Originally Posted by petetherock
It isn't my mains that have an issue.
The Audyssey setup my heights and wides to 60 Hz, and they are really small speakers..
And set my Usher 525 rears to 40Hz..
I have a F113 and a MBM and I think they are capable, just trying to understand how this mysterious game of surround works..
FWIW, Audyssey itself does not set the crossovers. According to their Chief Tech Officer, who used to post here a lot, receiver manufacturers insist on retaining that prerogative, much to our detriment in some cases.\
AFAIK, being an XT32 system the 4520 has enough filters that the "don't lower the crossover" advice is NA. On lesser Audyssey versions, lowering the crossovers leaves the frequencies between the -3dB point ant the user=imposed crossover point uncorrected. A potential problem, especially in the bass where EQ can really be important because exactly zero rooms in normal homes avoid signficant bas frequency irregularities, because none of them have a shortest dimension of even 32 feet (35 Hz wavelength) so all are subject to room modes.
BUT AIUI, all the XT32 systems have enough filters to correct below the -3dB point ofeach speaker, and they do, so that the problem simply evaporates . . .
But what is measured in your room is, generally speaking, what is measured. If the listing for your house said the living room was 20 by 24, but your tape measure says it's 18 by 20, you would not stand around and say the tape measure must be wrong. Unexpected things certainly can happen in measuring the performance of real world speakers in real rooms. IMO, when your crossover setting looks unusually high, unless you can identiry some oddity of the room/measurement position interface that caused it, you just have to accept that the rolloff comes higher than expected for one of the speakers covered by the crossover. MOreover, the test tones are theoretically somewhere around 75 dB, and potential max output from any individual speaker (for those who, unlike me, listen at reference level) is 105 dB. Truth is, a speaker whose -3dB point is 100 Hz at 75 dB may very well be rolling off at 150 Hz by 100 dB, because real speakers' drivers run out of excursion and compress . . . .
SO with an XT 32 system it's not so much a question of jacking up the EQ if you lower crossovers as potentially robbing the sound, when it reaches high SPLs, of some richness onacounta expecting or wanting or believing the speakers can do more in their current positions in the room than measurements indicate. OTOH, if a person were to do their own testing, even sighted testing, to compare the different crossovers, and were to determine that the lower crossover sounds fine, they will not be struck by lightning for their choice, nor will the sun go nova because they deviated from the received Audyssey wisdom.
Of course someday, it's possible a person's rational side will start pushing hard on the idea that you must be missing SOMETHING, sometimes, if you are crossing your speakers over at a frequency not supported by actual measurements of their in room performance . . .