Microphone Comparison : Line Audio CM3 ORTF “vs” Sennheiser MKH 8040 ORTF

I recently bought a second-hand pair of Line Audio CM3, mainly to use them as a second (rear) pair of mics in addition to my main Sennheiser rigĀ  in Double ORTF setup). The CM3 is made in Sweden and is a relatively cheap/cardioid/condenser/pencil microphone. Please note that the CM3 is now discontinued and replaced by the similar CM4. Click here to learn more.

This article is a quick comparison/shootout of a pair of CM3 “against” a pair of 8040, both in ORTF configuration.

I recorded both pair of mics into a Sound Devices MixPre-6 at the same gain level to get a fair comparison, then I matched the loudness to the same level, other than that, no processing have been applied.

The raw and level-matched recordings are included below :

Keys : Frequency Response and Transients

8040 ORTF / 43db of gain :

CM3 ORTF / 43db of gain :

8040 ORTF / matched to -23 LUFS

CM3 ORTF / matched to -23 LUFS

Moving Shaker : Stereo Image and Frequency Response

8040 ORTF / 43db of gain :

CM3 ORTF / 43db of gain :

8040 ORTF / matched to -30 LUFS

CM3 ORTF / matched to -30 LUFS

Roomtone : Noise Floor and Frequency Response

nb : windows are open

8040 ORTF / 56 of gain :

CM3 ORTF / 56 of gain :

8040 ORTF / matched to -35 LUFS

CM3 ORTF / matched to -35 LUFS

the test setup

Here are the spectrograms if you wanna take a look at the frequency response and ultrasonic spectrum.

Keys :

Sennheiser MKH 8040 ( click to enlarge )
Line Audio CM3 ( click to enlarge )

Roomtone :

Sennheiser MKH 8040 : by design the noise is rejected in the ultrasonic range. ( click to enlarge )
Line Audio CM3 ( click to enlarge )
  • The Line Audio CM3 pair / cheap is a good addition to my toolkit. These mics should work fine alongside the 8040s in a surround setup. Plus they are very light and relatively small and good looking. (yeah that counts too)
  • The CM3 have a natural and flat frequency response which is good for ambiences recordings.
  • The CM3 are way less sensitive than the 8040, I measured approximately 10 to 12db lower output with the same gain on the recorder.
  • When level are matched in post, noise is less audible on the 8040 because of the noise rejection in the ultrasonic range (although this can be a problem when sounds are pitched down for design purposes. We’ll talk about this in another article)
  • Ultrasonic response is pretty good on the CM3.
  • To me the stereo image is better with the 8040 pair (Moving Shaker example).
  • 8040 are RF-biased, to my knowledge the CM3 are not, which can cause issues in damp conditons.

I’ll try to upload more examples in the future if some of you are interested.

aXL

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Noise Floor Comparison : Sennheiser MKH 8040 ORTF – LOM Usi – Zoom H4n – Sony PCM A10

I decided to round up some of my mics and my 3 field recorders to do a little experiment. I wanted to compare the perceived noisefloor between different pieces of gear :

  • a pair of Sennheiser MKH 8040 in ORTF into the Sound Devices MixPre-6 ( center 8050 not used in this example )
  • a pair of LOM Usi Pro into the Sound Devices MixPre-6 ( a.k.a LOM XLR below )
  • a pair of LOM Usi ( non pro ) into the Sound Devices MixPre-6 3.5mm aux input ( a.k.a LOM 3.5 below )
  • Zoom H4n onboard mics in XY
  • Sony PCM A10 onboard mics in XY

Before you listen to the sound examples I’d like to add this : I know this is not a super scientific way to compare S/N ratio and self noise. I don’t pretend giving a thorough review of the listed gear above, consider this post as a quick comparison between 5 setups in 2 completely different situations.

These are all configurations that I used a lot / still use in various recording situations, this comparison is not meant to declare which equipment is fantastic and which is crap as this would be irrelevant.

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The first example is a simple apartment roomtone with construction works outside , I matched the recordings level based on the perceived loudness of the distant hammer hits,Ā  I switch between the tracks every 10 seconds or so, my good friend Bob will remind you what you’re listening to :

So ? What do you think ? With this first example only I’m pretty sure everyone must think the same… Click below to read what I think.

To me the 8040 + MixPre-6 combo is the obvious winner here, followed by the two variants of the fantastic LOM mics which weirdly perform pretty much the same way while one pair is plugged via XLR / 48V and the other via 3.5 mm Jack / Plug-in Power.

At first “glance” it seems like the LOM mics are quite noisy but to be honest I’ve been using them for a long time now and they are really good versatile mics, especially for the price. This roomtone + level match doesn’t do them justice. You can hear them all over my sound libraries or free sound packs.

The ” losers ” are clearly the H4n and the PCM A10 which are way “noisier” than the others and not well suited for such quiet recordings. You’ll note that the noise is distributed differently across the spectrum though.

Keep in mind that what you hear is the sum of the mic + recorder preamp.

Well okay the Zoom goes SHHHHHHSSHSHSHHSHS while the 8040/SD combo goes shhhh, but you can’t stop there to make a statement.

To me the only conclusion that we can draw from this first example is that high end gear like Sennheiser mics and Sound Devices recorders are better equiped to capture clean/quiet sounds than the small handheld recorders. Does that make the H4n and the A10 bad recorders ? I don’t think so.

I made very good recordings with my trusty old H4n, sounds that I still use and edit and I also recorded crappy sounds with my Sennheisers into good preamps, even though each 8040 is worth 6 times the H4n…. In short, the gear doesn’t make everything, it’s more about the ability to adapt to the recording situation and your equipment than the gear itself.

