Official DataSat RS20i thread. (Setup Tips, Questions,General Info, etc) - Page 15

Sorry fellas,

But I 've never seen such a published document. Each company keeps the details of their 'secret sauce' to themselves.
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Best Regards,
Carl Huff

Dan will be very helpful since he has great experience with Trinnov and Dirac. What I read about Dirac it seems is lesser tool for my needs. I absolutely love my Trinnov - the process is fully automated and at the same time has the tools to do what ever you want. I am still unsure why if you have Dirac you need to set levels and distance? If there is Dirac, why you need the PEQ? Trinnov does everything automatic and I have the PEQ disabled in the Rhapsody. I think I started to understand the price difference between Dirac and Trinnov...

From what I understand & read from here , DataSat RS20i is a shade better sounding than ADA but it is also an "unfinished" product , I will hold back for several months despite my interest for it , I just hope that DataSat will launch a smaller surround processor with no room correction , allowing easy setup & be used with my Trinnov MC - digi inputs , I need full automation . More time for movie , less time for troublesome thing .

From my many months of use , the Trinnov MC is surprising reliable . Never need a reset !

Larry

Dave,

You might actually try to use that sub at the rear of the room in an experiment:
feed it signal from the same channel as the front subs (invert the phase in the levels page) and add 22ms delay (assuming you're at sea level) : at that point it should act like an active bass trap- sucking the ring out (and the other bass energy as well- so you'll need to band-pass the info from that channel from say 20hz to 30hz).

You'll notice that the higher you raise the level of the rear sub, the more it grabs that energy.

The result may be that you can build a mass-loaded helmholz resonator to suck out that particular ringing. There are instructions how to do it in the Master Handbook of acoustics- in the later chapters, I think.


Larry,

Please don't misconstrue what I've said in the past about the RS20i; that unit I had before WAS unfinished- it was a prototype. Datasat has been very responsive to dealer requests and bug finds in their software. In fact, at the price the RS20i resides- I can't think of a more functionally feature-rich processor on the market. The new DSP card will be shipping soon (within the next 6 weeks) and with the capabilities added by that, I don't think there's another processor on the market that can compete (ADA Cinema Reference is an anomaly- really in it's won category).

And my preference for Trinnov processing vs. Dirac processing doesn't necessarily mean that I prefer ADA to Datasat- they BOTH perform very well, and I use BOTH. ADA is in my demo room, Datasat is in my personal room (second demo room hasn't started construction yet)

Dave's comment is right-on-the-money: fully automated doesn't necessarily equal better.

Dan

"Carl, Is using the PEQ EQ on top of Dirac a bad thing?"

Not necessarily a bad thing but if you do use it, setup the PEQ before and have it on when you are generating your Dirac Live filters. Dirac Live needs to be the last form of EQ that you put in place for the best optimization. If I am setting up a system with sealed subwoofers paired with big power amps that are capable of handling long excursions before tearing themselves apart, I will often turn on PEQ to 'pull-up' that bottom end before I generate the Dirac Live filters. However once I generate the Dirac Live filters I never touch PEQ, that is unless of course I 'clank a driver'. When that happens I quickly turn down PEQ, cross my fingers that I haven't damaged anything, apologize to the customer (argh ...) and start all over again.

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Best Regards,
Carl Huff

Carl, I am not sure I am following this. You seem to be saying that Dirac will interact with the PEQ (I thought they were both completely standalone). Is this what you are saying:

1) Set all eq flat (as Dirac recommends)
2) Take measurements
3) Add PEQ
4) Create Dirac filters

And this will be different than:

1) Set all eq flat (as Dirac recommends)
2) Take measurements
3) Create Dirac filters
4) Add PEQ

If you just want more bass in the bottom octaves, rather than mess with PEQ at all, wouldn't be better to just change the target curve?

George,

Dirac interacts with PEQ in that if Dirac is always used after PEQ any anomalous behavior introduced by the the PEQ can be corrected for. Many times when I walk into a customers home they have PEQ in place for their subwoofers. They have a predefined idea in their head what they think sounds good. In those cases I have learned to at least measure what they have so that I might emulate it while still improving upon it using Dirac Live room optimization.

