How to Properly Set Up EQ with RTA?

Using an RTA, what is the recommended way to adjust a Bit One in an active 3-way setup?

For example....

Have all channels off, except for the one you are adjusting?

Question on that...  When you turn the other channels back on, wouldnt that then "theroetically" change the frequency response of the speaker you just adjusted?

I had read somewhere a while back (though cant remember where) that to properly adjust an EQ, say you have to take 2db off a freq, that you are supposed to lower one speaker by 1, and raise another by 1.  But that doesnt seem to make sense....

Anyone have any input?

Nobody has any input?

OK...  How bout this one...

The bit one enables you to use a LR or Butterworth filter up to a 48db drop.

Im using the Focal KRX3 3 way system. Mercedes Benz 2001 AMG E55. Tweeter is mounted in an oval pod attached to the a-pillars. 3.5" in factory location about 4-5 inches and 90 degrees off axis from tweeters.  (I.E. 3.5" are facing for the most part... up.  while the tweeters are facing the driver.)

6.5" in factory location in door. approx 24" away from tweeter/midrange.

Which crossover should I use for each speaker (as they are all independent)

Anyone familiar with the KRX3 kit? Any advice on where the xover points should be? I had calculated around 3-3.5k for the tweeters, and 170 for the midrange.

eternalgraphics wrote:

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Nobody has any input?

OK...  How bout this one...

The bit one enables you to use a LR or Butterworth filter up to a 48db drop.

Im using the Focal KRX3 3 way system. Mercedes Benz 2001 AMG E55. Tweeter is mounted in an oval pod attached to the a-pillars. 3.5" in factory location about 4-5 inches and 90 degrees off axis from tweeters.  (I.E. 3.5" are facing for the most part... up.  while the tweeters are facing the driver.)

6.5" in factory location in door. approx 24" away from tweeter/midrange.

Which crossover should I use for each speaker (as they are all independent)

Anyone familiar with the KRX3 kit? Any advice on where the xover points should be? I had calculated around 3-3.5k for the tweeters, and 170 for the midrange.

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Heres some good advice about using an rta LET A PRO DO IT.Im not trying to bag on your skills or anything but trust me from experience.I have been in car audio for about 10 years diy stuff mostly done all kinds of systems and such.I have tried using an rta several times only to get frustrated after hours of adjustments and configuring.On my current install i literally spent 8 hours trying to tune with an rta to no avale.I took it to a good reputable shop with an experienced tech and 2 hours later I had the best sounding system ive ever owned!!!! well worth the 130.00 spent vs the coountless hours of frustration.As far as your crossover points go I think your good on the tweeter range of 3000 to 3.5 hz but your mid point is a little low for my liking I prefer around 250-300 hz for a 2way or 3 way set up.I do have some experience with setting up eq's and crossovers with an rta and would be willing to help all i can but trust me spend the money and have a pro do it once and do it right you'll be much happier that way.

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-A vision without a plan is just a hallucination-

Spmpdr. Thanks for the feedback. Only two things I have to say back is that I live in Hawaii. We do not have anyone who really specializes in tuning. I've asked all the shops here. Only one has an RTA and they haven't used it for many years...

Second. While I trust that a professional would do a quicker job adjusting it, I doubt they hve the same ears and musical likes that I do. The main reason why I DIY and have been DIY for 15 years, is I am never happy with someone elses work. I end up having to redo something because I am just not happy with the quality or layout or whatever.

I'm definitely not saying I am perfect. I make a lot of mistakes. But I learn from them so that next time around I do it better

Ahhh... The poor Focal buyer... I am sorry, but what I hear when someone tells me they bought Focal, is that they have no concept of flat frequency response. Fatiguing, overly-sibilant highs, and thin - at best - mid-bass, and NOT good remotely, AFAIAC. I am sorry if this offends you; I don't mean to, this is just what the brand name "Focal" says to me... You might have just as well purchased Bose.

Now... WHAT is your design goal? How do you want it to sound? An RTA will not help with that, because your ear will hear DIFFERNTLY what that RTA is telling you you should be hearing. If you can't have somebody tune for a flat response, you sit in it after said tuning, and be VERY happy with that tuning, then an RTA will do you zero good... Seriously. If you have an EQ, set it the way YOU want to hear it, and call it a day. The frequencies you have ckosen will probably work, but I would find out what the OEM passives are set to, and use those frequencies, don't go "hunting" for a new crossover point.

