Re: Channel summing for full range signal
After a few days, I was still having the same issue. Intermittently, the amp would shut off when the volume was up and the bass was strong.
So, I started over.
All gains on AC LCQ-1 & amp set to zero, I started at the AC LCQ-1.
HU volume at 29, all RCA's disconnected at amp, I played a few songs of different types of music (heavy metal, rock, country, indie, rap, ect...) and found a good avg of the "maximized" LED blink on the LCQ-1. The "maximized" LED comes on when the signal is clipped. Blinking slightly is at a "just starting to clip" signal.
With all RCA's plugged back into amp and all gains zero'd, with speaker wires now unplugged from amp, HU vol at 29, I played a 1k sine wave test tone and adjusted the ch 1-2 & ch 3-4 gains until I measured 15.5Vac on all four output terminals. (about 4.5Vac less than before)
Then played a 1k sine wave test tone and adjusted ch 5 gain till I got 35Vac on the output terminal. (about 5Vac less than before)
I reconnected all speaker wires.
Next I played pink noise, using the JL Audio RTA app and adjusted the EQ for a mostly flat response. However, I like warm, slightly bright highs (meaning sharp, but not harsh) and loud bass, but not muddy or boomy.
With the same varied music selection I then tuned by ear. I lowered the front gain slightly as it was just a bit distorted, with just a bit of hiss at zero volume. Also lowered the sub gain some as it was a little too loud, but then added just a touch of bass boost (about 5db). I also padded the LCQ-1 EQ on front ch 1 & rear ch 2 125Hz, 250Hz & 1kHz, attinuated 2kHz & 8kHz. I padded 50Hz & 63Hz on Sub ch 3.
For the AC LCQ-1 AccuBass setting, using the same music again, it sounded like the bass would reduce around volume 17-20 on the HU. So, at volume 18-19 I turned the AccuBass threshold to about 2 O clock until the bass came back up, so that restored the bass. Thats it, now bass is about the same level at all volume settings. NICE!
Now, I can go full volume if I wanted with very little distortion (clipping). 20-25 the optimum level, depending on song and recording level/quality. 29-30 is loud and the sub shakes all 3 mirrors! With strong deep bass, not only do the mirrors shake, but you can see the headliner shake too!
I am sure I am not done yet, but I am much closer than I was before.
AND, BEST OF ALL... EVEN AT FULL VOLUME THE AMP STAYS ON!!!!!