Crowsons AVM90 Integration
Lets get down to hooking the Crowsons Motion Actuator up with the AVM90.
One should note that both RCA connections and XLR connections on the AVM90 are “Active” at the same time. Meaning the AVM90 sends a signal out to both outputs at the same time. This is very useful for people like me using 4 subs and 1 crowsons. so i have now connected using RCA Sub1 out for the MA. The one circled in red below is sub1 out
So it turns out Minidsp 2x4HD is still required in my case. But before that, i had to first establish, which RCA preout to use, 1,2,3 or 4 ? IN my case, let me explains why i went with Sub out 1 RCA
if you see sub2 out above, it shows some boosting applied between 15-20hz
On Sub 3 out, cuts are applied between 15 - 20hz
Sub 1 preout above, had the least EQ applied to that channel. So that is why i went with using Sub 1 RCA out. You want a clean signal going into the Motion Actuators because they are not subjected to Room Modes unlike the subwoofers in the room.
my goal is not to use the actuators for frequencies above 15hz. So i am using a 15hz 6db Butterworth filter on this for the Motion Actuators, like the below
Remember to turn on the compressor settings as well on the mindisp
The other point to note is that the levels are not the same on RCA sub1 out vs XLR Sub1 out
One would need to compensate for a +6db gain on the RCA out due to RCA being 2v vs XLR 4v. So levels are much softer using RCA preout. You can see from the measurements in blue above that XLR connection is louder by 6db. You can also observe there is some cut applied by ARC from about 13-15hz on sub1 output, but thats insignificant. the rest of the signal down to 1hz is untouched by ARC.
Compensate for the levels in the Output side of Minidsp, so both crowson and sub levels are the same. I have also applied a 1ms delay to the signal for crowsons. thats personal preference as i would want the subwoofer energy to hit first before the actuators move. Some prefer 2ms, thats fine, as long as it doenst take away the inertia and energy from subs.
So why 4.64 milisecond delay on the minidsp ? we need to understand the difference in the distance applied in ARC
If you look at the sub final computed distance by ARC, sub 1 is 625cm, and the nearest sub 4 is 500cm. So sub1 has a further distance compared to sub4. Because sub4 is the nearest sub in the chain, the processor will have the most delays applied for that particular channel sub4, so it can match up the furthest sub. That means sub1 signal is faster than sub4 by 3.64ms. ie 625cm - 500cm = 125cm (use this calculator below)
So 3.64ms + my desired 1ms, thats 4.64ms and that is why you will see minidsp having a 4.64ms delay on crowsons channel
If you are lazy to use BEQ to load the filters all the time, here is one quick solution where you can utilise the crowsons to good use, even watching drama or other content.
Most source have freq butchered below 30hz, so the goal here is to apply a number of filters for general use. this is what i do.
I use 4 low shelf filters as follows:
The above is what i have been using for a number of years now, as i noticed most movies/content dont have much Low freq. So i use this specially for the actuators, in total it gives me +14db boost down low freq to 10hz
Enjoy! Crowsons is awesome, and yes you can send another signal out vide RCA output
