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So i downloaded the spl metter app on my htc.


I pointed the phone's microphone from the seating position to each speaker and started the test tune of the receiver with 60 volume. I got 75dB for each speaker with 60 volume . I also increased the +dB level of each speaker so that each speaker gives me 75dB on the SPL meter.


Did i do this right ?
 

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Quote:
Originally Posted by dazkyl /forum/post/20912022


So i downloaded the spl metter app on my htc.


I pointed the phone's microphone from the seating position to each speaker and started the test tune of the receiver with 60 volume. I got 75dB for each speaker with 60 volume . I also increased the +dB level of each speaker so that each speaker gives me 75dB on the SPL meter.


Did i do this right ?

No, you dont point the phone to each speaker. You leave the microphone in one position which should be your main seating position. Then adjust the speaker levels accordingly.


A Radio Shack meter would be more accurate but if the phone app is all you've got....
 

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What level do you set the receiver at? Do you put the receiver volume at 0 (+-) for reference and then adjust individual speakers to 75db from one position (78db for sw)?
 

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Quote:
Originally Posted by Sparktheyank /forum/post/0


What level do you set the receiver at? Do you put the receiver volume at 0 (+-) for reference and then adjust individual speakers to 75db from one position (78db for sw)?

I pulled this directly off the Rotel RSX-1550's Owner Manual.


Calibration with an SPL meter:

Calibrating the system with an SPL (Sound Pressure Level) meter, rather

than by ear, provides more precise results and improves the system’s

performance significantly. Inexpensive SPL meters are widely available

and the procedure is quick and easy. Both Dolby and DTS specify a standard calibration level for all theaters

to ensure that soundtracks can be played at the volume level intended by

the director of the film. This reference level should result in spoken dialog

played at a realistic level for normal speech with the loudest peaks in any

single channel at about 105dB. The receiver’s test tones are generated

at a precise level (-30dBFs) relative to the loudest possible digitally

recorded sound. At the Dolby or DTS reference level, these test tones

should produce a 75dB reading on an SPL meter. Set the meter to its 70dB dial setting with SLOW response and Cweighting,

held away from your body at your listening position

(mounting the SPL meter on a camera tripod makes this easier). You can

point the SPL meter at each speaker as it is being measured; however,

positioning the meter in a fixed position pointing at the ceiling is easier

and probably produces more consistent results.

Increase the master volume control on the receiver until the meter reads

75dB (+5dB on the meter scale) when playing the test tone through one

of the front speakers. Then, use the individual channel adjustments on the

TEST TONE menu to adjust each of the individual speakers, including the

subwoofer, to the same 75dB on the SPL meter. Remember the setting of the master volume control used during this

calibration. To play a Dolby Digital or DTS soundtrack at the reference

volume level, simply return to that volume setting. Note that most home

theater listeners find this setting to be excessively loud. Let your own ears

be the judge for deciding how loud to playback movie soundtracks and

adjust the master volume control accordingly. Regardless of your listening

levels, using an SPL meter to calibrate equal levels for all speakers in the

system is recommended.

Note: Due to meter weighting curves and room effects, the actual

level of the subwoofer may be slightly higher than you measure.

To compensate, Dolby suggests setting the subwoofer several dB

lower when calibrating with an SPL meter (i.e. set the subwoofer

to read 72dB on the meter instead of 75dB). Ultimately, the

proper subwoofer level must be determined by personal taste and

some listeners prefer to set it above 75dB for film soundtracks.

Exaggerated bass effects come at the expense of proper blending

with the main speakers and place stress on the subwoofer and

its amplifier. If you can localize bass from the subwoofer, the

subwoofer level may be too high. Music can be useful for finetuning

the subwoofer level as excessive bass is readily apparent.

The proper setting will generally work well for music and movie

soundtracks.
 
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