Just picked up a used RG5121 and thought I'd offer up some opinions and comparisons.
The Fishman pickups are fun. I was hoping for more versatility, but you just don't find metal pickups that do cleans well, so my hopes were a bit high. Fishman does seem to have some other offerings that may fill that request. I left my amp set the same as for my other guitars for initial testing. Voicing 1 is a nice balanced high gain and Voicing 2 is a darker slightly less gain, but still high gain. The cleans were acceptable, but left me wanting to see if I could coil split them. Chords ring out in a unique sort of hifi, holographic, layered way that sounds very cool. I found that lead work didn't make me want to move to the neck pickup like it does on some guitars. I could play the bridge pickup on voice 1 all day long. They also look completely BA, so they have that going for them as well.
These pickups do provide a significant improvement over stock. Whether or not they're your cup of tea is another story.
There is a problem here with your guitar which is not adequately addressed in these posts. The problem is that Ibanez has not implemented all
of the features within those pickups -- and the lack of choices is affecting your perception of the Fishman Fluence Modern pickups and what they can do.
The Fishman Modern Humbuckers offer FOUR selectable features to modify and control their output. On the RG5121, Ibanez seems to have implemented only ONE of those options. This is skewing your perception of what these pickups can do. Your opinion isn't wrong based on the guitar you are trying them in, but these pickups have been crippled by Ibanez in the RG5121.
When purchased as a pickup set, the Fishman Fluence Modern Humbuckers come bundled as two pickups, one Alnico ,the other Ceramic, together with 4 x 25k pots. Two of them are push/pull 25k pots, the other are non-push pull 25k pots. All of these pots are 25k. The pickups will not work properly with 250k or 500k pots.
The options on the Fishman Fluence Modern Humbuckers are:
1- Voice 1/ Voice 2 -
normally selected via push-pull;
2- HF Tilt
- This is a key feature of the pickups when used for more classic rock and is absolutely essential to enable on the Fishman Fluence Classic Humbuckers. You should do it as well on the Moderns. This brightens your tone and makes the cleans sound even cleaner. Normally activated via Push-pull pot;
3- V1 Gain
- This is a nice feature on the Moderns and it adds a darker, shreddier tone to the pickups when put on Voice 1. You can enable this via push-pull, or via a SPDT/SPDT toggle switch. You can jumper the pickups so that it is always on, but this will muddy up the pickups on the clean tones. You want this to be switchable, especially as when the HF Tilt is on, you will want V1 gain off.
4- Coil Tapping
- the Fishman Moderns allow you to solder leads to the back of the pickup and choose whether to tap the coils to single coil mode, either choosing the outer coils or the inner coils. You can implement this via push-pull, or via 5 way or 7 way switch.
The bottom line is that all of these features cannot be enabled using just the pots provided in their Modern pickup set. It's missing the two additional push-pull pots you would need to to this. The 25k push-pull pots are available directly from Fishman for $19.99 each; (or you can source another push-pull 25k pot somewhere online).
Alternatively, you can implement the V1 gain with a toggle switch and try to wire the 5 way switch to handle some of your coil-tapping wants.
If you contact Fishman directly and ask them about this, they will send to you the following response:
The voicing, coil tapping, gain reduction, and HF tilt are all options that are available with our pickups. There is plenty of info on these in the user guide (linked below). These are OPTIONS and are not required to be wired when installing the pickups. The modern pickups come with a singe wire plug that will allow you to activate the gain reduction when connected to ground (in the same fashion as the voice 2 push pull pot). The coil tapping is not incorporated into the harness and needs to be done differently on the modern pickups (see link below). There are different options when coil tapping. be sure you are using the proper switch when wiring it. If you want to wire all of these options to push pull pots you will need to order 2 additional pots from our parts store. Thanks.
Which brings us to the problem with Ibanez's implementation of the Fishman Fluence Moderns in the RG5121 (and to a lesser extent, in the Axion S61AL)
The problem is that there are not enough switches and pots on these guitars to implement every feature. Add to that the problem that the thin design of these guitars is such that the much taller push-pull pot won't all easily fit in the control cavity of the guitar and you begin to see the issue more clearly.
Lastly, the pickups are active pickups and, depending on your model, you will need to install a battery in the guitar to make the Fishman Fluence pickups work. There is a universal battery pack meant for this purpose for installation in Ibanez and PRS guitars (LPs. SGs, Strats and Teles all have custom battery solutions particular to their specific layout and design) but they won't necessarily fit in every control cavity. The Univ Batter pack tapes on to the inside back of the control cavity cover (you drill a 1/2" hole in the cover to your control cavity to allow the micro USB port to poke through the cover and be always accessible.)
This is a neat idea, but the battery is .43" deep. On a lot of S and SA series guitars, this can be too tight a fit -- especially when the additional height of push-pull pots crowds out the cavity. You need to plan and dry fit this battery carefully before drilling anything.
So what's the take-away on all of this? Simple. These pickups are awesome and they offer a great deal of flexibility. They shine brightest when they are pushed with heavy distortion -- where their clarity cuts through the competition and makes any EMGs or Seymour Duncan sound muddy AF.
But in order to get the best out of them, you need a wiring harness that exploits all of their features at the same time and makes them selectable on your guitar. There are not many (is there even 1?) guitar produced by Ibanez where everything on the Fishman Fluence Moderns have been implemented. The issue is number of pots, cavity size, switches, and thickness of the guitar. Ibanez's design mantra -- a thin minimalist design in terms of its controls -- runs contrary to the Fishman Fluence's technical design and its demand for more active control tweaking. The result is a compromise and half-hearted implementation that misses the mark and fails to show off all that the Fishman Fluence Modern Humbuckers can do.