Good calibration discs?

[Sawtaytoes]

This is typical for 3 way designs that often invert the phase of a driver for proper acoustic summation. Most streaming apps like Tidal have phase checkers.

Whoa! I never knew you could do phase checks in Tidal! The Roku and SHIELD apps are very barebones.

I guess I should've asked about that particular calibration disc before buying it.

 

[gene]

Whoa! I never knew you could do phase checks in Tidal! The Roku and SHIELD apps are very barebones.

I guess I should've asked about that particular calibration disc before buying it.

All isn't lost. You can still use the other discs available and compare your results and you may find their test suites are accurate. Or, use REW and the files I linked to.

 

[ReverendSlim]

LOL. When someone who never been trained by Dolby, never looked at the actual Dolby white papers (the ones available for public don’t count), and then claim that Dolby speaker placements to be wrong AND THEN sell calibration disc while saying that you can calibrate by ears… stay away. Stay very far away.
Even if he is the best Atmos content creator in the universe, that doesn’t make him suddenly know everything about Atmos and/or how to calibrate his studio.

Just curious, David... Is there something in particular on the SACT disc that you disagree with as a tool for checking and calibration? Just wondering what part of the product fails on the technical merits in your opinion.

 

[David Susilo Unscripted]

First of all, I refuse to waste $100 to get something that I can get for free or from a Dolby-approved source such as the Spears and Munsil disc.

Second, principally, if someone never even trained as a calibrator claim that Dolby speaker positions are wrong, that’s another red flag

Third, someone who claim that calibration can be done by ears should never be heard and making any of his/her claim dubious

Forth, knowing items 1-3 above, do you think you can trust test signals that are custom created by them?

 

[ReverendSlim]

First of all, I refuse to waste $100 to get something that I can get for free or from a Dolby-approved source such as the Spears and Munsil disc.

Second, principally, if someone never even trained as a calibrator claim that Dolby speaker positions are wrong, that’s another red flag

Third, someone who claim that calibration can be done by ears should never be heard and making any of his/her claim dubious

Forth, knowing items 1-3 above, do you think you can trust test signals that are custom created by them?

First, from the table of contents we've seen, the Spears & Munsil disc doesn't have many of the specific tests available on SACT and is pretty basic on that front. I agree that the price could be lower, but... there's nothing else like it on the market and producing it in a relatively small batch compared to a retail product like S&M comes at a cost. And hell, some of us have spent more money on dumber things. I have more invested in isolation feet alone than the SACT disc costs. I would argue that you've spent more on things in your videos.

Second, I agree with you in principle on this point as I've actually had that conversation with them on their show. But you can certainly understand the confusion given the way Dolby handles things like range constraint of the heights versus physical speaker positions. Their problem was that they were expecting a 1:1 translation between the interface and the room itself (i.e. the front/rear boundaries matching the steering), whereas it's actually fundamentally an allocentric representation of a larger space than your room. Regardless, none of that is relevant to the disc, as it does use the proper coordinates for each defined position up to 9.1.6 for the tests regardless of whether you're using top front/rear or front/rear height. The test tones do, in fact, come from the correct locations defined by Dolby in their renderer guidelines.

Third, I don't think they're claiming that you can do the same level of calibration with your ears that you can with calibrated equipment. That's why the disc includes a whole separate section for advanced calibration with REW and instructions for people who only have SPL meters. There are, however, checks that you can do with just your ears that can help you improve things like cross-channel imaging by tweaking delays. Plus, just having a sound steered around the room with a visual on-screen representation of its expected placement goes a long way toward confirming that you're hearing sound where you should.

Fourth, they are using the tones as spec'd by Dolby for level-matching, including the necessary range limitations, properly encoded at -20dBFS. Everything checks out. There are some variances in level for the sections that aren't level-dependent (i.e. some sections are louder than the level-matching tones by design), but that isn't an issue.

If there's something in particular on the disc that you take issue with, it's worth discussing. If you're just casting it aside due to videos where enthusiasts were trying to figure it all out instead of on the actual technical merits, I think that's a little short-sighted.

 

[William Lemmerhirt]

First, from the table of contents we've seen, the Spears & Munsil disc doesn't have many of the specific tests available on SACT and is pretty basic on that front. I agree that the price could be lower, but... there's nothing else like it on the market and producing it in a relatively small batch compared to a retail product like S&M comes at a cost. And hell, some of us have spent more money on dumber things. I have more invested in isolation feet alone than the SACT disc costs. I would argue that you've spent more on things in your videos.

