Which REL sub, R528 or B2

A few years back I had an opportunity to audition a REL Studio III, JL Audio 113, and a Velodyne DD 18.

Your description of the REL is what I heard along with the difficulty of integration. Running it through the Velodyne I was able to EQ out the bloat between 35-45hz in my room. Still, its presentation lacked the leading edge speed of the others. Using JL's onboard EQ alone I was always aware of its presences in the room.

The Velodyne completely disappeared until I turned it off. This was a huge difference from the REL. I've since replaced the DD 18 with two DD 12+s. As a working Bassist I have many raw track recordings on tape and digital files and I have never encountered any timing, coloration, or timbre issues with any of the Velodyne subs I've owned.

The ability to adjust phase, volume, and EQ presets on the fly with the Velodyne's remote control takes sub ownership into fun status.

My experience is limited to Velodyne SPL-1200R. I was not able to fully integrate it with the mains. I could feel some strange body in the system. Bass was to tough, not musical and tiring after long listening. I used hi level connection then. Maybe if I had used a better quality speaker cable ....
and reliability problem. I used to leave the sub in st-by mode. One day, after thunderstorm ... My electronic friend looked inside, no fuses, no protection, assembly quality like those from China. The authorised dealer said you have to replace whole electronics, can't replace parts. This is how it's designed. So I said to myself no more Velodyne.
The advantage of REL is it's connectivity, I'd like to use it in both, HT and stereo system.. I took a look what the guys from positive f use, mostly rel's if any. Unfortunatelly they are not available in my area for a test. I found some posts here, on audiogon saying a few persons used C1 and REL's with success hence the decision.
Thanks for your input, I'll have to rethink it....

Go for the 528. It's an outstanding sub, easy to connect and integrate. I was never happy with the B2. Been tremendously satisfied and still own the G1x2, 505x2 and a solitary 305.
All the best

As a fellow C1 owner I have been very happy with my Rel B3. I did at first think it was slow but that was because I didn't have the phasing/timing right. I had to move it about 3" back to finally get it right. Also on a whim I bought a Nordost Baseline made to Rel spec and I after putting it in place of the stock Rel cable I heard attack and decay I didn't even know I was missing.

The thing Velodyne does good is you have almost no acoustic problems anymore. But there is a big but.......it is still toooooo slow. Instruments and voices are still too big in proportion. My PLW-15 is superior in timing. But you need Audyssey pro to get it right. It has no acoustic system like Velodyne has. Velodyne speaker units are tooooo slow in respons. This is by far the weakest point of there subwoofers. Timing is crucial for using a subwoofer in stereo. For a long time I did not like it. The PLW-15 with Audessey pro did change my thought about this. Rel and Velodyne are both not capable og giving the stealth low freq. I want and need. Never buy a subwoofer with a bass reflex system. And Never one with more than only one unit in front. All the other kinds of sub's I test did fail in speed and in respons. You always will be aware of the flaw's. This can become very irritating!!