Official DataSat RS20i thread. (Setup Tips, Questions,General Info, etc) - Page 5

I am just trying to understand sub calibration fully, that is all. It's an area, as you can tell, I am not too hot on.

So, as I understand it.

Delays are independent, whether the subs are mono or not. Which is good. Channel trims are not. Hence if you set subs to mono and enter the audio levels and adjust sub chan 9 it makes no difference.

Eq is completely independent and can not be summed to mono. In that if you apply eq to sub chan 9 and then mono it to sub chan 4, that eq becomes redundant and only eq on chan 4 is used. As I found in my REW measurements.

I still do not fully understand tho if Dirac filters can be applied to each individual sub and then still used when mono. Or if one is to mono then the subs need to be calibrated as a single mono sub in Dirac? Ie, one channel with multiple speakers. Sorry if I am sounding thick, it's just I have not read the info I need in a way I fully understand.

The reason why I feel that subs need to be individually calibrated, eq'd by Dirac, is as stated above, my right front sub is by an alcove which causes weird interactions as apposed to the left sub. I understand that by letting Dirac see them as one sub and performing a single channel eq can work well, but surely if it can calibrate them seperately before being Monod then the room interactions will be much more acurately taken into account.

Ie, if I calibrate them as mono, and the right sub has a big suck due to the alcove, then surely it will try and fix this by applying a lift on some frequencies across all subs, which won't be correct as this could cause a peak on the left hand sub. Am I making sense?

Right, and after EQing them as a single sub, the delay of the subwoofer output can be adjusted to get the best blend with the speakers at the crossover point.

Yes, you are making sense, but you're leaving something out. I'll use random numbers in my example. Suppose you measure your right sub and notice a 6dB dip at 70Hz. Then you fire up the both the right & left subs together and notice that the interaction between the two subs has caused the dip to shrink to only 2dB. That's the dip you need to correct for (since you'll always be hearing both subs together), not the original larger dip (since you'll never be hearing each sub individually).

One of the cool things about using multiple subwoofers is that you can improve frequency response AND seat to seat consistency, not just output (amount of bass). In fact, if you have other locations where you can place the subs, you might want to try different combinations with your pair of subs to see where you get the best response. Just remember to send the same signal to both subs, exactly as you will be listening to them.

Plenty of people place their subs where they cancel room modes, which will free up your Dirac room correction to tackle only the problems that placement alone couldn't fix. Why use EQ when placement can fix some of those problems.

Thank you Sdurani.

You have just explained it perfectly in a way I fully understand. I cannot thank you enough.

I feel like I am back in chemistry learning about moles of chemicals. I never understood it, for 2 years. Then went to collage and my new professor explained it in 5 minutes and all made sense. Almost like trying to put a jigsaw puzzle together with one piece missing. You just gave me the missing peice.

Again, thank you!

Neil - I am under no illusion that you would be able to get much more out of my set up than my fumblings and really appreciate the contributions you make to help others get some further insights in maximising the capabilities of the RS20i. As schlitzie has indicated some of us are unable to have direct dealer support. I purchased my unit long before a distributor/dealer was established in Australia - I did this understanding I would have some limitations and that is why this thread is great for those without the direct benefit of a local dealer. Carl has been great in his support - always very prompt and of assistance with all my enquiries but there is also enjoyment (and frustration) in stumbling through these things yourself.

If you are ever in Melbourne I would love you to be able to come and redo my set up!

Dave,

This thread has sparked a conversation between myself and one of the engineers crafting the firmware that is in RS20i. In that conversation he pointed out that you can run 4 subs each under Dirac Live control in 'Bass Managed Mono' mode and here is how you do it ...

#1) Wire your four subs to channels #4, 9, 10 and 11 outputs.

#2) Turn OFF Bass Management and use the Dirac Live configuration tool to generate Dirac filters, treating channels 4, 9, 10 & 11 as stand alone channels.

#3) Load the Dirac Filters to the RS20i

#4) Turn ON Bass Management having configured it for only one subwoofer.

#5) Finally copy channel #4 to the 9, 10 and 11 outpuits

The result will be four mono subs (all seeing the same BM feed) but each with their own unique Dirac Live filter.

