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post #1 of 18 Old 05-10-2019, 01:10 PM - Thread Starter
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Reference Level

I have a question about how to get my new marantz 7705 set so that zero on the dial is film reference level. i would like to do this so Dynamic EQ works as intended when listening to films. I am using an emotiva XPA5 for the main channels and an outlaw 7000x for the rears and 4 atmos speakers. Both are hooked up via XLR connections. I am using the RCA preout connection to my 2 PSA XV30 subs.

I ran Audyssey and it set all my speakers well into the negative range. This is new for me as I had been using unbalanced previously with a marantz 7012 to the XPA5. A few speakers were set as low as -11. I understand that this is because of the 6dB gain increase from using balanced connections.

When I use the internal test tones of the 7705 and my SPL meter, I get 75db at 0 on the volume dial. I know this bypasses the Audyssey eq settings but it implies that audyssey set the levels pretty accurately. I have an old avia dvd that has test tones for the main 5 channels. I pulled it out to test the level with audyssey engaged. With master volume at 0 i was expecting the avia test tones to read 85dB but they only showed 80. I thought maybe audyssey was somehow cutting the level so i turned it off and tried again. I still only measured 80 db on my meter with the avia test tones. All measurements were done with by dynamic eq and dynamic volume turned off.

Why would measuring using the avia disk indicate the levels are 5db too low? is it because of dialnorm? I have loudness management under surround parameters turned off in the marantz. i thought that disabled dialnorm.
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post #2 of 18 Old 05-11-2019, 05:50 AM
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plausible causes, the mastering your disc is incorrect and/or your dB meter is inaccurate,

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post #3 of 18 Old 05-11-2019, 07:00 AM
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tbaucom,

If you did the Audyssey calibration correctly and completely, then the AVR is all set to reproduce Reference Level at -0db volume. It gets complicated when you start introducing outside input media to measure db levels. If you are happy with the Audyssey results and the system sounds balanced. You just have to trust that Audyssey did its job and all speakers should in theory be equal in loudness at the MLP and set to Ref Level.

The more important aspect, besides "Ref Level" is that all channels are set to equal loudness at the MLP. You can check this using the internal test tones for setting channel trim levels. The Ref Level part is not really as important as channel volume level balance. Making any channel trim adjustments will in fact change what Audyssey selected. The only area I ever adjust is the Sub trims. Many like to boost the Sub trims post Audyssey.

I hope this helps some. In the end you have to trust the Audyssey algorithm did its job. Good luck Sir!

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post #4 of 18 Old 05-11-2019, 04:00 PM - Thread Starter
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Originally Posted by Adamg (Ret-Navy) View Post
tbaucom,



If you did the Audyssey calibration correctly and completely, then the AVR is all set to reproduce Reference Level at -0db volume. It gets complicated when you start introducing outside input media to measure db levels. If you are happy with the Audyssey results and the system sounds balanced. You just have to trust that Audyssey did its job and all speakers should in theory be equal in loudness at the MLP and set to Ref Level.



The more important aspect, besides "Ref Level" is that all channels are set to equal loudness at the MLP. You can check this using the internal test tones for setting channel trim levels. The Ref Level part is not really as important as channel volume level balance. Making any channel trim adjustments will in fact change what Audyssey selected. The only area I ever adjust is the Sub trims. Many like to boost the Sub trims post Audyssey.



I hope this helps some. In the end you have to trust the Audyssey algorithm did its job. Good luck Sir!


Thank you. I’m not a novice. I understand how things are supposed to work. I do trust that audyssey balances the levels correctly with each other. That isn’t the question. The audyssey microphones have a tolerance. while the channels are in balance with each other (they all measure roughly the same with either the internal tones or Avia). I am curious why the 5 decibel discrepancy between the 2 sets of tones.

I don’t like to bump the subwoofer level. I use Dynamic EQ which IMO works better than a simple bass boost.


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post #5 of 18 Old 05-11-2019, 05:17 PM
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I apologize if I came across that way. Was not my intention.