That's all I have to offer, but I really do think you are chasing something that you are not even sure you want!

By the way... I've never done anything even REMOTELY close to what you are attempting... Those are also terrible locations for "audiophile" response. The mid-bass is FAR too far away from the mid, and the off-axis mid-tweeter mounting...? <shudder>

Pods, dude. ALL ONE PLANE. Do what you have to do to get them all on the doors.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

RTA= Real Trouble Ahead

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No offence taken at all. Everyone has thier opinion about speakers and those that produce them. Reason I chose Focal is because I listened to them, Morel, DLS, Hertz, and a few others and to me , they sounded better. The Krx3 with the bigger 6,5 gives out very nice low mid bass I thought. But anyow.

Please by all means tell me if I am wrong about this...
Yes everyones ears are different. I thought the use of an RTA was to help figure out where your peaks and valleys are so that when used properly can help you figure out quickly which frequencies can be cut slightly to battle cabin abnormalities.
For example massive peak at 315. Well unless you KNOW what 315 sounds like.. An rta will immediately tell you. Sure you can play with every eq setting till you find it. But that could take forever...

Also. Again.. Maybe I am wrong. But this has always been my belief.... And therefor.. Goals I suppose.. And please tell me and explain if /why I am wrong...
If you play a tone. Say 1k. Isn't the point of eq'ing left and right to get them to sound exactly the same? Shouldnyt 800hz also play at the same "loudness" if recorded at the same level? And the point of TA to get the tone to reach you at the same time? If you tune each freq to ruler flat does that not mean the speaker system will sound in theory as good as possible? Is music flat. Of course not. However they spend a long time in the studios mixing to get it the way they want it to sound.   But if your system is tuned flat, shouldn't then again in theory you woul be hearing it as they intended? Now granted some people like more bass. Some more highs. But once you tune to a flat system, could you not just use say the bass control on the HU to increase it?

INMO..... I have had my truck tuned with an rta and it sounded great!!I then tweeked my eq to my preferences,till it sounded good to ME, I beleive that you theoretics are correct about rta,eqing,t/a etc but to me I had my system tuned with an rta to give me a great starting point in wich to work with.

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-A vision without a plan is just a hallucination-

You should tune with all channels on because as a system plays you have both constructive and destructive interference. If you turn off speaker your readings will be off and will never sound as you would expect.

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This information is provided only as a reference.
All circuits should be verified with a digital multi-meter prior to making any connections.

This not my tutorial (though i wish i was this educated)it is written by c-music from diyma.com.I found it very useful i hope you do to
There are several different methods used to tune eqs. This is the one I use. An RTA is not needed if the steps are done correctly. This method uses crossovers and gain settings as the most important factor in tuning. I think the eq should be last in line when tuning. Remember after each step to write down your settings. If the sound gets worse, then you can go back to the previous step’s settings and start over.


1. Set all bands flat, as well as the head unit bass and treble.

2. Turn off the subs. Using music with a good bass line, run the highpass crossover up and down until the midbasses can play as low as possible without any distortion or excessive door panel vibrations.

3. Unhook the mids and tweeters, allowing only the midbasses to play. Listen to mono pink noise or a well-recorded song with a centered vocalist. Test CDs such as the IASCA test CD or Autosound 2000 Test CD 102 or 103 will work great. Listen to where the centered sounds are coming from. Then reverse the polarity of one midbass (Reverse the speaker wires coming from the passive crossover and going to the speaker, just flip the positive and negative wires. I usually flip the driver’s side speaker.) and re-listen to the test CD. If the sounds are more centered then keep it as is. If the centered sounds are more diffuse and un-locatable, then flip the polarity back to where it was originally.

4. Then unhook the midbasses and play the mids only and follow the same polarity and listening tests as before. Mark your best settings.

5. Do the same procedure for the tweeters.

6. When you have tested for the proper polarity from all three ranges of speakers, hook all of them back up with respect to each set of speaker’s best polarity. You can have any combination of polarity, such as all the midbass and tweeters straight and one midrange reversed.

7. Now you should have the correct “acoustic” polarity set within each set of speakers. Next is to set the acoustic polarity between the sets of speakers.

