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:
http://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
-A vision without a plan is just a hallucination-
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