Hi All,
I am faced with a recording challenge of sorts. My Martin DC 16GTE sounds great,mic'd up with several different mics. Problem is, I need to go direct in order to keep out noise pollution ( think kids, xbox , washing machine, etc.) I have moments where it is quiet, but it is definitely catch as catch can. (imagine the other night, great take about 2:30 into a 3:15 minute song, DAD! PHONE!). I never have a problem when going electric, except which of my favorite dozen amp sim  models should I use from the arsenal of good plugins I have (Amplitube,Revalver, TH2 producer, Guitar Rig 5.) out of all of those, the only two that seem to even attempt acoustic, are two models inside my aging Johnson Jstation. It ain't BAD, but it is piezo  (fishman prefix pro)which always sounds a little brittle to me. I haven't tried direct yet with my micro cube from Roland, but I'm not holding out a lot of hope there. Any good amp sims that address ACOUSTIC as more than just an afterthought? 

Piezo is not ideal as it picks up harmonics due to placement. I have a very old Dean Markley in-hole humbucker that works best with non-ideal environments.

Using the piezo can be very tough if it is the main instrument, and mostly by cutting the high end. I never get this to work well though, so end up using the Dean Markley a lot. I am sorry this doesn't directly answer your OP, but I can commiserate.

Edit: The pickup name is ProMag, I was checking to see if they still make them since mine is over 20 years old. I guess the ProMag Gold is the newer version of it (they have 5 models now).

I have been struggling trying to get a Piezo to sound acoustic. Amplitude3 has many acoustic setups from their preset exchange. The presets all seem to be, bypass amp, set EQ, maybe add (compression, reverb, and something to generate a stereo field. Peavey's Revalver has some ACT inputs to help that I have tried to help piezo's. They seem to help but last night I decided to bypass the amp sims. I chose a Craig Anderton PC EQ, Remix solo and a stereo generator(Meldaproduction was my choice). The result was pretty good. I also tried recording the guitar though a stereo mic at that same time and mixed the 2 with a good result (that would defeat your purpose though). I am going to try to add a trick that Craig Anderton had in his X1 video tonight. Craig's trick was to take the mono recording, split the high and low frequencies into a different tracks so you can pan the lows center, pan the highs left or right then the mids panned between. I have tried his trick by itself and have liked the sound. Tonight I am going to merge the 2 and see how it comes out.    

Good suggestions. My first inclination was to look at the acoustic AMP angle, but you have given me some good fodder for trying alternate approaches. Perhaps the ampless "miked room" approach available with some of the modelling plugs would be an option. Also, I forgot I have a TC Helicon voice live GTX. they have a pretty good sounding acoustic section, I'll give that a try. I'll try the Craig stuff too.
 

When I've had to record piezos (or deal with them in a live context) modelling an amplifier isn't where I'd start. I,d go for treating it like a different kind of microphone that has a frequency and volume response curve with ups and downs like your favourite mountain range.

Piezos tend to have a very bright, hard output with a bit of a "stick being dragged across metal railings" quality thrown in. They pick up what you'd hear if you pressed your ear to the instrument where the piezo is. It can also make quite a difference depending on the make and quality of the piezo itself and the preamp.

I'd start with the eq on the instrument, if it has any, and try and get that sounding as good as possible through the monitors. Then add compression and further eq, looking for the harsh spikes and reducing them. Dragging a narrow eq band with a lot of gain on it around while playing back some recorded audio helps. Where it sounds worst is where you should consider cutting. Adding a tight reverb with a low pass filter set to take off the harsh treble generally helps.

One of the new Anderton plugins is designed for piezo pickups, I've not tried it but you might find it worth trying as well.

^^^^ Very nicely written and accurate. The "issue" is not "where to" but that initial signal itself. Many amp sims tend to generate a lot of artificial harmonics you would not hear acoustically or from a real amp, so feeding any of them a "raw piezo output" just makes this more painful to deal with. Definitely EQ first.

The best amp sim there ever was in my opinion for Acoustics was Bodulizer - very old now though and I don't think available anymore, which is a great shame.
I use a Fishman Aura Spectrum to sort of the piezo pickup issue which works very well - still no where near as good as properly micing up your standard acoustic guitar, but there are many instances where you can't do this as you say, so it really helps in those situations. Great pedal and you are free from you computer as well!
Nigel
 

Hi,
Another way to put it is to consider a piezo guitar as an instrument in itself and which is not the same as an accoustic guitar.
Yes a piezo clearly does not sound like a miked guitar,but neither a Telecaster does and if one plays classical pieces on a tele,it won't sound the same as John Williams or Alexandre La Goya but it can sound.
Just to say that I'm not an expert but if one wants to sound accoustic with a mike ,it's better to play an accoustic and to mike it,but that doesn't mean that piezo sound is not usable, according to me it can stand in a mix like for example in Tracy Chapman's "Change" ,also Pat Metheny used that kind of guitar here and there.
Just to feed our thoughts.
All the best.
Olivier