8. Listen to some very familiar music with a good range of sounds. Then flip both midbass’ polarity and listen again. Before you only flipped one midbass, now you are doing both at the same time. For example if the left midbass was reversed and the right was not before, now the left will be not reversed and the right will be. Listen to the music again. If the midbass is more powerful and full then leave the wiring as is. If the midbass sounds weaker and wrong then restore the wiring as before.

9. Perform the same listening tests while flipping the mids and tweeters, and use the wiring configuration that sounds the best.

10. If you have went though all these steps adjusting the polarity of the speakers then the system should sound really good without any eq adjustments. You might want to play with the gain adjustments on the crossover and/or amp to better blend all the speakers together.

11. Now onto the eq! The first eq step is to adjust the tonality. While listening to familiar music, adjust each individual band up and down slowly. When the music sounds better then move to the next band. Adjust the left and right bands equally. (We’ll get to the separate left and right adjustments soon.) It really does not matter if the bands are boosted or cut, just that it makes the sound better. Not every band needs to be adjusted. In fact if you did steps 1 thru 10 correctly you should not have to adjust over half the bands. Having a 1/3 octave eq does not mean you have to adjust every band. It means you have the ability to adjust each band if needed. Watch out for big jumps from band to band, like one band set to +4 and the next band set to –6.

12. Continue through all the bands, take a break, and do the same procedure over again. But this time the adjustments will be smaller as you get the tonality dialed in. This step might take several days, weeks, or longer.

13. In tuning you will find some eq bands will raise, lower, move the sound closer, or farther away if adjusted in certain manners. For example, lowering 5 KHz will generally move the soundstage farther away and raising 2 KHz will make the soundstage rise. Each vehicle and system will have different settings that will be the best. The best way to achieve awesome sound is to constantly adjust.

14. When you are satisfied with the tonality of the system, it is time to start adjusting the left and right channels separately. These adjustments should not affect the tonality, but improve on the imaging and soundstaging. Using the Autosound 2000 Test CD 102 or 103 “My Disk” listen to the individual frequency pink noise tracks. (Test CD103 has the tracks arranged in an easier configuration.) Each frequency band should sound like it is coming from the center of the soundstage. If one band is off to one side, then use each band’s left and right eq controls as a balance control. This is very similar to the head unit’s balance control, only now you are balancing each frequency band by itself. For example if 200 Hz seems to be shifted to the left of center, lower the left 200 Hz band and raise the right 200 Hz band one dB at a time until the band is centered. If a frequency is shifted to the right, lower the band’s right channel and raise the left channel in small amounts.

15. When you have when through all the bands take a break. Then later go back through each band one by one and make any further needed adjustments until all the frequencies are lined up in the center of the soundstage.


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-A vision without a plan is just a hallucination-

Heres another i found over diyma.com by a guy named bikinpunk.We used this to try and set up my system with an rta ,out of all the methods i tried this gave me the best results:

This is what I’ve learned works best for me when using the RTA to tune. This may or may not work for you. This is simply a suggestion on how to tackle something that otherwise is a bit daunting.

You really need to be active, or have a way of controlling each ‘channel’’s gain/level separately for this to work well.


*I’m going to assume you know how to set t/a and x-overs. This is for EQ/levels work with the RTA ONLY.*


1. First off: Write all settings down, then reset your DSP/headunit. This is pretty self explanatory. You want to zero out all settings and start from scratch. But, you also need to note some of the basics that worked before, such as time alignment, phase and crossovers.

Enter your desired crossover points; I’m assuming you know what points work best for you.

2. Set your amp gains to the max desired output.. Whether you want to use an oscope, or DMM with 0db, -3db, -5db, etc tones, that’s of no concern to me. This is your amp and your system. You decide what you want to do. If you want to sit in the car while someone adjusts them for you, that’s fine. But make sure you mark somehow what your ‘don’t go past this point’ limit is. You need to state to yourself the maximum gain you want to use.

