My New C S Cardioid Mics

[A440]

I just got a pair of Core Sound Low Cost Cardioid mics with the Low Sensitivity option, and gave them a tough job to start with: the Mars Volta's rock at full blast, one of the loudest shows I've been to in some time.

I did not run them through an attenuator, but went direct to Mic-In and: NO PRE-AMP OVERLOAD. NO DISTORTION. True low sensitivity. I posted an excerpt in the Gallery.

http://forums.minidisc.org/index.php?act=m...&cmd=si&img=499

The sound is different from the omnis that I'm used to: more clinical in a way, with a flatter soundstage, and less bass than there was in the club. Core Sound (at www.core-sound.com ) says the frequency response is 40-18,000 Hz, with a rolled-off bass below 100Hz, so that makes sense compared to the 20-20,000 Hz of my omnis.

I'm curious what people think of the sound. It's a pleasure not to be using an attenuator, but I do miss some of the richness of the omnis.

[greenmachine]

Is this the way cardioids sound in general? For me it sounds as if you would have put omnidirectional ones into a pipe, much like a horn-driven speaker.

How did you place them?

It may be convenient not to use an attenuator or other additional gear, but at the expense of the sound? Are there no low sensitivity, high quality omnis?

I understand that there's a need for different directivities among microphones, but for my (our?) purposes (3-D ambient stereo recording in general), i've never felt the need of having to use cardioids.

What you're describing as 'missing richness' and 'clinical sound' is maybe the inability to capture true 3-dimensionality combined with their limited frequency range and 'tunnel sound'.

Edited May 8, 2005 by greenmachine

[nulldogmas]

I have the regular CS cardioids, not the low-sens ones, but it sounds like what you're describing is just their lack of bass. That rolloff, plus the cutoff at 40Hz instead of 20Hz, makes a huge difference in my experience. For examples, check out this recorded with my cardioids:

http://www4.archive.org/details-db.php?med...2004-03-12.shnf

with this recorded with CS (low-sens) binaurals:

http://www4.archive.org/details-db.php?med...2005-02-25.shnf

Different venues, but still, a huge difference in "richness." Of course, the upside is that no bass means no preamp overload - I never had a distortion problem in all the shows I used my cardioids, whereas the binaurals haven't been so lucky. (As noted in the other thread I just started.)

[A440]

The mics were both clipped to one lapel, one above the other about 5 inches apart. Not ideal, but I was at an angle to the PA system and there was loud conversation going on by my other side. The placement might have something to do with the flatness.

I have recorded another loud show straight-on from right in front of the soundboard, mics pointed directly ahead about 6 inches apart--a perfect position except for having to brace against the moshers. I'll upload a song shortly, but this time I'm going to try some EQ to restore some bass.

(EDIT: It's in the Gallery now.)

[A440]

I uploaded a direct comparison: Omnis and Cardioids side-by-side during the same song. The cards don't do well in the comparison.

http://forums.minidisc.org/index.php?act=m...&cmd=si&img=502

[greenmachine]

The extreme bass rolloff makes the recording to sound very thin and artificial.

Why do I hear so much noise from the crowd by the way? Are americans listening to rock concerts at opera house levels? hehe

[A440]

I agree with you, greenmachine, about the bass rolloff. In theory I had always been dubious about losing a chunk of the music in order to get it into the MD--to me, attenuation was a better choice than rolloff. There is, however, a big business in bass rolloffs, so I had entertained the distant possibility that I was wrong. And the ability to focus forward in a noisy room tempted me toward the cardioids.

Anyway, here's that other hard-rock cardioid recording from the ideal spot, right in front of the soundboard.

http://forums.minidisc.org/index.php?act=m...&cmd=si&img=505

This time I used EQ to compensate for the limited bass. Have to say, it's a nice clear recording.

[greenmachine]

Your recording has some nasty resonances at about 11 kHz, what could be the cause?

Also there's a somewhat too low lowpass at about 13 kHz, propably from the mp3 encoder?

