Bought the wrong subwoofer!

I own a pair of REL T/7i subs and a pair of SVS 3000 Micro subs. They are similar in size, but the Micro's are a bit smaller…an eleven inch cube. The T/7i has a single front-firing 8" active driver with a 10" passive driver on the bottom while the Micro's use dual opposing 8" active drivers.

I got the Micro's because I've been waiting for ages for SVS to make a subwoofer that's designed for audiophiles with dedicated 2-channel setups instead of the home theater behemoths that dominate their product-line. I was not expecting the Micro's to give my beloved T/7i subs much competition, but after living with them for a few months, I actually prefer the sound of my system with the Micro's.

I was using the high-level inputs with the T/7i, which I prefer, but my preamp happens to have s 2nd pair of outputs that can be used for subs, so no complications with hook-up. In both cases, I'm running my main speakers full-range, but controls on the SVS enable better integration than I could achieve with the REL's.

Before this, I did try the SVS SB2000, but I could never get good integration with them for 2-channel use, so they went back. The 3000 Micro's are completely different and definitely keepers. Most reviewers who have evaluated the new T/7x and 3000 Micro prefer the former. Perhaps I would too, but in my system, the Micro's pull out ahead of the T/7i's.

The REL b3 may be a 15 year old design but the one I brought home today looks great and sounds better. I was able to get it to blend with my Sonus Faber pretty easily and it truly does disappear from the room. You shouldn’t be so quick to dismiss vintage audio gear. I have owned and enjoyed some equipment almost as old as I am and most of it worked better than I do. I am really happy with my current setup which was put together on a pretty tight budget.

I had one of the old Rel subs. I rebuilt the amp and the woofer needed to be replaced at about 20 years. I ordered one from Volt in the UK, they still make the same driver.  It was a good sub.

I think bass is one of the last things audiophiles understand so I’m glad there are so many subwoofer experts on this site. 

I think bass is one of the last things audiophiles understand

I remember a time before subwoofers. Never had a sub nor needed it til 15-20 yrs ago. But I remember back in the late 70's early 80's when the notion of taming down the bass so as to get a cleaner sound and better midrange. Then over time it seemed that bass became so unimportant that it was pretty much stripped from the mains. my speakers specs say 20-20K. But without the sub the are sorely lacking in bass. Midrange to die for but little real bass...especially for R&R.But WITH the subs they are fabulous. So we lost bass, then we created a new business for sub woofers. They tell me this is progress

I think bass is one of the last things audiophiles understand 

That's for sure. Virtually all of them are still stuck in the understanding exemplified in this thread. OP went from one sub to another, swapping when he should have been adding.

Low bass is near impossible to do, for the simple reason you cannot fit 50 foot long bass waves into a 20 foot long room. The wave reflects and comes back and cancels itself before it even gets going. For many years I tried everything and never heard anything work properly and had given up. The physics are just too daunting.

Until a couple years ago on this site Tim (noble100) and some others were talking about a Swarm or Distributed Bass Array. Do a search for these if you want to understand low bass. Read everything you can find by Tim and Duke. Read the research paper and doctoral thesis that started it all. 

While you are at it check out the dates of the papers and discussions. Then reflect on how slow people are to change and learn and adopt new ways of doing things, even when clearly superior. Everyone who has been on this site more than 2 years knows all this. Half a dozen of them should have chimed in by now saying don't swap, add. Instead, crickets.

I think bass is one of the last things audiophiles understand 

Duke, Tim, DBA. Now you know how to not be one of those audiophiles.