Is this for a home theater or a hifi system?
If it's for HT, it's easy enough to hook it up. Just use the LFE output from the AV receiver or prepro.
For music, it's a bit more difficult. You might want to look at one of these boxes:
It's always a bit difficult to integrate a subwoofer with main speakers. One thing I try not to do is to muck with the main speaker's crossovers. The speaker designers have put a lot of work into the speakers' internal crossovers so adding another crossover stage in front of it is going to muck it up further.
Something like the Velodyne helps you adjust the subs output to make sure it complements the main speakers by augmenting what it can't fill rather than using a separate crossover in front of the main speakers.
10-28-12: Doggiehowser writes
Is this for a home theater or a hifi system?
>It's always a bit difficult to integrate a subwoofer with main speakers. One thing I try not to do is to muck with the main speaker's crossovers. The speaker designers have put a lot of work into the speakers' internal crossovers so adding another crossover stage in front of it is going to muck it up further.
Main speakers need an electrical high-pass filter to prevent unacceptable IM distortion unless they're sealed boxes with a high cut-off frequency (80Hz is too low for drivers 8" and under) and even then you may want a steeper roll-off to work around your room's height mode that takes another pair of poles.
For reasonable integration where that's not the case the most reasonable thing is to plug any ports, replace the speakers' two high-pass poles with zeroes, and apply your desired high-pass function where a Linkwitz Transform will give you two zeroes and two poles using one op-amp, a biquad will do it in the digital domain.
A mini-dsp in the digital domain
or Linkwitz wASP (Linkwitz Transforms for both high and low-pass legs, another pair of poles in each to give you 4th order acoustic slopes, optional all-pass for the midrange, pads for a pair of notch filters) in the analog domain will do it
You'll want to measure and neither is a plug-and-play solution.
I'm not a big fan of adding another crossover in front of the speaker's crossover.
I like the idea of running my main speakers full range and letting the sub pick up where my mains drop off. I ended up buying the svs pb plus 12. Im happy with it, I just notice alot of the bass I hear coming from my back right side corner of my room, no matter where the sub is placed, which is pissing me off. I ended up hooking it up to the left and right rca pre outs and Im using my xlr out puts for my amp. This seems to be working well with no ground loop hum.
Try downloading the Thiel SmartSub manual. There's a section on subwoofer placement.
I think centre between the 2 speakers is best for a single sub
What is your room dimensions and list of equipment? Have you tried placing the sub in between the speakers? Is the bass one-note bass or is it all bass frequency that you find annoying? If you can find the frequency that is bothering you, you can tame it with the Parametric EQ on that model.
I've tried placing it between the speakers and lose alot of output, and alot of the deeper bass. The bass I hear collecting in the back right side of the room does seem to be just a certain frequency whereas the other frequencies seem to be coming evenly from all over. I guess my next option is to do what you suggest and try taming it by ear with the p.e.q. Im also wondering if some room acoustics (bass traps) would help with that particular problem. Thanks hi end for the idea with the p.e.q. though.
Yes room treatment like bass traps would definitely help alot but that would not remove the one-note bass. When you place the sub in between, did you adjust the phase knob?
Having corner reinforcement increases the output but I think it also can be muddy and not be as tight.
I remember before Audyssey AutoEQ for HT, I used a Behringer DEQ2496 to tune the subwoofer. A good flat response from the subwoofer sounded "less" to me but after a while, you realize you get more low level information than before.
I liked having my single sub between the mains because it doesnt seem as directional. Now I run it in stereo.
ps if you can, you can push the sub against the wall (but still between the speakers) to increase the output a bit.
I did adjust the phase knob when I had it between the speakers but it didn't make much difference. I too was thinking that the corner placement might produce a muddy sound, but it really wasn't, from what I could tell. It's easy enough for me to center it between my speakers so I'll do some more a/b testing tommorrow (girl friend is coming over this afternoon). If I had two subs, wouldn't I be putting them in the front corners anyways though? A corner location is where the svs manual that came with the sub says it sounds best too. When It, positioned between the speakers I turn the volume to about 2 o clock vs 10 o clock for the corner position.
I never experience having two subs so I could not tell you. I have my sub in between the speakers which gives me the best blend and bass. I would keep trying with positioning to find the best blend and sound.
Corner placement just blows the center placement away in my particular application. Way more output, way lower bass and not muddy. I think Im going to look into buying another sub for the left side, that way the bass is coming from both areas.
Alright, I moved my sub back to the center of my front wall to give it another try, and yes, it does sound better there. I placed my sub on 4" cinder blocks to try to decouple it from the floor, turned the crossover down to 40hz and turned the gain up. Waaay cleaner and better sounding. You guys were right, I was wrong :-)
I've eat crow many times. Glad to hear you've got your sub sounding great.
I find that most times I need to leave something in for at least a week and go back to see which is truly better.
Change can fool the best of us into thinking it's a pos. when it's really not.