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Discussion Starter · #1 ·
First, I am pleased to announce that my NanoAvr-DL is functionnal. Dirac and Rew graphs for my fronts speakers are reconciled (thanks to a new bd-player, the old one was the culprit even it was upstream!)
I have successfully made a Dirac project for my 5.1 system and, everything works ! (je touche du bois!).
So I think that I am maybe reconciled with NanoAvr-DL. I make listening session to hear the difference and to decide if it worth it.

I am aware of the controversy about to put Dirac before to bass managed the hts.

Taking into count the manual eq capabilities fo my receiver, I would like to know what do you think of the following idea: use the best of the two worlds to reconcile the bass management problem and to get better results in terms of SS&I.

The receiver.
I can manually eq each channel and the sub with 5 filters for 0hz to 200hz and 5 filters for 1 100hz to 20 000hz frequencies leaving a "hole" between 300hz to 1 000hz that I can not Eq in the receiver.
I can send a full signal (20-20 000) through the .1 channel if I desire to get the full response of the sub (xover to off).

Dirac Live.
It corrected the impulse of all my channels by adding automatically 8ms delay to all. Also I can use the curtains to change the correction region.

Here's the idea: to use the receiver to bass managed and to manually EQ with REW the lowest FR and the sub and the FR above 1 000hz as it should be the best way to do so and to use NanoAvr-DL to correct the "hole" (200hz to 1 000hz) and the impulse. This way I also avoid to EQ twice the same fr.

Here's the steps that I imagined to accomplish that:

1- into the receiver, set all speakers to large, no sub, sub main volume off, no eq (of course) into the receiver = full range signal.
2- Dirac live, custom set-up with 5 channels, no sub, make a full set of 9 measurements, choose the correction region between 200hz and 1 000hz, optimize a flat target curve for this region;
3- connect REW (laptop) to NanoAVR-DL (I hesitate here with an other path that I will explain later) via HDMI input2
4- Run sweeps full range meaurements (one mic position for the moment) with speakers set to large and measure also the sub ;
5-Find the filters for the channels and the sub response fr for 20-200hz and 1 100-20 000hz with REW;
6- implement the filters into the EQ of the receiver;
7- Set speakers to small, xover to 80hz;
8- with the laptop via hdmi still connected to NanoAVR-DL, check with REW the results for all channels and the transition at the xover point, tweak sub distance if necessary;
9-listen a movie!
10-...enjoy ... or ...cry !!??

At the step 3, maybe should I connect the laptop and REW to the receiver and follow the rest of the procedure ?

Does this make sense? Or is it too complicated for nothing?
 

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First, I am pleased to announce that my NanoAvr-DL is functionnal. Dirac and Rew graphs for my fronts speakers are reconciled (thanks to a new bd-player, the old one was the culprit even it was upstream!)
I have successfully made a Dirac project for my 5.1 system and, everything works ! (je touche du bois!).
So I think that I am maybe reconciled with NanoAvr-DL. I make listening session to hear the difference and to decide if it worth it.

I am aware of the controversy about to put Dirac before to bass managed the hts.

Taking into count the manual eq capabilities fo my receiver, I would like to know what do you think of the following idea: use the best of the two worlds to reconcile the bass management problem and to get better results in terms of SS&I.

The receiver.
I can manually eq each channel and the sub with 5 filters for 0hz to 200hz and 5 filters for 1 100hz to 20 000hz frequencies leaving a "hole" between 300hz to 1 000hz that I can not Eq in the receiver.
I can send a full signal (20-20 000) through the .1 channel if I desire to get the full response of the sub (xover to off).

Dirac Live.
It corrected the impulse of all my channels by adding automatically 8ms delay to all. Also I can use the curtains to change the correction region.

Here's the idea: to use the receiver to bass managed and to manually EQ with REW the lowest FR and the sub and the FR above 1 000hz as it should be the best way to do so and to use NanoAvr-DL to correct the "hole" (200hz to 1 000hz) and the impulse. This way I also avoid to EQ twice the same fr.

