Why you should never use multi pattern mics

[ccaudle]

All good in theory, but have you listened to the Chesky recordings made with a C-24 in 90 deg. figure-8 mode? Most of those are really gorgeous sounding.
If someone came up in a recording session and said "no, you can't use that mic in figure-8 mode, KK said you should never" I would just have to say don't be daft, if it sounds good it is good.

 

[Recording Engineer]

Right. We’re where art and science blur together. Scientifically, we’re concerned with phase, but phase is a big part of our daily world.

I’ve heard Mark of Samar Audio on video where has the same premise as this topic, on why he likes the idea of LDC for cardioid, SDC for omni, and the ribbon for fig-8. But that’s just him speaking scientifically. I’m sure his favorite recordings don’t match that logic.

 

[tomas.borgstrom]

Interesting topic and great post. I've heard of it before but not in such detail. When I record pop music this is generally not a big problem. You're searching for interesting sounds and the multiple close mics and heavy processing during mix will make a lot more mess.

When I started recording classical music (mostly organ or ensembles in churches) I suddenly ran into problems I hadn't noticed before. Blumlein with the LDC's I had sounded really bad. For some reason MS worked better. I ended up using mostly AB with Pearl CO22 which are fixed omni but still two spaced diaphragms. Now I have a couple of different nice stereo pairs including DPA. I generally prefer the sound of LDC's and two years ago I betatested LDC omni with one diaphragm from Nordic Audio Labs (not released yet). The image was big and much sharper than all LDCs I've used before. It was also easier to hear the differences between various distances, both between the microphones and to the source. Now I own three and I've made my finest true stereo recordings with them.
For some reason I don't enjoy the "state of art clean microphones" on grand piano. I tend to use a pair of M269c or M49 (both multipattern) in omni. In the studio they are also my first choice for close stereo recordings of instruments or vocals, often AB omni. In lack of better words it just sounds right and closer to a final product. In a larger acoustic environment with complex material all my modern solid state microphones with single pattern sound a lot better.

 

[kingkorg]

It makes me really happy to see so many quality replies from so many valuable contributors. Quite a few things i learned myself in this thread. Thank you all!

I wanted just to correct myself in one aspect. Depending on capsule design, sound traveling from the back travels not just the distance of the backplate thickness. There is the delay network, a maze of sorts, so there is some additional distance it has to travel. K47 has direct through holes, and the backplate is thinner, so the path is much shorter compared to k67.

K67 is actually about 8 millimeters thick, plus the "maze" sound has to go through.

 

[Icantthinkofaname]

I used one mic for mid and one for side in terms of the signal, but of course it didn't actually make a literal mid and literal side recording with some intense finessing, it ended up being the cleanest way to create a stable stereo image of the target that sounded OK in the (terrible) recording environment, and it was coherent enough that it didn't make my neural network reverb removal spit it back out. It took a while, but I did manage to get something usable out of it.

Is that reverb removal DeRoom Pro?

 

[soliloqueen]

Is that reverb removal DeRoom Pro?

nah, izotope RX. i do post-production dialogue cleanup for a living.
View attachment he will rule the world 2.mp3
yep, this is the same recording. that little crackle from the cheap lav on "Right?" was hardest to get rid of, but it did end up a little awkward. here's a previous version before I did that
View attachment he will rule the world.mp3

but let's keep on topic from this point on

 

[ricardo]

There's loadsa stuff on this thread I'm tempted to answer but I'll just comment on one.
Original C12 & CK12 were designed by Bernhard Wiengartner of AKG for the BBC. He was miffed that Austrian Radio weren't really interested at the time.
For the BBC, Fig-8 in Blumlein was the MOST important pattern and early C12s had the best response/polar BW & AKG could achieve. That's the reason C24, which would have had early CK12s, sound good in Fig-8. It was the main mike in the Royal Albert Hall for the Proms for many years, replacing a pair of 4038 ribbons, and later replaced by a Calrec Soundfield Mk3A
It's only later when Pop engineers started to use C12 & its progeny in cardioid that AKG and its imitators abandoned Fig-8 performance and concentrated on cardioid.
I'm interested in this as I think it is possible to tune LDCs with K67 backplates to replicate Bernhard's original intent .. the most important feature being good Fig-8

 

[soliloqueen]

Tuning the chamber in a k67 does all sorts of wild stuff. You only ever see capsules with the standard 40um spacer on the market though. I feel like this is something someone should do more scientifically

 

[kingkorg]

Nice, somewhat complementary video. It shouldn't be an issue for intermediate DIYer to replicate the results. I have a couple of capsules like this, made them in the past. Not a rocket science, nor really unique idea.

