Originally Posted by snookfisher
It had my identical ceiling speakers rated to 50hz like this .. rear 250 front 150 also had the center crossed over at 250hz …. the older ausyssey in my old pre pro didn't come up with the same numbers in the same room for my 7.2 ?
Originally Posted by dfa973
With such high crossovers, it does not come as a surprise that the resulting sound is not right....
The right crossovers should be:
Magneplanar 1.7 = 40/50Hz
Magnepan’s CC3 = 80/90Hz
APG MC1 = 65/80Hz
Focal in ceiling (100 series???) = 50/60Hz
A few recommendations about crossover points and Audyssey, if I may:
1. Audyssey reads the point where the speaker starts to roll off sharply. This is usually lower than the speaker's -3dB anechoic spec just by virtue of it being in your room. If Audyssey is reading a sharp rolloff higher than that spec'd point, it's because of acoustic issues in the room. The only way to deal with that is by re-positioning, treatments, etc. to fix the issues. Audyssey = garbage in, garbage out.
2. Audyssey's software passes that rolloff data to the AVR to set system crossovers... but different manufacturers use different tolerances and headroom and may set things differently. Not every brand's software follows Audyssey's recommended guideline for this setting.
3. In-ceiling speakers may be rated to 50 or 60Hz, but may not be able to reach that extension once actually in the ceiling. If Audyssey is reading those channels at a much higher recommended crossover, you would usually want to address that with something like a backing box so that it has an enclosure to work with. Depending on your install, you can sometimes fix those issues with something as simple as the proper placement of a little insulation around the speaker. The area above your speakers can reinforce the low end... or cause your ceiling to act a phase-shifted passive radiator that creates a gap in the frequency response. But if Audyssey is detecting 150-250Hz rolloffs for 50Hz in-ceilings, that's a clear sign that you've got a little work to do above your room.
4. LPF of LFE should always stay at 120Hz if your goal is accurate reproduction. This only filters the LFE channel, which tends to be filtered during content creation anyway... but filtering it lower than 120Hz can reduce the level of harmonics that lend sounds in the LFE channel their perceived tone. Whether it will be a noticeable difference varies from person to person and room to room, but as a general rule, you shouldn't cascade the filtering done during content creation with additional filtering of that channel in your gear. The harmonics from the lower frequency sounds won't be significant enough in level to make your subwoofer easier to localize, but they do alter the way you perceive those sounds tonally.
5. Never set a post-Audyssey crossover LOWER than it was detected at. The range between that new crossover point and what Audyssey detected will essentially be unequalized, and worse, if you really do have an acoustic issue that is causing a suckout significant enough to trigger Audyssey's detection of the transition point, you are losing headroom trying to reproduce sound the speaker can't do efficiently in your room.
6. I've found that a good guideline for what you would WANT the crossover points to be is to take the speaker's lower -3dB spec and multiply it times 1.5 then pick the closest crossover point to this number offered in your AVR. This gives you a half-octave so you get a smooth gap-free transition from the point where the sub and speaker are reproducing those frequencies equally down to the in-room extension you get from the speaker. So if your speaker is good down to 40Hz before it rolls off, set it to 60Hz. If your speaker's good down to 25Hz, as tempting as it may be to set it to large, try it at 40Hz instead. Leave the heavy lifting to the subwoofer, where you likely have more amplification, and you will also get cleaner sound from those channels as a result. I see many say to set your crossover to the -3dB spec'd point, but a lot of times that can cause a loss of response during the crossover's transition because you're cascading the in-AVR filter with the speaker's natural rolloff slope.
7. I've also found that if your AVR provides a coarse display of Audyssey's measured in-room response for each channel, you can use this as a general check for what frequency you should be aiming for. So for instance, if I look at Audyssey's coarse graph and see that a speaker I expect to have a -3dB point of 50Hz is changing from below the 0 line to above it, I can tell at what frequency Audyssey is having to boost to bring it into line. And if that transition point is above the spec'd -3dB point, I know I have some in-room work to do to fix frequency issues. If that transition point shows on the graph at lower than the spec'd -3dB point (which is what you would ideally expect given room reinforcement), then I apply the 1.5x rule to the number on the graph where that transition occurs (i.e. where Audyssey goes from cutting frequencies to having to boost them). Again, the goal is to give a smooth transition from speaker to sub so that you aren't relying heavily on boosted equalization below the speaker's in-room capabilities. My half-octave rule tends to work nicely with the filter slopes typically used in system crossovers.
8. Specific to Atmos and whether you're hearing sounds placed well between the bed-level layer and the overheads: For the bed-level channels, you can easily verify cohesion of cross-channel pans using phase tests (i.e. test material that places sound 50% in one channel and 50% in another channel so you can hear if it images between those two channels). All things being equal, if your system distance/delay is properly detected and set, you should get good cross-channel transitions all the way around. HOWEVER, as the man says, a plan is just a list of things to go wrong. So here's what I recommend... After running Audyssey, setting your crossovers, and making sure DynamicEQ is off (because it plays hell with Atmos, as its development did not take into account the presence of overhead channels and how mixers might adjust that to give the intended results at lower volume levels than reference), play Dolby's LEAF demo on a loop. Listen specifically for the pans from bed level to above and across the room. If it seems like those transitions are going too suddenly from bed to overhead rather than making a smooth pan, try adjusting the distance/delay of ALL your overheads in small increments. More times than not, a relatively minor adjustment can snap that low-to-high imaging into place such that it works better across all of your seats. In other words, listen to the clip as-is... then set all of your overheads +0.1 foot and listen again... then repeat a few times... then go back to Audyssey's detected distance and try -0.1 foot increments. You will KNOW when you find the ideal setting... because you will hear that cohesive DOME of sound that we keep talking about here.
9. Another minor tweak for x.x.4 setups: Play the Helicopter demo on a loop and listen for cross-channel transitions between each overhead. If you hear the transition between each channel pair drop out or transition too quickly, try making small adjustments to that single channel to see if you can get a more cohesive pan between them. This is getting REAL nit-picky and may not matter to anyone outside of the MLP... but if you're in the MLP (and why wouldn't you be), you might as well strive for perfection there.