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post #6 of 18 Old 05-12-2019, 04:01 PM
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Quote:
Originally Posted by tbaucom View Post
...
When I use the internal test tones of the 7705 and my SPL meter, I get 75db at 0 on the volume dial. I know this bypasses the Audyssey eq settings but it implies that audyssey set the levels pretty accurately. I have an old avia dvd that has test tones for the main 5 channels. I pulled it out to test the level with audyssey engaged. With master volume at 0 i was expecting the avia test tones to read 85dB but they only showed 80. I thought maybe audyssey was somehow cutting the level so i turned it off and tried again. I still only measured 80 db on my meter with the avia test tones. All measurements were done with by dynamic eq and dynamic volume turned off.

Why would measuring using the avia disk indicate the levels are 5db too low? is it because of dialnorm? I have loudness management under surround parameters turned off in the marantz. i thought that disabled dialnorm.
I don't know what the test tones on that Avia is recorded at, -30 dBFS? It may be at -25 dBFS as you get 80 dB spl on the meter.
If that company is still in business, call them and ask. Or, the instructions with the disc may explain, or Google the disc and signal level someone may have that answer. Dial norm would apply to center only.

If you used the spl meter as well when using Audyssey and measure 75 dB spl with the trims set by Audyssey, then the internal test tones also 75, run that internal tone and see where the trims are. I bet it is where the Audyssey set it at so Audyssey uses the same -30 dB FS tones.
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post #7 of 18 Old 05-12-2019, 09:23 PM
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Quote:
Originally Posted by tbaucom View Post
...Why would measuring using the avia disk indicate the levels are 5db too low? is it because of dialnorm? I have loudness management under surround parameters turned off in the marantz. i thought that disabled dialnorm.
dialnorm is normalized to -31 dBFS or more recently -31 LKFS (loudness K weighted full scale). Early DD encoders defaulted to (-27 dBFS) which would result in exactly -4 dB attenuation in all channels.

So that would likely be your approximate - 5 dB measurement. Test tones can be difficult to measure accurately.

Edit: i don’t believe dialnorm can be disabled in the decoder, the only way it can be disabled was to set the dialnorm metadata to -31 in the encoding process.

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post #8 of 18 Old 05-13-2019, 06:24 AM - Thread Starter
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I don't know what the test tones on that Avia is recorded at, -30 dBFS? It may be at -25 dBFS as you get 80 dB spl on the meter.
If that company is still in business, call them and ask. Or, the instructions with the disc may explain, or Google the disc and signal level someone may have that answer. Dial norm would apply to center only.

If you used the spl meter as well when using Audyssey and measure 75 dB spl with the trims set by Audyssey, then the internal test tones also 75, run that internal tone and see where the trims are. I bet it is where the Audyssey set it at so Audyssey uses the same -30 dB FS tones.
The test tones on the avia disk are recorded at -20 dBF. It is supposed to measure at 85 dbl on the SPL meter when at reference level. I'm sorry if I wasn't clear about this in my original post.
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post #9 of 18 Old 05-13-2019, 06:34 AM - Thread Starter
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Originally Posted by Tomas2 View Post
dialnorm is normalized to -31 dBFS or more recently -31 LKFS (loudness K weighted full scale). Early DD encoders defaulted to (-27 dBFS) which would result in exactly -4 dB attenuation in all channels.

So that would likely be your approximate - 5 dB measurement. Test tones can be difficult to measure accurately.

Edit: i don’t believe dialnorm can be disabled in the decoder, the only way it can be disabled was to set the dialnorm metadata to -31 in the encoding process.
Thank you! Dialnorm being the difference was my guess but I wasn't sure if the loudness management setting in the marantx prepro turned that off or not. I googled around before starting the thread and the consensus I read was it did. The marantz manual isn't clear exactly what it does.
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post #10 of 18 Old 05-13-2019, 07:08 AM
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Thank you! Dialnorm being the difference was my guess but I wasn't sure if the loudness management setting in the marantx prepro turned that off or not. I googled around before starting the thread and the consensus I read was it did. The marantz manual isn't clear exactly what it does.
Greetings,

Yes i believe that wording is somewhat misleading, their dynamic range management (dynamic compression) system works in concert with the encoded dialnorm setting to limit the reproduced dynamic range.

