Been to "Electrical Audio?"

[Fran Guidry]

Steve Albini is hosting YouTube videos on audio recording working out of his studio. The clip I stumbled onto is about recording acoustic stringed instruments. I was pleased to see a terrific demo of a vocal and guitar recording done with dual figure 8 mics. The results using a Beyer M130 and an unspecified AEA ribbon are vastly better than I ever achieved with dual diaphragm LDs. The positioning he uses is quite a bit different than my approach and I'll definitely try his configuration next time.

Here's a link to the section on isolating sounds using figure 8 pattern: https://www.youtube.com/watch?v=Ualm3rCZRz0&t=368s

and here's the whole video:



Fran

[KevWind]

Interesting,,,, and makes perfect sense to help improve the isolation and reduce bleed
To clarify he is using 4 microphones

He has two (unspecified small surface mount mics) mounted at the bass and treble sides of the bridge = ostensibly to enhance the guitar detail and will be basically isolated from the vocal

Then the Beyer M130 on the guitar with the null towards at the mouth

And the AEA (N8) on the vocal null towards the guitar

I do a fair amount of vocal and guitar at once recording
I don't have any surface mic's but will give the two figure 8's mics a try in that position

[ChuckS]

I liked how they muted one, then the other, figure 8 to demonstrate how much isolation there is between the guitar and vocal sources.

Also, using two separate mics gives more flexibility in placement than using a single stereo figure 8 mic.

[AcousticDreams]

Originally Posted by KevWind

He has two (unspecified small surface mount mics) mounted at the bass and treble sides of the bridge = ostensibly to enhance the guitar detail and will be basically isolated from the vocal

Those are the Crown GLM 100 microphones. They are modestly priced at a little over two hundred dollars. Not sure if they are still in production.
https://www.electricalaudio.com/micr.../crown-glm-100

Here are the questions I have:
* Do figure 8 isolate more than Hypercardiod? And if so why?

* I often see two different approaches to recording acoustic instruments.
A. One where there is lots of acoustic panels to absorb.
B. And the other is Very Large Open Rooms, with either reflective brick walls, or wood walls. And or Wood Floors In this case they have brick walls and wood floors.

These two techniques are polar opposites. If I were to guess, I would surmise that the key to the success of second technique is a very large room. Possibly the large size acts also provides isolation. Because the reflected frequencies take too long to come back to the microphone? Thus giving an isolation effect & reducing phasing problems. But still getting the lovely sound of reflected brick and floor frequencies. Working more like a secondary room mic? This is just a wild guess on my part. But there sure seems to be enough studios who take the approach of a large room. I know I have always enjoyed playing in a room with a wooden floor.

I only briefly skimmed this video and plan to go back for a more intensive - critical listen later.

What are your guys technical takes on why the Large rooms with reflective surfaces work? Or do you think the absorption panels & no reflectivity always rule?

[Fran Guidry]

Originally Posted by Knives&Guitars

...
* Do figure 8 isolate more than Hypercardiod? And if so why?
...

You can observe the differences if you find some high quality polar pattern diagrams. The easiest way to understand the difference between bidirectional and hypercardioid is to recognize that a hypercardioid is a cross between a bidirectional and a cardioid. And a cardioid has significantly less rejection than a bidirectional.

There are two fundamental mic patterns:

omni - diaphragm over a closed chamber
bidirectional - diaphragm over a wide open chamber, basically no chamber at all

Other patterns are derived from these two by tuning restricted openings in the chamber.

Fran

[AcousticDreams]

Originally Posted by Fran Guidry

You can observe the differences if you find some high quality polar pattern diagrams. The easiest way to understand the difference between bidirectional and hypercardioid is to recognize that a hypercardioid is a cross between a bidirectional and a cardioid. And a cardioid has significantly less rejection than a bidirectional.

There are two fundamental mic patterns:

omni - diaphragm over a closed chamber
bidirectional - diaphragm over a wide open chamber, basically no chamber at all

Other patterns are derived from these two by tuning restricted openings in the chamber.

Fran

I did not know this about Bi Directional. Then one my deduce, that in some ways, Bidirectional might be the least restricted of the polar patterns? As it is neither tuned or obstructed.

Of course there are lots of other things that account for a mics sonic character. Just because it may be the least restricted, does not not necessarily equate to total accuracy. However, in theory it does offer some interesting notations as to the possibility.

