TOPIC:

asx77 wrote:

(...)
Edit: I’ve done that search for you!!
www.minidsp.com/applications/digital-cro...gration-with-minidsp

Edit2: also found this to help you with your time delays. www.minidsp.com/applications/acoustic-me...ts/292-rew-timing-ht

Thank you!

Ultrasonic wrote:

Superchunk wrote:

Literally everything in their description would lead one to believe it has Dirac support for subwoofers. It has the channels.

...

I'm still trying to figure out if you can upgrade Dirac for use on the ddrc, since I already have a license for Dirac multichannel.

You should contact miniDSP support regarding your complaints about the advertising.

I will though just respond to the points above as you're misunderstanding an important aspect I'm afraid. There are not enough channels and so it will not be possible to somehow upgrade. The DDRC-24 has two input channels, one of which will be for the left audio channel and the other for the right. You would need a third independent input channel for a subwoofer signal for it to work as it would in a multichannel system.

Superchunk wrote:

I guess I'll see how it works without shaping the subwoofer as a separate entity.

You can 'shape' the subwoofer response on it's own using the PEQ functionality of the plugin if you wish. You could used REW to make the required measurements and to design the filters.

I will be coming in from a preamp, I don't need a lfe channel or anything, just stereo in from my preamp.

www.minidsp.com/applications/digital-roo...0with%20Dirac%20Live.

I did read this over before purchasing. I was particularly happy to see that the explicitly say you don't have to learn rew (which I didn't want to do) and you can just run Dirac.

This was the documentation I searched for and read primarily. I looked over the info on the ddrc product page and skimmed over the manual. You're right that if I had fully read the Dirac live setup manual I would have finally seen that it's specifically a stereo device. Since I have Dirac and know how to use it I didn't read that before buying.

Certainly if I had searched for information I didn't think I needed instead of reading the specific information I was looking for I would have been better informed.

I read the minidsp documentation on integrating a subwoofer linked above over and I still see a lot of stuff suggesting that ddrc24 will be a great *Dirac* unit for subwoofer integration.

"is as a flexible tool for integrating subwoofers into your system along with Dirac Live"

And

"If you don't wish to learn how to use REW, you can simply use the Dirac Live Calibration Tool to perform this measurement"

Whatever.

What I'm going to "try" is to see if a) I can learn rew, which I had no interest in doing, I was looking for a Dirac device specifically and b) if I can make it integrate a subwoofer as well as it does when it is specifically setting frequency response, delays etc...for a subwoofer, something the ddrc24 does not do with Dirac. I'm going to "try it" and see. All logic tells me it won't do as good a job when it doesn't know that speakers exist as it would if it did. I can only imagine the Dirac devs would say the same, that youre better off telling Dirac what speakers are connected.

My suggestion to the dev team would be to change the documentation above to say something like "while the ddrc24 will not allow for Dirac to directly change frequency responses, timing and delays for your subwoofer you can achieve excellent integration using our suite of tools" ...or something. That would inform customers as to what they are getting.

Anyway, I'm over it.

Hi @Superchunk, I’ve just watched a short vid by NAD showing how to use Dirac with their units. You have a separate output for the sub, Dirac runs, checks left, right and sub independently then you move onto target curves. It occurs that at some point the user must have to decide the sub xo point. You do it on the NAD on the speaker set up page (yes?) or if not then you kind of have to do it when you set your target curve in the Dirac software. You have to set a curve that rolls off at say 80hz. If you don’t set a crossover somewhere then the NAD really isn’t doing a great job of Sub integration as your sub and main speaker target curves could overlap. The point is I’m sure at some stage YOU must be defining the sub to main xo point. You need to do the same with the ddrc24 except you need to do it before you start Dirac. So in that regard the automation level is similar. Where perhaps things are more complex (if you want them to be) is in set up of the speaker delays. The non-complex route is to simply measure distances and convert to ms delays and input these against he relevant ddrc24 output channels. What does your NAD do? Ask you for speaker distances on the set-up page? or measure with a mic?. If you want to measure the actual delays then you need REW. See my earlier post’s link.

But thinking about it, there might be another way without REW. I’ve not tried this approach so don’t know if it will work and another user might see its faults but... run Dirac with channel 1 as your left speaker and channel 2 as your sub. Forget the right for now. Take the first Dirac measurement and forget the others just go straight to target curve and have a look at the impulse response. The difference between Left and sub would be the delay required. You can then repeat for sub and Right. You’ll need to do some simple maths then as you’ll need to have the sub with 0 delay I think and actually add the delays to left and rights since you want everything arriving in time with the sub.

By the way I like NAD amps. I’ve had a number of them over the years.

asx77 wrote:

But thinking about it, there might be another way without REW. I’ve not tried this approach so don’t know if it will work and another user might see its faults but... run Dirac with channel 1 as your left speaker and channel 2 as your sub. Forget the right for now. Take the first Dirac measurement and forget the others just go straight to target curve and have a look at the impulse response. The difference between Left and sub would be the delay required. You can then repeat for sub and Right. You’ll need to do some simple maths then as you’ll need to have the sub with 0 delay I think and actually add the delays to left and rights since you want everything arriving in time with the sub.

