Originally Posted by Dockson
Hello again! The PBTL switch is set to SUB and the crossover is at its lowest (which should be 40Hz?). I've also enabled the small gain switches on the bottom of the amp. The amp is connected via a 1x to 2x RCA splitter
going out from one of the SUBWOOFER OUT inputs shown bottom middle-left on this picture
Those connections and settings are correct, which is very weird because it seems like the low-pass crossover isn't working at all based upon your symptoms. I would first try moving the Nobsound crossover over the full range just make sure it's working (shaking should get more intense and inappropriate as you raise it). If that crossover isn't working, then maybe try switching to PBTL just for kicks to see if the crossover is in the circuit then.
For the delay you are experiencing, nothing in the shakers or amp can add any delay -- the shaker/amp is exactly like a powered subwoofer or even a powered speaker (if you put a full-range signal through, you will hear music coming out of the shakers). If there is an actual delay, it would have to be in the Sony because it is the only device capable of adding a delay, but it seems unlikely unless your sub is also out of sync (or all
of the audio is out of sync). Are you also running a sub and is it out of sync? Is the overall audio out of sync?
As far as power, typically shakers don't require that much power to do their thing, but I have no experience with your shakers. I think I remember reading that that amp can handle 2 ohm, so if your shakers are 4 ohm, you could wire them in parallel to make them a 2 ohm load and get more power out of the amp. The 8 ohm load is much friendlier to the amp, so I would leave it as is unless (once everything is tuned correctly) you find the amp can't provide enough shaking power. I like to limit power to shakers to only the amount needed -- if you have too much power, unpredictable spikes in movie content can damage the shakers or maybe even the furniture (depending on what it's bolted to), so having just enough power is better than too much in my opinion.
As far as not feeling the lowest frequencies -- I feel like all of this (and maybe the perceived delay) is due to the shaker crossover somehow being too high. I'm not sure how that's possible, but that seems like the most likely situation. If the shaker crossover is too high, you will get a lot more shaking at upper frequencies (that should not generate shaking at all) and the lower actual shake content will be barely present. Once you can crank down the shaker crossover, you will be able turn up the gain to feel the lowest shake frequencies in balance with everything else. The other thing to look at is the subwoofer setting in the Sony to make sure it doesn't have some kind of subsonic filter on to filter out the lowest frequencies (which would make sense to protect smaller subs, but not for shakers).