I enjoy my Stealth 8s through the DC-1, but I'd like to experience more extension into the low frequencies. I'd have to run the sub via RCA as the Stealths are using the balanced connection. At least I believe both balanced and RCA are simultaneously active on the DC-1.
Are there any characteristics of the S15 that might not play well in a 650sqft finished basement with 7' ceilings? Can the S15 be tamed and tuned for less dynamic listening? I've never owned a 15" sub. For all I know, it's an obnoxious monster meant only for home theater impact. Any reason the S12 would be better?
Also, the S12 & S15 cutoff at 65Hz. How much LF overlap is usually acceptable between mains and sub? The Stealths are -3db at 35Hz. I have much to learn regarding LF overlap.
The Stealth 8 has some serious bass extension. If you are looking for even more then you probably want at least two subs and ones that extend low. I've heard the Basx 12 sub and it was pretty good imo. So you'll probably be well served with either one. But I would probably go with two 15's! Mainly because I'm concerned about the need for low extension. No it won't be "too much". Also to get more impactfull bass you should try room treatment. Though room treatment has little impact on bass absorption because the bass frequencies are low it clear up the mid range and treble. The muddiness here can make you feel like the bass is "muddy" or smeared. Also carpets and curtains make significant difference. After room treatment I feel that my bass has more impact and less smear. But I know that my room treatment is insufficient for bass treatment. But treating the other frequencies help make the perception smoother imo.
Transport: Sony UBP-X700 UHD-Blu ray player spdif PC using Musiland Digital Times WASAPI via BNC connection - DAC: DC-1->XLR XPA-1 , RCA->Basx A-100 CD: Denon DCD 600 PCM 61 DAC. RCA Amp: XPA-1 gen 2 using XLR connections. Speakers: Axiom Audio m80 V3, Sennheisser HD700 headphones. two pairs 12 guage each bi-wire speaker cables per monoblock Headphone amp: Basx A-100 (INCREDIBLE VALUE!!)
I know the 8s go lower, but I’m running the S12 right now with the Stealth 6s and it blends perfectly in my med size room. It sounds fantastic for music, but if you’re looking for perfection in home theater, you might want 2.
Living Room: Emotiva XMC-1 / XPA-5 / XPS-1 Pro-Ject Carbon TT, Sony UBP-X800, SqueezeBox Touch Ruark CL20 fronts, CL15 center, Emotiva UAW-8.2 rears Airmotiv S12 sub, Sony 65XBR-850C, Panamax M5300-EX Logitech UE-6000 & Grado SR60E cans Bedroom: UMC-1, Sony 55XBR-800E, Oppo BDP-93, Airmotiv 4s