Unfortunately, the 3.5 ft^3 cabinet that looks like it would fit the Audiopulse is out of stock but the 3 ft^3 cabinet might work with a small modification. I was planning on running the subs sealed as I believe they should have enough output down low as is.
Now, the P7000S can run the subs separately in stereo and I believe the S-Convert can also be used in stereo. I wanted to get something like the Reckhorn B-2 or eQ.2 for use as a high-pass filter and for some equalization. Unfortunately, the eQ.2 is backordered and it doesn't look like CSS sells the Reckhorn units any longer. I don't know if there is anywhere else to source a Reckhorn unit at this point. I'm currently trying to decide if I can run the subs without a high-pass but I don't if I'm comfortable with that even though it looks like I probably don't need it.
So, do I just need an RCA splitter in order to run dual subwoofers off of a single sub-out and does anyone know where I might be able to source a Reckhorn (B-1 or B-2)?
If the speakers are not an equal distance to the listener, you may have problems only using a Y splitter. If you get a miniDSP for EQ, I believe you can also use that to set time delay for each sub individually. I do not have a miniDSP, so hopefully someone else can verify this.