When Reverberators first came out, or at least when I was first aware of them, it was the early 60's and I was in High School. Now what could have been more cool than "making the rounds" (wording prior to "Cruising"), with your favorite AM radio station "reverberating" for all to hear - particularly in a Convertible. However, "back then", most Convertibles didn't have provisions for Rear Seat Speakers (which are required for the reverberation effect). Mine was even more of a challenge as it wasn't "just a Convertible", but a 1957 Ford Retractable. After minor modifications to the inner rear quarter structure (3/16" steel) using continuous drill bit holes to make a larger one (I didn't have hole saws then), I finally had openings to receive the magnets for the two 4" speakers.
In the Summer of 1963, I purchased a Motorola R200 Vibrasonic Reverberator and installed it. Over the next year and a half or so, I made minor customizing changes to the '57 (nothing too drastic that I couldn't change back to original "down the road"). Well, "down the road" came in 1976. Ironically, this was the same time that I purchased my 1966 Mustang (actually so I'd have another "fun car" to drive while restoring the '57). Of course, one of the "non-original" items that I removed from the '57 was the Reverberator. Not wanting to throw it away, or just set it on the shelf, I installed it in my Mustang.
After acquiring my Mustang, I did what I had done with the '57 (and all of the other cars that I subsequently purchased), and began acquiring all of the original Ford literature, etc. that I could that pertained to my '66. Imagine my surprise when I found that Ford offered a Reverberator ("Studiosonic Sound System" in Ford's language) as an Accessory in 1966, and it was made for Ford by Motorola. Over the following 40 years, I have acquired a considerable amount literature, along with knowledge about not only the aforementioned cars along with their available Options and Accessories, but also for the additional ones we have purchased and own, including my 1967 Mustang Convertible.
The earliest I have been able to document Ford's offering a Reverberator ("Studiosonic Sound System" ) is 1962 (Ford Part # C2AZ-18875-B). What is interesting about the 1962 unit (RV2F) is that it is not listed in my 1962 "Complete Selection of Accessories" (dated 1961), in my January 1962 "Ford Ready Reference Parts Book", nor in my 1962 Ford Master Parts Catalog (MPC), dated January of 1962. Thus, it must have been added "later in the year" to the "accessory line". To add to the confusion, is the fact that the first Motorola Service Manual that I have found (dated January 1963), shows that the kit for 1962 Fords is Part # C20Z-18875-C. The January 1963 Ford OSI book confirms this, showing that the C2AZ-18875-B was "Replaced By" C20Z-18875-C. Ford continued to offer this (although with different Part Numbers) until 1969 for sure, and I believe in 1970 (although I do not have a 1970 Accessory Catalog to confirm this).
The 1962-1966 units were all basically the same, using the Motorola R200 Vibrasonic unit, with the main difference being that each year had a wiring harness that was appropriate for that year Ford. The 1967 and up units were of a total different design, being about 1/4 the size of the previous year units, and totally enclosed in a metal case. I believe that the reason for the drastic reduction in size is the elimination of the mechanical spring assembly inside the unit which created the reverberation effect and replacing it with newer electronics (there is an addition of a second transistor in the 1967, 1968 and 1969 units). As I am not that familiar with the actual electronics or details of the later "Studiosonic" units, the remainder of this Post will concentrate on the 1962-66 units.
The 1962-66 Studiosonic Systems were all manufactured for Ford by Motorola, using its R200 Vibrasonic unit. The main difference between the "aftermarket" and the Ford version was that instead of a "generic" brown multi-wire harness and plastic chrome "on/off/fader" control knob with bracket, the Ford units (as noted previously) had wiring harnesses tailored to each model year, and control knobs (with no bracket) that emulated Ford control knobs of the early 60's (black ribbed plastic with a chrome disk insert). In addition, the aftermarket units all had "Motorola" and a Motorola Model number stamped into the metal portion of the enclosure, while the Ford units had either "RV2F, RV4F, RV4D, or RV6F" stamped into the metal side portion of the enclosure, along with a multi-digit (non-Ford) Part Number. I, personally, have never seen an "RV3D or F", nor an "RV5D or F" stamped into a unit, although it is of course possible they may exist.
Another "quirk" that I have noticed over the years is that while all of the aftermarket Motorola units that I have come across, have had metal sides and bottoms with a black cardboard top, I have seen Ford RV4 units with both cardboard and metal tops. I have never seen an RV6 unit with other than a black cardboard top, but once again, they may also exist with a metal top.
Also of interest is how Ford named this system through the years ; 1962 -1964 it was "Studiosonic (one word) Sound System" ; 1965-1966 it was "Studio Sonic (two words) Sound System" ; and in 1967-1969 it became "Studio-sonic (hyphenated) Sound System".
For the complete Article on Ford Studiosonic Sound Systems, including year-by-year specifics, pictures and installation diagrams, see the "Official Article List" for any year of the 1965-69 Models, located in the "Library" Section of this Forum.