While doing some recording in Steamboat Springs Colorado, I had the opportunity to measure a Bose L1 line array and B1 sub.
Bose L1s with B1 bass cabinet – owners guide
The rig sounds pretty good. The blue trace below is the L1-II system without the B1 sub plugged in. The green trace is with the B1 sub plugged in.
I’m curious about the peak just above 250 and the hole below 250. Maybe the 24 x 3″ speakers in the line array are being high passed to protect them. Note that without the sub, there is nothing below 250hz and with the sub, there is excess low end. Also note that the 3″ speakers seem to naturally roll off around 8k. I was curious how the rig might respond to eq. Here is the curve I came to:
EQ result is the pink trace:
You will notice the HF shelf I used really doesn’t do very much. The 3″ speakers just don’t go up that high. I think it sounded a better with that slight boost but it’s really not necessary. The clarity of this system is surprisingly good. The strange thing going on at around 250 didn’t respond well to my EQ adjustment. Could be a room issue. My coherence trace suggested the issue wasn’t eq-able but I gave it a shot anyway. The important eq adjustment I would repeat is the LF cut centered at around 70hz to balance the sub with the line array. If parametric eq isn’t available, it should be possible to use a high wattage resistor to reduce the sub volume by a few db passively. One could build an assortment of inline speakon to speakon adapters that would allow for adjustment of the B1 sub level based on the acoustic environment. For example, if the rig is in a corner you may have even more excessive LF. If outdoors you may need to run the sub wide open.