Cab Lab – Revsound RS88T

The Revsound RS88t presents a familier profile, with dimensions reminiscent of a classic Ampeg 8×10 “fridge,” though a little more height in relation to its width, thanks to the large slot port at the bottom of the enclosure. Of course, the overall size is diminished, with eight 8″ drivers, as opposed to eight 10’s. As with the RS112T, which we reviewed back in BGM #12, David Luke has opted for Celestion drivers, using the TN0820 stamped-frame driver. They are held in place using four bolts, secured by hurricane nuts. On a larger driver, I’d like to see more bolts, but for these 8″ drivers, four bolts seem to do a more than adequate job. The Selenium Super Bullet Tweeter is held in place with four wood screws (and some serious black sealing caulk).

The exterior of the enclosure is covered in black Duratex, with black metal non-stacking corners. The two spring-loaded handles on the side of the enclosure are very well placed, and let you carry the box high enough to avoid banging your knees. A single handle is placed on the top of the enclosure, closer to the back edge. There are four short, wide, rubber feet on the front edge of the bottom of the cab, and two more feet placed closer to the two casters built into the back/bottom edge. This provides a solid stance, but still allows for tilt-back-and-roll transportation. The metal grill is held in place by 22 screws. When I did the RS112T technical review, I noted that Revsound used “non-hybrid” square-head screws. This time around, they used the “hybrid” type screws – which can also work with Philips-head driver – but I still used a square-head bit in order to remove the grill, since I had one laying around, anyway (thanks to the RS112T!). Once again, I like the way the grill rests against a thin, wide strip of foam insulation – recessed about 3/8″ from the front edge of the enclosure. However, it appears that it was installed while the paint was still wet on the foam, such that when I removed the grill for my technical review, it was impossible to do so without pulling up a lot of paint and making a noticeable visual impact (which I was able to touch up pretty easily, admittedly).

The tweeter is connected to a recessed on/off switch. Considering the nature of this tweeter (which can draw attention to itself), I would think that an attenuator would make the tweeter a lot more useful (so that you can dial in how much you want). For my tastes, it was too hot when engaged, but I missed it a bit when turned off. Input options are limited to a single Speakon input jack. Similar to the RS112T, the RS88T features a Dayton Audio XO2W-3.5 2-way, second order (12dB/octave) Bessel alignment crossover. However, in this cab, the 8″ drivers are run full range, and the crossover serves only as a low-pass filter for the tweeter. David has switched to using a straight-up, custom-designed, low-pass filter on the tweeter for current builds. The internal wiring employs medium-heavy gauge wire, and speaker connections are soldered. The enclosure and baffle are made from 1/2″, 9-ply marine-grade okume, which contributes to its light weight, and the inside of the enclosure is lined with a thick layer of pink fiberglass insulation.

Fig. 1 On and off-axis (15, 30, 45) frequency responses

Fig. 2 Impedance curve