Here's the steps that I imagined to accomplish that:

1- into the receiver, set all speakers to large, no sub, sub main volume off, no eq (of course) into the receiver = full range signal.
2- Dirac live, custom set-up with 5 channels, no sub, make a full set of 9 measurements, choose the correction region between 200hz and 1 000hz, optimize a flat target curve for this region;
3- connect REW (laptop) to NanoAVR-DL (I hesitate here with an other path that I will explain later) via HDMI input2
4- Run sweeps full range meaurements (one mic position for the moment) with speakers set to large and measure also the sub ;
5-Find the filters for the channels and the sub response fr for 20-200hz and 1 100-20 000hz with REW;
6- implement the filters into the EQ of the receiver;
7- Set speakers to small, xover to 80hz;
8- with the laptop via hdmi still connected to NanoAVR-DL, check with REW the results for all channels and the transition at the xover point, tweak sub distance if necessary;
9-listen a movie!
10-...enjoy ... or ...cry !!??

At the step 3, maybe should I connect the laptop and REW to the receiver and follow the rest of the procedure ?

Does this make sense? Or is it too complicated for nothing?
Yes, the strategy does make sense. However, you might try just running with Dirac to see what it comes up with. You might be surprised how good it sounds without the manual EQ steps. It is easy to get caught up in the visuals of FR curves and end up chasing perfection in areas that one simply cannot hear.
 

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Discussion Starter · #3 ·
Yes, the strategy does make sense. However, you might try just running with Dirac to see what it comes up with. You might be surprised how good it sounds without the manual EQ steps. It is easy to get caught up in the visuals of FR curves and end up chasing perfection in areas that one simply cannot hear.

I already hear a difference. The SS&I is more detailed, the basses more punched.

But is it true that EQuing upstream before the bass management in the receiver is so wrong? It is why I had this idea so I could hear the difference.

I know that you are testing the D-88BM . You have tested the NanoAvr-DL before, maybe you will have a comment on this problem.
 

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I already hear a difference. The SS&I is more detailed, the basses more punched.

But is it true that EQuing upstream before the bass management in the receiver is so wrong? It is why I had this idea so I could hear the difference.

I know that you are testing the D-88BM . You have tested the NanoAvr-DL before, maybe you will have a comment on this problem.
It is definitely NOT "so wrong." Idealists will argue that BM before the Dirac is best, or ideal, because then each channel of the Dirac is operating on the signal to a single speaker - the subs, the Left Main, the Right Main, etc. It becomes necessary with an ATMOS system because the ATMOS processing, assumed to be in the AVR - no other options for that that I am aware of at this point anyway - has to proceed the Dirac so the Dirac receives the processed LPCM (or analog) signals per individual speaker entity in the system.

For a system where it is OK for LPCM signals to be the sole type of input, it can be either way. With BM after the Dirac, the Dirac output then applies "per speaker position," i.e. Left Main + sub, Right Main + sub, Center + sub, etc. It takes a little more planning in the way the target curves are set up, but the final result sounds every bit as refined and well-integrated as the other approach, there is no sacrifice in listening quality at all.

I have done it and listened to it both ways, and neither approach sounds "wrong." It is a matter of system planning and the types of source and AVR processing to be used.
 

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Discussion Starter · #5 ·
Thank you very much for this comment. It is reassuring!:whew:

...
For a system where it is OK for LPCM signals to be the sole type of input, it can be either way. With BM after the Dirac, the Dirac output then applies "per speaker position," i.e. Left Main + sub, Right Main + sub, Center + sub, etc.
It takes a little more planning in the way the target curves are set up,
What do you mean by "more planning"? By Dirac algorythm when it is calculating the auto target or by myself when I am customizing my personnal target curve to be loaded?

If I may ask a second question. Without NanoAvr-DL, I had the xover set to 70hz for the fronts and 100hz for surrounds. How to set the xover for Dirac? Would you suggest a single xover into the receiver of 70hz, 100hz or 140hz (twice the fronts xover value) for all channels?
 