[Doug Young]

Originally Posted by Fran Guidry

You can observe the differences if you find some high quality polar pattern diagrams. The easiest way to understand the difference between bidirectional and hypercardioid is to recognize that a hypercardioid is a cross between a bidirectional and a cardioid. And a cardioid has significantly less rejection than a bidirectional.

This is one of those things that's fun to play with on the Townsend L22 mic (which you can do with the free plugin and pre-recorded demo tracks without owning the mic). Since you can change polar patterns in the software and also "rotate" the mic virtually in the software, you quickly get a feel for things like off-axis response and how well the null in a figure 8 works, etc. it's kind of a fun virtual simulation lab for learning about mic patterns.

Those are the Crown GLM 100 microphones.

So basically they're adding a "pickup" which is common thing to do when you want some isolated guitar. That'd be fun to try with those mics, tho, seems like they might get a pretty nice stereo spread from 2 contact mics on each side of the saddle. Might be able to come close with just 2 lav mics.

[ChuckS]

duplicate post

[ChuckS]

Originally Posted by Knives&Guitars

... [snip]...

* I often see two different approaches to recording acoustic instruments.
A. One where there is lots of acoustic panels to absorb.
B. And the other is Very Large Open Rooms, with either reflective brick walls, or wood walls. And or Wood Floors In this case they have brick walls and wood floors.

These two techniques are polar opposites. If I were to guess, I would surmise that the key to the success of second technique is a very large room. Possibly the large size acts also provides isolation. Because the reflected frequencies take too long to come back to the microphone? Thus giving an isolation effect & reducing phasing problems. But still getting the lovely sound of reflected brick and floor frequencies. Working more like a secondary room mic? This is just a wild guess on my part. But there sure seems to be enough studios who take the approach of a large room. I know I have always enjoyed playing in a room with a wooden floor.

I only briefly skimmed this video and plan to go back for a more intensive - critical listen later.

What are your guys technical takes on why the Large rooms with reflective surfaces work? Or do you think the absorption panels & no reflectivity always rule?

One potential benefit of a large room is because the power of the audio signal is inversely proportional to the square of the distance. For example, if the distance of the reflected signal is increased by 3x, its power is reduced by 9x. Getting the power of the reflections down, as compared to the on axis signal, reduces the ratio of the reverberant:direct sound and reduces phase type of problems.

[Bob Womack]

Originally Posted by Knives&Guitars

Those are the Crown GLM 100 microphones. They are modestly priced at a little over two hundred dollars. Not sure if they are still in production.
https://www.electricalaudio.com/micr.../crown-glm-100

Here are the questions I have:
* Do figure 8 isolate more than Hypercardiod? And if so why?

No, their pattern is different. A hypercardioid responds well at the front, restricts and often colors the response at the sides, and then has a small response area at 180' degrees where it responds well again. A figure eight mic responds strongly at the front and rear of the mic and STRONGLY reduces the response with less coloration than a hypercardioid, as you approach 90'.

A couple of things obtain: Hypercardioids allow some response on the side and by virtue of the phase cancellation network in the headshell or body of the mic, some frequencies are cancelled in the off-axis portion of the pattern. As a result, if you are mic'ing another source that is in the off-axis portion of the pattern, it may be allowed in in an ugly form. Also, live, hypercarioids often end up with their back high response lobe pointed at the monitor. That's often less than happy. It's all in the application.

* I often see two different approaches to recording acoustic instruments.
A. One where there is lots of acoustic panels to absorb.
B. And the other is Very Large Open Rooms, with either reflective brick walls, or wood walls. And or Wood Floors In this case they have brick walls and wood floors.

These two techniques are polar opposites.

Yes. You see the same thing in control room deisgn:
1. Westlake and derivative control rooms have reflective surfaces at the front, absorptive surfaces at the rear, and "thrust" ceilings poking down in the space above the mixing position. They emphasize creative a lively but idealized version of a more typical listening environment.
2. LEDE "Live-End, Dead-En" control rooms have an absorptive front end and a diffuse rear end. The front shell is designed to be as anechoic as possible but as much as possible to steer reflections away from the listening point. The back diffuse area is designed to break up all reflections off the back wall into many quieter reflections, preventing summation with the direct signal from the speaker that would create phase issues and creating essentially a short-order reverb that gives the impression of a larger listening room. The main thrust of this design is to isolate the direct dispersion from the speakers to the listening area and to offer as phase-coherent a listening environment as possible. I'm sitting in an LEDE control room right now.

the upshot of this is that in any collection of acousticians and recording engineers there will be at least as many opinions of proper mic technique and sound treatment as their are people in the room.

