Mounting a surface-contact pickup

Bob Holo

An artist recently asked me which positions were best for mounting contact pickups such as Ischell, Schertler, Myers. So I'm posting this for two reasons. One is to answer the question, but the other is to test whether I can post videos on this forum instead of the more cumbersome Youtube route.

The answer is that in general, you want to put a contact mic on an area with some mass to it so that there is a minimum mechanical impedance difference. All that means in this context is that the sturdier the area for the contact mic mount, the more efficient the energy transfer is likely to be (within reason - I mean, the neck is sturdy but not where you want to mount a contact mic for obvious reasons, haha)

So in general, try to mount on a brace, at the intersection of multiple braces, or at least near the edge of a brace or near the intersection of braces. YMMV depending on the type & technology used in the contact mic and the guitar design. In other words, you'll have to experiment to get the sound that is best for you in your situation given your mic and your guitar. But in general, if you want the mic to be clear and loud and avoid other acoustic problems that might result from extremely inefficient placement - such as phase problems, wolftones & etc...

Then in general, some kind of braced area or reinforced area on the soundboard will likely give you better results and fewer problems.

Scoredog

very interesting and thanks for that useful piece of info!

Jazzaferri

Some insights on a McIntyre Feather. When I first got my DuPont (1998 new to me last year) it was very very annoyingly bright. Sounded like a piezo with lots of high end eq. Several months ago as part of a refret my luthier had a look at it.

Mounted part on the top part on the brace. Probably a gap. McIntyre told us that it should be mounted on the underside of the top close as one can to the bass leg of the bridge.

Huge difference. Now it's nicely balanced and with the internal mic makes for a good acoustic rhythm sound.

A different guitar would probably want somewhere completely different.

BluesBop Harry

I mount my cheap Dimarzio piezo right on top of the the bass side moustache... Half on/half floating... Works much better than sticking it on the top

Dwaine Majkrzak

Thank you for the tip Bob! It's good timing for me. I had just ordered an Ischell from Micheal. It should be here in a few days.

Bob Holo

Glad to help.

Yep, any of those sturdier types of locations are fair game for mounting. I've just seen a few people look for mounting spots by hitting a chord and feeling for the areas of greatest vibration and then reasoning that those would be a great place to mount a contact mic. It seems like that would make sense, but in fact it turns out to be the exact opposite. I suspect that braces act as good locations because they are node boundaries for multiple areas of soundboard breakup. Moving around to different braces and locations along braces seems to bear this out. On top of the soundhole tonebar gives you a very different sound than on top of the #5 brace & so on. Near, on, or around the bridge, its tonebars and accoutrement, are likely to be the most neutral areas, as the soundboard is designed to be acoustically loaded from that area, so you're getting I guess, in effect you're amplifying the energy coming out of the bridge, rather than the energy expressed by some particular part of the soundboard. But YMMV based on your likes and guitar. I seem to remember liking one placement over the HUGE soundhole tonebars on my old Busato Mde44. My old Busato has a lot of bass and that helped trim it so that I could play on small stages where our bassist and his huge GK amp were riding my backside ;-)