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What do you mean by "more planning"? By Dirac algorythm when it is calculating the auto target or by myself when I am customizing my personnal target curve to be loaded?
By you when setting your target curves. Just remembering that each target curve will end up acting upon a speaker + sub combination instead of a single speaker. You might end up using a different target curve for surround + sub than for main + sub, for instance. Also, some people like to tweak sub levels in different ways before and after tuning. This would affect all of those target curves, not just one sub target curve. There IS NO SUB TARGET CURVE, only the sub portion of he target curve for each channel! The Dirac target curve for the LFE input will need to be truncated at 120 Hz or below so Dirac does not try to make the LFE channel do super human HF stuff through the subwoofer (Dirac probably would refuse to do that anyway, I have never been able to get it to misbehave).

If I may ask a second question. Without NanoAvr-DL, I had the xover set to 70hz for the fronts and 100hz for surrounds. How to set the xover for Dirac? Would you suggest a single xover into the receiver of 70hz, 100hz or 140hz (twice the fronts xover value) for all channels?
I can think of no reason to set the BM crossovers any differently with Dirac vs. without.

A 100 Hz crossover for surrounds will protect the speaker from LF energy that it might not handle gracefully, but the bass sounds between 80 Hz and 100 Hz are now coming from the sub and are directional enough to our hearing that - with music especially - you might hear the bass "moving around the room" on certain notes (you are probably well aware of this, just being thorough). This will be the case with or without Dirac.

Another example: If your sub is good up to 80 Hz and your surround cuts off at 120 Hz, and the Dirac target curve is flat, then Dirac will try to pump more juice to beef up the 80 to 120 range (even as I say that I am anticipating the our friend Flavio at Dirac Research will say that Dirac has the smarts build in to not try to overdrive a dead area of response like that). That might or might not be a problem (along with the localization). One solution (if you can hear it pushing the surrounds too hard as a result) is let the target curve dip a bit in that range for the surrounds. Most likely, you will never miss it with actual content, music or movies.
 

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Discussion Starter · #7 · (Edited)
Thank you very much.
I will do experimentation.
Stay tuned!

In fact, it is the general shape of the target curve that is difficult to determine. Auto target gives a straight line between +2.5db at the LF side to -2.5db to the HF side. And there is the house curve, hard knee or ski-sloap shape or the "follow the natural response of your speakers" approach etc.

Difficult to know where to begin, which part of the curve to begin with, how much to change this or that etc.
 

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Discussion Starter · #8 ·
I would appreciate a technical advise about how to set output level before making mesurements with Dirac.

The problem is with the sub level.

I did the following procedure.
First, with my Galaxy sonometer and internal test tones in the receiver (EQ off) , I set the main volume of the receiver for the left channel at 75 db and adjust with the receiver's trim each channel to get 75db.

The user manual for Rotel suggest to put the sub volume at the same level than the speakers which I did yesterday (Until yesterday I always added 5 db to the sub). I lowered the main volume of the sub to read 75db instead of my usual 80db. I opened Dirac (NanoAvr-DL) and I followed the user manual to set mic input and channel outputs levels.

- I clicked the button to send the test tone to the left channel , I adjusted the output volume slider to - 33,5db. Doing so the blue bar just begin to appear at the left side of the scale reading approx -36 db.

- While the test tone is playing, I gradually adjusted the input gain slider until the indicator reaches the midpoint of the green area (-12) which gave me, if I am right, more than 20db headroom between noise floor and the signal level. I'm NOT using individual speaker level to get the bar to -12. I leave them all untouched to max position. Only using mic gain and volume control next to mic gain control to get all my speakers to -12.

- I checked each other channels before proceeding and each registered bull's eye at the -12 level as well at the exception of the sub channel. To get the blue bar in the green zone, I had to rise the main volume into the sub by approx 3 db. But to reach the -12db target, I would have had to add 3 db more. I decided not to go there and let the +3db for the sub, just enough to reach the green zone.

I was surprised by the result. The average curve in Dirac for the speakers was below the 0 line but the optimized auto target curve set the lwer end at 2.5dg as usual: bass were then way much more louder than before when i was setting the sub at 80db. Does it make sense?

