TOPIC:

denver8me4dinner wrote:

The 8ch looks great. I wish it had more taps across channels. But honestly, a non fir car can sound superb with all iir dsp. So , honestly anything is better than none. But for good control over the system more is nice .

How many taps does the 8 ch have?


My current setup includes a Helix DSP Pro, which is feeding my amp full active.

I also have an APL1 installed, but don't currently have it turned on. It's difficult to program. I'm hoping the Dirac Live setup is easier.

If I was on a budget and had a dsp but no fir and had to just get one box I would do the ddrc22xx Dirac machine. More fir power per convolution.

So the specs are better on the smaller units than the 8 ch?

If money wasn't a hindrance, is there any merit to the following signal flow for a traditional 4 way car stereo

spdif--> Dirac DDRC -22D -> nanodigi2x8 ->Dirac DDRC-88D -> 4 stereo DACs - > amps ?

That way each channel has dirac processing and then the upstream 22D can do the time alignment/ left right relationship.

subterFUSE wrote:

How many taps does the 8 ch have?

My current setup includes a Helix DSP Pro, which is feeding my amp full active.
I also have an APL1 installed, but don't currently have it turned on. It's difficult to program. I'm hoping the Dirac Live setup is easier.

Dirac is definitely easier than the apl, more intuitive and for similar results, in my case at least.
With the future apl3 it might be a different story.

For the taps I don't know, since it's the same sharc probably the same numbers than the 22 (12k?), but how are they distributed?
And the number is not so important, apl has less but can do as good.
Per the manual I'm guessing there's no advantage to go with any 88 vs 22 in car, unless you have some surround.
Dirac is still designed and optimized for stereo or multi channels, but not multi drivers.
But it's really hard to get detailed informations on this, I stopped searching.
Anyway a ddrc22d would be perfect in front of your helix, for ease of use and sq.

A 22D in front of some HDs IMHO is still the hot ticket for a car right now


Believe me , Dirac is good but live is not setup totally for car ,

Having fir crossovers and the PEQ with APF on the sliders is the shizznit .......



I’ve used REW and captured line in instead of mic and measurements and capture the output of the 22di post Dirac, had Dirac run measurements on pairs of speakers in a 4way , than pulled the curtains to one oactave last crossover and captured the impulse with REW , than exported into rePhase , than invert everything and draw out the correction in PEQ and Phase Eq , than convoluted output fir and iirs to 2x4hd fir bank and biquad slots, that way I can get a Dirac sweep like a ddrc24 would do just using the 22di , all except I am able to add linear phase crossovers and have iir All pass functions in the 2x4hd for dealing with combfilter caused by left and right interaction.

The all pass sliders on the 2x4hd is by far the best thing for car because you can steer combing to not only reinforce but also to shape the psychoacoustic sound stage and nail down the phantom center in a way that is simply not possible with just raw delay. Using Dirac is a baseline eq and room correction after everything is pre setup afterwards, Ive found this to give me about 6 of the 10 list dB back from Dirac because the normalized measurements are now within 3db of my target and the final Dirac run has so little left to correct it gets me linear to 10hz .


It’s more work than just running pure Dirac off of a 8bm or 8a or a pair of 24s , but it gives me the flexibility post Dirac to really shape the sound the way I want it to come at me and most importantly reinforce the combfilters without sounding hollow or dry because the lack of the ability to run an eq sweep afterwards.......
I also cleaned up the Ir quite a bit doing this, the filter ringing is much less , less Ir tail ripples.

With 52ms delay total no part of the Fft is longer than 14k

Coming up on a year with the live and hundreds (if not thousands) of measurements.


One thing I can definitely say about Dirac Live in car is it doesn’t average the FR correctly.

I’ve have found using 6 of the 8 measurement points around your head and the two top farthest measurements directly in front of you and passenger seat (for one seat tune) gets the closest.


One thing I would strongly recommend if a “car” version of Dirac was developed is definitely emphasis on a multiway, a moving mic average of FR with the mic moving around the front of your face and capture 100averages with some pink PN somehow incorporated with both Left and Right playing together than a separate Left Right seems the better approach to get FR and than some sort of fancy algorithms to each driver in a multiway. The 1st measurement also seems be just fine as it is,


Either that or at least 20-30 more measurement points.

subterFUSE wrote:

What about a DDRC-88A for in car use?

Anyone attempted this? For example, a fully active 3-way front stage component speaker set and subwoofer.