Second, I agree with you in principle on this point as I've actually had that conversation with them on their show. But you can certainly understand the confusion given the way Dolby handles things like range constraint of the heights versus physical speaker positions. Their problem was that they were expecting a 1:1 translation between the interface and the room itself (i.e. the front/rear boundaries matching the steering), whereas it's actually fundamentally an allocentric representation of a larger space than your room. Regardless, none of that is relevant to the disc, as it does use the proper coordinates for each defined position up to 9.1.6 for the tests regardless of whether you're using top front/rear or front/rear height. The test tones do, in fact, come from the correct locations defined by Dolby in their renderer guidelines.

Third, I don't think they're claiming that you can do the same level of calibration with your ears that you can with calibrated equipment. That's why the disc includes a whole separate section for advanced calibration with REW and instructions for people who only have SPL meters. There are, however, checks that you can do with just your ears that can help you improve things like cross-channel imaging by tweaking delays. Plus, just having a sound steered around the room with a visual on-screen representation of its expected placement goes a long way toward confirming that you're hearing sound where you should.

Fourth, they are using the tones as spec'd by Dolby for level-matching, including the necessary range limitations, properly encoded at -20dBFS. Everything checks out. There are some variances in level for the sections that aren't level-dependent (i.e. some sections are louder than the level-matching tones by design), but that isn't an issue.

If there's something in particular on the disc that you take issue with, it's worth discussing. If you're just casting it aside due to videos where enthusiasts were trying to figure it all out instead of on the actual technical merits, I think that's a little short-sighted.

I think these are all good points. And from what I’ve seen in the “other” forums thread about it, it’s very well done, very comprehensive. I don’t really like that almost all of the support is on discord, and seems to be a PITA to get help, maybe not. Joe seems helpful, but I won’t buy the disk simply because channa (techno-douche) grates against my skin. Wish he would leave the internet.

 

[gene]

My thoughts, for the layman, auto setup systems like Dirac, Anthem ARC, Trinnov, Audyssey and even YPAO already accurately set level and delay for ALL channels except sometimes the sub. Anything that requires more than level and delay calibration and phase should be done in REW with multiplexing in the processor to sweep any channels and/or subs in your set up.

Storm Audio and Trinnov have this. I'm trying to get Marantz and Denon to add this next.

I saw their recommendations for aligning multi subs by connecting each sub to the left/right preouts on your receiver if you don't have multi sub outputs, and cringed. You can't align subs properly this way unless you can independently delay from the channel groups and do bass management locally and also run the mains fullrange w LFE too. They also claim most subs add 10msec of group delay from DSP so you should add in 10ft of distance. Again this is not always the case and why you need REW to make proper amplitude response and wavelet measurements.

 

[ReverendSlim]

My thoughts, for the layman, auto setup systems like Dirac, Anthem ARC, Trinnov, Audyssey and even YPAO already accurately set level and delay for ALL channels except sometimes the sub. Anything that requires more than level and delay calibration and phase should be done in REW with multiplexing in the processor to sweep any channels and/or subs in your set up.

Storm Audio and Trinnov have this. I'm trying to get Marantz and Denon to add this next.

I saw their recommendations for aligning multi subs by connecting each sub to the left/right preouts on your receiver if you don't have multi sub outputs, and cringed. You can't align subs properly this way unless you can independently delay from the channel groups and do bass management locally and also run the mains fullrange w LFE too. They also claim most subs add 10msec of group delay from DSP so you should add in 10ft of distance. Again this is not always the case and why you need REW to make proper amplitude response and wavelet measurements.

I would agree that for the most part, auto-cal gets you there. I would exclude YPAO from that list because... well, it's YPAO and I've seen YPAO give some crazy results. And I would argue that Audyssey users not using MultEQ-X are definitely not getting proper delay times unless they manually adjust based on the known speed of sound error, and anyone doing curves with the app are likely not getting proper levels either due to the averaging. I would love it if D&M would add the integration you're talking about. But I do think that one very useful tool on SACT is the speaker pairs tones, so you can specifically check imaging between each adjacent speaker pair and tweak delays to solidify that imaging if needed. Even post-MultEQ-X with my particular tweaks, I find that you can improve imaging this way, then confirm with the torture test section to hear an object move between each adjacent pair in practice. I've gotten good results with actual content by doing this.

