Odd thought about using a ribbon trans

[kb9wyz]

I already posted this in E&P. I am double posting this in LC because I know that many a luthier hangs out here, and they may have seen/done this.

O.K.

I had this idea when I was lamenting the availability of saddle piezos. I know I could just go buy ghost pickups, but that would require a new bridge to run the wires through.

So I was thinking, "Most ribbon transducers are only like 3/32 inch thick or so. Can you sandwich an RT between the bridge and body on an electric and have it sound right?"

Anybody out there ever hear of this sort of thing? Anyone try it?

Thanks,
Beast

[T2W]

Its the 'having it sound right' part I aint sure of. Its successfully done on acoustic guitars, Id try it on an electric if I had a couple hundred bucks falling out me pockets, imagine recording a bass with a DI, a tlm103 on a 4x10, and the new possiblity of a rt on top of that. Wow, might as well have some whipped cream on your coffee while mixing that kinda sound, must be wicked. Anyways, sorry can't say Ive heard of it being done.... I wonder though, if an electric vibrates as much at the bridge as an acoustic does.... Ceramic or an aluminum strip, both are based on the same idea. transfer mechanical 'stress' into microvoltage. Id go for it.

[PilbaraBass]

to get the most string vibration vs. body vibration ratio (this equates to a useable signal) you really should use a pickup saddle vs. the "under bridge wedge" technique.

The reason is that the changing pressure is what generates the piezo electric signal and if you put it under the entire bridge you will get HUGE body sounds...not that you can't use that signal mixed tastefully with a magnetic to get you some nice "faux acoustic" sounds...but it's not nearly as useful, IMO.

The ribbon transducer I have on my Carvin AC40 is located under the moveable bridge saddle and not the whole bridge...again, a much more useable signal, IMO.

[T2W]

Your post makes a lot of sense.

[pilotjones]

What kind of ribbon are we talking about here? A ribbon-shaped piezo, which responds to pressure across its thickness, or the ribbon element like in a microphone, which is meant to respond to movement through the air with respect to its fixed frame?

[kb9wyz]

I was thinking of something like the L.R. Baggs ribbon which is 1/32 inch thick (install should be easy)
http://www.lrbaggs.com/html/products...ansducer.shtml
which they say "is responsive to vibration but not to pressure" so I would think that it might give a decent response. A guy on the E&P post gave me a link to some company that sells really inexpensive RTs. Like $9, inexpensive. I think I might buy one to mess around with.

Check out the L.R. Baggs one and see what you think.

[pilotjones]

Interesting. Despite the claimed method of operation, the mounting makes it seem at first face that it's responding to pressure, not vibration. I wish they specified which patent, it would make it easier to look up.

Either way, the mounting between saddle and bridge is not the same as between bridge and body. I would expect far less relative movement, so I guess you'd get different results. Good or bad remains to be seen!

[kb9wyz]

That's what I'm not sure of. On the one side, you speak of the amount of movement relative to the location of the transducer, and I totally see where you're coming from. I think you might have something, there.

On the other hand, bridges are made of metal (brass or aluminum, typically, right?) and bodies are made of wood. These two substances are of wildly different densities. When vibration energy has to pass through zones of density change, things happen.

Other types of energy do the same thing, too. VHF radio will reflect off of air pockets with a different air temp. Blast waves in water will pass through jellyfish (not the band, if anyone else actually remembers them) without incident, but will liquify a swimmer's lungs; Even AC electricity does fun things when it encounters a change in impedance in a transmission line (standing waves).

So I'm not sure what the physics are doing here., I guess would be the point I'm trying to make.

[Taylor Livingston]

I have clamped a piezo element onto the headstock of a bass, as well as into the straplock hole on the upper horn. Both of these created very interesting sounds (to me) which were very different from the magnetic sound. Combined, it was really unusual and cool. So you can most certainly get a sound from any part of the bass. Sound is subjective, of course, so what sounds great to me might sound awful to you.

[pilotjones]

I did a quick search on L R Baggs patents today. He has so many of them for different types of pickups that it would be hard to tell which applies to this particular product.