Onkyo 805 and Calibrating using SPL meter

SlowcarIX

jaysonbarnett wrote: »

Hey slowcar you finally sold your conquest i see. I really love my caliber there is now i could be without it. Those audyssey graphs are very informative thanx.


I know the surrounds do not sound like the fronts but before i could not hear them very well. Now i can hear ambient sounds that were not there before.

yep, sold the conquest to a local guy 2 towns away. its going into a dedicated ht room.

it takes a little effort to setup audyssey (eg making sure well positioned mic, keeping room quiet...), the result will be close to the ideal setup you can achieve from your setup.

dholmes

When I did my calibration it measured my subs at 28 ft from sitting area & my room is only 23 ft long.So I dont know if the audyssey is correct or not,can you turn it off on Onkyo?

kuntasensei

I'm assuming you have dual subwoofers. If they're co-located, then you're fine. Audyssey measures acoustic distance, so don't focus too much on the physical distance. If your subs are located in different places, that's going to make it next to impossible for ANY auto-setup to detect the best delay. That's why dual subwoofer aficionados typically locate the subs in the same place or alternately, run stereo subs (i.e. subs running off the main channels so there's less risk of cancellation due to placement issues).

That said, there are things you can do to ensure you're getting the right reading out of it. The first thing you need to do is make sure the crossover on the subwoofers are turned to their maximum or bypassed completely. Crossover circuits can induce delay that changes the optimal delay time. Also, if you're using external amplification or an equalizer in-line with your subwoofer, that can further induce delay.

Also, placement can throw off the proper delay as well. For instance, rear-ported or downfiring subwoofers should be placed at least 3-5 inches from adjoining walls, especially if you have drywall/sheetrock. These walls can often act as passive radiators when given too much energy, muddying up the arrival time of the sound to your seats. If you have hard walls (concrete, brick) nearby, this rule still holds, since you can get slap echoes from them. For that, I recommend acoustic treatments.

The biggest thing that affects the delay detection is the phase control on your sub, since proper phase alignment has a HUGE effect on what the proper delay time is for the subwoofer. Audyssey's not necessarily WRONG just because it detects something different from the physical distance. The distance/delay in your AVR/pre-pro essentially acts as a variable phase control, so the detection is choosing the optimal setting based on everything going on in the signal chain to ensure that the sound from the subwoofer arrives at the seats at the same time as that from your other channels.

A good illustration of this is: Set your subwoofer's phase to 0 and run the detection. Then set your subwoofer's phase to 180 (or try 90 if you have a continuously variable phase control the way your SVS should) and they will detect slightly differently. For most room setups, you should use the 0 phase setting and let the distance detection align phase.

Now, you can certainly manually change your subwoofer's distance/delay in the receiver. You can also disable Audyssey's equalization completely. But if you're using Audyssey's equalization, changing the subwoofer distance/delay after the fact can greatly affect the equalization that was done to the subwoofer, since altering the phase of the subwoofer can cause cancellation across the crossover range for bass redirected from the other channels.

My general thought on the matter is this: If you're within about 5 ft with Audyssey's detection, it's probably due to issues in the signal chain or the acoustics of the room and it's probably the right setting for your room. Play with subwoofer placement a bit or do some acoustic treatment and you'll not only get a detection that's much closer to the actual physical distance, you should get a better sound out of your system. Whether the difference will be all that audible to you is questionable... but the closer you get your room and placement to ideal before Audyssey, the better the post-Audyssey results will be.