What are your guys technical takes on why the Large rooms with reflective surfaces work? Or do you think the absorption panels & no reflectivity always rule?

There are sounds that sound weird in dead rooms and need the near reflections of a livelier room to sound natural to the ear when recorded. My studio has a live room and a medium/dead room. I use both. Drums love the live room, for instance.

Bob

[keith.rogers]

It's a good demo, but I haven't watched all of it (just guitar + vocal so far). It's obvious the room is quite large, compared to the space a lot of us work in, and I'd assume it's well treated.

That, along with the singer not having peel-the-paint pipes probably go a long way to reducing the sound picked up by the back half of those f8 mics. (@ChuckS mentioned this.) You can hear more of the guitar in the vocal than the other way around, which suggests the guitar is being played with more power than the singing, which is what it sounds like, though I don't know how much of the guitar is just the f8 mic here. He says "vocal microphone" when muting or soloing, but at the start he describes multiple mics on the guitar. Maybe this is described later, or I'm just not paying attention, but obviously those surface mounted mics are not going to pick up much vocal unless there's vocal energy turning the top into a dynamic mic.

IOW (my glass-half-empty POV...), it's interesting to pro-grade studio settings, but if it was really usable and produced these kinds of results routinely, *and* it was really necessary to produce those "evocative" recordings that were suggested, everyone would be doing it. (Oh, and plus, it's really only necessary if you're trying to punch in just one or the other tracks, right?)

[FrankHudson]

I'll agree, an interesting video. One of the real music engineers I worked with when I was with a radio network first hipped me to the figure 8 null point tactic though I've never successfully set it up. The large part of that is that I'm self-engineering all the time when recording acoustic, so the mics would get in the way in my setup as I worked the DAV and so forth.

I was surprised how well the Crown lavalier mics worked, even when soloed on the string instruments. I looks like they are no longer in production, and the nearest I could see that look similar are for wireless setups, which might even be a bonus, but increase costs beyond my "I'd like to try that" budget. The Crown mics look like they may have been flat "side-address" kinds of things, while most lavalier mics I see in current listings are "end address."

I did wonder how much the contact or lavalier mics (not sure which was used bilaterally by the guitar bridge) were mixed in on the guitar demonstration. The isolation on the voice was quite good, better I think that I can get with my iRig Acoustic Stage, which is an inexpensive way to get a more isolated guitar signal with a microphone that doesn't sound as artificial as a UST type pickup.

Someone upthread said you only need some significant level of isolation when you need to punch in a clam fix. There are also other issues:

Wanting to do different settings/effects on guitar and voice.

Vocals picked up off axis by close guitar mics tend to sound thin, "filtered" in a bad way. Given that my vocals are already marginal this one really bugs me.

[Chipotle]

Neumann put out a nice series of videos on recording singer-songwriters doing voice and acoustic guitar simultaneously. Each video covers a different technique. Part 3 shows using Fig8 mics:



(Part 1 is about using a single mic; Part 2 is using hypercardioid stage/dynamic mics).

I have experimented a bit with using a Fig8 mic like this (KSM44) on the guitar, although I only had the one multipattern mic at the time so the vocal was a regular cardioid set as best I could do pick up the vocal but put the guitar behind it.

I only had a small room to work in (about 12'x15') and as many here have surmised, the reflections picked up from the rear lobe weren't all that pleasing. The guitar had way too much "room" and not in a good way. It also picked up room reflection from the vocals, which not only sounded bad but ruined the separation. Putting some gobos right behind the KSM44 helped a bit, but I decided that in a small, untreated space the dual Fig8 probably wasn't going to be the best choice.

My studio room is even smaller, but I've done a bunch of treatment--and I now have another multipattern mic--so maybe I'll give it a shot in there at some point.

[Rudy4]

I have posted links to Doug Fearn's "My take on music recording" podcasts before, but the episode titled "Microphones!" is a great way to gain understanding about how this all works, and particularly the unique qualities of true bidirectional patterns vs. "figure 8" patterns.

Some of his other podcasts detail his microphone selection and process for close isolation of a performer singing and playing an instrument simultaneously.

[kurth]

Isn't it ironic his own vocal recording is seriously flawed. For an audio engineer, he needs to learn how to mic a masked person jaja