Monday, October 31, 2011

Review of the AVENSON STO-2 Omni Microphones

WOW. So I just picked up these weird little Avenson Audio STO-2 microphones. Originally heard about them from a forum friend mentioning them used on Overheads with great success. This is the type of "friend" that would usually use 414s, Coles ribbons, or 251s on overheads, so I was like, "uhhh...why are you using this $550 pair of mics when you could be using a $20,000 pair?" I was a little skeptical at first, especially considering their aforementioned price - $550US for a pair. However, I kept hearing about it and did some more research and finally picked up a pair.

They come in this beautiful cedar case and are built well. They're weird little mics, reminiscent of Earthworks, Naiant, and other mics of that sort. They are omni capsules and they're very tiny capsules at that. At first thought you might think "man I bet the low end on those sucks" as the diaphragm is so small it's like, how could it possibly get all that good low end goodness?

What I found was quite shocking. These little mics are actually very neutral sounding, in fact, almost a little bit dark! Such a surprising outcome considering the bright nature of most modern microphones. I first tried it on stereo acoustic guitar. Did a simple setup, 3:1 style spaced mic'ing running through some Vintech pres with no EQ. The results were impressive. Very smooth top end, NOT HYPED at all, not brittle or tinny. I played three different levels of guitar - quiet, average, and heavy strum. In the mix, I probably would have added some top end to the quieter strummed parts, maybe even the normal playing, but the heavy strum was great! Nice and smooth transients.

I flipped the mics over and tried them as drum overheads, again a simple spaced pair. WOW did these pick up the toms great. I was really expecting this to be the mic's weak spot - saying to myself "alright, it can do an acoustic guitar mic'ed up close, but can it deal with toms and kick drum low end without making it boomy and muffled?"

Well, it did. It sounded great, again very natural and smooth. Again, a little on the dark side, which depending on the type of song it could very well fit just fine. However, I decided to add a bit of EQ to the mics to observe how they took processing - i.e., you start boosting and all of a sudden you realize how terrible the high end on the mics really is. Yet once more I was pleasantly surprised. These mics EQ like ribbons sometimes do - very easy to boost and cut here and there without exposing weirdness in the tonality of the mic. I was able to easily bring out the crack of the snare and the zing of the cymbals, and it still sounded great afterward, go figure.

My favorite part about these mics is how they respond to the transients - both acoustic guitar and drums have some serious sharp transients at some times. These mics performed famously, softening them up, making them nice and natural, if not a little bit tamed. I found it to basically outpreform most all of my "go to" microphones on heavy strummed acoustic guitar, and my collection for this source includes 414s, Neumann KM184s, AKG 451s, some expensive tube mics, and some ribbons. It was smoother, more neutral sounding, and just easier to keep in control. Side note: This mic I found to be most opposite of the AKG 451, which is a very hyped, bright and clear sounding microphone. GREAT for Martins and darker guitars, quieter guitar parts, and quiet drummers. Almost no self noise. This mic, however, its warmer, smoother top, not hyped, and a little noisy -- which leads me to my next point...

Everyone on the net gripes and worries about ONE feature of this mic - its self noise. Technically speaking, the mic has a very high self noise. However, when I tested the mic on acoustic guitar and drums, the only time I even NOTICED the noise was in the "quietly played" acoustic guitar, and even then it's pretty minimal compared to the sound. It's noticeable, especially on long held out chords, super quiet finger-picking patterns, etc., but anything strummed normally, or even remotely quiet, it will mostly be irrelevant. And I can tell you, if this acoustic guitar was going in a mix of vocals and other instruments, you better throw out your worries - you aren't going to notice the noise one bit. If you were planning on making an arrangement with finger picked acoustic guitar and vocal only, the hiss on these mics may bother you too much.

One thing that is interesting is that many of the popular plugins today (Waves API, V Series, CLA series, SSL series, etc) all have self noise by design. You can flip off the "analog" switch and remove this noise, but still the theory serves that noise is not the end of the world. Tape had hiss, and much of it than these Avensons.

All in all, SO impressed with these little mics. If you've never experienced the difference that a decent pair of SDC mics can do, you may try these, especially if you record a lot of acoustic instruments (acoustic guitar, drumkit, strings, pianos, etc).


  1. Thanks for the great review! I'm always pleased when people dig the way the mics work.

    Brad Avenson

  2. Brad - I LOVE the mics. They saved my @$$ the other day doing a metal session. Used them on overheads for a more neutral sound, which really helped tame all the cymbal work going on. Big toms, fat snare, nice tone. They have also become my new go-to for heavy handed acoustic guitarists.