PS : the sound level of the files here is not a “normal” roomtone level, in a sound editing session, a roomtone would sit at a way lower level than this, thus the noise perception.

NFC - screenshot pt edit v2

The second example is quite different, I played around with a leatherman and keys in front of the mics, both have lots of sharp transients and a very dynamic/unpredictable quality. The kind of sound with which you want to keep a lot of headroom while recording.

Not so obvious this time right ? They do sound different obviously but with a sound like that, noisefloor is not a problem anymore, at least in my opinion. If I had to choose, for this particular sound, I’d probably pick a mix between the Zoom XY + LOM “AB” over the 8040s.

If you want to grab the full length, high res files to compare, click the link below :

Free Download

Now, of course for any serious recording session I would choose the Sennheiser LCR setup in the Cinela,Ā  I’d also take my pairs of Usi, and MixPre-6, no doubt it will give you better results. Oh shoot, I also need power, wind protection, a mic stand, …Ā  You get the idea ? The whole kit doesn’t fit in less than 2 bags.

The Sony PCM A10 ( + a small wind protection ) fits in the shoulder bag I carry everyday, the best recorder is the recorder you have.

There are plenty other combinations that I didn’t cover here, but for example a Zoom H4n ( or equivalent ) + a pair of LOM Usi + a small USB powerbank + one of these = super lightweight kit and quality kit to travel with, perfect for recording clean ambience sounds on the go.

aXL.

extra :Ā  two exterior sounds recorded with the PCM A10 onboard mics just to give you an idea

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Old German Siren Recording – Martin Horn Signal

I had the opportunity to get my hands on this “old” german siren, ( I’m not sure how old it is exactly by the way, if someone knows please let me know in the comment section). Anyway, it looked cool and I knew I wanted to record it but I didn’t know if it was still in working condition.

I asked a friend to help me, we jumped into the car and drove to a quiet and isolated place so we could try to make it scream without attracting too much attention as we were convinced it would be super duper loud and that an old school german siren in 2019 Belgium would seem … at least strange or even alarming aha…

The instructions on the siren metal plate said ” 12V ” so … with earplugs in place, we grabbed a pair of car jumper cables and connected it on my car battery.

The result was … quite surprising, to say the least, it sounded like a small chainsaw mixed with a sporadic duck quack :

Martin Horn – 1st try :

After a good laugh, we decided to have a look under the hood and use our tremendous knowledge of old german siren to see if something looked odd or broken inside.

Without fully disassembling the thing, which wasn’t planned anyway, we saw what appears to be 2 magnets mounted symetrically on both sides of a coil. My genious friend noticed that one of them missed a spring and a metal part that seemed to apply pressure on this very magnet.

OK
NOT OK
We tried again, but this time one of us manually pushed the magnet down to bring it closer to the coil…. and VOILA :

Martin Horn – success

It was already a bit louder ( even though not crazy loud as we thought ) but more importantly the tones and pattern felt right. You can hear that the beautiful chainsaw sound is still there but I guess it’s part of the charm of this oldie.

We then recorded it properly, 2 times ” broken ” and 2 times ” working ” , each time close and distant and … that was it, there was not much more we could do with it, and I was not really prepared to tape it onto the car and record dopplers ahah.

Back to the studio I edited/cleaned/metadata’ed it and decided to keep 2 versions of the siren sound (because you never know) : with and without ” the chainsaw “.

So I dropped it into iZotope RX and removed as much of the buzzing thing as I could without damaging the tones of the horns. I’m pretty happy with the result, what helped me is that the “unwanted” sound was more or less “noise” ( in RX lingo ) and what I wanted to keep untouched was “tonal” . So using a touch of spectral denoise and a pinch of spectral repair I managed to attenuate the chainsaw thing to a great extent.

Here are the before/after examples along with their spectrograms :

Ā 

Martin Horn – original audio

ORIGINAL ( click to enlarge )

Martin Horn – RXed audio (close)

Martin Horn – RXed audio (distant)

RXed ( click to enlarge )

If you’re interested in having the sounds, please let me know in the comments below and I’ll consider adding them in the next Free Sounds pack.

aXL.

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Microphone Comparison : Sennheiser MKH 8040 ORTF “vs” LOM Usi AB

For ambiances recording, I almost always use the LCR setup in the Cinela blimp, this setup is composed of a Sennheiser MKH 8040 ORTF setup + 1 MKH 8050 added for ” Center ” channel, which is really nice to have once in the edit room.

I often add the excellent LOM Usi omni microphones to get another sonic perspective and more edit possibilities afterwards, so I came up with the idea of mouting the Usi mics inside the Cinela basket in a unorthodox “AB” configuration.

Ā 

please note that I didn’t use the ” center MKH 8050″ in the examples below and that the Usi are plugged into the 3.5mm AUX input on the MixPre-6,Ā  the preamps are a bit noisier than on the normal XLR inputs in which the Sennheisers are plugged, so don’t use this as a noise floor comparison but more to compare stereo image and overall mic tones.

Here are the recordings for comparison:

rain on roof – 8040 ORTF

rain on roof – LOM Usi AB

quiet night – 8040 ORTF

quiet night – LOM Usi AB

no denoise applied here, I think the “weird” sound is due to the distance (approx. 1km) and sound diffraction through the valley

distant motorcycle – 8040 ORTF

distant motorcycle – LOM Usi AB

wind in tree in the background

diffuse car pass by – 8040 ORTF

diffuse car pass by – LOM Usi AB

For those who prefer a Pro Tools session, click on the link below :

aXLsound - ORTF vs AB in Cinela - Microphone Comparison ProTools.zip

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