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splitting octaves while tuning

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=101222
Printed Date: May 12, 2025 at 11:59 AM


Topic: splitting octaves while tuning

Posted By: greenbroncoguy
Subject: splitting octaves while tuning
Date Posted: January 16, 2008 at 10:43 AM

Is there a general rule or thought about this?

Say I have only 7 bands of EQ adjustment(DCX-730), but since I have a 3 way + sub system, I don't span enough full octaves to have 7 to adjust for each driver, but I also don't have enough bands to go down to 1/3 octave and be able to adjust every one. While I understand that I shouldn't NEED to adjust every one, I do want to try to make sure I get everything EQ'd right.



Replies:

Posted By: DYohn
Date Posted: January 16, 2008 at 11:32 AM
If you are looking to optimise a system with an EQ, you first need to know what problems your system exhibits.  I suggest using a good RTA with a calibrated microphone and measure your vehicle's response curve, then choose an EQ designed to address the issues you have.  You might not need any EQ.  You might only need a single band parametric or you might need 30 bands per channel.  You might need to replace your speakers or adjust your installation locations, you won't know until you meter.

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Posted By: greenbroncoguy
Date Posted: January 16, 2008 at 11:39 AM

^^^ While I fully understand the importance of an RTA machine, I can't quite get my head around the idea that just because an RTA says my system is flat, does not mean my ears are going to PERCEIVE my system as playing flat, since human ears hear different frequencies at different levels.

But I think maybe RTA'ing the car to find out where any large trouble spots are, EQ'ing it all moreorless flat for the RTA, then EQ'ing the system to my preference would be the way to go, NO?





Posted By: DYohn
Date Posted: January 16, 2008 at 1:16 PM
Use an RTA (and pink noise) to discover what problems your system might have (and by "system" I mean as installed in your vehicle, as the vehicle is as important as any other component in the system.)  An EQ can be a powerful tool to help correct significant output issues, but you may also have to move speakers around, change drivers, etc. to correct severe issues like nulls, for example.  Most people prefer not to listen to a "flat" curve as we humans tend to prefer a broad bump in the bass response around 120Hz and a roll-off in the treble after about 12KHz, plus you need to understand the performance characteristics of your system  that cannot be EQ'd (such as the normal bass roll-off after the fb of your subwoofer system.)  So I say use the RTA to see what your system is doing, fix those things that are major and need fixing, then turn off the RTA, play some music, and tweak it to make it sound good to your ears.  You may or may not need an EQ to do these things.

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Posted By: greenbroncoguy
Date Posted: January 16, 2008 at 1:21 PM

Cool - that's what I was thinking. Now I just need to find someone around here w/ an RTA...





Posted By: haemphyst
Date Posted: January 16, 2008 at 4:06 PM
www.truerta.com
Free, for level 1, and perfectly usable. All you need is a laptop, a microphone input, and an RCA cable to connect your laptop to your system somehow.

www.marchandelec.com
Download from his downloads section his free, and really quite nice, signal generator.

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Posted By: greenbroncoguy
Date Posted: January 16, 2008 at 5:55 PM

haemphyst wrote:

www.truerta.com
Free, for level 1, and perfectly usable. All you need is a laptop, a microphone input, and an RCA cable to connect your laptop to your system somehow.

www.marchandelec.com
Download from his downloads section his free, and really quite nice, signal generator.

Awsome - thank you. That should get me started.





Posted By: Steven Kephart
Date Posted: January 16, 2008 at 10:23 PM
greenbroncoguy wrote:

^^^ While I fully understand the importance of an RTA machine, I can't quite get my head around the idea that just because an RTA says my system is flat, does not mean my ears are going to PERCEIVE my system as playing flat, since human ears hear different frequencies at different levels.


That is true, but this is also how you are accustom to hearing things, so a flat response will still sound natural to you.  But as Dyohn suggests it is nice to boost frequencies that you have lost over the years, or enliven the music with some adjusting of frequencies.  To add to what Dyohn said, I suggest after achieving a flat response in your vehicle to live with it for a couple weeks.  Then after you are used to it that way, note the settings for future reference and then make your own personal adjustments.





Posted By: greenbroncoguy
Date Posted: January 17, 2008 at 3:34 PM
Steven Kephart wrote:

greenbroncoguy wrote:

^^^ While I fully understand the importance of an RTA machine, I can't quite get my head around the idea that just because an RTA says my system is flat, does not mean my ears are going to PERCEIVE my system as playing flat, since human ears hear different frequencies at different levels.


That is true, but this is also how you are accustom to hearing things, so a flat response will still sound natural to you.  But as Dyohn suggests it is nice to boost frequencies that you have lost over the years, or enliven the music with some adjusting of frequencies.  To add to what Dyohn said, I suggest after achieving a flat response in your vehicle to live with it for a couple weeks.  Then after you are used to it that way, note the settings for future reference and then make your own personal adjustments.


Sweet. I really the help guys. I know my questions may have been a little off the wall and different from the usual stuff that gets posted up here, but it was just on my mind.

Thanks,

-Matt





Posted By: dudehitt
Date Posted: January 17, 2008 at 4:53 PM

haemphyst wrote:

www.truerta.com
Free, for level 1, and perfectly usable. All you need is a laptop, a microphone input, and an RCA cable to connect your laptop to your system somehow.

www.marchandelec.com
Download from his downloads section his free, and really quite nice, signal generator.

I think the first link should be www.trueaudio.com.  The software is trueRTA.






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