That’s due to the fact dialnorm represents the level of compression used in the production process. It’s my understanding that this feature cannot be disabled in the decoder. I also seem to remember Avia unfortunately used Dolby’s default setting.

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post #11 of 18 Old 05-22-2019, 04:51 PM
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Quote:
Originally Posted by tbaucom View Post
The test tones on the avia disk are recorded at -20 dBF. It is supposed to measure at 85 dbl on the SPL meter when at reference level. I'm sorry if I wasn't clear about this in my original post.
I have seen other test discs, like the Goldline Audio Toolkit, where the encoded signals used the default dialnorm setting of the DD encoder. That will unfortunately attenuate the levels by 4 dB (as others already mentioned). I think the rationale for that was since DD movies are playing back 4 dB low due to dialnorm, the test tone should as well, thus accurately calibrating the volume control. But the days where most movies are encoded with Dolby Digital are long gone, and most BDs do not apply a gain reduction. So it's a bit of a mixed bag when it comes to knowing exactly what reference level is supposed to be unless your AVR can display the encoded dialnorm value, as do the Anthem units.

If you want a snippet of a known signal, this link will download a zip file I posted in another AVS thread. It is an MP3 file, 5 seconds of "THX style" bandlimited pink noise, then 5 seconds of sine wave, both at -30 dBFS. Unzip it and play it from a USB or however you play MP3 files -- turn on looped playback if you want it to repeat. It is stereo format with only the L channel having signal. The noise section should produce 75 dB SPL.

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Yes i believe that wording is somewhat misleading, their dynamic range management (dynamic compression) system works in concert with the encoded dialnorm setting to limit the reproduced dynamic range.

That’s due to the fact dialnorm represents the level of compression used in the production process. It’s my understanding that this feature cannot be disabled in the decoder.
While it is true that the DRC gain cut and boost values embedded by the DD encoder are determined relative to the dialnorm value of the soundtrack (so as to leave signals in the range of the dialnorm level untouched), the dialnorm value itself represents nothing other than the long term loudness value of the program. It is a fixed value for the entire duration.

It is also correct that the normalization process of Dolby decoders cannot be turned off. DRC of course, can.

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I also seem to remember Avia unfortunately used Dolby’s default setting.
That appears to be the case, but probably with good intentions. All that was needed was to inform the users how the signal was encoded. The newer Spears & Munsil Second Edition BD is a model of perfection in that regard. But unless you need all the video tests, it's a lot to pay for some audio test tones.
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post #12 of 18 Old 05-22-2019, 06:16 PM
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....While it is true that the DRC gain cut and boost values embedded by the DD encoder are determined relative to the dialnorm value of the soundtrack (so as to leave signals in the range of the dialnorm level untouched), the dialnorm value itself represents nothing other than the long term loudness value of the program. It is a fixed value for the entire duration.
This post is to benefit the OP ...due to your career with Dolby Labs, nothing i post will be news to yourself.

The dialnorm value is contrived from the measured long term weighted average dialogue level. Typically when the average dialogue level is elevated above -31 dBFS, overall dynamic is slightly reduced and overall program average volume is also increased. After crossing paths with Bob Katz, the correct way to compress dynamic range IMO is to slightly lower the mix room calibration target. A typical and very useful calibration target (-20 dBFS = 79 dBSPL) puts the mix engineer in an environment where he/she is motivated to raise overall program volume... and mild DR compression is the tool to manage things and dialnorm is what enables all DD and dts content to have the exact same average dialogue level.

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post #13 of 18 Old 05-22-2019, 07:37 PM
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This post is to benefit the OP ...due to your career with Dolby Labs, nothing i post will be news to yourself.
I'd like to further elucidate, if I may.

