Do electric bits change the acoustics?

[not darth]

I have a feeling this might be like asking "what's the best oil" on a motorcycle forum, but....

Does the mass and mounting of on-board pickups, battery and circuit board change, noticeably to the ear, the acoustic sound of the guitar?
If anything, I could imagine a muted deadness in a particular range, but I really have no experience or idea, that's just a guess. 
What's a 9v and some circuitry weigh, a few ounces?  How is it mounted?  To the internal surface of the sides, which would be least likely to impact frequency flow, or to the underside of the top, which would be most likely to influence the vibrations/projection?

I'm completely ignorant about A/E's, so this is all a question.
Thanks!

-K

[forhim]

I wouldn't know it it would be audible in most cases, but it's reasonable to assume that a guitar with smooth bracing and with an chamber that un-obstructed by things in the guitar would allow sound waves to freely circulate the way they were made to.

I'm guessing one would need an oscilloscope or some other sensitive piece of equipment to really here those differences.

[Iplay2]

I wouldn't know it it would be audible in most cases, but it's reasonable to assume that a guitar with smooth bracing and with an chamber that un-obstructed by things in the guitar would allow sound waves to freely circulate the way they were made to.

I'm guessing one would need an oscilloscope or some other sensitive piece of equipment to really here those differences.

I agree.  Much like a cutaway, there is probably a loss, but not one that can be heard. 

[DMBfan41]

My reply in the "cutaway vs non-cutaway" thread was a quoted Bob Taylor reply in Wood & Steel that addresses both the cutaway and electronics questions.

[michaelw]

i believe that it would depend a good bit on which electronics are installed -
Taylor ES has a very small, lightweight pre-amp/circuit board assembly &
the power supply (with 2AA or 9V) rests in a cavity routed in the tail block

the older Fishman OnBoard pre-amp are mounted right below the widest area of the
upper bass bout, with the 9V in the case (LR Baggs & BBand onboard are similar) -
removing the pre-amp from this type of system & leaving the hole open would
create a 'soundport' of sorts, which would likely direct more towards the player,
but i am uncertain if the size, shape & location are ideal for the optimal results

also, there are systems like the LR Bagg iMix that have soundhole edge mounted controls,
 a separate pre-amp & battery retainers, which is usually affixed to the inside of the back
(i've seen them mounted to the inside of the back, as far up & to the left as possible)

whether any of this has an effect on the acoustic tone or not would be less relevant, imho,
than the player's need to be able to plug the guitar in & play in an amplified situation -
removing a system that is not being used, with the hope of improving the acoustic tone
would probably be considered the 'point of diminishing return' ... it may work or it may not

the side of the guitar where onboard pre-amps are usually located & the area of the back
(upper bass bout edge) most likely contribute very little to the acoustic tone, as they are
are pretty much on the opposite side of where the cutaway would be, if the guitar has one

hmm ... or maybe, that is why most cutway models have onboard electronics - to balance everything out

[not darth]

So, it seems the consensus is that it may, or may not- and even if it does make a difference it probably is only noticeable on a scope and not to the human ear. 
Thanks, -K

[Jack Sparrow]

hmm ... or maybe, that is why most cutway models have onboard electronics - to balance everything out

I thought it was more because electronics and cutaways tend to both appeal to the same customer - often people who also play electric guitars, and therefore appreciate the ability to plug in and to reach the upper frets. Or at least, most people who want a cutaway don't seem to mind electronics, and vice versa, while a lot of acoustic traditionalists seem to frown upon both of those features.