Callibrating Velodyne DD+ Subs in Stereo

AutoEQ only works for daisy-chained subs. However, for the purposes of set-up you can daisy-chain them, run AutoEQ, and then connect them in stereo if you desire.

I should mention that I'm very unimpressed with AutoEQ. It does not produce anything like a flat in-room response. I recommend buying something like the Parts Express OmniMic system and measuring for yourself, using 1/12th octave smoothing. You'll have to tune things manually, but the best tuning is done by placement and some judicious equalization anyway.

I highly recommend reading the excellent review of your sub on the audioholics.com web site.

Locate a position for the subs. My system is on the long wall so I have mine to the outside of the main speakers and a few inches forward. This may not be the optimum position in your room with your speakers but it seems like a good place to start.

You will be making the Manual EQ Optimization adjustment for each sub individually with the calibration microphone at the same listening position for both calibrations.

Follow the instructions on page 32 of the User Manual for Manual EQ Optimization. This begins with running Auto EQ first. Take your time in doing this for the first time to get to know the software.

When you have completed the first sub you have the option of simply duplicating the settings for the second sub. If both graphs appear similar you should be good to go. If you have an irregularly shaped room and while the settings are the same the graphs are somewhat dissimilar you have the option to adjust for a similar waveform. In this case I would suggest doing some serious listening before making the change to give your self an aural baseline for when the change is made.

With the calibration completed connecting an RS-232 cable between the two subs will allow you to control both subs with one remote.

You should only notice the subs when they're turned off. With only one sub playing then turning on the second sub you should hear a widening of the sound stage.

There is also the option of connecting the subs using both the line level (RCA) inputs as well as the high level (speaker cable) inputs. Depending on your main speakers this method can help with integrating the mid bass.