Would this be possible for linear phase crossovers plus Dirac room correction?

What about the Bass Management plug in? Would this be useful, too?

Well I am heavily leaning that way. Both the 88A and the BM addition.
It will be another couple of months though with the holidays and general extra family and work business happening.

Basically going from active cross overs to a whole-hog approach.

denver8me4dinner wrote:

Coming up on a year with the live and hundreds (if not thousands) of measurements.
One thing I can definitely say about Dirac Live in car is it doesn’t average the FR correctly.
I’ve have found using 6 of the 8 measurement points around your head and the two top farthest measurements directly in front of you and passenger seat (for one seat tune) gets the closest.

What do you mean « doesn't average correclty »?
Other than the probable different settings I too noticed a difference between REW avg and Dirac avg, I just think Dirac puts a lot more weight into the 1st measurement, there’s a high bias (and it’s good).

For the measurement method, after thousands like you I got best results with a different layout, sort of a mix of chair and sofa.
It might be specific to my under dash horns with high crosstalk, so:
- 1st at my nose, head leaning back, usual
- 2 points per seat, chest and let’s say 1ft in front of the belly
- 2 points over the center console, same height than for the previous seats
- and 2 points more extreme, like left of my left ear near the glass, not too close, and right of my hip (or the inverse).
Basically I tried to give it a sense of the symmetric response (because it is), while adding bad positions so it doesn't over correct.
Might be all in my head, but it works very well.
One seat only was a little too clinical, and sofa too broad, stage a little too much on the right.
Also it is easily repeatable.

denver8me4dinner wrote:

One thing I would strongly recommend if a “car” version of Dirac was developed is definitely emphasis on a multiway, a moving mic average of FR with the mic moving around the front of your face and capture 100averages with some pink PN somehow incorporated with both Left and Right playing together than a separate Left Right seems the better approach to get FR and than some sort of fancy algorithms to each driver in a multiway. The 1st measurement also seems be just fine as it is,
Either that or at least 20-30 more measurement points.

Man you need tor try the APL, it’s basically that except it’s with the impulse.

New Dirac live for next year:

www.audioxpress.com/news/dirac-research-...platform-at-ces-2018

Apparently it will work on tablet, at least the control.
They also talks about the dumbed down UI for average Joe, I hope not too much

I have the APL1 in my car now, but still have not really learned how to use it after nearly 2 years.

And I'm not a tuning novice, either. I have tuned cars that won world championships. But the APL1 is still baffling to me.

I don't use REW anymore because I run Smaart and SysTune Pro with a 5 mic array, which let's me to real time spacial averaging without having to move the mics. I can measure and tune the DSP at the same time, which makes life so much easier.


I'm going to give the little 2 channel Dirac box I've got a try soon. My only concern is that the internals of the MiniDSP stuff might not be the best quality in terms of SQ.

I also wish it had a digital output like the APL1 does, because in my upcoming build I'm planning to use the Sony GS9 analog out into an APL1 with short RCA cables behind the dash, and then run a long digital cable to the trunk where my Helix DSP pro 2 is located. And then run short RCAs to the amps. But if I use the miniDSP box, it only has analog out so I would have to buy long RCA cables which will be expensive since I am using all Straight Wire in my cars.

Oh yes I remember your cool mic array. Well with your level there’s maybe not much to gain with Dirac.
Could worth a try anyway to see how it works.

I don't remember if the APL has optical out, but if so you could put the HD in the trunk with a long optical cable and keep short RCA to the Helix. Or maybe use the nanosharc as it has digital out and can run the same plugin, but at this point a ddrc-22D would be even better.

beginner here with minidsp, never used dirac, currently own a 2x4hd and a c-dsp 6x8. Thought about putting dirac in my car, but not sure how much benefit there will be over rew, and if it's worth the cost. I guess dirac will do stuff that rew won't? Like impulse correction, etc? Is the difference audible?

If it's worth it, basically I'm looking to get the ideal equipment (any benefit of using anything other than ddrc24 upgrade?) denver8me4dinner mentioned using my c-dsp as post dirac processing, but I don't understand why. I thought dirac does everything I need.

Right now everything is still stock in my car, but I have the two minidsp boxes, and a new alpine wireless carplay head unit, idatalink maestro stuff, some focal speakers, and a sub driver. The car has a bose amp I plan to use for now, and I have a small amp for the sub, but I will probably put a new 5ch amp in later. I'm planning to install everything soon, and I could really use some friendly personalized help with all the minidsp/rew/dirac stuff.

