M/S with different Mid mics - AUDIO SAMPLES

This thread is in response to a previous thread on M/S mic selection. I made three quick M/S recordings with my acoustic with very old strings. All mic positions approximately the same, aimed at about the 15th fret (cause I had a capo on 5th), on axis and about 4 inches from the strings. The side level was generally about 14 dB lower than the mid.

Audio samples can be found here.

They are labelled as such:

"K2 and K2"
Mid: Rode K2
Side: Rode K2

"K2 and B1"
Mid: Behringer B1
Side: Rode K2

"K2 and 58"
M/S 3:
Mid: Shure sm58
Side: Rode K2


My opinion? For mid/side recordings, you're probably gonna want some matched mics or something pretty darn similar. The reason being the way mid side works. The side uses a clone of the signal with one panned left and and inverse panned right. If you take out the mid, this sounds very weird, as I'm sure you all know. Crazy phase problems going on here. If you use two identical mics, using the mid as your primary and bringing up the level of the side till you get enough width, that weird phasing is not an issue. You don't notice it as it works together with the mid signal. If you use a different mic, no matter what you do, they won't work together and you get the phase problem. It just sounds weird and out of place. The more different the mic is, the worse it sounds - as can be heard from the 58 sample. After this test, I suggest you use the exact same mic or something very similar. Otherwise you might as well be doing the old 'clone and track and flip the phase and send it off to the side for stereo width' trick. That never works well unless you do mid side with the same mic.

I'd also like to add that the side mic level was actually highest with the matched pair. It certainly doesn't sound like it to me. That's because it works so much better with the mid that you don't notice the phase issues.

And remember the mid mic is your primary mic, that's where most of the sound color comes from.

The End.

I would certainly agree that my results are inconclusive. These tests are great to do because they make us think and learn and better understand things. I'm always happy to re-evaluate my conclusions.

As for the different frequency response of the K2, figure 8 and cardiod have the same response. Figure 8 is just made by two cardiods back to back (hence the lack of a figure 8 frequency response chard on Rode.com, it only has cardiod and omni). Then again that exact response is quoted for on axis. It gets tricky. If I were using this with figure 8 and omni, then we certainly are working with quite different responses. It gets a bit to complex to really try and work out in your head when you bring in all the angles and everything. Best to not think too much and just record!

Maybe my experiment suggests that M/S will PROBABLY be easier to make work well with a closely matched pair (I do understand that they are not exact) but you might still be able to get good results with mismatched mics if you are a) lucky and/or b) spend the time to make it work well.

As for M/S in general, I'm not really a fan for my recordings. It doesn't really come up as being useful in my music. But it's always good to know it and understand it as best as I can in case the need arises. But at the moment I find much more use with a coincident (working with various angles depending on what I need) pair.

No worries. I'm actually going to do a test today of one of the hot topics in recording today - 44.1 vs 48. I need to do it to hear it for myself. So of course I'll share my findings too. I'll record a bunch of instruments to make a quick 15 second song with lots of high frequency stuff going on, lots of processing, probably even over processing. A song with lots going on is more important than just a single acoustic side by side comparison and I remember Bob Katz suggesting that you really hear the differences only when you start to do some calculations (apply effects). I'm interested to see how it goes. I don't expect to hear a difference but we'll see. And as we'll be dealing with all different performances with a lack of high end gear, this certainly can't be a conclusive test! But this is something I have been needing to do for myself for a long time... If you have any suggestions, please let me know. Especially if you have read anything about specific things where the differences can become apparent.