I don't think this would work well I'm afraid, and might not actually work at all depending if stereo Dirac can cope with a measurement that isn't full-range. The issue is that an in-room impulse response from a sub it a mess really, and so not a good way to try to somehow judge an arrival time compared to a main speaker. This is one reason it's far better to use a phase matching approach (in REW).

Ultrasonic wrote:

I don't think this would work well I'm afraid

...well I did say someone that knows better might put me straight!

asx77 wrote:

Ultrasonic wrote:

I don't think this would work well I'm afraid

...well I did say someone that knows better might put me straight!

And I'm just sharing what I learnt from others on the REW forum when I asked for help trying to time align using a subwoofer impulse response .

Ultrasonic wrote:

And I'm just sharing what I learnt from others on the REW forum when I asked for help trying to time align using a subwoofer impulse response .

What technique does REW use when measuring the sub against the selected acoustic timing reference?

asx77 wrote:

Ultrasonic wrote:

And I'm just sharing what I learnt from others on the REW forum when I asked for help trying to time align using a subwoofer impulse response .

What technique does REW use when measuring the sub against the selected acoustic timing reference?

OK I might give you something about that (I am just an amateur be carefull!) But before to that I might add that what we are searching for is maybe a kind of DDRC-88BM but with only 3 inputs instead of 2 : one for right, one for left and one for sub.
Now about REW I can confirm that phase aligning my one sub with my fronts speakers improves the response at the xover region better than only time delaying the sub and the mains. You measure with a timing reference (absolutly needed) the fronts without the sub but with the xo settings full sweep and then measure the sub only disconnecting the left speaker for instance. After that you use the alignment tool to find the best delay to phase matche the sub and the mains.
Hope that I am on topic!

Hi it’s not the method to follow I was wondering about but the actual acoustic method that REW uses. @Ultrasonic said that can’t simply use 1ch on L and the other on Sub and then look at the impulse response generated by Dirac to see the differences. But reading the ‘digging deeper’ section at the bottom of www.minidsp.com/applications/acoustic-me...ts/292-rew-timing-ht it suggests that REW is using impulse response. I was wondering what @Ultrasonic had read on the REW forum as to ‘how’ REW calculates the delay that it reports after you follow the procedure described in the link.

I have never tried using REW functionality to calculate time delays so I can't comment on this. I've used the phase plots in REW to work this out for myself.

I'm trying to follow along with these suggested workarounds. It's difficult for me, my brain doesn't work in this way at all, engineering type stuff...I'm not able to create images out of words so I struggle to understand engineering type talk. I'm a history/philosophy guy

I wish I could try this stuff but the mail has basically failed in Canada and my 2 day shipping is on day 18.

This is why I was looking for automated

Now, based on what you folks are saying, I could perhaps run Dirac with my nad and extract the information and inter I to rew and get the same results? But not really, because then when I run Dirac with it seeing the sub as a speaker woofer it'll overwrite those results, correct?

I've seen mention of subwoofer input a couple times, I don't understand what that is in a stereo application...

For my purposes, the main hope I'm holding out for is that the limitation is entirely software, and I can simply run Dirac multichannel, which I got with my nad, on the minidsp. Seems like processing power would be the only issue and I can't fully tell if the 88 and 24 have the same processor. Seems to be called the same but there could be variations.

Or is that silly and obviously won't work? I guess I don't know if the software resides on the minidsp or the minidsp just has some memory to save a curve and a processor to act upon it, and so it's the license on the computer end that determines if you are working in stereo or multichannel (it has 4 output channels so...), Or the software that lives on the minidsp.

Anyone have any idea on that as a possible workaround?

The workarounds posted above are a little confusing to me. If I take timing information given to me by Dirac alfir my sub (taken by running with my nad) and enter it into rew, it won't interact well with running Dirac as 2 speakers, will it? Would rew and Dirac not be... fighting each other?

Superchunk wrote:

For my purposes, the main hope I'm holding out for is that the limitation is entirely software, and I can simply run Dirac multichannel, which I got with my nad, on the minidsp.

As I've tried to explain above you definitely cannot do this. For your stereo system I also don't think you would even want to.

Superchunk wrote:

Would rew and Dirac not be... fighting each other?

No. You use REW as a measurement tool to help you decide on crossovers and time delays. You then enter these in the miniDSP plugin and then run Dirac live. These are complimentary processes.

@superchunk what model is your NAD?
What make/model are you main speakers and what make/model is your sub?

Sorry, didn't see this before.

I don't think the nad matters much, I'm not actually using it for my 2 channel (but it's a t758 if you were asking for another purpose).

I'm going from a tube preamp - minidsp - tube amp - Harbeth shl5 and Martin Logan depth.

I just finally got my minidsp in 25 days after it was supposed to arrive and am about to start messing with it...

I do have all the delays that dirac calculated with my NAD which I can see up on the screen of my NAD, maybe I can enter that into the minidsp and save myself some rew measuring.

Hell i don't know what's going on ....