SPL and receiver (1 Viewer)

[ChadLB]

I used the spl meter and thx optimizer from monster inc and followed these directions:
Set the meter to 80db C-weighting and slow responce.
Now turn your receivers main volume control (the big knob on front of the reciever) till you read 75db on the
meter at your listen position with the left main speaker playing it's test tone. This may seem a little loud
but it's only for calibrating!

Question:is it right that at like -23 on my receiver i ended up with the following:

FL - 0 was used as main test speaker to read 75db
center - (-7)
FR - 0
SR - (-5)
SL - (-6)

Do other people have odd settings like this.
FYI the FR and SR speaker are about a 1 ft. farther from the center point of sitting then the FL and
SL speaker.

 

[Bob McElfresh]

This is quite normal.

If all 5 of your speakers were identical, and they were all placed on the edge of a perfect circle and all angled to face the exact center - then you should not have to do any of these adjustments.

The bits of volume you add/subtract compensate for:

- different speaker distances
- different angles of your speakers
- different brands of speakers
- and the effect of nearby reflecting surfaces

If you moved your equipment to a different room, your adjustments would all be different as well.

 

[ChadLB]

Thanks for the post...I wasnt sure

 

[ChadLB]

I havent had time to even watch a full movie since i did the adjustments. Guess I will have to wait.

 

[Lee Carbray]

Please note that these tones are not for adjusting the volume level of each speaker. Instead, this test is solely an aid in identifying improper level settings. You should use your receiver's internal test tones to properly set each speaker's volume level. Only these internal tones should be used for critical adjustment of your system's volume level for each individual channel.

You should use your internal tones or a setup disc like Avia or Video essentials. Although you can use the tones to inspect if the volumes are off you should not calibrate with them. Most people do not use internal receiver tones either because they do not take into account output of your dvd.

But hey, if it sound good do it.

P.S. your speaker values are going to be different from one another, other wise there would be no point in the calibration.

 

[Lee Carbray]

Sorry, the above quote is off the THX web site under the Optimizer section.

 

[ChadLB]

So using the thx optimizer is too high and not correct for volume settings?

Which disc is better? Avia, SOund and Vision, Video essentials.

 

[Lee Carbray]

Somebody else may be able to explain why not to use the optimizer to calibrate speaker volume.

All three of those cd's should get the job done. I use Avia, but I have heard Sound and Vision is good, and much cheaper. Avia has more video test patterns than Sound and Vision I believe. You may have a hard time finding Video Essentials as it is out of production. If you are just concerned with audio I would go with Sound and Vision to save a couple bucks.

 

[ChadLB]

So I got the S&V disc and here is what my settings ending up being compared to THX Optimizer:

at like -23 on my receiver i ended up with the following:

FL - -2 was used as main test speaker to read 75db
center - (-5)
FR - -2
SR - (-5)
SL - (-6)

Which isn't much off from the THX Optimizer....Interesting
if you ask me.

Where do most people set there receiver volume when doing this?

I just turned it up until my Left main read 75db on spl meter....any other thoughts.

 

[Bob McElfresh]

Most of us use 75 db when doing this.

I have sometimes used 80 db just because that is in the center of my SPL meter and makes it simpler.

The receiver test tones are a great way to do a quick test/adjusment. But some receivers like Yamaha do not include a test tone for the LFE output. This is a problem if you have a external sub.

The setup disks are nicer because:

- They maintain the test-tones for many seconds while you adjust.
- They do have LFE output tones.
- They have have tutorials on how to level adjust.

Hope this helps.