I've also taken it a step further, made a 10cm ball with a 34mm large omni capsule

 

[tomas.borgstrom]

Nice, somewhat complementary video. It shouldn't be an issue for intermediate DIYer to replicate the results. I have a couple of capsules like this, made them in the past. Not a rocket science, nor really unique idea.

I've also taken it a step further, made a 10cm ball with a 34mm large omni capsule

This is the microphone I mentioned in my previous post. Sounds great and definitely different to all the microphones I've used before. I think it's really refreshing when a designer of a commercial product says "this is not a microphone for everybody".

 

[ccaudle]

Nice, somewhat complementary video. It shouldn't be an issue for intermediate DIYer to replicate the results. I have a couple of capsules like this, made them in the past. Not a rocket science, nor really unique idea.

I've also taken it a step further, made a 10cm ball with a 34mm large omni capsule

The measurement microphone companies never stopped making larger diaphragm omni capsules. Microtech Gefell have a 1" diameter capsule with 11dB (A-weighted) self-noise. The DPA 4041 has 8dB(A) self-noise. Nice and quiet for orchestral recording.
Both the MG and DPA are expensive, I don't see any way to add to my collection.

So not sure why that video from Nordic Audio makes it seem like no one has made any 1" omni capsules in many decades.

 

[Recording Engineer]

That video was just a teaser of things to come… We certainly don’t know what he’s actually presenting there yet. I do know that what you’re speaking of specifically are 1” omni metal diaphragms though; stainless steel and nickel, respectively. At the very least, that’s a big difference from a Mylar-type diaphragm; not that we know that that is what he’s doing or not. In the NU100K, he’s tensioning aluminum, not growing nickel or anything.

The Microtech Gefell M960 is the only current production I can think of. Of course I shoot myself for not jumping on trying Kelly Dueck’s extremely short-lived Vertical Microphones The Space with its in-house LDO-1 capsule. Can anyone else think of any? MBHO makes one, but it’s dual-diaphragm. Does that count in this discussion? Maybe, maybe not. Did T.H.E. Microphones ever produce something of the like? I don’t remember and their website is down. Are they even still around?

 

[GeorgeToledo]

There's loadsa stuff on this thread I'm tempted to answer but I'll just comment on one.
Original C12 & CK12 were designed by Bernhard Wiengartner of AKG for the BBC. He was miffed that Austrian Radio weren't really interested at the time.
For the BBC, Fig-8 in Blumlein was the MOST important pattern and early C12s had the best response/polar BW & AKG could achieve. That's the reason C24, which would have had early CK12s, sound good in Fig-8. It was the main mike in the Royal Albert Hall for the Proms for many years, replacing a pair of 4038 ribbons, and later replaced by a Calrec Soundfield Mk3A
It's only later when Pop engineers started to use C12 & its progeny in cardioid that AKG and its imitators abandoned Fig-8 performance and concentrated on cardioid.
I'm interested in this as I think it is possible to tune LDCs with K67 backplates to replicate Bernhard's original intent .. the most important feature being good Fig-8

Konrad Wolf developed the CK12, C12, and some predecessors for that matter.

 

[kingkorg]

Any thoughts on using both triodes as impedance converters for each capsule side, dual transformers, and combining the signal at the output?

 

[emrr]

Any thoughts on using both triodes as impedance converters for each capsule side, dual transformers, and combining the signal at the output?

Why combine at all if you've taken it that far? Ok, make a dual output mic that has an option to combine at the output - now you need a bunch of extra switches and pots AND a TOTALLY knowledgable operator OR a complex auto pattern logic system. Is it better?

 

[kingkorg]

That is so simple and good answer that i feel stupid for even asking

 

[emrr]

https://groupdiy.com/threads/tlm67-modification-to-dual-output.68096/
I can't say it sounds any different doing it in post here than using the stock single electronics, I still have a set of those too.

 

[tomas.borgstrom]

Any thoughts on using both triodes as impedance converters for each capsule side, dual transformers, and combining the signal at the output?

