JL Audio CR-1 Crossover

Hi. Not really, Ozzy. Partly because I have not done much with it and am not sophisticated. However, as long as I level matched the subs, set phase, ran DARO, there was nothing left fine enough for the damping control to "fix". In my measurements, there is no dip or peak that broad to correct without some compromise. The manual states to set it by ear by way of too lean or full at 80Hz. I have done that with just one decent bass guitar song, and it sounded fine (no revelatory moment of perfect integration ;) +/- 1, then worse beyond that.

I replaced a pair of RELs (using high level input from the amp) with a pair of fathoms with a CR1. This was to correct a 60Hz room mode on the vertical axis generated by the main speakers.  There are measurements pics of this on my system page. The CR1 has a button to switch on/off the crossover circuitry, so A/B is easy. In my case bass extension is a little less and the blurriness around 60Hz reappears with the subs and crossover circuity off. The promise of decreased upper frequency distortion was not materialized in my case, although the coherence between the woofer and the "midrange/tweeter" improved. I have just used factory settings at 80Hz which seems like an obvious choice based on my problem. Playing the damping only made it wound worse. I am still experiemnting with placement/DARO a little bit as well as phase. It seems damping would be normal last step. As a side I find DARO pretty havey handed through its band, making "good enough" placement idiot proof. I am still working through it, though.  

I had help from acoustic frontiers in sub/speaker relocation to smooth out bass. I have at least a hundred REW measurement from this misadventure. The subs ended up near opposite corners of the room, which flattened all but the 60Hz. Elevating them half way up the wall helped partially, and the crossover eliminated it. With the fathoms, I now have a 20 Hz issue, below what DARO controls. I pulled one sub out in the room as far as resonable to flatten it, but created a massive 34Hz issue that daro amazingly corrected. I did waterfall overlay between the two radically different positions, and there was not much difference even in decay time. I could not really hear a difference either. I may try moving one sub to the corner, so the pair are symmetric to see what happens. 

Like you suggest, I also EQ’d it then adjusted levels, which is easy. The LF trim control’s bandwidth is too broad, so of course volume has to be adjusted. Unfortunately I do not know how to use stereo with separate phase controls and use DARO at the same time. Are you using master/salve configuration?

Thanks for your reply, Ozzy. I may try to set the DARO individually. My subs are positioned  to cancel a 40Hz mode, and I do not know how the equalizer will react. Obviously it can only really work at minimum phase. Doesn't hurt to try. 

The ground switch is a good tip I overlooked. Thanks. 

I switched from master/slave mono to stereo. At that time I phase adjusted R and left channels to 80Hz with an SPL meter and also volume corrected the right channel at 80Hz. Phase was zero in mono mode and the xover was best at 12db.

Either way works the overall results were a compromise. The mono mode at 12db cover luckily reduced 115 and 170Hz peaks while producing a dip at 28Hz. Subjectively I prefer the mono mode, but neither is a slam dunk. 

The damping knobs have a broad reach. Broader bandwidth than I was exprecting and easily measured. At 80Hz, I created a "satellite" dip that went up to over 200Hz.