With an average bitrate significantly above 128 kbit/s it shouldn't cut the high frequencies so abrasively.

Did you transcode from one lossy format to another?

Edited May 13, 2005 by greenmachine

[A440]

Thanks for the spectrum analysis. Very interesting.

I recorded at Hi-SP, not PCM, because I expected a long set. Then I used dbpoweramp with Lame to encode to mp3.

The 11K peak could be a resonance of the room, or it may be in the mics. It could also be some quirk in Audacity's Amplify function.

"The Low Cost Stealthy Cardioid microphones have a frequency response of from 40 Hz to 18 kiloHertz. They have a rising frequency response over that range with the exception of a slight (2 dB) peak between 9 kHz and 12 kiloHertz and a bass response fall off of roughly 6 dB per octave starting at 100 Hertz."

If I don't send these back, I'm only going to use them for truly noisy rooms and for music without a lot of bass.

A lot of people see that cardioids are more expensive and assume that they are thus automatically better. Cardioids are clearly for a specialized function: directionality. These are bottom-of-the-line, it's true, but from this experience I'm more convinced than ever that omnis are the way to go.

[greenmachine]

I recorded at Hi-SP, not PCM, because I expected a long set. Then I used dbpoweramp with Lame to encode to mp3.

May I ask you which setting you used there? ATRAC3plus Hi-SP doesn't cut at 13 kHz.

If I don't send these back, I'm only going to use them for truly noisy rooms and for music without a lot of bass.

I wouldn't use them for music at all if accuracy is important, maybe for directional one track (mono) voice recording, like interviews.

[A440]

I assume you mean the dbpoweramp settings. Lame encoder, VBR min160- max 320

Stereo, 44100 Hz.

I'm as suprised as you are about the cutoff at 13Khz. The EQ curve I used with Audacity was flat (after 100 hz) up to 20K. Core Sound is reputable, and if they're saying the frequency response is 40-18K, I would believe them.

There are a lot of people who use cardioids for music, and Sound Professionals' FAQ recommends cardioids as the "if you only have one mic" choice. But maybe they're talking about cardioids at twice the price, or people are so relieved not to have the preamp overload that they're willing to accept the lack of bass. Beats me.

[greenmachine]

Core Sound is reputable, and if they're saying the frequency response is 40-18K, I would believe them.

To know is better than to believe in some cases. Microphones don't cut with such a high order (extremely fast falloff), usually about 6dB/oct, only digital (or extremely complex analogue) filters can do that, so it's propably the mp3 encoder setting.

I guess dBpoweramp's built-in LAME encoder is not configured optimally by default.

I'd suggest to use 'alt preset standard' for optimal results (under advanced options), or - if you really have to and know what you're doing - other presets, described here.

Maybe you could update the file with the suggested setting, and we'll see if it still has such a low cutoff.

[cbud]

It may be convenient not to use an attenuator or other additional gear, but at the expense of the sound? Are there no low sensitivity, high quality omnis?

I understand that there's a need for different directivities among microphones, but for my (our?) purposes (3-D ambient stereo recording in general), i've never felt the need of having to use cardioids.

←

There are low sensitivity omnis from Core Sound.

But, I think A440 has the stealthy option, which only comes in cardioid.

I have the Low cost regular sensitivity binaurals. They sound great at aucostic shows. But they will over load the pre-amp at almost every loud concert, unless you are far away. I plan on also buying the low sensitivity omni mics, not the stealthy cardioids, for loud shows.

I really don't see why anyone would pay more for mics, in my limited experience, the quality of my recording depends more on the PA system and the drunks around me, then my mics.

[javertim]

But, I think A440 has the stealthy option, which only comes in cardioid.

The CSBs and the CSCs look identical, actually, except for the vent holes at the base of the cardiods. They're both "stealthy" models.

[Jonesyl1]

1.Mars Volta Rocks

2.Audition, Cool Edit Pro, (whichever) Rocks.

I like you guys already.

What kind of omnis is A440 talking about?

I'm looking to purchase soon.

[A440]

What kind of omnis is A440 talking about?