But you are right, if Dirac Live can give you the gain that you need simply edit the target curve.
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Best Regards,
Carl Huff

Thanks Carl, but I am still confused.

If you set PEQ in the RS20i and then run Dirac won't Dirac cancel the intended changes of the PEQ by simply creating the target curve? I mean whether the PEQ is there or not won't Dirac just create the Dirac curve?

Good question! Guidance from Datasat tech support is to run Dirac solo and NOT touch any of the other EQ's, just leave them at default.

Yes, Dirac Live will work exactly as you described. The PEQ is only useful in those cases where you are looking to add gain that is greater than the 10dB of gain found in Dirac Live. Adding PEQ before crafting your filters will 'fool' Dirac Live into suggesting a lower cutoff for that subwoofer. However doing what I described can easily destroy lesser capable subwoofers. USE PEQ sparingly (if at all) and be sure that you've got big enough amplifiers and subwoofers capable of the handling the extra power.
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Best Regards,
Carl Huff

That's why these systems have limits to how much they will boost or cut frequencies.It's to prevent possible clipping and driver damage.You need to make sure you have the added headroom and driver excursion before you start adding additional gain on top of what is already being boosted.

I've seen that "tunneling" before on REW graphs.It's usually associated with low frequency vibrational noise, ie from railways, roadways, aircraft flyovers,HVAC systems etc ...The kind you can't hear,but calibration mics can pick-up. Is your set-up completely isolated from low frequency noise from outside the room?

In that REW graph with the depression centered around 800hz,I'd say it's an example of how an "actual" measured in room response after EQ is applied,can differ from what Dirac Lives' calculated "after" graph responses show.
Edited by StevenLansing - 2/18/13 at 1:49am

Absolutely. That was the most important part of my response. However if your system allows ...

_____________
Best Regards,
Carl Huff

Try putting a short across the speaker terminals. That will prevent air from moving the cone.

It depends on what you like,the capability of your system,speaker on and off axis characteristics and the room acoustics.I''ve only really seen one published curve and that would be the one that Sanjay has posted a few times that is very similiar to the Harman used "tilt" that's up +10dB at 20hz with a straight down sloping response ending -10dB down at 20khz .

You may also want to check this link out http://www.whatsbestforum.com/showthread.php?723-Target-Curves

There was info about an x-curve in the AP20 manual. I suppose that's a type of house curve. But it IS your house; make it what you like.

Dan

Wish mine did!

The X-curve really only applies to dubbing stages and theaters.Depending on the size of the system/room, it might sound alright.

In a more domestic environment THX Re-EQ is the translation designed for smaller rooms that is the equivalent of the studio X-curve.

Please, don't get me wrong- I wouldn't want that x-curve for any system I did in a home, I'm not espousing it, I just figured that Dave asked and I knew he had the AP20 manual....

I'd much rather see more of an overall curve like the ones posted in that link to what's best, that's generally how I tune my systems.

Dan

Seems the default target curve from Dirac also has a downward tilt:



But you can find that sort of curve going back almost 40 years:



And similar preference-based target curves from Lyngdorf, Harman and DTS (AES paper on proposed room correction).

The things they all have in common are a downward tilt and smooth response (minimized peaks & dips). Those are the same two qualities that were most preferred in Sean Olive's room correction comparison.

The Harman Synthesis target is pretty good IMHO. The bass rise agrees with my taste. It does not necessarily have to roll off below 25 Hz...

This has always been a preferred target curve for my taste.

Speaking of Dirac Live,wasn't one of it's features that it would create a target curve based on the room measurements?

You'll notice that the top of the Dirac screenshot says Dirac calibration tool BETA- it's the program for your computer to correct for what's connected to it.

Yes the version that we use with the AP20 and RS20i is the "old" version- this was referenced earlier in the thread. It is on Datasat's radar to change that to allow usage of Dirac live runtime v2.0 but don't hold your breath, it's going to take a while. Dirac v1.0 works just as well as v2.0 just doesn't look as pretty and can't be easily used on a Mac (though it DOES work with VMware Fusion!).

Dirac's default curve seems to agree with what's been posted (research curves).

BTW- Roger, I like the way your thoughts about that target curve.

Dan

That's not my Dirac Live software, just a pic I linked to from the Dirac site (to illustrate a downward sloping target curve).