______________
Best Regards,
Carl Huff
Edited by Carl_Huff - 12/28/12 at 9:00am

Good timing as I am in the midst of running Dirac on the new RS20i. My primary observation at this point is a complete reinforcement of how much I really dislike having to work with PC's (XP). Could microsoft make it any less intuitive? Over an hour later and I haven't gotten to dirac yet as I have to go through the typical acrobatics to get the damn computer to run the software.

Hopefully I'll be able to use Carl's SW tip today...

Arrgh. I hit the Dirac wall...

My software is for my AP20, so Dirac is looking for that, not an RS20... I tried to rename it, but no luck, so until I get this straightened out I am stuck.

On top of that, I am having trouble getting the VU meters to register other subs (3 total) beyond the main channel 4 one... The subs fire, but nothing shows up on the screen - is that normal? I don't recall it being that way with the AP20.

The good news is that I am running the old AP20's dirac configuration, so it sounds pretty good. I just know it can sound better! I'll deal with it next week after the holidays settle down.

"My software is for my AP20, so Dirac is looking for that, not an RS20 ..."

What software is that? The Dirac Live configuration app is the same for the RS20i as it is for the AP20. Or are you speaking of something else?

_____________
Best Regards,
Carl Huff

Schlitzie - when I use Dirac it recognises my RS20i even though it lists it as an AP20. Have you checked your IP address of the unit on your laptop.

Why would you EQ each sub individually when you'll never listen to them that way? Wouldn't it make more sense to EQ their interaction, since that is always what you'll be hearing?

Yours is a reasonable argument. I would be interested in hearing 4 subs configured both ways. Your method is certainly easier to realize. Building filters for each sub has a clear value when you are doing a Front/R, Front/L, Back/R and Back/L Bass Managed mix and the subs are spread about the room. However in a case like Dave's where the 4 subs are on a common wall I would expect configuring them as one channel would have good results.

I've never configured a system like what Dave has, so I don't know from experience what the best way is. I invite Dave to try both methods and report back his results!
_____________
Best Regards,
Carl Huff

OK, crisis averted! I had to re-start everything in the chain, and wham, Dirac saw the RS20... I was just paranoid because in my experience the software is sooo sensitive - so everything is currently running in the theater.

I guess if I do this another half a dozen times the learning curve will be less painful!

Dave,

In a nutshell ...

Bass Management was invented years ago by Dolby. It was intended as a way to reproduce the lowest octaves in film soundtracks played at home. At the time most home loudspeakers ran out of gas by 60Hz to 80Hz. The scheme was to mix the missing lows from the main channels along with a new specialty LFE (Low Frequency Effects) channel. When properly configured the result was a new and full range audio experience. The 'small' and 'large' are really about describing the low end capabilities of you loudspeakers.

How does BM interact with Dirac Live??

They are two entirely different things. Dirac Live should be configured with Bass Management turned OFF. If you have it ON the Dirac filters generated will not be optimal for your system because of the channel mixing behavior of Bass Management. You should also have all delays and all PEQ and 3rd octave EQ shut off as well when configuring Dirac Live. The reason being that you are much more apt to experience digital clipping when you have too many forms of EQ running concurrently.
______________
Best Regards,
Carl Huff

"... What happens below 20hz in Dirac Live?"

ANSWER: Nothing if you shut off the HI-PASS filter. You will pass to the analog lower limits of the RS20i which is 3 to 5Hz.

"... What exactly happens when bass management is engaged and you have two subs, left and right. With the RS20i, you have LFE from left and right channels going into the left and right subs. What advantages does this setup have? And what happens with the rest of the LFE?"

ANSWER: Using the two subwoofer BM setting of the RS20i you effectively convert your LEFT & RIGHT mains into actively crossed multi-way loudspeakers. This is an optimum situation assuming that your subs are located physically near their associated main. As to, "What happens to the LFE?", it gets divided evenly between the two subs and its level 'automagically' adjusted.

_____________
Best Regards,
Carl Huff

Dirac Update -- Not so good at this point. I have concluded that Dirac 2 can't get here soon enough cause Dirac 1 is just one clunky piece of software

After messing with it for 4+ hours yesterday it crashed just as I was exporting the data. So I gave up for the day and hit it again this AM for several more hours

This time everything ran fairly smoothly, except subwoofer #2 which I cannot get reasonable levels on through adjustments on the RS20, so I have to use the gain on the sub itself. OK, but not ideal...
(And that brings up a questions - subs are JL Audio F113's that recommend setting a Hi and Low pass filter at 12db/octave @ 80HZ for Bass management processors -- Does Dirac deal well with that, or should I just turn the filters off?
And I noticed that the VU meters for subs #2 and #3 are not active unless Bass Management is enabled... Not a big deal, just surprising. Is that a bug, or is that normal behavior?