←

I'm talking very basic binaurals: Sound Professionals BMC-2, itty bitty things in a mini-gumdrop-shaped rubber housing. Sometimes Sound Pros has them on sale on their own site for $29, or around the same price on eBay (search for soundpro99 , which is the name they use as an ebay seller).

The soft rubber housings allow me to use this clip:

http://www.bhphotovideo.com/bnh/controller...u=217592&is=REG

which fits snugly around the tapered rubber end. Some ofther mics that use the same capsules aren't that easy to find clips for.

They are stealthy, secure in those clips and they sound good. Core Sound apparently uses the same basic mic capsules for its binaurals--they have exactly the same specs--but claims to do some extra tweaking and to make sure they're well-matched pairs. The clips on the Core Sound cardioids are great, so I assume binaural ones are also good. But the price is higher.

If you want to hear some recordings I and others have made with various mics, you can go to the Gallery here or go to the Yahoo mailbox (mail.yahoo.com) livefromminidisc with the password 1minidisc1 .

Greenmachine, I changed to Lame's alt-preset-extreme, for higher-fidelity mp3, and uploaded it to the gallery.

[greenmachine]

Looks (and sounds) much better now, but i'd still like to know if the resonance comes from the microphones, it's really annoying...

The drop at slightly above 19 kHz is intentionally caused by the mp3 encoder and should not be audible anymore, the mics would propably capture frequencies even beyond 20 kHz with a slight falloff.

Edited May 14, 2005 by greenmachine

[greenmachine]

1.Mars Volta Rocks

2.Audition, Cool Edit Pro, (whichever) Rocks.

I like you guys already.

What kind of omnis is A440 talking about?

I'm looking to purchase soon.

←

Are you shy? You're pretty often hiding behind a mask for no obvious reason.

Or are you planning to go shopping with a mask and a revolver?

[nulldogmas]

There are low sensitivity omnis from Core Sound.

But, I think A440 has the stealthy option, which only comes in cardioid.

I have the Low cost regular sensitivity binaurals. They sound great at aucostic shows. But they will over load the pre-amp at almost every loud concert, unless you are far away. I plan on also buying the low sensitivity omni mics, not the stealthy cardioids, for loud shows.

I really don't see why anyone would pay more for mics, in my limited experience, the quality of my recording depends more on the PA system and the drunks around me, then my mics.

←

Core Sound does sell low-sensitivity stealthy low-cost binaurals - I know, because I have a pair. They've been great for me so far, though they're "low-sensitivity" only compared to the regular binaurals. (I.e., I still have to watch for preamp overload, though setting the MD to LOW SENS seems to have helped - see my other thread about this...)

I had used CS cardioids prior to these, and agree that there's no comparison - the cardioids are clear, but flat and thin. I suspect this is less from the bass rolloff than from the 40Hz bottom end, which can't be helped by EQing.

[Jonesyl1]

Are you shy? You're pretty often hiding behind a mask for no obvious reason. 

Or are you planning to go shopping with a mask and a revolver? 

←

Yes, I was born shy, so I was forced to become a ninja.

But no actually, I'm gonna go shopping with a mouse and a credit card.

Really I'm just compensating for the lack of personality on my forum posts.

A little ninja wont offend ya.

Okay, that was cheesy.

[greenmachine]

What you're perceiving as bass loss, thin sound or whatever you call it, is caused by the so-called 'proximity effect' of directional microphones. The closer you move from the source, the more bass you'll get, the further you move away from the source, the less bass you'll get. This pickup pattern related characteristic is independent from the price of the microphone, all cardioid microphones show it. They have a flat response at a certain distance (in this example 0.3 m) - for all other distances you need to compensate by equalisation. Omnidirectional microphones don't show this effect.

This characteristic along with other general differences between directional and omnidirectional microphones is explained here:

http://www.dpamicrophones.com/page.php?PID=25

Edited June 16, 2005 by greenmachine

[A440]

Out in the real world, I don't ever really expect to be 30cm from the source.

