Phase issues w/ mic placement & DI

[taylor16]

Witg my Heil PR40 needing to be placed 10" away from the grill, I've noticed some phase issues with my clean DI signal coming from my Noble. To get around any phase issues in a life setting, are there any good quality mics that be placed right up to the grill of the cab?

 

[Jay Corwin]

When all else fails, stick a 57 in front of it.

 

[Ulf_Hansson]

When all else fails, stick a 57 in front of it.

Yes! Ye olde trusted 57, my go-to mic.

 

[Yetti Bass]

One option, is put on a good set of headphones, and while someone is playing the bass, take the mic and move it until the sound is good. Sometimes that means going closer to the speaker, and other times I have set the mic back several feet away from the speaker. Whatever works best for the blended sound you are looking for.
or just use either one, and forget the blend

 

[beans-on-toast]

Mic placement is one way to fix it but may not be enough. Worth trying first.

Another is to fix it in the DAW Phase Correction Plugin – InPhase | Waves. A bit expensive but you can demo it for free. There are other similar products.

There are analog phase alignment tools as well: [Invalid or Expired Link Removed]

 

[rudy4444]

Witg my Heil PR40 needing to be placed 10" away from the grill, I've noticed some phase issues with my clean DI signal coming from my Noble. To get around any phase issues in a life setting, are there any good quality mics that be placed right up to the grill of the cab?

The TYPE of mic isn't going to make any difference with phasing, or at least not from a relative standpoint.
The only thing that's really going to make a difference is mic position, and you really need to check phase relationship to determine how far out of phase it is.

Listening to headphones won't reveal anything unless you collapse the signal to mono, and that sometimes doesn't work with human hearing.

Use a phase meter or sum the two inputs to mono and listen through a single speaker.

 

[Grumry]

I've always had the re40 right in the grill with no problems. Great results, actually.

Then slightly delay the input of the di to meet the time of the signal hitting the mic.

 

[Yetti Bass]

Listening to headphones won't reveal anything unless you collapse the signal to mono, and that sometimes doesn't work with human hearing.

The Headphones help me when moving the mic myself. They are quite revealing when listening for phase issues, in fact I can slowly move the mic further, or closer to the speaker, until it sound "hollow" or weird due to the phase relationship between 2 sources. Sometimes I will lock in the mic at that point, and then flip the phase on the mic preamp, and it's day night. I understand what you are saying regarding checking a mix in mono to listen for phase problems, and that's very true when stereo micing....but specific for Bass guitar, the signals are typically panned in the center, and not a left / right stereo. Although some old 60's recordings have like the entire drum kit mono left, and bass guitar mono right...I guess it had it's time out of the center pan position. lol

 

[Badwater]

One way it to align the tracks in the DAW. Depending on your DAW, you may have this ability to make very small adjustment in the track to align them.

 

[miiitch]

another issue with such a big distance from mic to cab: stage bleed will be a lot stronger than that of close-micing

 

[seamonkey]

Dump the mic. Use the DI and you can always re-amp later if you think there's some benefit to a mic on a cab.

 

[lakefx]

One way it to align the tracks in the DAW. Depending on your DAW, you may have this ability to make very small adjustment in the track to align them.

This is what I do, especially with kick drum and overheads. It's really easy. Just zoom in so you can see a peak, then align peaks for both tracks.

 

[silky smoove]

The TYPE of mic isn't going to make any difference with phasing, or at least not from a relative standpoint.

Intrinsically you are 100% correct, but in practical terms for the OP's situation it actually can make a difference in the phase relationship. I believe the reason the OP is placing his PR40 back a minimum of 10" from the grill is to reduce proximity effect. With the mic placed off the grill, the phase relationship between the DI sending signal down a cable at roughly the speed of light compared to a mic picking up a signal across 10" at the speed of sound becomes greater than if the mic were placed right on the grill. If the OP were to use a mic like the venerable RE-20 which can be put right on a source with considerably less proximity effect than most mics the phase relationship will have the potential to be much more coherent.

That said, I almost never mic bass cabs right on the grill if I'm using a DI, and either live with the phase issues, or correct them in post.

One way it to align the tracks in the DAW. Depending on your DAW, you may have this ability to make very small adjustment in the track to align them.

This may or may not work. Phase is both time and frequency dependent, and time aligning two tracks in a DAW only accounts for the time portion of the equation. Line them up and you'll be in phase at the point you're aligning with mixed results following. Add EQ and compression to the mix and the whole thing potentially goes out the window again. Typically I find a time-aligned mic/DI combination to sound better than without it, but I would rather use a phase correction tool that accounts for both time and frequency.

 

[taylor16]

@silky smoove Totally correct. The Heil is just so "boomy" that it needs to be that far away from the cab for my needs. And keeping a "clean" tone from my Noble early on in the signal chain gives me plenty of low end. Hence my interest in a mic to pick up my "dirty" effected tone that can simply be put against the cab to 1) minimize negative interference from poor phase alignment, and 2) minimize bleed from other sounds sources (kick drum, guitar, etc).

Any recs?

 

[silky smoove]

The RE-20 is tough to beat in terms of not caring about proximity effect. It's my favorite bass cab mic when I don't want to spend a lot of time auditioning mics and placements. Throw it anywhere in the room or right on the cab and it delivers. It might not be the best for all situations, but it will always give you something workable.

If you can manipulate things in post my favorite approach is to use any of the wonderful phase correction plugins available today, and then allow yourself the flexibility of placing the mic when wherever you want it as opposed to being limited by technical issues.

 

[ofajen]

The only mikes immune to proximity effect are true pressure omni mikes. If you want accurate rendition of the sound right up by the grill, a good omni mike will give you that.

A budget option that is actually an incredibly useful mike is either an EV RE-50 or EV 635A. They are substantially similar dynamic omni mikes. They roll off just a little on the low end, and don't do much above 13K, but they are surprisingly useful on many things, from bass to piano.

Otto