presence may not suit jazz, blues or country etc. Some genres really require more experimentation with mic positioning to get the right sound.

Thanks for that post dude, will give it a try tomorrow!

Seziertisch · 08-05-2009 3:49pm

woodsdenis wrote: »

Always independently of whatever mic positioning you use, record a guitar
DI simultaneously. You can then reamp/use gtr amp sim etc, If you need to.
If you never use it so what, disk space is cheap.
It has saved my bacon many times.

My experience with reamping has been that there is always a trade off even just adding the DI to the signal chain (even with a really good DI). You lose some of the aliveness and dimensionality, not that is sounds terrible, just never as good as a straight guitar. This is particularly true in cases where you aren't using any pedals in the chain (just guitar - cable - amp).

trackmixstudio · 08-05-2009 4:02pm

Seziertisch wrote: »

My experience with reamping has been that there is always a trade off even just adding the DI to the signal chain (even with a really good DI). You lose some of the aliveness and dimensionality, not that is sounds terrible, just never as good as a straight guitar. This is particularly true in cases where you aren't using any pedals in the chain (just guitar - cable - amp).

I use a splitter box which works GREAT!
http://www.morleypedals.com/dtripler.html
I can go guitar to input. Output one to amp, two to rack tuner and three to DI.
There is no audible signal loss through this unit and the switch for each output lets you turn off the feed to the amp when tuning without having to use a tuner inline or unplug the guitar to tune.
To reamp you REALLY need a dedicated reamp box. Line out into the amp doesn't work for various reasons (impedance, level etc).
I use a radial x-amp reamper.

Seziertisch · 08-05-2009 4:13pm

trackmixstudio wrote: »

I use a splitter box which works GREAT!
http://www.morleypedals.com/dtripler.html
I can go guitar to input. Output one to amp, two to rack tuner and three to DI.
There is no audible signal loss through this unit and the switch for each output lets you turn off the feed to the amp when tuning without having to use a tuner inline or unplug the guitar to tune.
To reamp you REALLY need a dedicated reamp box. Line out into the amp doesn't work for various reasons (impedance, level etc).
I use a radial x-amp reamper.

I've used both the Radial JDV and the the Little Labs Multi Z Pip and found signal change (loss?) with both. Nothing terrible, but enough that I would prefer the direct amp signal. Little Labs make a purpose-built guitar splitter (the PCP Distro) using the same technology which is used by the likes of Aerosmith and Neil Young so I reckon it should be up there with the best of them.

Niall - Dahlia · 08-05-2009 6:17pm

Don't quite see the reasoning behind the pink noise trick, no personal dig at you Mick, I know your genre is metal so you have a pretty clear picture of guitar tone from project to project, but for me the tone of the guitar in relation to the rest of the track is what's important, I can't see the point in listening to anything other than what you're going to be recording.

Personally, I leave the guitarist alone and let him get the amp sounding like he wants it in the room. Once he's happy with the sound I might offer my opinion on it, but most of the time I'll get straight to micing it up and adding baffles to dry the sound if need be.

I like to stay in the control room and have somebody sweep the mic while the guitarist plays his part over the track. That way I can hear how everything is going to fit together. If it's not really sitting right or finding it's place I'll try different mic, amp tones, guitar tones etc and then try different guitars/amps if we have that luxury (and time). Guitar pedals can be a real tone killer if you're not careful, and I hate when guitarists try to play through a bypassed tuner!

Interesting what you're saying about the bass Paul, I'll have to have a think about that next time.

PaulBrewer · 08-05-2009 6:24pm

Niall - Dahlia wrote: »

I hate when guitarists try to play through a bypassed tuner!
.

We have a Racktuner on an Auxiliary so we can fire anything out to it for a check at any stage ...

Niall - Dahlia · 08-05-2009 7:01pm

PaulBrewer wrote: »

We have a Racktuner on an Auxiliary so we can fire anything out to it for a check at any stage ...

Clever. Stealing that one.

PaulBrewer · 08-05-2009 7:07pm

Niall - Dahlia wrote: »

Clever. Stealing that one.

That's Two ....

Like I say ... Kop-on, Science, Taste

trackmixstudio · 08-05-2009 7:21pm

Niall - Dahlia wrote: »

Don't quite see the reasoning behind the pink noise trick, no personal dig at you Mick, I know your genre is metal so you have a pretty clear picture of guitar tone from project to project, but for me the tone of the guitar in relation to the rest of the track is what's important, I can't see the point in listening to anything other than what you're going to be recording.

Personally, I leave the guitarist alone and let him get the amp sounding like he wants it in the room. Once he's happy with the sound I might offer my opinion on it, but most of the time I'll get straight to micing it up and adding baffles to dry the sound if need be.

I like to stay in the control room and have somebody sweep the mic while the guitarist plays his part over the track. That way I can hear how everything is going to fit together. If it's not really sitting right or finding it's place I'll try different mic, amp tones, guitar tones etc and then try different guitars/amps if we have that luxury (and time). Guitar pedals can be a real tone killer if you're not careful, and I hate when guitarists try to play through a bypassed tuner!

Interesting what you're saying about the bass Paul, I'll have to have a think about that next time.

I totally agree with you for most types of music but for modern metal you have to get total clarity in the guitars and work the mix around them rather than sit the guitars into the mix. This will, of course, involve triggering the kicks and snare too and cutting eq holes in the guitar bus to fit the snare and whatever else into. For metal I always record the bass after the guitar for the same reason.
As for a send to the rack tuner, I tried this before but you need to send a di track because it is hard to tune from a miced amp track because the resonant peak is exaggerated by most amps sending the needle way sharp on the attack. I prefer the splitter pedal method.
As regards tuning for heavy players, it is much better to tune the attack rather than the sustained note. Get the player to repeatedly hit the string while you or somebody else in the band tunes the string to pitch with the machine head. This is especially true if the band are tuned low.

PaulBrewer · 08-05-2009 8:05pm

Again we disagree Mick! But sure what harm!?

It was in an Interview with Neal Avron who produced/mixed Fall Out Boy, Good Charlotte and Weezer that I heard the 'record the bass second' idea, so pretty intense on the guitar front there.

The main reason we have a tuner on the Aux is to keep an eye on the feckers tuning ... I agree a pre fx send is more desirable certainly if you've chorus on!
We use floor tuners too but rather than degrading the signal with unnecessary electronics we plug em in and out!

Using Vovox cables with Neutrik plugs that mute we don't get clicks or bangs.

With regard to the process of tuning the recommended way according to Peterson Tuners is to use a neck pickup and use your thumb (as opposed to a pick). The theory behind this is that you're outputting a duller sound (neck pickup/thumb strum) with less harmonics. Therefore it's easier for the tuner to read accurately i.e. closer to a pure sine wave.

I've not tried tuning the attack but surely the attack is the shortest part of the note with the least 'music' and most noise harmonics. The sustained note is the one to focus on and where the 'music' is?

It's the left hand pressure and closeness to the nut that makes things sharp, to my mind.

Seziertisch · 08-05-2009 8:49pm

Or you could just get a tuner with true bypass switching (like the Peterson)

PaulBrewer · 08-05-2009 9:10pm

Seziertisch wrote: »

Or you could just get a tuner with true bypass switching (like the Peterson)

Aye, but she's a bit noisy to have in the control room - what with spinning motors 'n' all ...

Mic placement for guitar amps?

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