Axiom Home Page Forums General Discussion Technical Questions Need a little help with audio calibration

I am getting ready to do my audio calibration using Avia. I have my trusty RS spl meter so I'm all set. But I have a few questions.

First where is the starting point for adjusting?? Do I set all of my speaker levels at 0?? How exactly do you get the reference level starting point. All speakers are supposed to be at 75 or 85db, but how exactly do I get to that point to start adjusting all speaker levels. Does that make sense??

Also when adjusting the sub level do I do it through the receiver, or the subs own volume??

Thanks

This will be a non-technical, bare bones tutorial. The starting point for Avia is 85db on the SPL meter. This might equate to about -10 on your receiver volume. You will be surprised how easy this is to do. Also, it's not necessary to pack overnight provisions - this is a 20-30 minute process.

Keep this thought in mind - all you are trying to do is have each speaker push the same amount of air/have equal volume. When they do this, it is a noticeable improvement. Don't make it any harder for yourself than that.

Go into your receiver setup menu and set all speakers to "small". Then go to the individual speaker volime controls and set them to 0.

Set the gain (volume) on your sub at about 40% of maximum.

Put the Avia disk in and go to the speaker calibration chapter (7?). Sit in the listening position and hold the SPL meter at arm's length in front of you . Rather than point it straight up, tilt it to about 45 degrees (halfway between vertical and horizontal). You will use this specific position for every speaker. Do not move the meter around or point it at each speaker.

The left front speaker is set to 0. Turn up the main receiver volume until you register 85db on AVIA on this speaker. This will be your reference point. DO NOT adjust this speaker in the receiver menu. Having it set at 0 and using the main receiver volume gives you the same starting point for each speaker. After setting this speaker, the others will be adjusted in the receiver menu.

Move to the center speaker. For this one (and the remaining speakers), adjust the individual volumes inside the receiver setup menu. You won't be far off 85db on Avia when you start and you can adjust up or down (usually) by 1 db increments.

Cycle through the remaining speakers. You are pretty much done.

As far as the sub is concerned, Avia runs the sub into the speakers anbd you are essentially balancing as you go. No need to do anything separate for the sub. Once you are all set up, Avia suggests that you run the sub 2-3 db "hot " (more gain). You can choose to run it as hot or cool as you like. I run mine 5-6 db hot for movies and 2 db hot for music. If you aren't satisifed with the sub, add a bit of gain until you are. This thing is there to support LFE. No magic here; if you notice that insects and small wildlife begin to die in close proximity to your HT, you probably have the sub gain a tad high. Back down such that the paint stops peeling.

If you want to get really tweaky with this process, google Avia hints or something similar. You will get a mind boggling array of expert advice.

Also, Alan may pop in and correct any incorrect advice I've given you . Good luck with it.

I am not familiar with the Avia disk, but if you have not done so, play through the audio adjustment section of the disk without doing any calibration just to see what instructions they give you. It should tell you whether the reference level you want is 75db or 85db.

I don't know what receiver you have, but check your receiver's manual. Somewhere in there it should tell you what volume setting is "reference," which is where you want the volume to be set when you begin calibration.

WARNING! Reference volume can be very loud. Protect your, and your family's, hearing!

On my Onkyo 797, I have my display set to "Absolute" which displays the volume with a minimum reading of "0," for no sound, and "100" the maximum. As I turn up the volume, the numbers on the display get bigger reading 79, then 80, then 81, then REF (instead of 82), which tells me that the 82 reading is reference.

I have the option of setting my display to "Relative" which displays the volume as a decibel value on a scale which runs from from -81 (db) up to +18 (db) with "0" being the reference point which equals the volume setting of "82" on the "Absolute" display. If this is the way your display reads, look for that "0" setting.

Yes, assuming you have a subwoofer, I'd start with all my speakers set to "small," and everything set at 0 in the receiver menu.

As far as which subwoofer volume knob to use, it's a balancing act. You might start with the knob on the sub set about midway, and the receiver set to "0," and go from there. You don't want to find yourself turning the volume level in the receiver too high or too low, and the same with the knob on the sub itself. The receiver setting doesn't have to be exactly at "0," but if you find your setting it in excess of -6, or +6 to reach reference, then you might want to get a little closer to "0," and compensate with the knob on the sub itself.

Hope this helps some.

Oh Ray! You're just too damn fast you rat! I use a tripod for the SPL. It has a threaded hole on the bottom which will fit a tripod. If you don't have a tripod, you might find a way to prop it up in the correct position, at approximately ear level, in that "sweet spot, right in the middle of your seating postion.

So I am basically going to start with my left front speaker set to zero, and then use the receiver volume to get to reference point. Then adjust the remaining speakers using the receivers speaker level. Is that correct?? Is there a paticular reason that you start with the front left instead of the front right or center??? Just curious.

Also there is no way I could even have the volume knob on my sub to half way w/o destroying anything not bolted down. I was tinkering with it last night and at less than 1/4 it was peaking at around 90db.

Very odd Jack - that is EXACTLY what my wife says to me a couple of times a week.

