ACI Titan II vs. Rel Storm III

I would like to add a sub to my system. My speakers go down to around the upper 30's but without a lot of output. I was sold on the Rel until I heard about the Titan for considerably less money.
I had the same decision to make about 6 months ago ....

I've read that the Titan can be a bit more difficult to integrate than the REL, and may need high pass filters (passive) between the preamp and power amp (which would be tricky if you have an integrated). Once integrated reviewers still felt the REL was more musical, but that the difference was small. I believe that the ACI is more powerful and will give higher SPL, but I have a small room and listen exclusively to music (no HT).
The RELs are very expensive in the US (seems to be a huge markup, given how strong the USD is at the moment) but after a few months of waiting I found a 6 month old Strata3 for $800 and it integrated perfectly with my floorstanders (spica angelus).
Obviously the first choice would be to do a home demo of both and decide if the REL is worth the extra cash or hunting around for on the used market.

In summary I think the REL is probably a safer bet and you have the choice to pay the extra and get a new REL or be patient and wait for a deal. The Titan may work just as well in your application so if ACI have a good return policy and you don't mind the hassle then try the ACI first ... you might save some money. However if ACI don't have a good return policy then I wouldn't get one without a home demo first, because if it doesn't integrate you'll hate it and eventually get rid of it at a big loss.
If you have a home theater I would say just because of the way the REL hooks up you'd want it. It mixes both the .1 signal and the speaker level signal so you get all the bass not one or the other. My $0.02. leo.
I have not used the Storm, but I have had a Rel Strata III (more equivalent in price to the ACI) in my music system partnered with NHT 2.5i speakers, and now have the current ACI Titan II LE, which I have partnered with the NHTs (e relatively "slow" speaker), as well as a pair of Gallo Nucleus Solos (a very "fast" speaker). In MY particular system, in MY particular room, I was never satisfied with the Rel; I am very happy with the ACI.

The ACI has the same inputs as the Rel--speaker level, "Theater", and pre-amp out--but I don't have my manual in front of me and can't say if it sums inputs as Leo describes above.

Auditioning a subwoofer (and any speaker, for that matter) in your room is crucial. ACI does have a generous audition policy, though you are out some shipping. If you can't audition the Rel, I would say that the ACI is a safer bet. How's that for conflicting advice!

John K.
I use the Titan powered sub woofer in my 2 channel system. I have heard the REL at dealers and it also sounds very good. BUT for the money the Titan is outstanding, very musical.
My 0.02$ worth
Bryan P
When I first heard the Rels, my notion of how well subwoofers could integrate with main speakers was radically altered. I then spent a lot of time with a Vandersteen 2WQ, which is excellent but does not integrate as easily. Then I read about the ACI Titan II and was intrigued.

When I was ready to buy, a used Rel Storm was a financially feasible and I knew it would work well in my listening room. But ACI had just announced the Titan II LE which was cheaper, brand new, beautiful-looking, and I could try it out for 30 days for the price of shipping.

So I tried it out and have not looked back. It works even better than the Rel Storm in my room and goes louder if necessary (not necessary...). It integrates seamlessly, even though it cannot be located optimally (due to room and aesthetic constraints), whether I run my Vandersteen 1Cs full range Rel-style (as I did at first), or I use ACI's transparent high pass (65 Hz.) filters between my preamplifier and amplifier quasi-Vandersteen style for some subtle benefit to my 2-way 1Cs' woofer/midrange drivers (as I do now).

The ACI Titan II LE is a most musical subwoofer. It serves as a very powerful subwoofer for movies as well.
Titan II LE by a mile! Tighter and more accurate than a Storm III. As much output as the $2500 REL Stadium. The Titan II LE is the real standard in reasonably priced musical subs. If you take the time, the integration is absolutely seamless. REL used to be my fav until I heard the Titan II. Do give it time to run-in. Mine was still sounding better after at least 100 hard hours. BTW, as others have said, this is a beautiful piece of furniture. My ex-girlfriend even loved it:)
Positive Feedback, Soundstage and Bound for Sound all loved it in recent reviews.
In my opinion the Storm III offers much better integration. I tried them both side by side and although both are very good subs I was always aware of the Titan's presence. The Rel simply disappeared and I could feel it only when the music material called for it. For home theater use only you could be better off with the Titan.
Several friends and I spent the better part of a weekend comparing the Storm III vs. the Titan II. This was over a year ago before the LE came out. Both subs were well broken in. We played a large variety of music, we tried different placements, we adjusted levels and carefully tweeked the setups. Wasn't really very close. The Rel is good, but on many recordings it drew attention to itself, the Titan II never did that. The Titan II could also play to substantially higher levels without distortion. This isn't just something that is a factor for HT. A big difference on large scale classical music that uses a lot of percussion, pipe organ etc. With the Titan II we were also hearing more bass information and detail. The Titan II never lost the beat.
I've now had a pair of the Titan IIs playing in my system for over a year. In over 20 years as an audiophile I've heard countless systems in the loftier price ranges, I've rarely heard this quality of bass.
Considering the ACI is significantly less money, it is a pretty easy call. One of the nice things is that ACI has the 30 day money-back guarantee. I'd suggest that anyone who thinks the Rel is even close, (the Stadium III is probably a closer bet), get them both in-house, break them in good, tweek the setups, and I know which one you'll keep.