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The dialnorm value is contrived from the measured long term weighted average dialogue level.
Yes. See ITU-R BS.1770-4 for details.

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After crossing paths with Bob Katz, the correct way to compress dynamic range IMO is to slightly lower the mix room calibration target. A typical and very useful calibration target (-20 dBFS = 79 dBSPL) puts the mix engineer in an environment where he/she is motivated to raise overall program volume... and mild DR compression is the tool to manage things and dialnorm is what enables all DD and dts content to have the exact same average dialogue level.
The scenario you describe sounds like it is intended to achieve a certain reduced dynamic range in the mix itself. That's swell if one wants to mix for TV, for example.

But when discussing movies, especially in these days where people watch them on all manner of devices large and small, the ideal is to preserve the full dynamic range in the source, and let the playback device use the DRC metadata in the bitstream to provide a suitable dynamic range -- or allow the full tilt original when desired. While this concept has been around for many years in TV broadcasts, it is getting some serious traction in the CTA standards group R4WG8 to deal with OTT content.

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post #14 of 18 Old 05-23-2019, 07:50 AM
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Originally Posted by Roger Dressler View Post
...But when discussing movies, especially in these days where people watch them on all manner of devices large and small, the ideal is to preserve the full dynamic range in the source, and let the playback device use the DRC metadata in the bitstream to provide a suitable dynamic range -- or allow the full tilt original when desired. While this concept has been around for many years in TV broadcasts, it is getting some serious traction in the CTA standards group R4WG8 to deal with OTT content.
Hi Roger

I believe you’ll find many theatrical HT remixes are done midfield in a room calibrated 81 - 83 dBSPL and not SMPTE standard reference. Any well done mix, HT or otherwise will have some level of compression, else average dialogue will be relatively difficult to parse..i.e. post action scenes one will note its challenging to clearly hear nominal dialogue.

Dynamic range compression is a powerful tool when correctly implemented. I’ not talking about over use and or content that has little dynamic range. When applied properly it goes unnoticed and the mix still has significant dynamic range.

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post #15 of 18 Old 05-23-2019, 02:38 PM
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Originally Posted by tbaucom View Post
Thank you! Dialnorm being the difference was my guess but I wasn't sure if the loudness management setting in the marantx prepro turned that off or not. I googled around before starting the thread and the consensus I read was it did. The marantz manual isn't clear exactly what it does.
I think I need to revise a previous answer where I said Dialnorm was not able to be defeated in Dolby codecs. It looks like Dolby has softened its stance on that. Marantz has bundled both the Dialnorm and DRC functions so they can both be bypassed in one step.

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Originally Posted by tbaucom View Post
The test tones on the avia disk are recorded at -20 dBF. It is supposed to measure at 85 dbl on the SPL meter when at reference level. I'm sorry if I wasn't clear about this in my original post.
With the Loudness options turned off, do you then get the expected 85 dB SPL?

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post #16 of 18 Old 05-23-2019, 02:43 PM - Thread Starter
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I think I need to revise a previous answer where I said Dialnorm was not able to be defeated in Dolby codecs. It looks like Dolby has softened its stance on that. Marantz has bundled both the Dialnorm and DRC functions so they can both be bypassed in one step.

With the Loudness options turned off, do you then get the expected 85 dB SPL?
No. I get the same reading with the avia disk either way(loudness management on or off).
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post #17 of 18 Old 05-23-2019, 02:59 PM
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No. I get the same reading with the avia disk either way(loudness management on or off).
Ok.

Have you tried playing the MP3 file I provided? That at least is a known quantity.

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post #18 of 18 Old 05-23-2019, 03:01 PM - Thread Starter
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Ok.

Have you tried playing the MP3 file I provided? That at least is a known quantity.
Not yet. I have been busy the last couple of days. I will try it over the weekend and report back. Thanks for the file and the information you have shared.
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