Monstermile (a name added to your profile would be so nice, unless of course this IS your name). (NON-TECHNICAL SWITCH ON) Something I forgot to mention in my post. I have never understood what "reference volume" is or what it is intended to do other than be really loud, much louder than I normally listen.

First and foremost. The only thing y0u want to hear at 85db is the Avia test tone. DO NOT play your music/movies at this level. Once you calibrate, you can fool around with your volume.

At 85db, the Avia test tones will be pretty loud, but they will only be on for a short time. You are only going to this setting to calibrate the speakers. Once the speakers are calibrated/balanced, set the volume wherever you like. The key message is that all of the speakers will play at whatever volume you choose in calibrated balance. Said another way, you are not required to listen at 85db and the speakers will sound great (and in unison) at whatever level you choose.

Think of it as taking a new rowing team out to the river and getting them to row in unison. The intent is for them to be in unison at whatever number of strokes per minute they row at. Hmmm, not my best analogy and the grammar is a bit rough, but you get the idea.

Also, Avia suggests using 85db as the volume level for calibration because they feel this is loud enough to assure pure test tone audio and eliminate any ambient sound that migh cause measurement anamolies. There is no magic at 85db; try 75 or 80 if that floats your boat. Again, this is not precise science requiring hours of labourious tasking. If a couple of old farts like Jack & I can pull this off, it proves that a Nobel Luareate of Calibration is not required. (NON-TECHNICAL OFF)

BTW, I like Jack's idea of the tripod, I was just too lazy to go through the additional aggravation to set one up. What you are really trying to do is keep the SPL meter far enough away from your body to assure you aren't blocking or bouncing the audio being measured.

Final thought. Although they don't actually say this in the manual (Shhh, now), it's OK to recalibrate several times if you want to. I certainly did and I learned a few things each time. Now pick up that meter mister and kick some calibration butt!!!!

I guess that means you're NOT a 60 minute man (as the song says).

Another good thing about the tripod is that it keeps the meter in the same position. I found it hard to hold it at arms length and still be sure it didn't drift around, and up and down, as I adjusted volume, etc. I bought an inexpensive, lightweight tripod for around $25. It works just fine, and I can use it with my digital camera also, so it was worth it to me.

I think very few listen to music or movies at reference level. I know I don't. If "82" on my volume display is reference (which it is, DUH!), I rarely ever get above "70" for movies, and I'm usually lower than that for music.

But, as Ray points out, we're a couple of OLD goats.

How'd that happen, Ray? A minute ago I was in my 20s with hair down to my shoulders, and feeling invincible. Wha' hoppened?

There is magic to Avia's suggestion of 85db. The magic is that the Avia tone is 20db below reference. Reference is 105db at the listening position which is the maximum that your speakers should hit during the loudest part of the movie (not including the LFE). So if you want to hear what the sound engineer intended, calibrate your system with an Avia disk to 85db at 0 on your receiver. then set your receiver to 0 when listening to a Dolby Digital DVD (which would now be reference) and you will hear what the sound engineer intended (at least with regard to volume levels).

I hope this does not qualify as hi-jacking it is on topic. I am in the same position and am getting ready to calibrate my system. I have DVE and not Avia but I hear that they both do the same thing. I have read the above posts and get 99% of it but my question is; when I watch movies right now I turn my Yamaha RX-v630 in between -40 to -35 and it is loud. If I calibrate at 0 is would be deafening, are you really supposed to calibrate at 0?

Thanks Mike

Mike,

All you are doing when you calibrate is listening to and using test tones and running them through an SPL meter so that you can balance the audio (sound pressure/amount of air they are moving). Once the speakers are calibrated/balanced, you can listen at whatever volume setting you like. The key message here is that whether you listen really loud or listen really quiet - the speakers are all in balance. If -40 is too loud on your receiver when you are listening to a movie, then listen at -50. Listening levels have absolute;ly nothing to do with calibration levels.

When you are done calibrating, the speakers will be in balance. You will be calibrating using the DVE disc, not using a movie. It sounds like you will need to watch the DVE disc for instructions before you begin the actual calibration process. BTW, I think DVE has you calibrate at 75db.

Also, set your individual speakers to 0. When you begin with the left front speaker, use the main volume control on the receiver to turn up the test tone for the left front until you get 75db on your SPL meter. The receiver volume may be 0, -16 or +2. You simply need to get the left front to 75db regardless of the volume level the receiver reads out. As a matter of fact, for this execrise, you could put a piece of tape over the volume read out of the receiver.

Said a different way, keep your eye on the SPL meter as you turn the volume up using the test tone for the left front speaker. Don't even look at the receiver. When the meter shows 75db, stop turning the reciever volume knob.

Once you have the main volume set at 75db for the left front, you don't touch the main receiver volume again in the process.

At this point, calibrate each remaining speaker to 75 db by using the individual speaker adjustment in the receiver setup menu. It will allow you to adjust 1 db at a time, up or down. Fine tune until you get to 75db on each speaker.

I hope this is helpful. I understand how daunting it can be the first time. As I explained earlier, this is not life-threatening.