How To Refine Your Home Theatre calibration: things to do after the first calibration

So, you have done that Audyssey recalibration, and followed the checklist

It is also important to get the subwoofer position right, even before you run that Audyssey. So do read up on 'crawling for bass', before you even do your calibration.

And make sure your speaker positions follow the recommended guidelines as fas as possible.

This is a nice video to follow:

Well, the step is refinement. Audyssey is only the first step to getting that mix, where you feel totally immersed in the movie. This means setting the levels right in each channel, so when sound transverses from one channel to the next, you feel that the intensity, and the object is truly moving in space from one place to the next, as the movie maker intended.

The next stage is to measure the frequency response. Now this can seem daunting for the casual computer user, and I admit, that PCs are not my strong point, so I looked to friends to use this, and if you are handy with PCs, they promise that it isn't that hard.

Some guidelines I got from the net for Macs:

The REW software can be downloaded here:

And you can use the MiniDSP Umik:

Essentially this seems rather like rocket science to the average HT hobbyist, so feel free to skip this or better yet, get someone to help with this, but essentially if you are willing to go to this extra step, you will definitely gain a lot. Really, a lot.

Once you have your curve up, then you can see what are the parts that don't work so well.

Audyssey is suppose to smoothen out the curve and cut any bumps in frequency, but it does not always do a solid job.

For the bumps, you can rely on traps to try and smoothen out the frequencies, but for the dips, and the room nodes, it's a lot harder.

Some tricks you can do:

Play with the phase. Again even though Audyssey is supposed to help, in my case, a simple switch of the phase, from 0 to 180, immediately help.
Furthermore, in my case, I had two subs, which usually helps even out the frequencies, but there was a bass suckout right at my listening position at 33 hz. This is despite having one sub right next to my listening position. By switching the phase, we almost totally eliminated the dip.

As for getting that thump and rumble, well, it's all about the SPL. If you aren't prepared to play it louder, at 80-9-db or more, one may not get that tactile bass. In my case, I prefer saner levels, so I put up with less of the low end stuff.

Now in order to refine the levels, you have to get a test tone disc. There are many you can download off the net, and now, they will also cover all 11 channels used in Atmos or even DTS.

It is vital that you AVOID using the internal test tones, which will not give you the accurate levels after Audyssey calibrations!

Play with the various levels, see what level of immersion do you like. It's like cooking curry, some like it hotter, and so in setting the Atmos ceiling channels, some like to play those channels a little louder.

As always, your mileage may vary. YMMV.

Then play something that you like and are familiar with, that has a lot of sound transitions. I like to use the gunfight scene from the Book of Eli, when they bring out the Gatling sound and listen to the shots transiting from one speaker to the next, whilst there are bullets flying everywhere, and the sound of the house being destroyed around you.

Good luck!

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