Maybe I should make my own thread since I'll be on here quite a bit for help?

subterFUSE wrote:

I have the APL1 in my car now, but still have not really learned how to use it after nearly 2 years.

And I'm not a tuning novice, either. I have tuned cars that won world championships. But the APL1 is still baffling to me.

I don't use REW anymore because I run Smaart and SysTune Pro with a 5 mic array, which let's me to real time spacial averaging without having to move the mics. I can measure and tune the DSP at the same time, which makes life so much easier.


I'm going to give the little 2 channel Dirac box I've got a try soon. My only concern is that the internals of the MiniDSP stuff might not be the best quality in terms of SQ.

I would be interested in whether the DIRAC is noticeable.

Oddly I can picture that APL1 being better in a home theatre setting than DDRC-88A (which is made for home theatre - as the delay is ~1 mS .
And the DDRC potentially be better is a car where one is not looking at lips out of sync with voices.

subterFUSE wrote:

I also wish it had a digital output like the APL1 does, because in my upcoming build I'm planning to use the Sony GS9 analog out into an APL1 with short RCA cables behind the dash, and then run a long digital cable to the trunk where my Helix DSP pro 2 is located. And then run short RCAs to the amps. But if I use the miniDSP box, it only has analog out so I would have to buy long RCA cables which will be expensive since I am using all Straight Wire in my cars.

I cannot imagine a need for an APL1 going into a Helix ? What does one do that the other does not?

It would be easier to just have a longer RCA and skip one of the boxes?

Holmz wrote:

I cannot imagine a need for an APL1 going into a Helix ? What does one do that the other does not?

All of my systems are fully active.

APL1 is only 2 channel. The Helix DSP Pro is 10 channels out. The Helix is needed for crossovers and active outputs to the amps.

Holmz wrote:

It would be easier to just have a longer RCA and skip one of the boxes?

Easier, yes. But MUCH more expensive because of how much my RCA cables cost per foot.

You are paying WAY too much for rca cables. Go to bluejeanscable.com and read about the science behind rca cables and actual measurements of the electrical properties and exactly how it affects the audio. And then you will stop overpaying for cables. I have a 500 ft spool of coax cable here that has just about the best conductor and shielding properties available for analog audio.

Also, the money you are spending on cables, if spent on speakers or acoustical treatment will actually give you audible gains. Not to mention your signal is degrading by repeatedly being converted digital to analog to digital to analog.

grandpixel wrote:

You are paying WAY too much for rca cables. Go to bluejeanscable.com and read about the science behind rca cables and actual measurements of the electrical properties and exactly how it affects the audio. And then you will stop overpaying for cables. I have a 500 ft spool of coax cable here that has just about the best conductor and shielding properties available for analog audio.

I am familiar with Blue Jeans cable, and agree they make very good product for the price. My friends did an extensive listening test of various cables, and Blue Jeans did very well in the blind listening tests. But it was outperformed by several other cable brands, albeit much more expensive brands. Anyway, I have chosen a brand of cable which I like and I am keeping all of the cable in my cars within that brand for personal reasons.

Also, the money you are spending on cables, if spent on speakers or acoustical treatment will actually give you audible gains.

Are you familiar with the equipment or sound dampening in my cars? Seems a bit presumptuous to assume that more money spent on speakers is necessarily going to improve the sound. For one, not all expensive speakers sound great or work for a particular application. Or maybe I already have speakers that are more expensive than just about anything else on the market?



Anyway, my greater concern is actually the quality of the internal components of miniDSP equipment. The analog out from the Sony RSX-GS9 is outstanding. And the ADC and DAC on the Helix DSP Pro 2 are also very good. Tossing a miniDSP into the chain would likely be the weak link, not the ADC on the Helix. But, if the processing done by the miniDSP adds enough benefit to outweigh the cons then it might be cool to use.

I already have the APL1, but it's incredibly difficult to learn how to use. I've only gotten it tuned 1 time where it sounded great, and to do that I basically had to tune the Helix first normally..... then run the APL workshop and upload the filters, but the APL only improved the tonality. It totally killed the imaging. So I went back into the Helix and retuned the left/right EQ balance manually using SysTune Pro for my measurements and when I did that, the soundstage came together. I got the widest soundstage boundaries I've ever achieved in my car when I did that. Haven't been able to duplicate that again, however. It might have just been a fluke.