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I wanted to post this in case anyone was needing help tuning their system. I have tuned several 1st place vehicles that comped in IASCA in the Pro Classes.

If anyone has any questions, please feel free to ask. What this process will do is completly balance your system to where you can play any CD with any type of music and the system will sound musical and balanced.

This is all about Balance.

The areas that will need to be addressed will be

Crossover base level 5%
Gain Levels 40%
EQ 50%
Crossover 3%
Fine Tuning 2%

The percentage is acculative and shows you how much futher you need to go.
Tuning can not be done by ear alone. Tuning by ear brings personal preference into the equation.

Equipment you will need access to do this correctly.
Radio Shack Digital DB meter.
CD with Pink Noise track.(This is a track that plays a 1 watt signal at every frequency from 20hz to 20K
Real Time Analyzer, most audio shops of any talent have these. I am in Charlotte, NC if you cant find one and are within driving distance.

The first thing to do is set your basic crossover points
For the highs and mids, set the break at 3.5K between tweeter and midrange. For the subs. For a 10" set it to 75-85 and for a 12" move it down to 60-70
Second set all EQ and Tone adjustments to flat.

Place the Radio Shack digital DB meter on the arm rest, set the volume to 3/4. Unplug the highs and mids. so that just the subs are playing. Insert the pink noise cd and play it.

Fins a level that is comfortable without distortion where it sounds like the subs are not breaking up.
Write the number down on the dB meter. If you have gains for both left and right, use the balance on the radio to set both to the same. They will not be the same.
Once you have a number.
Unplug the subs then plug up the mids. do the exact same process, this time the mids should be 3-5 db lower than what the subs were based on the number you recorded.
When done, unplug the mids and plug in the higs, do the same process and they should be 2-3 db quieter than the mids.

Once this is done, take the Real Time Analyzer hang the microphone from the rear view mirror, se it up to medium speed. Play the pink noise CD with all speakers hooked up with the volume on 1/2. Also set the level of adjustment to be 3db

Now what you are looking at on the RTA is the acoustical curve for the interior of the vehicle. You will notice that some frequencies are louder than others, and some are quieter than others. This is where you have to adjust for the acoustical flaws in the car. That curve should not be straigt, but there should not be more than a 3db variation between each frequency and when you are done there will be a smooth curve between frequencies. When you are adjusting, it is important to reduce levels before raising levels. When you raise a level you are adding information to the signal that is not there. Sometimes you have to do it, but do as little as possible.

In the list above I mentioned that you may have to make crossover adustments to get the levels to move, This is where you would do that.

Once you are done you are 95% there. If you put in any CD it should sound awesome at any volume level.

Now, Fine tuning. This is where you do your own personal prefernces. If the system hsa too much bass for your liking or too much mid or high, look at the RTA, to see where the peek is or dip is that you dont like and make the adjustment there. Stay away from the treble and bass controls.


If you have any questions please let me know
Let me know how it turns out for you.
Bryan
 

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Very nice write-up, Bryan; thanks a lot! I actually had written you a PM asking for just this but your inbox was full. Probably I wasn't the only one writing ;) or you can read minds.

One question, though. Why would you hang the RTA microphone on the rearview mirror? Shouldn't it be rather where your ears would be i.e. somehow fix it to the driver's headrest or hang it from inbetween the center of the two headrests?

I know the rearview mirror is more practical but you never have your ears at that point and I imagine the proximity of the windshield could screw the readings a bit, too.

Till
 

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Where in Charlotte do you work? I've been in A/V in Charlotte 22 years, maybe we know each other.
 

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Discussion Starter #4
tfar said:
Very nice write-up, Bryan; thanks a lot! I actually had written you a PM asking for just this but your inbox was full. Probably I wasn't the only one writing ;) or you can read minds.

One question, though. Why would you hang the RTA microphone on the rearview mirror? Shouldn't it be rather where your ears would be i.e. somehow fix it to the driver's headrest or hang it from inbetween the center of the two headrests?

I know the rearview mirror is more practical but you never have your ears at that point and I imagine the proximity of the windshield could screw the readings a bit, too.

Till
Balance. If you put it at your ear and tune it in that area of the car, the system will not be balanced for the passenger. In addition, you will start to effect frequency dependent imaging. This is a bad thing.
 

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Discussion Starter #5
vmaxNC said:
Where in Charlotte do you work? I've been in A/V in Charlotte 22 years, maybe we know each other.
If I said Red 86 Pontiac Fiero published in April 99 Car Stereo Review, with Pioneer and A/D/S system does that help?


Drop me a pm and lets hook up.
 

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lunapark said:
If I said Red 86 Pontiac Fiero published in April 99 Car Stereo Review, with Pioneer and A/D/S system does that help?


Drop me a pm and lets hook up.
You're too popular to accept my PM! You need to clean out your box a bit.
 

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I agree with everything you posted except for measuring the bass level with the Radio Shack meter. It is not very accurate at measuring bass levels. I have a high end HT and sound system and with some research have found this to be true. There is a formula to use to compensate for this.

I can do a search to find the info if you would like.

Again great post.
 
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