Helix RTA & Auto EQ - A Car Audio Junkies Exclusive

[Clintonl]

So got some new gear and trying to do auto eq again, using DSP tool 4.75. In the RTA section i start analyzer then started measurement then hit autoset. The timer is going down but nothing is adjusting. It then sometimes says check measurement and reference curve. I can see the volume is going up to the curve so i'm not sure what's going on.

[Chris E.]

I did this in June last year and it worked great, Ill find my notes and post them for you. The process is a little tricky, not intuitive. the only negative thing is that it only works on the regular eq not the parametric eq. I want to try the manual tuning using REW and the parametric eq, and go back and forth between the two programs. I was going to follow the Audiofrog method. it takes a long time compared to the autoeq. I still needed to fix the left and right channels they weren't close enough for me.

[Chris E.]

Overall Sequence to follow:
Prerequisites:
Set X-overs
Set Time alignments
Speakers should be in-Phase, (electrical polarity the same)
Levels should be matched to same, for all speakers as close as possible.
Be able to play pink noise on your system. (mono).

Order of tuning:
1. Left side first, link all speakers not including the subwoofer.
2. Right side next, all speakers not including the subwoofers.
3. Subwoofer alone
4. All channels, together.

Auto EQ procedure in Software. (Left Channels).
1. On main screen: reset the EQ. Reset all output EQ. (rst button on lower left).
2. Link the Left side first. For a three way system, I use:
A,C,E. (A= left high, C=left mid, E=left woofer). To link the channels click the little red box next to the appropriate channel letter.
3. Make sure the right side and subs are muted .(Main program screen). The speaker ICON should have a red line through it, for channels: B,D,F, and sub.
4. Click on RTA button, to open RTA screen
5. Click settings button.
6. Load a house curve. You can make a custom one and save it if you like. Click back button, to return to main RTA screen.
7. Set the band range. Use drop-down boxes to select the proper frequency range. For this example, I will choose, 100 – to 20K Hz. (it depends on your x-overs)
8. Use sliders on right side of screen to adjust the reference and measurement curves to same level. Gray is house curve, and white line is measurement curve.

9. Play pink noise (mono/correlated = same thing). About 80-90dB.
10. Click Start Analyzer button.
11. Click start measurement button.
12. Click autoset button, , then click YES to proceed, to start the measurement. Every 10 seconds it will show the average and adjust the EQ to match the house.
13. When curve looks matched press STOP measurement button.
14. Turn off your pink noise.
15. Repeat the procedure for the right side, sub, and whole system. Make sure to change the linking of channels, frequency range, and muting, for each measurement.

Some things to keep in mind:
Some people use a battery charger/maintainer while doing this so the battery doesn’t drain too much. I assume its better to do this while the engine is off.
Move the mic around your head while the autoeq is running to get a better average.
You can check the results using REW.
In the DCM menu of the PC Tool, make sure EQ Link Mode is set to Relative, for any adjustments needed for eq.
It is suggested to use mono pink noise (correlated), but for some reason ATF includes uncorrelated pink noise in the test files ???

[Clintonl]

Just wondering what the best way incorporating auto EQ with rear fill is? Would i do it as normal and add rear fill to left side/right side/sub/together. Or would i do left front stage,right front stage,rear fill,sub,together.

Cheers

[Chris E.]

Rear fill seems to be a controversial subject in car audio. It seems most installers suggest not to have rear fill at all. I try to keep up with state of the art in car audio and this is one area that seems to be a bit of a mystery to me. I would like to do it, if someone would prove to me that its worth the extra cost in speakers, amps, tuning, etc. So for now I just don't do it, I'm still trying to get my grip on tuning a system with just a front stage and sub in the trunk.
On the other hand.... I have looked at audio systems in super luxury cars, (which I assume have the latest and greatest), that have 14+ speakers and 9+ amps all over the place that supposedly sound phenomenal. I was referring to the Rolls Royce Phantom using the lexicon sound system. A $500K car. Now these cars are using the body of the car, and heavy (200+ lbs. of sound deadening material), internal mics to dynamically adjust the sound, and ideal placement of the speakers. Most of which can't be achieved for the masses yet. I can add sound deadening, and speakers , and amps, but the dynamically adjustable sound is not yet available to the common person. I believe that will be the next iteration in car audio but we will need more advanced dsp's and software to achieve these goals.
So unless you are willing to get into some serious tuning techniques, I would say forget about the rear fill for now. if you want to play around with it, it won't hurt. If you are going to use the rear fill speakers for rear passengers or as part of the front seat driver listening position then that would effect how you tune it. I would think you would have to start getting into multi-mic averaging to get the best sound for multi-seat positions, or using multi-tunes and switching them depending on who is listening in the car. this kind of thing can get complicated.

[Newday]

Hello
I can not play the video I really need help to adjust the phase and set up my dsp
😣
Could you please upload it again 🙏

[Newday]

Hello dear chris
Your note helped me alot but still I have issues about those phases
By any chance is there any instructional video showing steps for VCP ATM RTA and VCP setups?
Thanks a ton

[Chris E.]

Hi Newday,
It is hard to find good video's on performing tuning setups. YouTube is a lot of hit and miss, mostly miss. I think the reason is that many new features on the Helix DSP have not been know yet. I have seen some videos from MSC America, but they don't get heavy into tuning techniques. I have seen two options for dealing with phase correction. Smaart by Rational Acoustics and Systune. Smaart has some excellent videos on how to use the software like many hours of instruction, its really good but not directly showing how to tune a car. They offer a free 90 day evaluation of the software so you can get familiar in the car audio environment and trying some tuning techniques. I have not looked into Systune yet but I know its a good option as well. I would imagine that Helix will add some kind of phase correction in the future using a dual channel fft. they always seem a little lagging with information on how to use these new features, but over time people will start posting more information. AS of right now, I'm just trying to figure things out on my own by reading posts in the forum and looking at vendor sites like Audiofrog, Helix, miniDSP, REW, etc. If I ever get to the point of mastering these techniques, I will post a video someday to help support this hobby. its great to have these new tools that make our systems sound great, but it is emerging and changing quickly. The way I look at it, a system from today blows away anything from 30 yrs. ago even without proper tuning. So it is just fine tuning to me, getting that little extra. at some point you have to appreciate what you got now.

[Jdunk54nl]

There is also open sound meter which is similar to smaart, but free right now.

[Gio]

Hi! How can i see the video? It says private