Mixing subs?

@bobbydd Manufacturer ratings: Your E112 -1.5dB@22 Hz / REL No.32 6dB@15Hz / Perlisten vented R212 small room filter -10dB@18Hz.

Garmin JL Audio, SVS and Rythmik Audio produce subwoofers that produce substantial extra low frequency. Adding a fourth subwoofer you'll enjoy the stunning benefit of a full room distributed bass array using minor asymmetrical corner placements.  

Because of their dramatic roll off the REL and Perlisten are sub-bass woofers. While they'll definitely add their limited low frequency, just not what you're used to. -6dB of 15Hz is barely audible and simply won't excite a rooms standing waves which is why they can be stacked up most anywhere in a room. 

When I purchased my two Velodyne DD-12 Plus I moved the older version DD-18 and my HT's Earthquake Nova 15 in the corner areas. I ran the Velodyne Auto EQ then balanced the gain on the Nova. The bass array literally eliminated all the rooms standing waves.  

Today I use just the two DD Plus positioned crawl determined room bass modes and no treatments leaving me with a single standing wave within unused corner of the room. Both the SVS and the Rythmik offer different but very useful equalization that may surprise you. All the best with your outcome. 

In the past I have used different brands of subs at the same time with pretty good outcomes. For my room 3 subs are the magical number and right now I am using all SVS but different models. An SB2000 pro, a SB4000 and a PC4000. I cross them over at different levels to cancel modes and have the added benefit of 1 app on my phone. This works really well for me.

Hey @bobbydd 

Sorry if this is going off topic but I wanted to ask about your experience with the REL 6packs as I've been considering going that way for my own setup.

Broadly speaking I've heard good things about them but haven't heard one myself. Wondering if you can share a bit more about your experience with the Carbon Special / 31 six packs?

I have been thinking.  My subs have nice bass. Only problem is they start to roll off at 40 Hz.  My Crites will go to 35 but it sounds better with subs. I started looking aound. Flat to 20 ish.  SVS, HSU, SPEEDWOOFER were all considered.

Used is hard to find.  Local pickup.

SVS have prodigious output but the helper insisted you can’t mix sealed with ported.

HSU. More serious subs.  

Speedwoofer.  10" will go to low 20s for $500.  Description of parts sound pretty good.

All this and I’ve never moved my 1st two around.  I just thought I could avoid all that by only moving the new one around.  

Check all your connections, fuse, controls first, if you haven't already.