# EQ tuning without a RTA?



## mattyjman (Aug 6, 2009)

so, i'm a bit lost... i got things up an running in my system... a hybrid L831v2, bitone, jl amps, and w12gti sub... 

things sound really good right now, but i have a feeling there are a few areas that could be fixed to sound even better by some eqing here or there...

the problem is, i have 31 bands... and i don't know what parts i need to adjust. i think a rta would be helpful to identify these problem areas, but i don't have one at the time.. 

so i am looking for a good way to tune this without just "guessing" on the frequencies and seeing if the improvement sounds good or not... problem i see with that, is it may sound better in one song, yet worse in another... this could go round and round without any concrete conclusions for a while.. 

so, this brings me to my question.... what methods are there that you have successfully used to tune your 31 band eq without an rta? i know that i am not looking for a "flat" tune, but i want to eliminate peaks in my frequency response that contribute to the harshness of the sound....

any help would be appreciated

-matt


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## Austin (Mar 12, 2009)

there's not much more than guessing... you can only tell so much just by listening. 

An rta is the only way to do it accurately from my point of view.


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## TREETOP (Feb 11, 2009)

If you have an iPhone, or access to one, there's a free app called "RTA Lite". It's not perfect but you can select 1/3 octave resolution and the bands shown will coincide with your EQ's 31 bands.

Another option is to get a CD with test tones recorded at the same level, at the frequencies you have on your EQ. You can use a cheapie Radio Shack SPL meter, and leaving the head unit's volume the same throughout testing, chart out the levels of each track. It's kind of a pain but will give you a decent idea of which frequencies are peaking or dipping the most.


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## sqnut (Dec 24, 2009)

Go to your local RS and pick up an spl meter. Should be about $50-70. Don't buy the cheaper one as it would be less accurate. Download the focal test tones from here and burn it on a cd. If you're running active measure the test tones for the 31 frequencies you control, one driver at a time. If you're passive do it once for left and then for right. 

Compare the L/R reading for each frequency to know how much you have to adjust from which side. Lets say 315hz is 98db from the left and 92db from the right. Now you know this frequency is 6db louder from the left and so on. 

After you have adjusted for L/R measure again to correct for sharp peaks or holes relative to the other frequencies. Now listen to some music that you are very familiar with and level match between the 31 frequencies to dial in the tonality. Some hints

1. attenuate before you boost
2. In the example above you can adjust the 6db's by lowering only the left side. Thats one way. a more balanced way would be top attenuate the right side by 1-2db then attenuate the left by 7-8db's. 
3. Differences of +/- 1-2dbs can be ignored.
4. With sound everything is connected what you do at 800hz can affect 8khz and everything in between. 
5. You will need to invest a lot of time and be patient. But results will follow.

good luck.


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## ~Spyne~ (Oct 17, 2008)

pft, use a test tone cd but just do it by ear. it's really quite easy to tell when a certain frequency is peaking or dipping compared to the rest.


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## bloodlord (May 31, 2009)

yes. x2 on the test tones. At least you could get them to sound ear-flat and then just adjust according to personal preference after, e.g. you want brighter tweets or crispier mid-highs.

you'll know if there are giant peaks and dips just by tuning through ear with test tones


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## mattyjman (Aug 6, 2009)

so, is the proper way to tune each speaker, then each side (left or right) and then to tune the individual speaker pairs together (tweets, left and right; mids, left and right; midbass, left and right) and then the entire system as a whole?


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## sam3535 (Jan 21, 2007)

http://www.diymobileaudio.com/forum...888-help-my-soundstage-ate-my-windshield.html


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## bkjay (Jul 7, 2009)

sqnut said:


> Go to your local RS and pick up an spl meter. Should be about $50-70. Don't buy the cheaper one as it would be less accurate. Download the focal test tones from here and burn it on a cd. If you're running active measure the test tones for the 31 frequencies you control, one driver at a time. If you're passive do it once for left and then for right.
> 
> Compare the L/R reading for each frequency to know how much you have to adjust from which side. Lets say 315hz is 98db from the left and 92db from the right. Now you know this frequency is 6db louder from the left and so on.
> 
> ...


This is what I did and it worked out real good. Only thing I will add is after 1k hz adjust by ear.


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## sqnut (Dec 24, 2009)

bkjay said:


> This is what I did and it worked out real good. Only thing I will add is after 1k hz adjust by ear.


Yes spot on. Above 1khz the reflections play havoc with the readings.