So here's the basic question:

Why does anyone use cardioids for live audience recording? As I see/hear it, the lack of bass response, the flat soundstage and the necessity to stay immobile outweigh the slight muffling of noise from behind, especially when I can clip omnis to my shirt so my body blocks some noise.

Cardioid fans, I know you're out there--what am I missing?

[greenmachine]

There are several standarized stereo positioning techniques which require the use of cardioid microphones. For unobtrusive recording though, nothing beats the HRTF method in my opinion.

[mrsoul]

Out in the real world, I don't ever really expect to be 30cm from the source.

So here's the basic question:

Why does anyone use cardioids for live audience recording? As I see/hear it, the lack of bass response, the flat soundstage and the necessity to stay immobile outweigh the  slight muffling of noise from behind, especially when I can clip omnis to my shirt so my body blocks some noise. 

Cardioid fans, I know you're out there--what am I missing?

←

A440-

I agree. Having just used the same SP mini omnis to make a great stealth show that was last year ruined by lack of bass and too much wind noise at the same show with cardiods, I am now a firm believer in the use of omnis for stealth recordings.

However, 90% of my recordings are taper friendly environs and I set up my AT853s in mic holders (see below, got those from Sound Pros as well). The cards really cut out some of the bass which is a good thing in most cases and cut the chatter. I also use hypercard elements if the venue is really booming or I am farther away from the source. Cardioids have a great pickup and are my main taping pattern. But, when stealthing, I will forever go omni for the pickup pattern that allows me to move around and when I clip to the front of my shirt (one facing up, one facing down) it does cut a lot of the crowd chatter from behind that otherwise might get on the recording. Wind noise is very limited by omnis and for that alone at outdoor shows when stealth, there is no other element or pattern to use than omni.

Check out this Mic Placement Link for the Oade Brothers info on mic placement. To be honest, I usually just go NOS or something close to 90 degrees straight ahead.

Well, that something about why I like cardioids for my non-stealth and omnis for stealth.

[attachmentid=384]

[kooterb]

My 2 cents, having used both of the Core Low Cost Bi's and the Cards is the Bi's

sound fantastic with headphones and car, but not as great on my living room sound system.

The Cards have a really more defined sound on my living room set. The Cards seem to preform best when you can get them pointed right at the speakers as the Bi's hear what you hear. I'm using a MZ-NH900 with a Sound pro battery.

[jevsah2]

A440,

When recording with your BMC-2's and RS volume control at a large venue, have you experienced any distortion or overloading? Was crowd noise a factor? I noticed the mics do pick up a lot of bass too. Thanks in advance!!

I'm talking very basic binaurals: Sound Professionals BMC-2, itty bitty things in a mini-gumdrop-shaped rubber housing. Sometimes Sound Pros has them on sale on their own site for $29, or around the same price on eBay (search for soundpro99 , which is the name they use as an ebay seller).

The soft rubber housings allow me to use this clip:

http://www.bhphotovideo.com/bnh/controller...u=217592&is=REG

which fits snugly around the tapered rubber end. Some ofther mics that use the same capsules aren't that easy to find clips for.

They are stealthy, secure in those clips and they sound good. Core Sound apparently uses the same basic mic capsules for its binaurals--they have exactly the same specs--but claims to do some extra tweaking and to make sure they're well-matched pairs. The clips on the Core Sound cardioids are great, so I assume binaural ones are also good. But the price is higher.

If you want to hear some recordings I and others have made with various mics, you can go to the Gallery here or go to the Yahoo mailbox (mail.yahoo.com) livefromminidisc with the password 1minidisc1 .

Greenmachine, I changed to Lame's  alt-preset-extreme, for higher-fidelity mp3, and uploaded it to the gallery.

←

[A440]

You can hear some of my recordings in the Gallery and judge for yourself.

I have gotten a tiny bit of overloading at some of the most brutally loud shows. That would be the mic overloading, since the RS prevents the preamp from overloading. (Generally, MD overload problems are from the mic preamp, not the mic itself.) But most of the simply loud shows I have recorded have had no problem with overloading.