3. Now, pull out the RTA.
*******If you have a program that allows for a-weighting I HIGHLY suggest using this instead of C-weighting or no weighting. It’s my personal preference. If you want to know what the difference is, here:
https://www.diymobileaudio.com/forum/...ht=a-weighting

In a nutshell, a-weighting is a weighted curve for how you actually hear things. It takes less power/loudness for you to hear higher frequencies than it does lower frequencies. The a-weighted curve adjusts for this automatically. C-weighted ‘sort of’ does, but not like a-weighting. **********

4. With the RTA setup play each side (left/right) SEPARATELY. DO NOT play the entire system together. Your goal here is to level match left and right. To me, this is the single most valuable tool the RTA has the ability to do. Use pink noise or sweeps; whichever you prefer. I use pink noise mainly, but IME sweeps work well. It’s all dependent on the software you use. Kick the headunit volume up to the level at which you would rock out to (where your gains are set to for max output). I say to do this because I typically only listen to music when it’s wailing. Also, if you don’t, you have to realize that the loudness curve (which I linked discussion about above) will be changing for each incremental volume you make; so your settings for ‘loud as crap’ may not be the same as for ‘my neighbors live in my car’ (aka: low volume). So, set this up as you would typically listen.

5. Now, when level matching everything you should go down the line; and what I’ve found works best is to start with the best link.
You know that you have 2 drivers up front and you know the band they cover. Obviously you’re not going to start off with a flat line right off the bat, BUT you AT LEAST KNOW where your speakers play up/down to. Use this knowledge to level match the speakers on the same side.
I start with the ‘strongest’ link (the speaker that’s at the highest level). I do this for one reason: you’ve maxed your gains; you don’t want to max them anymore. So, if the tweeter is playing a bit higher than the midrange, knock the tweeter down.
If your tweeter rolls off pretty badly, what *I’ve found* works well is instead of knocking down the entire tweeter level, just knock down the portion that plays higher than the rest of the tweeter. For example, your tweeter plays from 3k-20k, but it rolls off hard at 16k. Knock down 3k-16k via EQ (but don’t worry about flattening it yet) so that you can level out the tweeter itself. You can also do this for the midrange/midbass, too, but typically, I don’t trust the RTA below 100hz for accuracy. I typically do this by feel/hear.

6. Once you’ve leveled out the tweeter roughly, try to level match the tweeter/mid together the best you can. Try to make that line as flat as possible using the gain and the EQ.
Once you’ve gotten as flat a line as you can (I don’t know what kind of processing you have), write down the level. The level may be 40dB on the RTA software, for example. THIS IS IMPORTANT so you can level match the other side to the same point. Otherwise, all the work you’re doing for level matching is pointless.
To flatten out the results, I suggest picking a point that seems to be a good middle ground for your current graphical response. Then, start at 100hz and go up to 20khz, making adjustments as needed. I HIGHLY suggest NOT doing any boosts in the EQ. Only use cuts if at all possible. Keep in mind a boost could put you into a higher ‘gain’ than you wanted.

7. After you’ve level matched one side, and written down the level… do the other side. Same way. Start with the speaker playing at the highest level and match that to the one that’s playing at the lowest level. Flatten out the graph via your EQ the best you can.

Now, you’ve really gotten about 90% of the RTA work done. Congrats! You should have a very balanced system right now.

8. Now, you want to sum the response by playing both sides at the same time and check the EQ. You’re NO LONGER DOING LEVEL MATCHING here. You’ve already matched the two sides. You simply want to EQ for flat at this point with a summed system response. You really shouldn’t have to do much work here.

9. After you’ve level matched individual sides and flattened the total system response get back in and LISTEN. Use the RTA to your advantage. Play reference tracks and see what doesn’t sound right to you. The RTA can help pinpoint frequencies if you don’t know right away. Also, you’ll no doubt have to toy around a bit with time alignment. You shouldn’t have to touch phasing, though. Truthfully, t/a shouldn’t require much adjusting at all, but there will likely be some small adjustments needed.


That’s it. I know I’m forgetting things, but hopefully I can edit this later and add them. Sorry for the long post. I tried my best to keep it short and sweet.




NOTE: I realize there’s a LOT of subjectivity here. I really don’t want to hear all of it in this thread, as most of us are smart enough to realize the pitfalls of tuning to flat or anything I’ve said. Nothing is perfect. I’m only posting to provide what I’ve found works well for me. I don’t expect everyone to agree, really. But, I ask that you try it before you discount it completely. If you have suggestions, I’m all for learning.

Thanks,
Erin

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-A vision without a plan is just a hallucination-

Thanks sp. That's basically exactly what I was looking for!

eternalgraphics wrote:

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Thanks sp. That's basically exactly what I was looking for!

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Your welcome friend,let me know how it works for you.

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-A vision without a plan is just a hallucination-