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How to do a "proper" mic pre shootout? Microphone Accessories
Old 24th December 2010
  #1
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Scott Whigham's Avatar
 

How to do a "proper" mic pre shootout?

I have two pres and want to keep just one if possible. My plan is to track electric guitar (mic'ed), and acoustic guitar (mic'ed) through six tracks (one per take, per pre).

I'm thinking something like this is the best idea:



This particular one is the one here: Hosa YXM121 Y-Cable XLR female to two XLR male, 6" | Full Compass

Is this a good way? This is for me to make a decision on keeping/selling a chandler LTD-1 so it's a big deal to me
Old 24th December 2010
  #2
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Scott Whigham's Avatar
 

Six o'clock in the mornin' bump.
Old 24th December 2010
  #3
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For electric guitar, reamping is probably the best way to do it.

I think that there is no ideal way to do a shootout on acoustic.
The "Y" cable may cause audiable difference because of impedance change.
Also beware of phantom power.

Splitter might be a better idea, but it still won't sound exactly the same.
Old 24th December 2010
  #4
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Scott Whigham's Avatar
 

To me, the problem with reamping is that I had to use one of the pres first to do it. These are some fairly colorful pres and, even though I haven't tried DI guitar with them, I'm fairly certain they would impart a bit of color. Is that really prefered to splitting and/or playing the same part twice?

Good thinking about the phantom power thing - hadn't thought of that. Certainly wouldn't want to fry my mics with 48Vx2!
Old 24th December 2010
  #5
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Of course it would add a bit of color, but it would add exactly the same amount to each recording.
Old 24th December 2010
  #6
Gear Guru
 

while playing the same part twice is not 'scientific', there should be enough difference between two colorful pres to hear the character and make your choice.

I would stay away from the splitting

as far as reamping, maybe you could borrow a "clean" pre from somewhere to do the original track.

or even just borrow the track. Maybe someone has a clean sounding DI track. The fact that the source preamp is "unknown" would make the test somehow fairer, IMO
Old 24th December 2010
  #7
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Okay - I'll just do the two takes thing. I don't have another pre that is more transparent - basically I have a Chandler LTD-1 and an Aurora GTQ2, and I'm trying to hear the differences. Those are the only pres I have.
Old 24th December 2010
  #8
I would stick to the "one mic > one preamp" paradigm.

The most critical part, aside from trying to consistently duplicate the performance each time, is to make sure the output levels are matched to within .1 dB. A difference of even .5 dB between the levels of the two will sway your sonic impression and you may choose the louder of the two regardless of the other differences.

You might get some insight here: Not a Mic Preamp Shootout

I could talk about setting it up properly for hours. I did a lot of research before I did both of mine, including phone chats with Greg Mackie, George Massenburg, Dan Kennedy and lots of others who "know" preamps.

https://www.3daudioinc.com/catalog/ Look for the Preamps in Paradise set.
Old 24th December 2010
  #9
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Thank you, Lynn. The 3daudioinc article wanted a password though?

I hope you can help me understand this comment in the "Not a Mic Preamp Shootout" article regarding levels:
Quote:
Preamp levels were matched by inverting polarity, then subtracting (nulling) via oscilloscope.
So I should level match as best I can by ear/SPL meter, then flip the phase on one track, and thennnnnnnnnnnnnnnnnnnnnnnn? I'm missing Step 3 in terms of how/what.

Thanks so much!
Old 24th December 2010
  #10
Quote:
Originally Posted by Scott Whigham View Post
So I should level match as best I can by ear/SPL meter, then flip the phase on one track, and thennnnnnnnnnnnnnnnnnnnnnnn? I'm missing Step 3 in terms of how/what.
You would flip polarity and adjust levels until they cancel the most (sound disappears) in order to get the level exactly matched. This would not work if you're working with different takes.

I wouldn't get this scientific if I were you. Just record 2 takes as closely level-matched as you can, then listen to each while raising and lowering your monitor volume by hand. If you can't hear the difference between the pre's, then it's probably not very significant to begin with. Colored preamp differences are usually easy enough to hear. Perfectly level-matched double-blind ABX tests blah blah blah are more useful for more subtle things like external clock or high end cable comparisons...

.
Old 24th December 2010
  #11
Quote:
Originally Posted by Trakworx View Post
You would flip polarity and adjust levels until they cancel the most (sound disappears) in order to get the level exactly matched. This would not work if you're working with different takes.