There are also recordings, from me and others, in the mail.yahoo.com box livefrommd with the password 1minidisc1 , including a loud rock one.

Crowd noise is a problem. If your ears hear it, the mics pick it up. You just have to get away from the talkers, the "WHOO!"-ers, the clappers, the sing-alongers, etc.

But as I've written elsewhere, using cardioids in the hope of limiting crowd noise introduces a whole new set of problems--limited bass, flattened audio perspective, wrenching changes if you turn--that, for me, outweigh the crowd noise. Cardioids are still going to pick up the crowd within the mic's pickup pattern--in front of you and to the sides. It's a concert, not a recording studio.

The mics don't seem particularly weighted toward the bass--they just pick up what's there. If you can move around, you can try to find a spot in the room where the bass isn't quite as heavy. As long as the bass doesn't overload the MD, then you can always use EQ (bass and treble controls, Sound settings) to decrease the bass when you play back.

I don't understand the fashion for extremely bass-y mixes for live bands--even a bluegrass band I saw the other day!--but you can't fault a mic for good fidelity.

[insrc]

Interesting discussion, keep it going, thanks.

I've seen people post at TapersSection.com: "I wouldn't recommend low cost CSB", so maybe the reason is just in the low cost CSB mic, and not the cardioids in general? A440, don't you have SP-CMC-4 also? How does that compare to SP-BMC-2?

From the SP: Binaural vs Cardioid FAQ it follows that cardioids are better than omni's if you are not close to the sound source (20-75 feet away from it). The only reason for that as I see from the FAQ is that cardioids are directional and therefore reduce reflected sound from the walls and audience noise. The FAQ doesn't even mention bass loss! According to the FAQ omni's beat cardioids only if you are located rather close to the source (like FOB maybe?) in a venue with good acoustics and quite crowd.

This SP FAQ is very convincing towards cardioids and that could be one of the reasons why people prefer them to omni's, but I agree with A440 who question this for the real world. It surprises me that cheap BMC-2 omni mic produce rather good results. I wonder how better would be its more expensive version, BMC-6? Does it come close to DPA 4061?

Here is another quote from TapersSection: "The reason a majority of stealthers use Cardioid pattern mics (unless you've got the money to blow on DPA4061s, of course), is that the results are crisper, and you eliminate some of the audience noise around you."

[insrc]

oh, and I forgot to add that even this bass loss for cardioids seem to be not enough and people use additional bass rool-off in battery box, which now looks even more strange.

[A440]

A440, don't you have SP-CMC-4 also?

←

No, the low-cost CS are the only ones I have for music. (I have the SP-SPSM-16 one-point cardioid that came with my recorder, but that's only useful for speech.) So I'm not condemning all cardioids, but I would suggest anyone buying them look closely at specs. Even Core Sound is weaselly about its specs for the mics I have. It claims 40Hz, then backtracks and says there's a bass rolloff below 100 Hz.

Greenmachine's links suggest that the bass problem isn't only on the cheaper cardioids. But I wish someone with higher-grade cardioids would post some recordings in the gallery.

I don't understand that distance limit in the SP FAQ. I have heard arena-sized sound systems that are clear and loud well past 75 feet and that drown out most of the audience noise. Any decent sound engineer will use the reflected sound to make the music sound bigger and better. And even with my little binaurals, I have sometimes gotten recordings that sound clearer played back than they did at the time.

A lot of the taperssection folks are concentrated on jam-band recording, and for some reason those audiences are real chatterboxes. Perhaps that explains their (unsubstantiated) preference for cardioids, although the real fanatical tapers put the mics up on poles above the crowd anyway. Meanwhile, one person's "crisper" is another one's lack of bass. People who haven't heard good bass response may not know what they're missing.

[greenmachine]

I think SP's FAQ is pretty confusing and contains some vague statements. I don't agree with #6.

Here is another quote from TapersSection: "The reason a majority of stealthers use Cardioid pattern mics (unless you've got the money to blow on DPA4061s, of course), is that the results are crisper, and you eliminate some of the audience noise around you."

