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 rig 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 )
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.
i never liked mkh8040 because of myths. there are many alternatives.