Audyssey measurements... or I am having mic problems?

[Torsion]

Hey everyone, hopefully I can pick your brains for a bit.

I took some before/after Audyssey frequency response measurements using REW and my old-style Radio Shack SPL meter.

It appeared to me that Audyssey was boosting my bass... and I wondered why:

http://www.hometheatershack.com/foru...html#post97798


Chris from Audyssey suggested that I take multiple measurements and average them together... and I check my mic calibration.

So I downloaded the proper calibration file from the Downloads page and took 6x readings and averaged them together.... and got this:

http://www.avsforum.com/avs-vb/showt...0#post13857860

As you can see, Chris said that I must have something wrong. Does anyone have any insight into what I can fix?

I almost get the feeling that I could go spend $150 on a mic setup, send it off to get calibrated, take measuements, average them together... and *still* someone would say "oh, those can't be trusted".

[brucek]

Your Radio Shack meter could have a problem I suppose. Perhaps you could borrow someone elses and make a comparison.

I see you're attempting full range measurements with the Radio Shack meter. It's not really a good idea to use a Radio Shack meter above ~3KHz.

Doesn't the Audyssey system usually come with an ECM8000? Why not get a mic preamp for it. The ECM8000 calibration file on our download page is quite adequate for the ECM8000. Then you can be fairly confident with the results and you can also do full range measures.

brucek

[Torsion]

Thanks for the response, bruce.

Oh, sorry for any confusion, I don't have the full-up Audyssey unit... I'm only using the MultEQ XT version in my Onkyo 705.

I've only recently learned that I can't take full range sweeps using my RS SPL Mic... my latest are only 15-200hz.

I'm contemplating buying the ECM8000 and Xenyx 802 setup... wondering how far I want to take this new interest of mine.

[JohnM]

Bob,

Your full range measurements look to be typical of an RS meter, so they are probably OK. An interesting experiment would be to connect your Onkyo's sub output to your soundcard input in place of your meter, unload the soundcard calibration file and make sure the C weighting compensation box is not checked, then measure what is happening to the sub electrical output with and without Audyssey applied. That removes any doubt about whether the meter is accurate or not. You should also check that a loopback measurement is still giving a flat line, i.e. that your soundcard cal is OK.

[brucek]

unload the soundcard calibration file and make sure the C weighting compensation box is not checked

I'm sure you must have meant to say meter calibration file and not soundcard calibration file..

brucek

[JohnM]

brucek wrote:

I'm sure you must have meant to say meter calibration file and not soundcard calibration file..

Oops.