However, my goal is not to get a 'crisp' (treble/high frequency-weighted, light in bass) sound, but rather to capture it as neutral as possible. If i want to color the sound in a certain way, i can do it afterwards in post processing. My opinion.

oh, and I forgot to add that even this bass loss for cardioids seem to be not enough and people use additional bass rool-off in battery box, which now looks even more strange.

Many people seem to play back live recordings through loudspeakers (which is actually a pretty bad idea). This way you'll get twice the room information (basically a 'virtual' room -the room in which you taped- in a 'real' room -the room where you play the recording back). Small to medium sized rooms tend to pronounce low frequencies. You have to apply some kind of bass lowering not to get it too boomy through speakers, preferrably afterwards to keep compatibility with playback through headphones.

[insrc]

I would suggest anyone buying them look closely at specs. Even Core Sound is weaselly  about its specs for the mics I have. It claims 40Hz, then backtracks and says there's a bass rolloff below 100 Hz.

I agree, of course. But did you check the specs for BMC-2 as well? I understand it's omni and its frequency responce should be flat, but look below what I've found!

I searched Audio Technica website for frequency responces of their mics. I don't know what is inside BMC-2 (SP site doesn't tell), but its higher price brother BMC-6 has AT803b inside (omni). Cardioid CMC-4 has AT853 inside. Now look at the graphs! They are in the pdf files:

- CMC-4 (AT853) - cardioid

- BMC-6 (AT803b) - omnidirectional

Both mics have the same frequency response!?

I checked the other omni's mics too to be sure it's not a mistake - some are more flat, some are less (for example: AMT10a - super flat, AT804 - less flat).

Let me type the specs now for comparison, note how they look almost the same:

- Core Sound Low Cost Stealthy Cardioid

freq. resp. = 40 - 18000 KHz

low freq. roll off = from 100 Hz at 6 dB/oct

- Sound Professionals SP-CMC-4 (AT853) Cardioid

freq. resp. = 30 - 20000 Hz

low freq. roll off = from 80 Hz at 18 dB/oct

- Sound Professionals SP-BMC-6 (AT803b) Omnidirectional

freq. resp. = 30 - 20000 Hz

low freq. roll off = from 150 Hz at 6 dB/oct

It would be interesting to see BMC-6 vs CMC-4 (or BMC-2 vs CMC-2) comparison. In my opinion low cost CSB/SC is worse in general.

[greenmachine]

- CMC-4 (AT853) - cardioid

- BMC-6 (AT803b) - omnidirectional

Both mics have the same frequency response!?

←

Obviously not, the AT803b shows a pretty strong treble boost. Both microphones have the same lowest and highest frequency response, what's happening in between isn't specified. Other manufacturers specify the frequency response deviation in between a certain range, for example +-2 dB. Audio-Technica for some reason doesn't. You have to look at the graph get closer to the whole truth.

But this graph shows only the on-axis response at a certain distance. Cardioids tend to colour sounds entering the microphone from the sides and the rear less smooth and even than Omnis - the industry names this "the curtain effect". Expressed in a graph it looks roughly like that:

There's also the 'proximity effect' which i mentioned above - the bass response varies for different distances.

These two effects have a strong influence on the frequency response of cardioids under non-ideal, real world situations. Two reasons why i perceive omnis as more versatile.

It's all explained here:

http://www.dpamicrophones.com/page.php?PID=25

[A440]

The capsules in virtually everyone's cheapest binaurals have the same specs as the Panasonic WM-61 or WM-60AT. I don't know how flat the response is.

[greenmachine]

http://www.panasonic.com/industrial/compon...m61_a_b_dne.pdf

http://orca.st.usm.edu/~jmneal/pre_meas.htm

"On average, the mics maintain a remarkably flat response which deviates less than 0.5dB up to 6kHz, transitioning to a gradual rise peaking at +1.9dB at 12.8kHz, and finally settling back to the 0dB reference slightly above 20kHz."