where do you cross over your ht setup


hello. i am just wondering where everybody else crosses over there ht system at. thx says 80hz with speakers set to small. some speaker co. say set front mains at 60hz the rest set at 80hz set to small. i even read one speaker co. in a reveiw say 20-30hz and set speakers to large. if you are driving a full range speaker system with a stand alone powered sub what do you fellow audiogoners find best. also when using a spl meter do you set up your system at 75? thanks.
theaterhome
Vedric...Agreed that LF from a SW has directional aspects which should be preserved. (Unless you are playing an LP where the LF has already been mixed to mono). I think that every speaker should have its own SW: at least 2, and I have 3. However, I thought that this post was about crossover frequency.
OK.I give.This has been the most fun yet.I guess my small room is a problem and or has multiple problems and all the other rooms have or had problems and the only house calls are from clients with problematic rooms.Cross over freq. is room dependent and not speaker dependent.Problem rooms are easier solved with a higher cross over freq.Thus allowing one to adjust one channel.So.....we are all right!
I'd like to add that in addition to the importance of room acoustics/speaker placement discussed above, it is also extremely important to avoid "double filtering" the audio signals to your active sub. The results can be very unpredictable if you feed a sub's filtered line-level input from a processor's filtered LFE output. (Nearly ALL receivers/processor's LFE outputs are filtered). This can either cause the dreaded bass "suckout" or "boom" even if the sub is positioned properly in the room. This is especially problematic when you set the active sub's crossover frequency close to the frequency setting in the processor. The interaction of the two filters, which may have very different characteristics (different slope, etc.), in the signal path can wreak havoc with the sound.

Many higher-quality subs offer an unfiltered line-level input for exactly this reason. It's usually labeled something like "LFE-in" or similar. Or there may be a "bypass" toggle switch you can set to bypass the sub's built-in crossover.

If your sub lacks the unfiltered input and you are going to use your processor to set the crossover point for LFE, you should turn the sub's crossover as high as it will go.

My $.02 ;)
John Z, I do exactly what you say not to, and I am not 100% satisfied with how my Sub sounds. Although 100% satisfied with audio is an oxymoron, especially with Subs. Anywho, can you or someone else, explain the technical reason the two filters will interact poorly.

I am going to tinker with cabling tonight and I intend to try your recommendations, but I would like a technical foundation on which to ponder. Thanks in advance.
Yeah you can run into problems if you stack crossovers or interstect them. It's often best to set the crossover on the sub as high as possible if you don't have a bypass, and are using the processors internal crossover. If you like the sound you are hearing "distortion", then there you are!
If it ain't broke, don't fix it!
Still, there are numberous articles by industry professionals that say you shouldn't do what you're doing in general. Still, tinkering and tweeking is ultimatly where it's at, as system set ups and equipment matching will have a great deal to do with all this. Still, what I find is that the single greatest areas or down falls for most is both speaker placment, seating placment, and system set up paramaters and tweeking!...not to mention other room acoustics problems. All that is followed by poor gear selection for appropriate needs being a distant last!
Good luck