Is it crucial to first put all channels including the sub at 75db via the receiver?

After applying the Dirac target curve as optimized at this level for the sub, should I let the main volume of the sub untouched or is it better to return to the level prior to Dirac measures, i.e. lower it by 3db in order to have 75db as suggested in the Rotel manual?

Thanks for your help
 

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I would appreciate a technical advise about how to set output level before making mesurements with Dirac.

The problem is with the sub level.

I did the following procedure.
First, with my Galaxy sonometer and internal test tones in the receiver (EQ off) , I set the main volume of the receiver for the left channel at 75 db and adjust with the receiver's trim each channel to get 75db.

The user manual for Rotel suggest to put the sub volume at the same level than the speakers which I did yesterday (Until yesterday I always added 5 db to the sub).
Not sure that this matters. I think some play with sub level at pre-calibration to manage headroom and available gain. Its benefit would depend on individual system characteristics and user preference for resulting amount of low bass.

I lowered the main volume of the sub to read 75db instead of my usual 80db. I opened Dirac (NanoAvr-DL) and I followed the user manual to set mic input and channel outputs levels.

- I clicked the button to send the test tone to the left channel , I adjusted the output volume slider to - 33,5db. Doing so the blue bar just begin to appear at the left side of the scale reading approx -36 db.

- While the test tone is playing, I gradually adjusted the input gain slider until the indicator reaches the midpoint of the green area (-12) which gave me, if I am right, more than 20db headroom between noise floor and the signal level. I'm NOT using individual speaker level to get the bar to -12. I leave them all untouched to max position. Only using mic gain and volume control next to mic gain control to get all my speakers to -12.
A terminology clarification. I believe you meant to say "headroom between clipping and signal level." And the amount of headroom would be 12 dB ("-12"), not 20 dB. Correct me if I have misunderstood.

There are different places and ways to get a gain, a level, and to calculate headroom in a complex system like this. For instance, at the Dirac level set screen, with a -18 reading on the Dirac Live Calibration Tool level meter, my system gives 72 dB SPL. Alternately, with REW driving the same channel, I get 72 dB SPL with a -32 dB signal on the DDRC-88BM plugin output meter. What does this mean? I do not know.

- I checked each other channels before proceeding and each registered bull's eye at the -12 level as well at the exception of the sub channel. To get the blue bar in the green zone, I had to rise the main volume into the sub by approx 3 db. But to reach the -12db target, I would have had to add 3 db more. I decided not to go there and let the +3db for the sub, just enough to reach the green zone.

I was surprised by the result. The average curve in Dirac for the speakers was below the 0 line but the optimized auto target curve set the lwer end at 2.5dg as usual: bass were then way much more louder than before when i was setting the sub at 80db. Does it make sense?

Is it crucial to first put all channels including the sub at 75db via the receiver?

After applying the Dirac target curve as optimized at this level for the sub, should I let the main volume of the sub untouched or is it better to return to the level prior to Dirac measures, i.e. lower it by 3db in order to have 75db as suggested in the Rotel manual?

Thanks for your help
My suggestion (you have already done most of this):
  1. Set level with AVR as you have. Then never touch them again. The 88BM controls give far more flexibility.
  2. Set Dirac Live levels for good readings (I usually stay between -12 and -18). Do not get too hung up on the absolute levels, there are too many variables. With Dirac correction on or off, a level can change by several dB. And Pink Noise is... NOISE! So levels are constantly changing a little.
  3. Run Dirac calibration.
  4. With desired Target Curve, optimize with Dirac.
  5. Now all levels should be properly set, relative to each other. To manage headroom, they can all be changed up or down by the same amount if needed. "Managing headroom" can get a little complicated.
  6. Do not change the sub level relative to other levels after running Dirac. Get the sound you want with the Target Curve.
 

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Discussion Starter · #12 ·
(...)

A terminology clarification. I believe you meant to say "headroom between clipping and signal level." And the amount of headroom would be 12 dB ("-12"), not 20 dB. Correct me if I have misunderstood.

