pointing the SPL?? (1 Viewer)

[Brian Warren]

using the radio shack digital spl, I get different levels if I opoint the meter tip at the speaker with pink noise or if I just point it strait ahead at the TV and leave it there instead of rotating the direction based on which source is emminating the pink. this will surely affect the levels esp. the back and side speakers. do you point the tip at the speaker or leave it pointed to the TV throughout set up?

Denon 3803
paradime minis, cc370, adp170's and titans.
velodyne cht15

thanks
Brian

 

[Edison Tinker]

I've always aimed the meter upward, at about a 45 degree angle so that it was pointed kind of at the ceiling but facing toward the display and left it stationary while calibrating...I can't remember where I picked up that method, I think it might have bee from an article I read on how to calibrate one's home theater...

---Tinker

 

[Patrick Sun]

Straight up!

 

[Leon B]

Straight up!


Do you mean pointing at the ceiling???

 

[Gabriel_Lam]

What if your surrounds are ceiling mounted?

 

[Phil Iturralde]

45-degrees - as recommended by Dolby Labs 5.1-Channel Production Guidelines (and Video Essentials - Dolby Labs Roger Dressler consulted) ...

as you did for the front speakers.

If it's good enough for the Mixing Engineer that encoded my Blockbuster DD-5.1 DVD's, . . . it good enough for me!
Phil

 

[Edison Tinker]

I knew I got that 45 degrees from somewhere!

 

[Geoff L]

Good job Phil, to the source the only way to get the proper information.

To add to that, this dose not matter if your setting DD DTS 5.1, 6.1, 7.1, the meter stays at the 45% and remains their & motion-less. Even your body to the side, front, or behind where your ears will be will creat a false or less than accurate reading. This is why a tripod is recomended....

No tripod:
Get low, low to the ground that is. Holding the meter in your listening postion with your arm exteded so as to keep as much of YOU out of the sound path as possible.

Re-check your system once every couple of month or so, things will change on their own belive it or not. Especialy if you have brand new speakers when calibratng for the first time. A few db's here and their can make a differance. And it happens slow so you don't usually notice. As soon as you re-calibrate (like I did just recently) you might be shocked at how far off somethings got (even though nothing had changed-in the room or with equipment) and how much better it sounds after doing the re-cal...

Every speaker was off one way or the other (+ or -) by at least one db from the front left main....All new speakers in the bedroom system and 4 months had gone by sense the original Avia calibration & nothing had changed at all anywhere.

Made quite a differance after doing it again and getting levels back where they belonged.

Later
Geoff

 

[TonyTone]

VE shows the meter pointing upwards at about a 40-degree angle (maybe less) from vertical, but clearly not straight-up vertical...at least that's what I see on my copy of VE.

 

[Brae]

Patrick [Sun], it is interesting in your response to point the SPL straight up. I bought my first SPL yesterday (RS 33-2050) and the instructions clearly state to point it straight at the driver (speaker).

So, what is it you know that they do not? Not trying to kick your bucket over, but simply wonder if the good folks (albeit ignorant at time) over as RS is missing something?

I think I am going to go back and see what they say on the Avia DVD, but I am willing to bet its also straight up (as I do remember seeing the scene where the instructor is holding it straight up, and almost too high IMHO), too.

Just curious. I do understand that speakers do have an off-axis performance issue (my Studio Reference have a high-frequency issue at 30-degrees off axis) which may need a averaging condition to be in a happy-happy zone.

 

[Geoff L]

You are correct in that RS states this in there all purpose directions....

But both Dolby and Avia state clear for their use (measuring your system while setting up channel levels) that you use the aprox-45 degres at the listening position and pointed 45-degree straight ahead with end of the meter. This is definitly (not a word for word) but the basic implatation of use.

Avia mentions ear/head level I belive but I use it with the mic at ear height, pointed straight toward the center and at apox 45-degrees. Remains in that position threw all testing and setting of levels. NO pointing at the source (ie) speaker being tested.

Nothing wrong with experimenting, (off axis responce) but I prefer to use it the way Dolby & Avia recommends for setting up your system.

If you have a tripod or friend, try toe-ing in and out while whatching the meter useing test tones or full frequency dics.

Jusy my 2-cents
Geoff

 

[Patrick Sun]

IIRC, Avia recommends pointing the SPL meter straight up.

 

[Geoff L]

Rutt Rrooo, My bad on the Avia... :b

Still (not pointing) meter at the source though!!!

 

[Frank Carter]

Why at chest level? This doesn't make sense to me, it seems logical that it should be at ear level.

 

[Phil Iturralde]

... it seems logical that it should be at ear level.

It does and Video Essentials DVD (created w/Dolby Labs assistance) recommends that, so @ home, I use a tripod, titled 45° - 50°, raised to approx. ear level @ my 'sweet spot'. Works great!!

Phil

 

[Frank Carter]

Thanks for the explanation Phil.

Frank