I wouldn't get this scientific if I were you. Just record 2 takes as closely level-matched as you can, then listen to each while raising and lowering your monitor volume by hand. If you can't hear the difference between the pre's, then it's probably not very significant to begin with. Colored preamp differences are usually easy enough to hear. Perfectly level-matched double-blind ABX tests blah blah blah are more useful for more subtle things like external clock or high end cable comparisons...
I disagree with those statements in bold. While it's true that you can closely match the volume after the fact (the final few tenths of a dB), thinking that you can get close enough by just turning the volume knob up and down is a mistake.

If you can't calibrate them closely enough as you record them (which is not that hard to do), then at least put them on two adjacent tracks and adjust the faders on playback so you can A/B back and forth between them at identical levels.

Try this. Pipe a 1K tone into a speaker that is positioned in front of the mic at a level that approximates what the acoustic source will be (vocal, gtr, whatever). Record that and read the peak value. Then swap preamps and try to get the level the same. Because of the adjustments on the preamps, you may not be able to get closer than 1 to 5 dB. Then take those two recorded tones and match them up on playback so that they are identical. Now, without touching the playback levels, you are ready to record to those two tracks with those two preamps and have them matched closely enough to make informed, and not mistaken, decisions.
Old 24th December 2010
  #12
Quote:
Originally Posted by Scott Whigham View Post
Thank you, Lynn. The 3daudioinc article wanted a password though?

I hope you can help me understand this comment in the "Not a Mic Preamp Shootout" article regarding levels:


So I should level match as best I can by ear/SPL meter, then flip the phase on one track, and thennnnnnnnnnnnnnnnnnnnnnnn? I'm missing Step 3 in terms of how/what.

Thanks so much!
The first article was written by Eddie Ciletti, not me. Can't help you there.

Sorry about the second link. I was signed in as admin when I copied the URL. You can click the link above now and it will take you to the product I was referencing.

I would suggest you use the method I described in the post above for your calibration. I'm sure I've written a more exhaustive tome on the subject somewhere but I can't find it at the moment.
Old 24th December 2010
  #13
You can read more about it here but I don't know if I get into the details of calibration. I don't suspect you'll want to go to these same lengths to do your comparison though.

2004 Preamp Summit Listening Test
Old 25th December 2010
  #14
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steveschizoid's Avatar
Forgive me if this is a stupid question, but why not "reamp" a vsti/soft synth?
Old 25th December 2010
  #15
Quote:
Originally Posted by Lynn Fuston View Post
thinking that you can get close enough by just turning the volume knob up and down is a mistake.
I agree with you on that. But I was not trying to describe level-matching at all. What I was trying (and failing) to communicate is that choosing preamp coloration for electric guitar is more of a musical vibe thing than a scientific method thing. Precise level-matching has little bearing on how the guitar will sound at loud vs. soft listening volumes, or how it will sit in a mix.

I whole-heartedly agree that level-matching is very important when evaluating other things, as I already mentioned.

.
Old 25th December 2010
  #16
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Jerrick's Avatar
 

Quote:
Originally Posted by steveschizoid View Post
Forgive me if this is a stupid question, but why not "reamp" a vsti/soft synth?

Thats what id do. Put together a 1min long track of all samples, drum track, keyboard, a guitar loop, vocals, whatever. Have it playback in a room with your mic of choice, which will never have to move.

Get your first preamp have it all off, no gain or anything. Start the track and set it to loop. As its recording through the preamp, start slowly messing with the settings and sweep through the whole range of the preamp so you get from inaudible, to 'that sounds nice' all the way to maxed out possibly ugly sound.

Repeat the recording and sweeping through the settings with the 2nd preamp, then listen to them. Then you get to hear the full range of sound from each preamp instead pf just hearing one setting against another setting.

Take your time with it, if you sweep through the settings in 30 seconds, that isnt going to tell you much. If you let the track loop for 10mins as you adjust, youll probably find a lot of sweet spots and feel out how the preamp will react to the source.

