3 to 1 Rule is vague at best

[Ping Pong]

Greetings,

In an effort to apply the 3 to 1 rule for mic spacing and minimal phase issues it is said that the 2nd mic should be 3 times the distance from the first mic that the first mic is from the source. It is also said that precision is of great importance to get the mics perfectly in phase.

How can one realistically use such a rule (3:1) when the point of source is questionable as with a mic pointed at an amp grill cloth or drum overheads. Grill cloth is not the source the speaker is. The speaker is not flat it is conical. One would have to remove the grill cloth to acurately measure from the targeted area of the non-flat speaker cone to derive the actual 3:1 porportion. With drum overheads what is the source? The cymbal, toms, snare,etc.? How can you apply such a rule when the origination of the source is not a precisely fixed point?

Seems that this rule when applied does little to zero you in on "the spot." If may get you into the area but can not precisely deliver perfect phase without one moving things around to finally dial it in. In the case of a DAW it seems so much simpler to record a breif sample of the instrument. Puff up the wave form to maixmum magnification and literally view the multiple wave forms to see if their peaks and valleys are aligned. If not, then re-adjust you mic position and record another sample to see if you nailed it.

No need for superior ears by using such a method.

Or.......one can just not worry about pahse relationships and just record with multiple mics and when in the DAW simply slide the out of phase track in time until it aligns with peaks and valleys of the other mic.

Am I on the right track here or hopelessly out of phase ; o ]

Thanks for your time!!!!

[The Dougfather]

In the case of the drum overheads you might want to consider an XY config over a spaced pair to practically eliminate phasing issues.

For the rest...to quote...'There are no rules, only guidelines' The true way to test for phasing is to switch in to mono and listen for a phasey type sound. If you need to try and reverse the phase of one of the mics to remedy it. Load up a 1 band EQ in PT and the phase reverse switch is the circle with the line going through it...i think. It turn orange when selected.

Cheers

PS: Have you read 'Modern Recording Techniques', it's a great reference book to have?

[peppertree]

The 3:1 rule is absolute horse***** and should never have been uttered much less declared a "rule". Ignore it. Forget you ever heard of it. It's only purpose is to make you feel inept and screw up your tracking process.

Yes you should listen for phase issues when placing mics. Yes you should correct for any you run into after the fact when possible by time-shifting. No you should not feel there is some magic "rule of thumb" that will either prevent phase problems or solve them.

[Ping Pong]

Thanks for your point of view. Your statement:

"The true way to test for phasing is to switch into mono and listen for a phasey type sound."

Yes, it is a way to check. I am not sure about it being the "true" way. You did not answer the question of the DAW technique of "aligning wave forms" being relevent.

As you said, many of the techniques are guidelines only so they get you in the right area. It is through your own perseverance that you achieve perfection ; o ]

Anyone else?

[Slim Shady]

Yes, it is a way to check. I am not sure about it being the "true" way. You did not answer the question of the DAW technique of "aligning wave forms" being relevent.

When you put in a CD do you watch it or listen to it? You can make your PT session look as aligned and pretty as you want, it doen't mean it's going to sound good. Not to mention you can align waveforms all day and all it takes is one plug-in on one track to induce a little delay and your aligning is no longer relvant.

You're working with sound waves, so use your ears.

[Ping Pong]

Now Peppertree sez it like I like to hear it!

Thanks Pep!

[Ping Pong]

Of course when working with sound waves your ears are of great value. But don't think that your eyes don't help too. And if you are experiencing latency then.....correct for it. Not everyone is 21 years of age with fresh ears. And if you are over 60 years old you may have some hearing challenges. So....does this mean you can no longer record and mix. Hoooooie! Your eyes can help make up for what your ears may not be able to hear.

How about this: If it looks right it is right.

Just kidding........the ears are obviously the best choice but not to be considered the only input source.

Thanks to all for the input!

[Naagzh]

Ping Pong -- I think your interpretation of the 3:1 rule is a bit misleading. The reason the distance between mics should be greater than 3 times the distance from the source is to minimize phasing. And the reason this works is that the two mics' signals are now significantly different from each other. Since the two signals have less in common, there is less interference (constructive or destructive) between the two soundwaves.

As for drumset, consider an overhead mic and a snare mic. These two mics, in a typical setup, obey the 3:1 rule, because the overhead is a few feet from the snare, while the snare mic is only a few inches away. This will alleviate, but not eliminate, most phasing problems.

The two overheads themselves, however, will require additional care to minimize phasing. XY is one method, but a spaced pair can work well, though it helps if they are equidistant from the snare (since the snare is a main focal point of the drumset). The other elements of the kit aren't in danger, because with a spaced pair, the mics are positioned differently, and thus record sufficiently different signals.

As for the waveform, it helps to remember that it is a 2-D computer graphic, and nothing more. It serves to tell the location of a recorded event, but tells barely anything of a signal's sound. Did you ever notice that a snare drum's waveform looks suspiciously like a bass drum's? Yet, the two signals are audibly (to say the least) very different. An overhead track and a snare track may be more similar, but lining them up isn't a phase panacea (in fact there's no such thing, except a mono recording), because the distance between mics has created very different signals. But could it help to line them up? Maybe, but it could also hurt. Try this experiment first:

Close mic a snare, and then set up an overhead 3 feet away, and a room mic 15 feet back. Line up the waveforms. Impressed? Try the same thing with a guitar amp.

[stoneinapond]

When you put in a CD do you watch it or listen to it? You can make your PT session look as aligned and pretty as you want, it doesn't mean it's going to sound good. Not to mention you can align waveforms all day and all it takes is one plug-in on one track to induce a little delay and your aligning is no longer relevant.

You're working with sound waves, so use your ears.

This should be printed out and placed on the monitor of every DAW newbie.

As does this.

...As for the waveform, it helps to remember that it is a 2-D computer graphic, and nothing more. It serves to tell the location of a recorded event, but tells barely anything of a signal's sound.

Just for the record, I'm over sixty years old and can still record a good sounding track (according to others - I would never make such a statement myself.)

[bluesboyiv]

What's wrong with a source being out of phase? Right now I have a drum kit that I'm mixing that actually sounds better out of phase. The snare was too deep and making the bottom snare out of phase loosens that up a bit. Throw in some Who and Rolling Stones records and throw them into mono. The snare all but disappears.

Just about every single Rhodes piano I have ever recorded and mixed has been horribly/wonderfully out of phase. That's really the only time I find it sounds any good though, I'm a fan of the Wurlitzer I guess.

I can't stand sitting in front of the computer lining up waves. In order to minimize that I usually spend extra time setting up drum mics to record with minimal phasing. I would suggest doing that before you begin to enter the tedious process of aligning eight to sixteen drum mics. Believe me, that's not fun at all.

Ian