sE Electronics BL8 boundary layer microphone: Throw it on (or at) anything

sE’s latest BL8 boundary microphone will have you surprised at all the tasks it’s ready to take on.

In 1978 it was discovered that when a microphone was mounted flush to a surface the sound it recorded benefitted from some significant gains in coherence, particularly when the capsule of that microphone was placed parallel to and facing the surface (or boundary) itself.

The sE Electronics BL8 carries on the strong conceptual basis of the boundary microphone, with some handy tweaks that make it feel at home just about anywhere (In fact, boundary microphones have been used for years to record the body blows of ice hockey players!).


Built around the same capsule as the celebrated sE8 small diaphragm condenser microphone, the BL8 is designed with versatility and rugged durability in mind.

Throw it in a kick drum, pop it in a conference room, put it in your piano or just have it in the room to record some ambience.

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The satisfying heft and all metal build quality, along with the nitty gritty features of this inconspicuous mic make it not only technically capable of just about any task you could throw at it, but it also feels like it can take them on too.

Three switches on the rear of the unit allow for some distinct shaping of whatever source you give it.

A variable low cut allows you to cut signals below 80hz or below 160hz to reduce unwanted footfall, rumble and to assist the clarity of room miking and speech.

A switchable attenuation pad can lower the mics signal by either 10 or 20 decibels to help it withstand your thundering blast beats or any of your other high SPL sources. 

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The third switch was most exciting to me. It allows for selections of settings labelled ‘classic’ and ‘modern’ which both shape the frequency response of the low mids in their own unique ways to really help to bring out some attack to your signal.

It’s pretty clear that these switches are designed for kick drum recording and the labels are relatively true to their function.

The ‘Classic’ voicing will give a brighter, snappier, 70’s-esque sounding kick drum, while the ‘Modern’ voicing accentuates more of the subby thump, without dropping that snap completely.

Let’s talk polar patterns because the BL8 is interesting. The box pictures 4 polar patterns with a spotlight on the cardioid. This initially confused the audio team here into thinking that the mic has switchable polar patterns.

After a bit of digging we discovered that the BL8 comes standard with a half cardioid polar pattern, however it is also compatible with the sE8’s omni capsule to provide even further variety for your recording needs. 


Doing this requires opening up the mic (easily done with just one screw), unscrewing the cylindrical cardioid capsule and replacing it with the omni capsule from the sE8.

The catch is that whilst these capsules are out there to purchase, they are only readily available as a pair, and coming in at around $360 AUD for the pair, you might as well pick yourself a single sE8 at closer to $290 for the capsule and add another mic to your locker in the process.

We’ve all come across the difficulty of keeping our boundary mics in place inside a kick drum and to aid that the BL8 has been designed with the Kelly SHU FLATZ™ shock mount system in mind which aids in stabilising and isolating these boundary microphones.

Using this system ensures you a consistent, reliable recording and even allows you to transport your kick drum and leave your BL8 inside, which is particularly for gigs on the road.


The design of this microphone really speaks to its qualities. What I hear this microphone telling me is – “yes I can record your kick drum, and I’ll do a great job of it, but don’t hesitate to throw me at some other things too, I might surprise you”. 

The BL8 comes in at around $500 AUD and in the box you’ll get a nice looking red carry case along with your microphone.

For more details, check out sE Electronics.