I dont know, worth a shot maybe.
Old 25th December 2010
  #17
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Aisle 6's Avatar
With regard to the original post, re: splitting the signal. Would iso transformer splits not make a good solution to this problem? A one in eight out box would be easy to get hold of.
Old 25th December 2010
  #18
Quote:
Originally Posted by Aisle 6 View Post
With regard to the original post, re: splitting the signal. Would iso transformer splits not make a good solution to this problem? A one in eight out box would be easy to get hold of.
If you will be recording everything through that splitter, then yes, it would tell you what the preamps will sound like when sourced by that splitter. If not, then what you'll learn will be immaterial since you'll be comparing them in a way that is unlike how you will be using them.
Old 25th December 2010
  #19
Quote:
Originally Posted by Lynn Fuston View Post
The first article was written by Eddie Ciletti, not me. Can't help you there.
Just read Eddie's test setup. If you are using identical mics placed very close to each other (as he was) sourcing different preamps, then you can invert the polarity of one and sum their outputs, looking at the level of the sum and adjust until it disappears, or as nearly as possible. I would use a digital or high resolution meter for this instead of your ears. I've seen people adjust for what they thought was an audible null and the difference signal was still -70 dBFS, as opposed to -130 dBFS or greater, which is what I consider acceptable. With two different mics in two different places, I doubt you'll see -130.

With your setup, using one mic, that won't work.
Old 25th December 2010
  #20
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monkeyxx's Avatar
Quote:
Originally Posted by Trakworx View Post
Colored preamp differences are usually easy enough to hear.
+1, just do a couple of "similar enough" takes of some familiar material and make a judgement there. I don't think matching the volume for playback is that hard, or that critical, but I'm not a preamp designer. Do you match levels with phase flipping when you're comparing two distortion pedals or acoustic guitars??
Old 25th December 2010
  #21
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Scott Whigham's Avatar
 

Quote:
Originally Posted by steveschizoid View Post
Forgive me if this is a stupid question, but why not "reamp" a vsti/soft synth?
Quote:
Originally Posted by Jerrick View Post
Thats what id do. Put together a 1min long track of all samples, drum track, keyboard, a guitar loop, vocals, whatever. Have it playback in a room with your mic of choice, which will never have to move.
Great ideas if I was testing the pres on a variety of sources but this is purely for my guitar. I could care less how it sounds with cellos, singers, synths, etc.
Old 25th December 2010
  #22
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Scott Whigham's Avatar
 

Quote:
Originally Posted by Lynn Fuston View Post
Try this. Pipe a 1K tone into a speaker that is positioned in front of the mic at a level that approximates what the acoustic source will be (vocal, gtr, whatever). Record that and read the peak value. Then swap preamps and try to get the level the same. Because of the adjustments on the preamps, you may not be able to get closer than 1 to 5 dB. Then take those two recorded tones and match them up on playback so that they are identical. Now, without touching the playback levels, you are ready to record to those two tracks with those two preamps and have them matched closely enough to make informed, and not mistaken, decisions.
Brilliant - thank you! Reminds me of how I used to use a pedal compressor to generator white noise before I had an IBP. I'd move one of the mics until the wave forms lined up. Someone had suggested it and I thought, "OMG - why didn't I think of that!" Same with your suggestion.
Old 25th December 2010
  #23
Quote:
Originally Posted by monkeyxx View Post
+1, just do a couple of "similar enough" takes of some familiar material and make a judgement there. I don't think matching the volume for playback is that hard, or that critical, but I'm not a preamp designer. Do you match levels with phase flipping when you're comparing two distortion pedals or acoustic guitars??
Really?

Before doing that, try this.

Take the same take, exactly the same, put it on two adjacent channels and make one .5 dB louder than the other. Then compare the two and see if you hear any difference. Which one do you prefer? Try to forget that the source material on both tracks is IDENTICAL.

I've done this test so many times to the chagrin of the listeners when they discover there is NO difference between A and B except level. All those attributes they thought they heard? Purely imaginary.

And I agree that if you're going to be using it for guitars, listen to guitars.
Old 25th December 2010
  #24
Quote:
Originally Posted by Lynn Fuston View Post
If you will be recording everything through that splitter, then yes, it would tell you what the preamps will sound like when sourced by that splitter. If not, then what you'll learn will be immaterial since you'll be comparing them in a way that is unlike how you will be using them.
+1. The splitter's transformer will color the sound.

Preamp shootouts are hard to control. And we tend to focus them too much on isolated sounds, neglecting how they will work in a mix. Nothing beats using a pre in sessions over time to see if it works for you. I prefer to demo or buy them and then keep them only if they make themselves indispensable.