Anyway, I re-ran Dirac measurements, (planned on 12 locations, got up to 11 before it lost the 12th - it reports that it can't hear the speaker - , so I just proceeded with the 11). Dirac did it's thing, and exported the data, though when I tried to run the delay and gain calibration no sound was generated. Besides that, all appeared OK - however on playing a blu-ray my two rear surround channels are very static-y, which is a brand new development.

Frustration is starting to set in -- I may give it one more go, but this may have to wait until after the holidays so I can start all over

I love the machine, but this thing is gonna make me cry

I do not think delay and gain correction part of Dirac has ever worked on the ap20 / rs20i. I remember reading that somewhere recently.

Hi Carl,

A sort of related question. Usually the mix ratio of redirected bass and LFE is the normal +10 dB in favor of LFE (assuming a single sub). Some AV processors allow the user to adjust the mixing level of the LFE. For example, there were a lot of 5.1 music mixes released on SACD where the LFE is printed 10 dB hotter than standard, so these require no boost in the playback system. Is there an easy way to twiddle the LFE mixing ratio as an end user? As in make an "SACD" preset or the like?

Wouldn't that have more to do with the signal being sent to the subwoofers than their placement? If you're sending independent signals to each subwoofer, like we do with speakers, then it makes sense to EQ them individually. When it comes to your L/R speakers, how close or far apart they are doesn't determine whether they're EQ'd together or separately. Because those speakers are receiving independent content, they're always EQ'd separately.

So when you have 4 subs (whether they're on a common wall or spread to the four corners of the room), the determinant for EQing them independently or together should be the signal they're getting, not their placement. If they are getting the same bass managed signal AND you'll always be hearing all 4 of them together, then I don't see the advantage of EQing them independently. I'll use a real-world example:

Below is a graph of one sub in the front of the room, measured from 8 seats (8 traces):



Here's a graph of 4 subs in 4 corners of the room, measured from those same 8 seats:



The interaction of the 4 subs (Front/R, Front/L, Back/R, Back/L) not only reduces frequency response variations (smaller/fewer peaks and dips) but ALSO minimizes seat-to-seat variations (greater consistency). So why waste EQ resources trying to reduce problems for 4 individual subs that measure like the first graph when interaction from the other subs will do much of that for you, as seen in the second graph? This way, you use EQ to address only the problems that the multi-sub interaction doesn't fix. Does that make sense? Agreed, since every room is different, the results in the example above might not translate to Dave's room and subwoofer placement.

Hello Roger,

Yes, there is a +10dB LFE switch that you can set on the decoder page that is associated with an input.
______________
Best Regards,
Carl Huff
Edited by Carl_Huff - 12/29/12 at 8:32pm

"Dirac Update -- Not so good at this point. I have concluded that Dirac 2 can't get here soon enough cause Dirac 1 is just one clunky piece of software. After messing with it for 4+ hours yesterday it crashed just as I was exporting the data.

Sounds like you lost your session between the Dirac Live software and the RS20i. Were you fiddling with the touchscreen? That would cause the RS20i to drop out of setup mode and you would lose your session with the Dirac Live application.

Did you save your project locally to your laptop? I've learned to always save my projects at logical points along the way. That way you never have to start from scratch should something happen. I learned this the hard way years ago when I was doing a time critical install for a very important client in an upscale commercial theater. The laptop that I was using crashed after taking 26 samples! And I hadn't saved the project. My leg had been blocking the cooling fan and the laptop had simply overheated.

Doh!! My workmates have never let me forget that one ....
_____________
Best Regards,
Carl Huff

Djnickuk is correct. You have to manually enter the delay on the RS20i outputs screen.
_____________
Best Regards,
Carl Huff

Schlitzie - I also have two F113s so am interested in what you set up - I have set the low pass filter at 24db@120Hz (both on Dirac and in the crossover set up) as I understand it is preferable to have the LFE low pass set at 120Hz.. But I expect I may mistaken. My F113 are right next to my L&R speakers and while I have tried the 'mono' option for my subs as described in earlier posts I prefer the dual sub bass management option (LfrontRfront) in my set up (I maintain both presets and separate EQ options for each preset).