Bose 901 Speakers with Anthem MRX 700 AVR?

Question:
I have a pair of Bose 901 Series VI speakers, and I recently purchased an Anthem MRX 700 AV receiver. Are the speakers compatible with the receiver? The salespeople at the store said they are, but they’ve had many problems finding a receiver that is compatible with them. The problem seems to be the active equalizer box that comes with the speakers; it requires a tape-monitor connection, which most receivers don’t have any more.

– Vernon Hodgins
Thunder Bay, Ontario
Canada

Answer:
Putting aside the active EQ box for a moment, the Bose 901s will work fine with the Anthem MRX 700 if you connect them directly to the receiver’s speaker outputs. The 901 is rated with a nominal impedance of 8 ohms and the ability to handle power from 10 to 450 watts. The MRX 700 is rated to output 120W into 8 ohms with two channels driven, and the measurements I’ve seen confirm this to be an honest rating.

To use the included active EQ box, it must be connected to the receiver’s tape-monitor loop or preamp-out/main-amp-in connections. This type of connection diverts any input signal you select on the receiver through the EQ and back into the receiver’s power amps. As you point out, very few receivers offer this feature any more, and the MRX 700 is no exception. The Anthem does have two pairs of recording outputs, but these have no corresponding inputs on the receiver; they are intended to send the signal from a pre-assigned input to a recording device.

The bottom line is that you cannot use the Bose active EQ box with the Anthem MRX 700—or most modern AV receivers for that matter. In fact, the 901 Series VI manual says, "If your receiver does not have this PRE AMP OUT/MAIN AMP IN section, the 901 speakers will not be usable in your home theater system." However, the manual also describes connecting the speakers directly to the receiver’s speaker outputs without the EQ, so that will work despite the warning.