The S30 surround sound speakers still exist in their first incarnation. They perform surround duties in my reference setup, and they were used here as well. You can read my previous review to learn more about the S30.

The original B15 subwoofer now has the suffix "a" as part of its name. The B15a has the same driver and amplification section as the original B15. You can read about the B15's muscular capabilities in a previous Revel Performa system review.

In this article, I will focus on the back-panel modifications that are part of the B15a. The most obvious change is a cleaner layout of the controls on the back-panel. Controls that are logically tied together are grouped together and enclosed by a black outline. There are also a number of new controls on the B15a.

The B15a retains the three-band parametric equalizer from the original design, but adds a bypass switch. To disengage the parametric equalizers on the B15 required setting the level control to 0. Having a switch makes the bypass operation easier and cleaner. This switch is labeled "EQ ALL" and has two positions, "In" (on) and "Out" (off) settings.

The second new control is the "Contour" switch which provides three convenience settings: "Film", "Music", and "External Trigger". The Film setting can be used to provide a boost at the low-frequencies which some may find desirable while watching movies. The Music setting does not alter the subwoofer's response. The External Trigger option allows you to switch between the Film and Music settings by using an external trigger. On the B15, one needed the Revel LFO software to help choose parametric equalizer settings to yield the effect of the new Contour control. Adjusting multiple dials to switch settings to get a boost or a flat response is cumbersome. The new Contour switch solves this problem, and the external trigger option allows you to do this from the comfort of your seat.

The final modification is the addition of a "Power On Mode" switch with two settings: "Auto" and "12V Trigger". Auto turns the subwoofer on in the presence of a signal and takes it into standby mode in the absence of a signal for some length of time. The 12V Trigger option can be used to turn the subwoofer on/off by applying a trigger voltage through an external device such as your SSP. I used the Auto setting in my setup. There were a couple of instances where the B15a would not come out of standby mode. I had to power the subwoofer on/off a few times to get it to come out of standby mode. At one point, I tried to see if there was a particular sequence that would result in this problem, but I was unable to reproduce it.

When the B15 first came out, it was among a small group of subwoofers which offered this level of customization. In fact, it still offers a three-band parametric equalizer where many offer either a single-band parametric equalizer or no such control at all. But there are several manufacturers who are now offering a microphone-based automatic set-up procedure. At this price-point, I would certainly like to see Revel add this functionality to their subwoofer offerings.

Click Here to Go to Part IV.