# Calibration Questions



## graydodge14 (Jul 17, 2010)

I recently bought an SPL meter and am trying to learn how to use REW. My question is though i was messing with my setting which is an onkyo 808 and found it has the eq setting to raise the decibal level for each frequency for fronts center and sub. My question is how do i know how much to raise each setting, what is trhe method to figuring that out. For now i just raised each one a few db's but i know that isnt the proper way.

Im trying to figure out how to properly calibrate everything and ive read hundereds of threads but i cant seem to figure it out so if someone could help mne out id greatly appreciate it.


----------



## Wayne A. Pflughaupt (Apr 13, 2006)

> For now i just raised each one a few db's but i know that isnt the proper way.


Correct, that is not the proper way to use the equalizer. Basically, adjusting every filter up by the same dB figure, you’ve just accomplished the same thing as turning up the receiver’s volume control. That's poor use of an equalizer.

For a “seat of the pants” evaluation, start with each filter set for 0 dB. Adjusting one at a time run each filter up about 4-5 dB and notice how each affects what you hear. Then go back and start over and do it again. If you boost a filter and it doesn’t seem to make much of an audible difference, that might mean your speakers are weak in that area, so leaving that filter boosted a bit might help.

On the other hand, of a 4-5 dB boost gets an immediate and exaggerated audible difference, then that might mean that your speakers are overly-hot in that area. So, return that one to 0 dB, or even perhaps cut it 2-3 dB if that seems to smooth things out.

The only caveat, any filters at the extremes – 8 kHz and higher, or 40 Hz and lower – the sound is often naturally lower than usual. Don’t go overboard boosting at the extremes, as that can blow the tweeters or the woofers.


Regards,
Wayne


----------



## shinksma (Aug 12, 2010)

Your Onkyo 808 comes with Audyssey MultiEQ, I believe. Use that function (with microphone supplied, not your SPL meter) to get your speaker distances, relative (overall) levels, and EQ for those main channels. It will do automagically everything you would want to try using your SPL meter and REW, for the most part, except it only does very coarse adjustments/filters to your Subwoofer - for that I suggest using REW and an outboard EQ like a BFD1124. If you intend to use an outboard EQ like an 1124, you probably want to eliminate the Audyssey EQ settings for your SW in your receiver and let REW and 1124 do all that work.

On the other hand, if are really intent on doing all the EQ manually yourself across all speakers using the Onkyo's internal EQ, an SPL meter and REW, you probably want to check out the REW section just to get a feel for how you would use REW and the SPL meter. You'll measure for each speaker separately. Then once you get a handle on that, you can interpret your graphs and adjust the 808's EQ settings to tame any peaks or valleys.

Good luck, 

shinksma


----------



## grn1969c10 (Sep 18, 2008)

The spl meter, if it is of the radio shack variety, may not be very accurate above 3-4KHz (or below 35Hz). While few people would use it for full range measurements it is a great tool to enable you to experiment with and learn to use REW.

Matt


----------



## viccmw (Dec 15, 2010)

Hi,

Very new to calibration and Home Theatre. I have a 7.2 config at home with a Onkyo 608 AVR. The only EQ I have done is through the AVR's Audeyssey 2EQ.

I am curious to see a bass response graph from my 2 subs, so was hoping to tinker with REW. I don't have a SPL meter yet. Can I use the supplied Onkyo mic as the microphone for REW? 

Thanks.


----------