.
Old 25th December 2010
  #25
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Scott Whigham's Avatar
 

Quote:
Originally Posted by Trakworx View Post
Preamp shootouts are hard to control. And we tend to focus them too much on isolated sounds, neglecting how they will work in a mix. Nothing beats using a pre in sessions over time to see if it works for you. I prefer to demo or buy them and then keep them only if they make themselves indispensable.
Well, I record mostly solo, instrumental guitar so "in a mix" is sort of not what I'm after for this test. And I'm with you on how to decide on gear. However I'm not a studio, I'm just a "home studio solo, instrumental" musician. These are similar pres and, since I only two channels, if I can get rid of one channel, I'd like to since it costs a fortune!
Old 25th December 2010
  #26
Quote:
Originally Posted by Lynn Fuston View Post
Really?

Before doing that, try this.

Take the same take, exactly the same, put it on two adjacent channels and make one .5 dB louder than the other. Then compare the two and see if you hear any difference. Which one do you prefer? Try to forget that the source material on both tracks is IDENTICAL.

I've done this test so many times to the chagrin of the listeners when they discover there is NO difference between A and B except level. All those attributes they thought they heard? Purely imaginary.

And I agree that if you're going to be using it for guitars, listen to guitars.
Yes, the "louder sounds better" psychological effect is well documented here on GS. That's why I listen at varying levels - to negate that effect, and to simulate real world situations. After all, I'll have my hand on the fader when I'm mixing that guitar...

"Does this tone still feel powerful when I turn it way down? Does it make me smile when I turn it way up?"

Precise level matching doesn't help me with those questions when it comes to electric guitar.

It helps me a great deal when choosing a DAC.

.
Old 25th December 2010
  #27
Quote:
Originally Posted by Scott Whigham View Post
Well, I record mostly solo, instrumental guitar so "in a mix" is sort of not what I'm after for this test. And I'm with you on how to decide on gear. However I'm not a studio, I'm just a "home studio solo, instrumental" musician. These are similar pres and, since I only two channels, if I can get rid of one channel, I'd like to since it costs a fortune!
Oh, OK. In that case to me the most important factor would be if either pre imparted some kind of tonality that positively affected my playing. I have had many experiences where euphonic recording equipment helped inspire better performances.

Barring that, I'd just perform reasonably controlled comparisons. If they are so similar that you have a hard time deciding, then you can't really lose...

.
Old 25th December 2010
  #28
On the record I'm currently working on, we're switching back and forth between those two exact pres on the guitars - it's definitely a tough choice you're making.

I found the LTD-1 to be thicker sounding (and it has a more extensive EQ) while the Aurora seems a bit more open and a bit less colored.

I like the Aurora for versatility and the Chandler for thickness/color. TOUGH choice.
Old 25th December 2010
  #29
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monkeyxx's Avatar
Quote:
Originally Posted by Lynn Fuston View Post
Really?

Before doing that, try this.

Take the same take, exactly the same, put it on two adjacent channels and make one .5 dB louder than the other. Then compare the two and see if you hear any difference. Which one do you prefer? Try to forget that the source material on both tracks is IDENTICAL.

I've done this test so many times to the chagrin of the listeners when they discover there is NO difference between A and B except level. All those attributes they thought they heard? Purely imaginary.

And I agree that if you're going to be using it for guitars, listen to guitars.
I'll have to try that tomorrow
Old 25th December 2010
  #30
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ARIEL's Avatar
Quote:
Originally Posted by Lynn Fuston View Post
If you will be recording everything through that splitter, then yes, it would tell you what the preamps will sound like when sourced by that splitter. If not, then what you'll learn will be immaterial since you'll be comparing them in a way that is unlike how you will be using them.
But wouldn't using a splitter like the Box that radial makes be a good option ?, The whole point is too hear the difference between 2 or 3 pre-amps all from the same source . By splitting it 3 ways you will be able to exactly how each preamp colors the sound. I did a test with 3 mics , each in a different preamp and I heard differences but when I used my radial splitter box , 1 mic into , I found the differences to be not as big - The problem was trying to get 3 mics perfectly on 1 source altered the sound more than the splitter . My tests were done on drums , snare , kik tom etc . I found that to be the best test for me to hear preamp colors.I also did a test with the direct out with 2 additional splits all into the same preamp - Millenia HV-3D and I found it to be very transparent. All 3 channels sounded identical in playback . I wanted to see if the 2 additional splits had tier sound altered . This is what I used Radial Engineering - JS-2 Jensen transformer equipped mic splitter .
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