Axiom Home Page Forums General Discussion Advice from Axiom Owners Need a <$1200 Receiver recommendation ASAP!

I have to admit I never even bothered to look for this setting on my Integra. I found it was set to "80 Hz (THX)" so I bumped it to 120.

My statement came from researching the Audyssey thread. Chris (from Audyssey) along with Mr Holman (creator of THX), have often stated that there is NO crossover of a sub, this really is a Low Pass Filter. Why would you be crossing over the sub? If you think about it, you adjust the crossover knob on subs to either bypass or to the highest setting, usually 120hz.

The THX recommendation of 80hz, is for the other speakers to crossover to the sub channel, not the .x channel. He explains that this should be set to 120hz, as there is no LFE above that point. For whatever reason, some manufacturers have started to include this setting.

Dave, not sure, but I would image if you set it lower, maybe your restricting the Low Pass Filter from receiving frequencies above the 80hz point. They would be in the twilight zone.

Ha ha, SUCKER!

David, the separate LFE channel(this isn't bass redirected from "small" speakers)theoretically goes up to 120Hz, but in practice little or nothing useful is present over about 80Hz and most is much lower. Whether to set the LFE low-pass at 80Hz or 120Hz isn't really critical. Some want to set 120 in case something useful might be up there, others want to set 80 to mnimize any noise content that might be near 120Hz. I'd suggest 80Hz.

Ok, gonna admit some ignorance here... how does one determine what their speakers' crossover settings should be, based on manf's specs? I understand that ultimately it's preference, though.

John, since you support the THX recommendation of 80hz crossover for the satellite speakers in a 5.1 or 7.1 setup, I'm suprised you would not agree with the setting. Prof. Chris Kyriakakis and Prof. Tomlinson Holman (creator of THX) say that this is a LPF and should always be at 120hz. They go on to say that LFE material in movies goes up to 120hz, so I would think you would want to follow their recommendation and not limit your system.

I value your input on this stuff, but come on, Prof. Tomlinson has a pretty impressive resume.

Prof. Tomlinson Holman - Chief Engineer of Henry Kloss' Advent Corporation, founded Apt Corporation (maker of the Apt/Holman Preamplifier), and has written three books on audio. For his work at Lucasfilm Ltd in developing the THX Sound System, Holman won an Academy Award. He is currently professor of film sound at the USC School of Cinema & Television.

Prof. Chris Kyriakakis - is Associate Professor of Audio Signal Processing at the (USC) University of Southern California's Viterbi School of Engineering. He is founder and Director of USC Immersive Audio Laboratory, and Deputy Director of the Integrated Media Systems Center, a National Science Foundation research center. He has authored two books and more than 100 journal and conference publications.

Flip, when you run through the setup, Audyssey looks at your room environment's acoustics, and looks for the speakers -3dB point. 40hz is now the determination most receiver manufacturers use to determine the small/large setting. So speakers like the m80's will most likely be set to Large, when done with the setup. You still want to change this to small, and bump up the crossover from 40hz to 60 or 80hz, and let the sub do what it does best, below the crossover. Also, the filter resolutions in Audyssey are best suited for the sub channel to handle as well.

In my situation the Qs8's were set to 90hz crossover, which I will leave alone, and you never want to lower this setting. Audyssey only provides correction the the crossover points it determines for the speakers -3dB point, so if you lower the setting, those frequencies will not be managed or corrected.

If you don't use Audyssey, all of this doesn't matter. So far I am VERY impressed with what Audyssey offers. Dynamic EQ and Dynamic Volume are wonderful.

Yeah I still need to purchase the feature pack upgrade and re-run audyssey... as of now I do not have audyssey enabled.

Then it takes a coffee break, heads to Paris, learns another foreign language, tries to derive its own set of math rules, attempts converting between imperial and metric by first bouncing a balloon off the surface of Mars and losing it, then eventually remembers something about a home audio system and believes that any good randomly chosen setting should be a value related to pi in the least.

That's great, Chess.