Originally Posted by filmguy123
Ryan -- Aha - that's interesting about the 60hz potential - with a Denon X4500H and 125w/channel on a 5.1.2 setup on those efficient Klipsch speakers, I think dropping the crossover to 60hz might be a good fit. Now, obviously this will come down to sound and I *must* test that (but I can't for a few weeks!). But out of intellectual curiosity, in theory, is there any reason why this would be better/worse? Was my speculation on-point regarding such?
Russ -- Ahhh this may invalidate my above question to Ryan. I did not know that, someone somewhere gave me misinformation. I was told the cross over was a hard stop for the speakers, not the point where it gradually fades off (which makes a lot more sense to me). So, what you are saying is below 80hz, the towers taper off and the sub tapers in? If that's the case, it would seem to make zero sense to set my crossover lower at 60hz? Or is there any reason at all to do that?
(also, how does the AV receiver calculate how much and at what curve the crossover taper takes place?)
You're getting a lot of good input here in this thread. There's one point I do want to make, that "it goes both ways" about crossovers, but first, just at a high level (and to repeat some of the points that have already been made):
You definitely don't want to cross over at *higher than* 80 Hz if you can help it. The only reason you "couldn't help it" is if your speakers aren't capable of playing down to and through 80 Hz without much roll-off. It sounds like this is not your situation (which is good). From about 80 Hz on down, sound is pretty much "omni-directional", so sending those frequencies over to be output at the sub doesn't tend to shmear or otherwise mess up your stereo imaging / directivity.
But otherwise, there's a trade-off to be had, as-follows:
1) On the one hand, crossing over higher up (80 Hz rather than 60 Hz or 40 Hz) tends to "off-load" the work-load from my 250 watt (125-watts-per-channel, into 2-channel, @ 8 ohms) Denon AVR, and let the 800 watt amp in my Rythmik "eat".
But, the one thing to keep in mind, is that a "cross-over" is not a hard, abrupt, changepoint. It is not as if an 80 Hz crossover means that 82 Hz tones, 81 Hz tones, 80.1 Hz, plays *entirely and only* from the speakers, and 79.9 Hz, 79 Hz, 78 Hz, etc. plays *entirely and only* from the sub. That's not how it works. They "cross over" into each other gently. It's not a hard, discrete, switch. With an 80 Hz cross-over, you're speakers are still playing some at 70 Hz, 60 Hz, etc, and your sub is still playing some at 90 Hz, 100 Hz, 120 Hz, etc. I think what what kind of software you're using to control those cross-overs generally dictates how sharp-or-gradual that handoff is? It's my understanding that I think Audyssey uses 12 db/octave as it's default setting, at least for how quickly the sub rolls off above the cross-over point. If I'm right about that (which, fair warning, I might not be), that means that the subwoofer is still playing, all-be-it 12 dB lower, at 160 Hz, with an 80 Hz cross-over...
2) SO, the "pro" to reducing your cross-over below 80 Hz is it helps get your subwoofer "out of the way" for frequencies that are directional and can shmear your stereo imaging...
I like to keep the 80 Hz crossover because I'm using a conventional 125 wpc AVR (for dual purpose music-and-movies) rather than a beefy dedicated 2-channel HiFi Amp. And I bought a subwoofer (Rythmik F25) that has a few extra knobs/control capabilities I can turn, including the ability to "roll off" at 24 db/octave above 80 Hz rather than 12... which I think helps.