As far as the multi-sub thing, I'm not sure where they said that, so I can't comment. But given discussions we've had, I'm fairly certain that Joe doesn't believe most subs would add 10ms of delay due to DSP. He's been a big proponent of using REW and MSO for multi-sub.

I think these are all good points. And from what I’ve seen in the “other” forums thread about it, it’s very well done, very comprehensive. I don’t really like that almost all of the support is on discord, and seems to be a PITA to get help, maybe not. Joe seems helpful, but I won’t buy the disk simply because channa (techno-douche) grates against my skin. Wish he would leave the internet.

I can understand about Discord, but that's specifically so it isn't on other forums and there is a community just for users. They still monitor some other forums, but not nearly as quickly as someone will respond on the Discord. And it isn't a PITA there. If they don't answer, there are other experienced users (myself included) who discuss these things and outline ways to utilize the tools on the disc. I do think that one problem is that people think it is going to be a guided calibration, when it's really just a series of tools, and which you use depends on what you're trying to address/check with your system. There's a lot of utility there for tweakers.

 

[gene]

I would agree that for the most part, auto-cal gets you there. I would exclude YPAO from that list because... well, it's YPAO and I've seen YPAO give some crazy results. And I would argue that Audyssey users not using MultEQ-X are definitely not getting proper delay times unless they manually adjust based on the known speed of sound error, and anyone doing curves with the app are likely not getting proper levels either due to the averaging. I would love it if D&M would add the integration you're talking about. But I do think that one very useful tool on SACT is the speaker pairs tones, so you can specifically check imaging between each adjacent speaker pair and tweak delays to solidify that imaging if needed. Even post-MultEQ-X with my particular tweaks, I find that you can improve imaging this way, then confirm with the torture test section to hear an object move between each adjacent pair in practice. I've gotten good results with actual content by doing this.

As far as the multi-sub thing, I'm not sure where they said that, so I can't comment. But given discussions we've had, I'm fairly certain that Joe doesn't believe most subs would add 10ms of delay due to DSP. He's been a big proponent of using REW and MSO for multi-sub.

I can understand about Discord, but that's specifically so it isn't on other forums and there is a community just for users. They still monitor some other forums, but not nearly as quickly as someone will respond on the Discord. And it isn't a PITA there. If they don't answer, there are other experienced users (myself included) who discuss these things and outline ways to utilize the tools on the disc. I do think that one problem is that people think it is going to be a guided calibration, when it's really just a series of tools, and which you use depends on what you're trying to address/check with your system. There's a lot of utility there for tweakers.

The latest ver of YPAO on the RX-A6A nailed delays and trim levels. You can also use a laser ruler and aim at each speaker with very precise results as I shown here: https://www.youtube.com/shorts/eOFcwj_UPT4

Phase tests between channels is readily available on Dolby and THX test discs for anyone that doesn't want to spend $100 for SACT.

I do appreciate having access to test files all centralized on one disc like they are doing, so I get the appeal.

Personally I'm pushing for the multiplexing feature from AVR companies. This shouldn't be hard to do.

 

[ReverendSlim]

Phase tests between channels is readily available on Dolby and THX test discs for anyone that doesn't want to spend $100 for SACT.

What Dolby and THX discs have phase tests between left and left wide? Left and left top front? Left side surround and top mid? There have been tests like these for 7.1 (my favorite being the AIX disc), but do any discs have tests like that specifically for the common Atmos speaker positions? Because that's kinda' the point.

 

[gene]

What Dolby and THX discs have phase tests between left and left wide? Left and left top front? Left side surround and top mid? There have been tests like these for 7.1 (my favorite being the AIX disc), but do any discs have tests like that specifically for the common Atmos speaker positions? Because that's kinda' the point.

The Dolby Atmos demo disc does 7.1.4 which is the limit to most test discs. 95% of people are using speaker configurations under this channel count. Checking speaker polarity and using a laser pointer if you don't trust auto setup gets you there for higher channel counts.

 

[ReverendSlim]

The Dolby Atmos demo disc does 7.1.4 which is the limit to most test discs. 95% of people are using speaker configurations under this channel count. Checking speaker polarity and using a laser pointer if you don't trust auto setup gets you there for higher channel counts.

