I also play a Taylor Acoustic (614CE) in a band with electric guitar and electric bass and drums. I also play in an acoustic duo and play at open mics with other musicians with all sorts of instrumentation in the impromptu bands we form, and I play solo acoustic. So I would like to share what I have learned from personal experience. The most important part is at the end.
First I want to address those who have suggested switching to an electric guitar.
I don't think you want to do that at all. The acoustic guitar is really a totally different instrument than an electric guitar. Sure they have similarities, but the sound and playing style are as different as a banjo is to a guitar. If the acoustic guitar is an integral part of your band's sound, stick with the acoustic by all means. And don't go with an electric amp for your acoustic. That will rob your guitar of some of the rich, resonant sound that endears us to the acoustic guitar.
In my band, we play mostly songs that an acoustic guitar complements well. There are a few songs we play that are more authentically rendered with two electrics and no acoustic. For those songs I would use an electric. But I would never substitute an electric for an acoustic, if the acoustic sound was what I am looking for.
Now let's talk about how your acoustic can be heard in your live performance.
First of all, it is a very common problem getting an acoustic guitar to cut through the mix in a live setting with electric bass and electric guitar and drums. Turning it up louder does not help much. Part of the problem is the sound envelope of the electric instruments and the drums is such that the sound will be perceived as louder. The sound of an acoustic guitar blooms and swells as the strings cause the soundboard to vibrate which then causes a sympathetic vibration in the strings which goes back to the guitar and creates a certain resonance and overtones. The pickup in your acoustic is detecting these vibrations in the top. In the electric guitars, the pickup is responding to an electrical response between the string and the magnetic pickup - so it's reacting directly to the strings. The resulting sharper peak in amplitude will travel more rapidly to the ears of the audience and be perceived as louder - even though the volume may be set the same as measured independently.
But there are several things you can do to overcome this common and natural phenomenon.
Start with EQ: You can EQ your guitar alone but then it is vital that you EQ the entire band as a whole. The guitar might sound great by itself, but be completely lost in the mix once the full band is playing. So you must EQ the band - not just the acoustic guitar.
Let's start with the acoustic guitar. If you have a Taylor with the Expression System, you can use a TRS to XLR cable to plug directly into the mixer. This will actually give you a higher output signal and more volume with a given setting on the mixer than using a standard guitar cable. Taylor ES System from Taylor Guitar I am not sure why you need the Fishman Loudbox when you are using a PA. Another note on the Expression System. If you have a 2008 or newer Taylor with the ES, there is a switch inside the guitar that will turn off the body sensor(s). Using only the neck pickup will reduce feedback with stage volumes.
If you skip the Fishman Loudbox you would start with your volume, bass and treble controls in the neutral (on Taylor the detent) or middle position. Plug your guitar into a channel on the mixer and adjust the trim or input gain on that channel by turning it up until you can cause it to clip (red) by strumming hard, then back it down until it no longer clips. Now you have the input gain set and can adjust the channel volume and channel EQ from there.
If your mixer does not have individual channel EQ with at least 4 bands, you might want to consider a DI BOX with an equalizer such as the LR Baggs Parametric EQ DI box LR Baggs Website PARA DI or this one for less than $30. 7 Band Danelectro DJ14
. When you are playing with a band as you describe, you will EQ your acoustic guitar entirely differently than if you were playing acoustic solo.
When playing with a bass guitar and a kick drum, there is no need or room for the low end of an acoustic guitar. If you have a high pass filter (HP) on the guitar channel of your mixer you can use that to keep the lows in check - but otherwise, you want to roll off the lows with your EQ. I have found that most acoustic guitars sound better with the mids (600-800 Hz) pulled back. Try boosting the 1,000 – 3,500 Hz range slightly but not so much that the vocals can't find their place - and boosting the 3,500 – 12,000 Hz range. There is some trial and error involved. Remember when you are EQing your acoustic for part of the overall band mix, it is not going to sound as good as you think it should by itself.
So once you think your guitar EQ is dialed in, and the bassist, electric guitarist, and drummer have their EQ adjusted, and everyone's gain is adjusted properly, it's time to listen to the overall band as a whole. Mixing for a full band isn’t about getting the best sound out of each instrument - but rather about getting the best overall sound from the band as a whole.
Mixing the band will involve adjusting the relative volume of each instrument, and to the extent your equipment allows, further tweaking the EQ of each instrument so they each occupy their intended and appropriate tonal bandwidth. The object is to achieve an ideal balance by blending and contrasting among the instruments.
To get one instrument to stand out more in the mix, start by cutting down the volume of the instruments (or vocals) that appear to be stepping on or drowning out the instrument that needs more prominence. If you start compensating by turning up the instrument that needs to be heard, then some other instrument might need to be turned up and the volume wars start. During this band mixing process, it's always best to turn down than to turn up. After the optimal mix is achieved, you can turn up the main volume without affecting the relative mix.
After adjusting relative volume of all the instruments in the mix, you will want to tweak the EQ settings. Obviously you want the bass and kick drum to occupy the lower end of the tonal spectrum, the cymbals and snare, the higher end, the vocals in the middle and the guitars somewhere between the cymbals and vocals. The cutting before boosting adage applies to EQ as well. Again, trial and error and a trained ear are a big part of this process.
After getting the overall band mixed properly there are a few other things you can do to get better results on stage with your acoustic.
The monitor volumes need to be just loud enough for the musicians to hear what they need to hear, particularly your monitor. If your monitor is too loud, you will get feedback and will have to dial back the volume of your guitar. Also, if you hear your guitar too loud in your monitor, you might subconsciously play softer, thereby reducing how much of your acoustic the audience hears.
Another idea is to use a simple 20db boost pedal with your guitar for those parts of songs where the entire band is playing/singing really loud and you want your guitar to be heard. Of course you would set the volume control to give you far less than 20db. Here is a link to information about one that is geared towards use with an acoustic electric guitar. Signal Boost Pedal for acoustic guitar
If you are using phosphor bronze guitar strings, you might switch to 80/20 bronze for playing with the band. It will give your acoustic a brighter more present tone and may help it cut through better. Obviously old dull strings will not sound as good as fresh strings.
Okay, now that I have covered the things you can do to get your acoustic heard as much as possible in the mix - we still have the inherent problem discussed earlier that brings us back to the reality that no matter what you do - an acoustic guitar will never be heard over an electric guitar in a band situation like yours.
So what now? The next part of the puzzle was mentioned in Todd Wilcox's excellent answer - arrangement and performance dynamics.
The only time an acoustic guitar is really going to shine on a stage with all the other instruments in your band, is when it is playing almost by itself. There may be some parts of some songs where you want the acoustic guitar to be featured. In those cases, the other instruments need to either drop out completely, or play very softly at much lower volumes.
The other thing that will help if your acoustic is the primary rhythm guitar, is to have the electric guitar play around you instead of on top of you. This means while you are chunking out the beefy acoustic chord progression that carries the verses or chorus, the electric guitar should just play fills and single note runs almost between chords. When it comes time for the lead solo, that's when the electric should be drowning out the acoustic.
I know that's a tall order for many electric lead guitar players. Some of them seem to want to hog the spotlight. But if your electric guitar player is playing too much all the time, that may be the biggest part of your problem of not being heard on your acoustic. A good guitar player knows when to play and more importantly when not to play. So arrangement and performance dynamics should facilitate the acoustic and electric guitars working TOGETHER and complementing one another - not competing with one another (the electric will always win)!
I hope some of this helps. Good luck ... and rock on brother!