TOPIC:

Hello experienced SHD users!

My SHD will arrive soon and I have a question about the measurement with Dirac.

The low frequency response in my room until until 100Hz is nearly perfect because of the very good measurement system of my two Subwoofers Velodyne DD12.
Before I start Dirac, should I leave the settings i.e. phase, peq, crossover etc. in the Subs as they are now or should I set everything to default?

Also I changed the phase of the mid/high section of my fronts 180° because that flattens the curve about 200Hz.
Should I leave this or should I change it back to normal operation?

Greetz, Thorsten

I would suggest leaving your subs as they are, at least to begin with. That will provide more meaningful Dirac On/Off comparisons.
I would suggest having all your front sections in the normal phase. Dirac will flatten the curve far better than section phase reversal which will obviously have effects on phase and distort the impulse response Dirac generates and receives for early reflection suppression.

Before using Dirac you should time align your subs with your fronts. If your subs are behind your fronts this means delaying the fronts in the SHD plugin. Although it should be possible to work out delays using distance measurements and the speed of sound in air I found I got a better result using REW to measure the delay. There is an article on this site which explains how to use REW for that.

Thank you much for your suggestions. That are exactly the solutions I feel most well with.
The (closed) Subwoofers stand near and a little bit behind the listening sofa. Their distance is about 60-70cm shorter than the frontspeakers' distance to the listening position. And that is probable and hopefully the reason for a disunited sound in the transient area.

OK, so I will have a look at REW. In the past I made the control measurements with Audionet CARMA. It is very easy to use but the functions are limited.

I am very anxious to hear the first results because I never had the possibility to change time parameters.

I will let you know what the SHD has made out of my listening room.

Cheers

www.minidsp.com/applications/auto-eq-wit...measuring-time-delay

That's the page describing how to use REW to calculate time delay differences. It's a little complicated but it only needs doing once so its worth doing properly. Until I used that method I couldn't arrive at decent delay compensation either by guessing or calculation. Oddly REW gave strange graphs for my sub but came up with a delay different to my calculations that just integrated the sub superbly.

Your 60-70cm should be a delay of a few ms but trust whatever REW tells you, often the actual acoustic centre of subs is not where you might expect it to physically be.

Aaah okay, thanks again!
In the manual of the SHD I read that the machine is also be able to determine the delay within the measurements. Do you think they are not as precise as REW?

Dirac can determine the relative delay of left and right channels. What it doesn't know is what drivers you have for each channel and so it can't align the different drivers in a channel. That's why you need to align the sub with the fronts in the SHD Plugin. That makes all the drivers in each channel time aligned. Dirac can then align left and right to each other.

Ok, I understand. I hope tomorrow the gear will arrive...

Remember the SHD has 4 slots for presets so if you are impatient you could do a Dirac calibration in preset 1 quickly just to ensure all the parts work together. Then time align your sub with the fronts using REW and SHD Plugin and do another Dirac calibration for preset 2. Then you can compare preset 1 and 2 to persuade yourself that preset 2 does in fact sound better with full time alignment. Or not.

I did about 5 calibrations over the course of a few months before I settled on one I was happy with. You don't have to get it perfect first time but the 4 preset slots does allow you to easily compare different calibration attempts.

Yes, that's a good idea. To reach the actual settings incl. fine tuneI tried about 2 years all kinds of configurations. Sub in front or back, two subs in front or back and so on.
The best result in my ears is now without any active crossover in the fronts and only lowpass in the subs at 125Hz, phase 45°.

Thanks to the presets I will run 1. without any changes, 2. with Dirac without time alignment, 3. with time alignment and 4. maybe with "loudness" curve. What a luxury....

Okay, it was not quite easy to setup all the things but now it's done.

Here is an old measurement from only my front speakers Aurum Vulkan 9.


These are the Vulkans together with 2x Velodyne DD12 with their own correction (EQ + phase+ crossover)


This is the first Dirac correction with the old settings of the Subwoofers.


And here is the second Dirac correction with all settings done by Dirac.


As you see, the best optical response was the work of Dirac.
But I am not sure if I really like what I hear.

It sounds more tight now and there are more details. But also it sounds a little bit cool and harsh like mp3.
Maybe I miss the analog warmth and smoothness of my old tube preamp.
But that's just a first impression for now.

It can take at least several days to get used the sound without room/speaker effects. Given we've spent our whole life getting our ears and brain used to wrong sounds I guess we're lucky it only takes a little while to get used to correct sounds

Stick with it, just listen to music. Many SHD owners are unable to turn Dirac off because the old room/speaker effects can sound ridiculously bad when you get used to the correct sound.

Okay, I think I have to experiment more with different crossover configs and listen a few weeks.
Maybe it's just an imagination but in my ears there is some digital distortion in the highs.

But all other users seemingly are satisfied with the allover sound quality.

I'm possibly too old to even hear all the highs but although most folk are happy and believe the SHD to be as transparent as needed there have been a couple of folk who just couldn't get used the sound and heard something in it they didn't like. I've possibly spent less than them on my overall system. Or maybe they just didn't allow long enough to get used to the sound, it sure can sound very different to start with. I suppose its also the case that the nearer your system was to correct, the less Dirac will need to do, its possible that some systems are just too far away from optimal for it to cope transparently.

I always find it hard to be objective about changes to my system and often what sounds stunningly different to begin with sounds completely normal after very little time. In hindsight its always obvious what changes get me listening to more music. I have never listened to more music than since I got an SHD and acoustic room treatment. Getting the SHD allowed me to hear some remaining room effects. Installing room treatment allowed me to get a better calibration. I personally find the SHD to be of very high sound quality and Dirac is the nearest thing I've found to magic. But on day 1 it sounded incredibly bass light compared to my boomy old setup which I now find unlistenable.

Yes, every day our ears are in a different constitution. Therefore I alway ask someone else if I am not sure, in this case my wife. As she heard the result of Dirac this afternoon, she said it sounds lifeless and less dynamic. I will try another measurement with other parameters.

But every time I tried digital soundcorrection in the past, I had the impression that it destroyed the high mid and high frequencies.
I use Audirvana as Tidal player and there are plug ins like EQs.
Several times I tried the parametric EQs. Only one band with moderat gain makes a curtain fall and it sounds dull. Not only at the frequency I edited.
Okay, let's see, what the next experiments show...

There are mathematical reasons why poorly implemented digital filters can sound dull, generally that problem is reduced significantly with higher sample rates. There are also reasons why even analogue parametric equalisers can sound bad when boosted, which is why it's common practice in studios to only use cut where possible, or to use a very low Q if you really must boost.

Note that you can control the frequency range Dirac operates over. If you aren't happy with its apparent effect on highs reduce the high frequency it operates up to. Many people have done this and since the worst room effects are generally at lower frequencies you can still achieve a decent response.

Your pre-Dirac response was actually pretty good and it wasn't obvious that Dirac had really achieved much. In my case it achieved a huge amount so possibly those huge improvements have distracted me from any negatives.

In your case the main Dirac change to my eyes is a reduction of several dB just above 10kHz which could be what your wife is hearing. You can also tweak the Dirac target to suit your preferences, so you could add the original boost above 10kHz back in to the Dirac target.

By a combination of limiting Dirac's operating frequency range and adjusting its target most people seem to find what they want.