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Hi Sean,

Thanks for your feedback and certainly glad to hear that you're thrilled with the improvement brought up by the DDRC-88A!
We'd love to see your setup in the showcase section of this forum. It's fun to see a showcase of systems and where/how our products are used.

In answer to your questions, it's very hard to answer that question because it will all dependent on Dirac Live algorithm. The algorithm will first try to figure out what is the "furthest" speaker away (i..e having the most latency) in its first set of measurement (i.e. UNIT1). Note that it will also be doing this for the "first measurement". It will then "delay" all the other speakers around to time align to that speaker.

In the setup of the second unit, it will do the same thing once again. I'm therefore curious (would need more experience I guess to double confirm) if you could actually figure this this out with a simple measuring tape. Look at your speaker arrangement and try to figure out what's the speaker that is the furthest away. If you have some spare channels in your setup, I'd actually be inclined to try the trick to "share" that channel in the 2nd unit. i.e.. connect that speaker to the 2nd unit as well. This way, when the system tries once again to perform its first measurement, it will use that same speaker for the delay calculation. You'd be very close at the point.

Does this make any sense? Hard to explain without diagrams.. We should do some app note I guess at one point.. We'd love to get your feedback though.

DevTeam

devteam wrote:

Hi Sean,

Thanks for your feedback and certainly glad to hear that you're thrilled with the improvement brought up by the DDRC-88A!
We'd love to see your setup in the showcase section of this forum. It's fun to see a showcase of systems and where/how our products are used.

In answer to your questions, it's very hard to answer that question because it will all dependent on Dirac Live algorithm. The algorithm will first try to figure out what is the "furthest" speaker away (i..e having the most latency) in its first set of measurement (i.e. UNIT1). Note that it will also be doing this for the "first measurement". It will then "delay" all the other speakers around to time align to that speaker.

In the setup of the second unit, it will do the same thing once again. I'm therefore curious (would need more experience I guess to double confirm) if you could actually figure this this out with a simple measuring tape. Look at your speaker arrangement and try to figure out what's the speaker that is the furthest away. If you have some spare channels in your setup, I'd actually be inclined to try the trick to "share" that channel in the 2nd unit. i.e.. connect that speaker to the 2nd unit as well. This way, when the system tries once again to perform its first measurement, it will use that same speaker for the delay calculation. You'd be very close at the point.

Does this make any sense? Hard to explain without diagrams.. We should do some app note I guess at one point.. We'd love to get your feedback though.

DevTeam

Hi DevTeam,

Many Thanks for the great support again. I will try as you say, however I'm not clear one point you raise: it is no problem for me to connect one common speaker (furthest away) to each unit, in turn, during the calibration(s). However, as I am running a subwoofer through unit 1 in the custom config would this not be "seen" by DDRC 88A (unit 1) as being the furthest away due to some slight pre EQ dsp I'm running through it from the inuke sub amp prior to running Dirac?

If not, and this does not matter, it is no problem for me to connect up as you say.

One other point; The Atmos height channels which I'm going to EQ through the DDRC 88A (unit 2).I assume I should NOT have the "subwoofer present" checked in the first level and setup page of Dirac when running Dirac (unit 2)? So. will these height speakers still be EQ'ed with full range bass management when they hand over to the subwoofer for the low Hz stuff, or will Dirac (unit 2) "think" there is no subwoofer connected and so try to boost EQ the small height speakers all the way down to as low Hz as possible?

Many Thanks in advance.

Sean

Sean,

Unfortunately hard to answer that last question without a measurement (e.g. REW or others) because there could indeed be few variables here..
For the height channels, go with the "customs" configuration and indeed don't tick the sub. Dirac will optimize and sweep each speaker independently (without regards to bass management knowing it's upstream of the DDRC-88A). Does this answer your question?

DevTeam

Hi Dev Team,

Perfect! thanks again for the great support!

Sean

Have you done it yet?

Sent from my LG-VS980 using Tapatalk

jagman wrote:

Have you done it yet?

yes he has

Hi All,

Sorry, been so busy lately.

To summarise. Yes I integrated both 88a units together a few weeks back to enable full DIRAC correction on all channels of a 7.1.4 Atmos setup. The results are, as expected, simply amazing. The second unit applies DIRAC to the 4 Atmos overheads and 2 front wide speakers I have left setup from DTS Neo X days. The most pertinent question is "is there any inherent delay between the two 88A units after separate DIRAC processing?" After testing the answer I got was "yes", but only very small 1-2 milliseconds difference. I just applied the delay to the second 88A, and was then good to go!

So, all in all, you can have full DIRAC correction for "just" the price of dual 88A units, rather than RS20i level prices!

Cheers

Sean

Great Stuff Sean and thanks for your update!

Sounds like yet another successful update as we know few other customers did their ATMOS setup with dual DDRC-88A.
Thanks again for sharing your positive experience with the community. Being an early adopter takes some trust and we're glad to see that all went well.

Sounds like you got support from our good friends @ IdealAV? Great job guys!

DevTeam

Hi devteam

Yes, great support from Alan at ideal AV and you guys. Thanks to minidsp for allowing the mere mortals among us to have state of the art 16 channel room correction performance without the rs20i price point.

Cheers

Sean

Hi DevTeam,

Would like to know how to measure the delay between two DDRC-88A units using the UMIK-1 USB mic and REW?

I don't think it's that straight forward from discussions at AVS forums.

stephenting99 wrote:

Hi DevTeam,

Would like to know how to measure the delay between two DDRC-88A units using the UMIK-1 USB mic and REW?

I don't think it's that straight forward from discussions at AVS forums.

Any response to this question somewhere?

Oops... We're so sorry that we've missed this post! Sorry Stephen.. It's a really good question too..

How about removing the UMIK-1 and speaker from the equation. If it were us, we'd be doing it with the actually DDRC (i.e. loopback to the PC for one unit then the other. Then we completely remove the element of acoustic unknown in the measurement... The way we see it is there are going to be 2 offset:
- Per channel OFFSET (i.e. Dirac doing its magic to figure out timealignment per speaker for one project).
- Per unit general offset (i.e. 2 x project files that probably have a different overall delay).
If in your setup of 2 units, you put 1 speaker shared among the 2 units AND make the first measurement at the same place for both units, then you can remove from the equation the "Per Channel OFFSET". You'd be looking only at the "Per uni general offset" that you need to apply to your AVR..

Does this method make any sense? Do you guys agree? Happy to hear some ideas....

DevTeam

DevTeam

Hi DevTeam,

Which speaker would it be that is common to both DDRC-88A units? Does it matter if one chooses the center channel speaker?

What about the sub channel? If the subs are connected to one DDRC-88A and not the other, would that have an affect on group delay of one DDRC-88A vs. the other?

@ Stephen,

We were suggesting to select one speaker and I don't think that it matters which one you select.
e.g. take the feed from your AVR for say the center and feed it to 2 DDRC-88A.

This idea was "one" method we could think off to use "one" speaker that is the same for both units so the per channel offset is the same.
Makes sense?

DevTeam

Nice Dirac Live and Dolby Atmos with two DDRC-88As... image from kbarnes791 post here:
www.avsforum.com/forum/90-receivers-amps...89.html#post39568786