Double Bass Mono or Stereo Contact Mic?

[dnsachs]

Hi guys, I've heard that upright bass setups prefer mono contact mics over stereo contact mics. I was wondering why this is? Thanks!

 

[Eric Hochberg]

An example of a stereo contact mic?

 

[dnsachs]

like two piezzo pickups leading to one male quarter-inch

 

[Eric Hochberg]

OK, these are not wired in stereo. They are usually designed to fit in the bridge wing slots. Some people prefer the use of one element in the E side slot to using both. Some brands come with one element and some with two. Of course you could combine two wheel adjuster or underbridge pickups, or a combination, too. What people use depends on the sound they are after and how a pickup interacts with bass and amp. No hard and fast rules here on which is best.

 

[dnsachs]

thanks for the reply eric - do you have any details about phase cancellation reducing the low end (when using both wings), and why this effect occurs? or if you could direct me somewhere that would have this information...thanks!

 

[Eric Hochberg]

I can tell you that I have experienced phase cancellation using 2 elements and prefer the use of one if going into one input without phase control. It has been discussed here, but I can't tell you where. Try searching...

 

[T-Bird]

Hi.

Like Mr. Hochberg said, those pickups aren't usually wired stereo or 2 channel, but in series or parallel. On better ones those sensing devices both have their own pre-amps.

If You don't have an absolute control over both of the signals independently, in theory the end result won't be satisfactory. It does work to some degree of course, and sometimes the praised tonal characteristics of said systems take an advantage of the wave propagation.

The effect of wave propagation including phase cancellation, is explained in great lenght on various texts that can be found on any acoustics textbook and all over the 'net.

The problem is that nearly all of those texts dig way deeper than a layman can comprehend. Here's a few with a simple phase cancellation Google search:Google

For the phase cancellation to occur, it doesn't have to be a piezo mic, nor does it have to be audio frequency waveform (=sound), any phenomenon with wave characteristics will do.

Regards
Sam