RTA Assistance

[Souths1der]

I figured since there was a new thread talking about RTA and some people seem to be in need of an education (like myself), maybe a thread doing some active analysis may help. I primarily listen to rock/alternative and most derivations.

My system:
Pioneer AVH-4000NEX
PPI DSP-88R
2 x JBL MS-A1004
PPI 3-ways
PPI 8" Sub

Everything is up and running just fine. I believe I have the TA, gains, levels, all set. Actually it sounds pretty good. Right now I'm doing no EQ on the DSP. The following graphs are with the Pioneer EQ set to flat and the DSP set to flat. Until I can make positive changes to the DSP EQ, I have been using the Pioneer preset EQ setting of "Powerful" and it honestly sounds pretty good. Maybe some highs need to come down on it it and the sibilance can be pretty bad at times, but it's OK.

Reminder, these graphs are when everything is FLAT. The low end seems high, but honestly, in reality it doesn't sound so. I'll keep track of where my settings are and tune to how you guys direct me and we'll see if I can get a better sound. I've tried some things myself and made the sound worse and have always gone back to flat on the DSP and using the powerful on the Pioneer. Let's have some fun!

Full


Left


Right

 

[BradKnob]

See if you can get left and right responses overlapping on the same screen, so we can see the difference a little easier.

Looks like the difference in the two at 150hz, 300hz, and a few others, vary pretty drastically. Try to cut the side that is higher to match the side that's lower.

Is that REW? Have you tried the auto eq feature?

 

[Etroze86]

What brad said it will help a ton.

 

[Souths1der]

Yes, I'm using REW. I don't know about the Auto-EQ, haven't had time to look yet either. Spent some time figuring out what I was doing wrong with the screen captures, I think I have it figured out. In the process I noticed that I had the head unit EQ on when I thought it was off. So I re-did the measurements, made some changes to start getting the sides close to the same. This is after about a half hour, had to call it quits and do some stuff with the family.



I tried bringing up the right side where it's dipping, but nothing changed. Based on what I read, if you see no difference by bringing up a side, you should bring down the other side because there is most likely some cancellation. I'll have to try that next I think. I'm not happy with the bass either, so I should bring those levels up. Since it's just general "bass" that I would like to bring up, what's the best way to I attack that?

 

[Etroze86]

if you can bring your levels up from 40hz to 80hz on your sub channels as you have a huge dip where there should be the meat of your deeper bass. Or you can bring down your eq across to try and meet the dip in bass so you can get a little more clean power out of your setup.

 

[troutspinner]

Here is a link to a video that should explain how to use Auto-EQ. The video is long, the guy is a character but it should give you a good understanding.

https://www.youtube.com/watch?v=Fa9qlB6LK4c

Etroze86, aren't you running the same DSP as he? I am thinking a boost at 63 with a little width in Q could flatten that?

 

[Etroze86]

Yep I am, I am a hands on kinda guy so little tough for me just looking at graphs.

 

[BradKnob]

Theoretically to boost something 3db, you need to double the power. So it's best to cut rather than boost. What I do sometimes is raise the level of one side so when REW asks me to cut one band by -15, it's not too drastic of a change. I suggest getting familiar with auto eq bc it will tell you exactly which bands to cut and how much....





That way it takes a lot of the guess work out of it. It took me a while to figure out auto eq. Of need be I can do a picture tutorial (to the best of my knowledge) of how to get started

 

[troutspinner]

Good point Brad. Forgot about that. I se 3 as max on Auto EQ so that was easy to forget.

 

[BradKnob]

Yep, mines set as 3 max also. That's also why I gave myself HEADROOM FTW!! Nice to have the power on tap if need be.

 

[Souths1der]

I think I'm getting a handle on the Auto-EQ. There's just a couple things I can't figure out.

1. How do I load a custom curve? All I can tell is that you select a point and a slope on the high and low. Maybe that's all there is, but I thought you guys were matching to custom slopes of personal taste.

2. When I do measurement, I raise the volume until the RTA says it's around 80db, however when it's viewed on the graph, its much lower, the curve starts up to like 40ish and then comes back down to negative numbers. Am I missing some sort of setting?

 

[BradKnob]

I think I'm getting a handle on the Auto-EQ. There's just a couple things I can't figure out.

1. How do I load a custom curve? All I can tell is that you select a point and a slope on the high and low. Maybe that's all there is, but I thought you guys were matching to custom slopes of personal taste.

2. When I do measurement, I raise the volume until the RTA says it's around 80db, however when it's viewed on the graph, its much lower, the curve starts up to like 40ish and then comes back down to negative numbers. Am I missing some sort of setting?

Got to this link and theres a list of house curves...

Car Audio | DiyMobileAudio.com | Car Stereo Forum - View Single Post - Quick tip using 'Auto EQ' with RoomEQ(REW)

Save them to your computer and then in REW go to "preferences" and theres a "house curve" tab. Load one of the curves and when you auto EQ, it will be loaded in there.

As for the DB reading, i may not be much of a help. it was my understanding that you needed to calibrate the computer and/or mic to get accurate db readings. Therefore i never payed much attention to the number, but i do kind of use the range of db readings as a reference. hope that makes sense

 

[troutspinner]

If you are using a calibrated mic, loading your configuration file for that mic takes care of all calibrations you will need so any measurement you make should be pretty accurate for DB.

If not using a calibrated mic, which sounds like the issue??? You will have to look at some tutorials for setting up and calibrating a mic.

I personally do not use house curves, I get to as flat as possible and then EQ each side by ear. I could take that end EQ data and and turn it into a house curve I suppose but what fun would that be.

 

[BradKnob]

If you are using a calibrated mic, loading your configuration file for that mic takes care of all calibrations you will need so any measurement you make should be pretty accurate for DB.

If not using a calibrated mic, which sounds like the issue??? You will have to look at some tutorials for setting up and calibrating a mic.

I personally do not use house curves, I get to as flat as possible and then EQ each side by ear. I could take that end EQ data and and turn it into a house curve I suppose but what fun would that be.

That's good to know about the calibration file.

I agree, i matched my response to one of those curves very closely and it sounded like $hit to me. Way too bright and not enough lows. So get left and right sides matching, then eq as a whole to your desired response.

 

[Souths1der]

If you are using a calibrated mic, loading your configuration file for that mic takes care of all calibrations you will need so any measurement you make should be pretty accurate for DB.

If not using a calibrated mic, which sounds like the issue??? You will have to look at some tutorials for setting up and calibrating a mic.

I personally do not use house curves, I get to as flat as possible and then EQ each side by ear. I could take that end EQ data and and turn it into a house curve I suppose but what fun would that be.

I use the UMM6 mic, and I do have their calibration file loaded. I'm going to play around with it some more this weekend hopefully.