Respectfully, Gene, you literally just said, "Phase tests between channels is readily available on Dolby and THX test discs for anyone that doesn't want to spend $100 for SACT." But there are no phase tests on the Dolby Atmos demo discs, just the wideband tones per layout, and the THX discs pre-date Atmos. So what discs were you referring to that have an equivalent test?

 

[Sawtaytoes]

Phase tests between channels is readily available on Dolby and THX test discs

How do I get those discs? I only have a phase-test video for DTS-HD (7.1). SACT was the first time I had a Dolby Atmos one or anything that could test my height channels.

This might be a good video too. How to buy/download calibration discs and properly use them.

 

[gene]

Respectfully, Gene, you literally just said, "Phase tests between channels is readily available on Dolby and THX test discs for anyone that doesn't want to spend $100 for SACT." But there are no phase tests on the Dolby Atmos demo discs, just the wideband tones per layout, and the THX discs pre-date Atmos. So what discs were you referring to that have an equivalent test?

I think the 2nd edition Atmos disc I have does phase checks. I will have to dig to find it. THX calibration discs do phase checks for 7.1. Again, there are 4 ways you can test phase of the height channels without a disc:
1. Use auto set up and let it check phase, they usually get this right except in the 3-way speaker scenario that I previously mentioned.
2. check speaker polarity connections on amp and speaker side, something that should ALWAYS be done during install.
3. Disable all speakers but the heights as pairs at a time and listen to Spatial Audio music. You will hear if there is a phasing issue pretty quickly.
4. Download the REW files from AV Nirvana and measure.

 

[gene]

How do I get those discs? I only have a phase-test video for DTS-HD (7.1). SACT was the first time I had a Dolby Atmos one or anything that could test my height channels.

This might be a good video too. How to buy/download calibration discs and properly use them.

Yea I requested the Spears & Munsil disc that just came out and will see if it has that capability.

 

[Sawtaytoes]

Yea I requested the Spears & Munsil disc that just came out and will see if it has that capability.

Mine just shipped. I'll be able to see pretty soon as well .

 

[ReverendSlim]

I think the 2nd edition Atmos disc I have does phase checks. I will have to dig to find it.

I look forward to it. I have 2014, 2015 and 2017 and don't see phase tests on any of them. The TOC for the new S&M disc doesn't list phase tests, but does seem to have tests for level matching and crossover points in the various formats, as well as some pans. Looking forward to playing around with that one too.

But I still maintain that the point here was that despite you and David saying those tests were easily available on other discs, they kinda' aren't. Even if they were on the Dolby or THX discs are previously stated, those aren't typically available to consumers the way a purchasable product is. Hopefully, S&M's new disc has enough to deal with most situations. And for those who want to dig deeper and are willing to spend the money, SACT has a place in the market too.

 

[isolar8001]

Checking for phase when you've hooked up a million systems is kinda' a moot point anyhow.
Although, I have seen some of the system setup programs call a speaker out of phase when there is no way in hell that it is.

 

[gene]

I look forward to it. I have 2014, 2015 and 2017 and don't see phase tests on any of them. The TOC for the new S&M disc doesn't list phase tests, but does seem to have tests for level matching and crossover points in the various formats, as well as some pans. Looking forward to playing around with that one too.

But I still maintain that the point here was that despite you and David saying those tests were easily available on other discs, they kinda' aren't. Even if they were on the Dolby or THX discs are previously stated, those aren't typically available to consumers the way a purchasable product is. Hopefully, S&M's new disc has enough to deal with most situations. And for those who want to dig deeper and are willing to spend the money, SACT has a place in the market too.

Agreed and they should be included on the new THX and Dolby calibration discs. I will reach out to my contacts to both companies and request this. We should have the ability to test up to 9.1.6 speaker formats. Anything beyond that requires a Trinnov or Storm Audio processor which has built in multiplexing to easily interface with REW. Thanks for the suggestions.

 

[ReverendSlim]

Checking for phase when you've hooked up a million systems is kinda' a moot point anyhow.
Although, I have seen some of the system setup programs call a speaker out of phase when there is no way in hell that it is.

Bear in mind that we're not talking about polarity here. We're talking about adjacent speakers being in phase, which is dependent upon the delays in the processor.