(...)
Thank you again for a much appreciated reply.

I still stuggle along with the concept of headroom (I am slow ! at least to understand ...my wife would agree!). Headroom to avoid clipping at the signal level is one thing. I was referring to a difference between noise floor level and signal to get a good calibration.

I was not referring to the level indicated at the right side of the output volume slider but to the scaled level indicator for each channel. For instance, let's say that I put the receiver main volume at 69 instead of 75 (this number gives near 69db in the sonometer at mlp) , then, in Dirac, I may need to read -20db next to the output volume slider if I want that the blue bar appears in the scaled level indicator for the left channel. The left end of the scale is marked -36db. Gradually adjusting the input gain to get the blue bar at -12, I thought that was giving me enough space between the noise floor and the signal level to have a good calibration. If I was with REW, I would measure the noise floor with the meter (let's say 57db), and would adjust the output volume level to 77db so I have a difference 20db to get the same result; that I thought was also :)sweat:) headroom [email protected]

An other question if I may. Am I right to think that the difference between nanoAVR-DL and 88BM (bass management after or before dirac) is less important in small-medium size room as mine ( 1 500 cube feet approx) ?
 

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Discussion Starter · #13 ·
To whom it may concerns !
When setting output/input in the levels tab in Dirac for measurements with nanoAVR-DL (trims in the receiver for each channel are previously set to get 75db for all channels including the sub), I have better results if :

-first, increase the input gain until the blue bar begins to appear in the left end of the level indicators of all channels;
-second,with the test tone playing for the weaker channel (the sub channel in my case), rise the output gain to reach -12db in the green area of the scaled indicator;
-third, using the individual channel volume (at the right end of each channel line) lower the volume to adjust the blue bar precisely at -12db.

Now, I have a question about how to use the target curve. If I want to increase the bass by 2 db between 20hz and 80hz, for instance:

Do I change the target curve for the sub only or do I change the left end of the target curve for all 5 channels?
 

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Since all of those channels will feed into bass management in your AVR, each channel must have the increase you are seeking in the low frequencies added to its target curve.

The L Mains target curve, for instance, will cause that increase for the L Mains only, which will be sent to the sub. and be heard there. The R Mains signal will not be affected unless its own target curve is modified. The LFE target curve will only affect the LFE signal, not any of the other channels.

And that is one of the main differences between the nano and the 88BM - in the 88BM, only one target curve would be modified to give that effect. The difference between products and approaches would not be audible if done properly. It just takes a little different approach to achieve that sonic equivalence.

====

Your approach for setting Dirac levels looks reasonable. You have met the main goals of having good acoustical signal to noise ratio while not frying our ears or speakers, and keeping channels closely matched in level.
 

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Discussion Starter · #15 ·
The LFE target curve will only affect the LFE signal, not any of the other channels.
Just to be sure that I understand correctly: so I increase the target curve of 5 channels by 2db from 20 to 80hz but I do not change the sub-LFE target curve? Or should I increase also the sub-LFE channel?

(...) The difference between products and approaches would not be audible if done properly. It just takes a little different approach to achieve that sonic equivalence.
I agree. It would be great if that could be confirmed. Knowing miniDSP and Dirac professionnal approach, I like to think that the results should be nearly the same for those 2 products.

====

Your approach for setting Dirac levels looks reasonable. You have met the main goals of having good acoustical signal to noise ratio while not frying our ears or speakers, and keeping channels closely matched in level.
Thanks !
 

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Just to be sure that I understand correctly: so I increase the target curve of 5 channels by 2db from 20 to 80hz but I do not change the sub-LFE target curve? Or should I increase also the sub-LFE channel?
Yes, increase the LFE channel EQ as well. Then all channels receive the same LF boost.

I agree. It would be great if that could be confirmed. Knowing miniDSP and Dirac professionnal approach, I like to think that the results should be nearly the same for those 2 products.
As far as I am concerned, I just confirmed it. No theoretical or audible difference exists, when it is approached properly. It is just a little more complicated to get there.
 
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