The resonator will certainly work at reducing specific frequencies of exhaust notes (as RPM increases, so does the acoustic frequency) . Your problem to solve is "which frequencies?" A resonator designed to mute specific exhaust notes has to be designed specifically for that exhaust system and the engine characteristics, because it acts on an acoustic principle.
The acoustic principle? Well, sound waves can be manipulated; if two waves of the same frequency are combined out of phase, the result will be no audible sound whatsoever. If they are combined in phase, the result will be twice the volume at that frequency.
There are some other factors that in reality come into play ... no sound in nature is a pure tone, for example, and generally there will be partial cancellation and partial increase at various frequencies that make up the exhaust note, and probably at multiple RPM points (but not a continuous range of RPM points), but only mentioned so you understand the complexity of it all ... the primary frequency attenuation is what you really should concentrate on and let the rest fall where it may, unless you want to drive yourself crazy with math.
You are left with some choices, and chances are that none is perfect, but maybe you get lucky.
O1: You can spend hours learning acoustic theory, make precise measurements of your exhaust notes and the area and shape of your entire post-turbo exhaust system, and apply that data to an expensive computer program (or go through reams of paper and a few pencils) and voila ... you will have a very effective resonator that does exactly what you want. Assuming the guy you hire to fab and weld it does what you tell him to do, exactly.
O2: You can trust the OEM, who has actually done all the steps in Option1, plus "voiced" the result to be pleasing to the ear (versus being as quiet as humanly possible) and buy a resonator specified by the OEM for your vehicle. Note this is not an aftermarket option, usually; you will be buying from the dealer or the junkyard. Will probably work well.
O3: You can trust a 3rd party supplier who may have done the steps in Option1 but probably doesn't have the engineering talent or hardware to actually do Option2 as well as the OEM. Might work.
O4: You can buy a number of resonators and try them, to see what works via experimentation.
O5: You can just buy something that looks like or claims to be a resonator, and install it, and live with the results.
O6: Try a muffler. Some mufflers operate solely on acoustic principles, like a complex resonator. They are not very restrictive (even a resonator which is not considered restrictive is still *slightly* restrictive, but if it or a muffler passes enough CFMs of exhaust that doesn't really matter; it's *effectively* non-restrictive. Others combine acoustic and gas expansion / thermal dissipation to reduce overall volume somewhat while remaining only moderately restrictive, and of course there are the restrictive versions that quiet the exhaust down significantly. Somewhere in those choices, possibly combined with a resonator, you might get what you want.
You do have one thing going for you ... because it's a turbo car, you don't have to worry about exhaust tuning for maximum engine efficiency ... the turbo negates the need. So all you need to concern yourself performance-wise is passing enough CFMs to satisfy the breathing needs of the turbo on full boost at redline RPM.
So-called "Turbo mufflers" if a true turbo type are not restrictive as they do pass enough CFMs for the application. Because the turbocharger itself sits between the engine exhaust and the tailpipe, a turbo by itself is a somewhat effective noise barrier; combined with a turbo muffler the vehicle tends to meet reasonable noise requirements. So maybe consider one of that type if you decide to seek out a solution that contains any kind of muffler at tall.
A Glass Pack *is* a muffler. It reduces exhaust noise by acoustic, gas and heat dissipation principles. If you use one, do not get a cheap louvered version (you can usually just look down it to see; beware those that come with bends to prevent that). Seek one with a perforated tube (many tiny holes that don't intrude into the tube).
However Glass Packs have the effect of lengthening the exhaust path (they act like an exhaust pipe of longer dimension and same diameter). Broadly speaking you want a short exhaust path with a turbocharged vehicle; as mentioned earlier the turbo sits between the motor exhaust passage and the tailpipe and exhaust length does not improve performance as it might in a non-turbocharged vehicle (by modifying the torque response through exhaust tuning).