I'm interested in this too. Pearl microphones developed TL-4 in the early 70's. It's a very early transformerless (hence the name TL) low noise fet microphone with one amplifier for each side. It had 4mm between the membranes and according to the founder and designer Rune Rosander it didn't have any noticeable phase issues below 8K.
I don't know if it was the first of its kind but Rune was very progressive. In the 50's he developed their rectangular capsules which they still use. Schoeps CMT-20 released in 1965 is often claimed as the first solid state microphone. I have an article about Pearl TC-4 from the same year. KM84 was released in1966 and U87 in 1967.

Both TC-4 and TL-4 are great microphones. Today Pearl also have the DS70, a quad microphone with two capsules mounted on top of each other at an angle of 90 degrees.

 

[Marik]

Right. We’re where art and science blur together. Scientifically, we’re concerned with phase, but phase is a big part of our daily world.

I’ve heard Mark of Samar Audio on video where has the same premise as this topic, on why he likes the idea of LDC for cardioid, SDC for omni, and the ribbon for fig-8. But that’s just him speaking scientifically. I’m sure his favorite recordings don’t match that logic.

Indeed, I've been saying so for quite awhile and keep reinforcing this idea every time. My preference for the true SDC pressure omni and fig8 ribbons because those are native patterns and as such, they are much more natural sounding due to the way of forming their flat response.

That is, the fig8 is a mass controlled system with diaphragm tuned to the lowest frequency, so when going up the response naturally drops 6dB per octave. However, the forces on diaphragm get increased with the same rate each octave up--that's how we get linear response. Those times when the ribbons had limited response on top of bandwidth are long gone and modern ribbons can by far surpass fig8 dual diaphragm condenser mics response on top end (not to mention all deficiencies of low end response of the fig8 condensers). This is not to mention that ribbon because of its narrow size has BY FAR superior polar response than any condenser could possibly dream.

On the contrary, the pressure omni is a stiffness controlled system tuned to the top of the bandwidth, so its frequency response gets formed in the same manner, just opposite direction and the polar resonse is defined only by physical size of the diaphragm.

With the cardioid LDC the things are much more complicated. Since they are tuned into the midband (usually around 1000Hz) above that frequency they are mass and below are stiffness controlled. This by itself creates a huge (up to 60dB) peak, which needs to be flattened with what's called "acoustical resistance". This resistance is what responsible for more strained, compressed, and less natural sonics. Also, double diaphragm designs introduce additional challenges and problems, so in general, it is much easier to optimize and fine tune a single diaphragm capsule (also called 'vented') for frequency, phase, and polar responses.

Best, M

 

[soapfoot]

Indeed, I've been saying so for quite awhile and keep reinforcing this idea every time. My preference for the true SDC pressure omni and fig8 ribbons because those are native patterns and as such, they are much more natural sounding due to the way of forming their flat response.

That is, the fig8 is a mass controlled system with diaphragm tuned to the lowest frequency, so when going up the response naturally drops 6dB per octave. However, the forces on diaphragm get increased with the same rate each octave up--that's how we get linear response. Those times when the ribbons had limited response on top of bandwidth are long gone and modern ribbons can by far surpass fig8 dual diaphragm condenser mics response on top end (not to mention all deficiencies of low end response of the fig8 condensers). This is not to mention that ribbon because of its narrow size has BY FAR superior polar response than any condenser could possibly dream.

On the contrary, the pressure omni is a stiffness controlled system tuned to the top of the bandwidth, so its frequency response gets formed in the same manner, just opposite direction and the polar resonse is defined only by physical size of the diaphragm.

With the cardioid LDC the things are much more complicated. Since they are tuned into the midband (usually around 1000Hz) above that frequency they are mass and below are stiffness controlled. This by itself creates a huge (up to 60dB) peak, which needs to be flattened with what's called "acoustical resistance". This resistance is what responsible for more strained, compressed, and less natural sonics. Also, double diaphragm designs introduce additional challenges and problems, so in general, it is much easier to optimize and fine tune a single diaphragm capsule (also called 'vented') for frequency, phase, and polar responses.

Best, M

Excellent post!

A follow-up question, if I may: the old Western Electric/Altec 639b achieved its directional pattern by combining a pressure omni moving-coil and a bidirectional ribbon, each in their native pattern, summed to create cardioid.

What would be the advantages/disadvantages to reimagining this fundamental principle in a more-modern design? Perhaps a pressure condenser combined with a ribbon, selected/designed to have very similar bandwidth characteristics.

Obviously the two elements could not exist in the same physical space which may present a trade-off. Are there other reasons this would be inadvisable?