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## TREETOP (Feb 11, 2009)

Or make an RTA for $100:
http://www.diymobileaudio.com/forum/diyma-tutorials/38290-how-make-your-rta-100-dlls.html


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## mikey7182 (Jan 16, 2008)

Matt-

Do this: http://www.diymobileaudio.com/forum/diyma-tutorials/33740-simple-way-tune-courtesy-cmusic.html


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## HondAudio (Oct 19, 2006)

TREETOP said:


> If you have an iPhone, or access to one, there's a free app called "RTA Lite". It's not perfect but you can select 1/3 octave resolution and the bands shown will coincide with your EQ's 31 bands.
> 
> Another option is to get a CD with test tones recorded at the same level, at the frequencies you have on your EQ. You can use a cheapie Radio Shack SPL meter, and leaving the head unit's volume the same throughout testing, chart out the levels of each track. It's kind of a pain but will give you a decent idea of which frequencies are peaking or dipping the most.


I've done this before. You're going to have to be sitting in the car to do it. Turn the car on, but don't start the engine. Turn off the fan and close the windows.

I highly suggest earplugs or "earmuff" hearing protection. Some of those pure tones are painful to hear.


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## bkjay (Jul 7, 2009)

HondAudio said:


> I've done this before. You're going to have to be sitting in the car to do it. Turn the car on, but don't start the engine. Turn off the fan and close the windows.
> 
> I highly suggest earplugs or "earmuff" hearing protection. Some of those pure tones are painful to hear.


Also you can put your meter under the headrest(divers) and keep track from outside the car. Thats the way I did it.


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## coefamily (Sep 24, 2009)

The Iphone app Is a good starting point.
Ive tried the splt meter method, Its good for lower mids and bass, but really make the highs wayyyyy to bright


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## bmwproboi05 (May 3, 2009)

why not use the free version of the true RTA. Get a laptop,microphone, aux cord. Plug the laptop into your h.u,get the mic set in the right area, turn the car on, check too see your laptop sends sounds to the h.u, take the alptop outside the car , shut the door, and start playing the tunes stated above.


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## ErinH (Feb 14, 2007)

^ free version is 1 octave. Not enough to really show you what's going on.


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## bmwproboi05 (May 3, 2009)

true, but it gives you a good idea right?


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## ErinH (Feb 14, 2007)

IMO, not really. 

if you're simply trying to match levels it might be alright, but unless there's a HUGE issue it's not going to tell you much... and even at that it won't really tell you exactly what the problem is. In short, IMO, 1 octave is useless.


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## ErinH (Feb 14, 2007)

^ a trueRTA employee (owner?) posts here so he'll probably see that.


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## audiogodz1 (Jan 5, 2010)

mattyjman said:


> things sound really good right now,
> 
> -matt


Walk away.


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## 2DEEP2 (Jul 9, 2007)

Use an old IASCA Set Up CD or My Disk.
Any disk with frequency barks at 1/3 oct center.

Old IASCA set disk will play music with a 1/3 oct center frequency cut or boosted 3 dB and normal with no cut or boost.

Good way to train your ears for judging cars or tuning cars.


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## coefamily (Sep 24, 2009)

the free version gives you a starting point, by the way did you know it was FREE? 
what do you have to lose?


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## ErinH (Feb 14, 2007)

coefamily said:


> the free version gives you a starting point, by the way did you know it was FREE?
> what do you have to lose?


free is better than nothing, sure. But the free version is free for a reason. It doesn’t really give you much detail. If you have a 31 band eq, buy the 1/3 version. Otherwise you do yourself little good.
See my post above. 

Besides, if you want to talk about FREE, then you can try aRTA and holmImpulse which are both free and measure 1/3 octave.


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## titansfan (Jan 27, 2009)

IMO, the audiotools app for the iphone is a good choice. I bought it and found the rta to be fairly accurate when tuning my system. For the price, you really can't go wrong.


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## ErinH (Feb 14, 2007)

^ audiotools gets a lot of good reviews. if you dig around you'll find where sound engineers have compared their results from programs such as smaartlive to the audiotools results and have been nearly the exact same. that's pretty sweet for a $10 app, especially for what it is.


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## sam3535 (Jan 21, 2007)

coefamily said:


> the free version gives you a starting point, by the way did you know it was FREE?
> what do you have to lose?


free version, in general, means that said item is free. hence the term "free version".

could not resist, too easy


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