First, your math is off.
sqrt(40*4) = 12.65V
Not 16V.
And beyond that; This is the voltage your amplifier's speaker outputs should read, not the preamp inputs.
And even further beyond that....this is only the (theoretical) maximum that you should not go beyond. This does not mean that it is the best position for the gain settings. Since you are active you have much more level matching that needs to be performed.
I wouldn't.
I would set the gains with the crossovers off (and the amp disconnected from the speakers) and just use a simple 50-60hz tone to set them all. Assuming your amp doesn't have any large frequency response anomolies...it should measure the same voltage at 60hz as it does 9khz (assuming all processing [xovers, etc] are turned off).
Real Time Analyzer
Used to measure the frequency response of your system.
It would come in infinitely useful when attempting to properly level match the speakers and set xover points and slopes. Problem is, they are very expensive. Best hope is to see if a shop has one locally you can rent for a couple hours.
You can do these things by ear....but better results can typically be had by using an RTA.
- Thread Starter
- #3
Thanks...I used the computer's calculator and did 40*4 ^.5 which gave me 16. When I did it another way and actually hit the "^" button on the calculator's interface I got 12.65. Go figure.
The second portion, yea, I don't know the wording, but I knew what I was meaning to say.
3rd, I had planned to set a little bit lower than what my calculation was.
4th, I'll do as you suggested. I just saw the tutorial and it says to set mids while playing a 1khz test tone, so I assumed you picked a number in the middle of what it's playing frequency is.
Thanks for the help. I appreciate it.
Settings gains for active, and...can someone tell me why I would need an RTA?
You don't *need* any test method to set active parameters. You can set your gain and
crossover frequency by ear, skew up and down and choose the best sounding setup.
Takes a minute if you have 'arms reach' of your crossover.
You don't *need* any test method to set active parameters. You can set your gain and
crossover frequency by ear, skew up and down and choose the best sounding setup.
Takes a minute if you have 'arms reach' of your crossover.
And that is many times a much more daunting task for novices (and even more experienced users) than what it sounds like.
Yes, an RTA shows you your systems frequency response.
It not only comes in handy for EQ'ing, but also xover point and slope aswell as level matching as these are also directly related to frequency response.
That's what seperates the elite from the lame //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif
Jump in the fire and trust your ears, otherwise you learn nothing. //content.invisioncic.com/y282845/emoticons/yumyum.gif.0556df42231b304b9c995aefd13928a8.gif
It's an active setup, the crossover point and levels don't *have* to be fixed,
feel free to adjust the sound as you please. That is one reason why active
rules, to create different *sounds* from your system.
My home speakers have a digital crossover with 12 presets, to create 12
different sonic scenarios. I can create more if I want, but 12 if fine for now.
DIY audio is about custom sound so the user should learn how to tweak
for their ears. If they can't do this, then learn.
And you would learn more by utilizing an RTA during this process rather than just shooting in the dark //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif//content.invisioncic.com/y282845/emoticons/moon.gif.9d317aec3339ffe7fde0638df52c628a.gif
analogy.
Learning math with brain, paper, pencil [old school]
vs.
calculator [new school]
//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif
That's not really a good analogy, since in either instance you get to actually see the process you are performing and work through it. And, using a calculator gives you a "condensed" version of the process/work, whereas using an RTA is simply showing you a graphical representation of what you are doing.
I can't really think of a good analogy off hand.
But, using the RTA you can actually see how the changes you are making are affecting the frequency response and why the changes might sound better to you. I fail to see how this is anything other than an asset, and how this wouldn't aid you in learning? It will train you in learning what sounds fall into what frequency ranges, what type of response best suites your tastes, how various speakers with various xovers interact with each other, what problems are arising as a result of vehicle acoustics, what certain frequency response anomolies actually sound like, etc etc. Sure, you could do all this by ear....but it would take you far more time and you would simply be shooting in the dark and for the most part guessing (and likely coming to many inaccurate conclusions).
Would it be better to learn how to drive a car by listening to a cassette tape, or by sitting in the drivers seat and driving down the road with the assistence of an instructor?
Provide me one example of how having an RTA in addition to tuning by ear could be a detriment as opposed to simply tuning by ear.
I just don't see it. And I don't see how you could possibly think you could learn more without using an RTA.
- Thread Starter
- #12
^ thus the reason I was asking in the first place.
I don't want to use an RTA only, but more to learn where the bad areas are in my car and tune accordingly. It's much easier seeing what you're doing than trying to pick those fine-tuned notes out. I believe you get to a point where you need extra assistance- like an RTA.
I don't want to use an RTA only, but more to learn where the bad areas are in my car and tune accordingly. It's much easier seeing what you're doing than trying to pick those fine-tuned notes out. I believe you get to a point where you need extra assistance- like an RTA.
helotaxi
5,000+ posts
Kilroy was Here
Unless you know what you are listening to, you are just flailing wildly in the dark.
Here's an analogy that I think works. Imagine trying to assemble a complex object while blindfolded. You know what you want it to look like when you're done but you can't really tell what you're doing. You might get it done eventually, but it would be much easier to actually see what you're doing. After doing it while watching a few times you get to where you can do it while blindfolded, but learning while blindfolded from the beginning isn't the best way to learn. The eventual outcome might well be the same, but learning blind isn't the best method and certainly not the quickest.
Here's an analogy that I think works. Imagine trying to assemble a complex object while blindfolded. You know what you want it to look like when you're done but you can't really tell what you're doing. You might get it done eventually, but it would be much easier to actually see what you're doing. After doing it while watching a few times you get to where you can do it while blindfolded, but learning while blindfolded from the beginning isn't the best way to learn. The eventual outcome might well be the same, but learning blind isn't the best method and certainly not the quickest.
I'm optimistic when it comes to DIY audio. If can do it, anyone can do it too.
The more obstacles you place, the harder it is for a noob to make progress.
I'm saying 'turn the knobs and listen'. What do you like?
You are saying 'you need test equipment to make this work".
You don't *need* any test equipment to install a killer car audio system,
but a $5 DMM comes in handy.
By making the active install more complicated with extra procedures, you
dissuade the person from making the attempt.
Car audio tweaking is cake vs. other venues. You are confined to a small area,
so easy a caveman can do it.
If a person doesn't recognize what good sounds when tweaking a sound system by
ear, then give up audio and take up fishing as a hobby. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Don't worry, you are not alone. People in home DIY are just as confused about DIY sound
design.
The more obstacles you place, the harder it is for a noob to make progress.
I'm saying 'turn the knobs and listen'. What do you like?
You are saying 'you need test equipment to make this work".
You don't *need* any test equipment to install a killer car audio system,
but a $5 DMM comes in handy.
By making the active install more complicated with extra procedures, you
dissuade the person from making the attempt.
Car audio tweaking is cake vs. other venues. You are confined to a small area,
so easy a caveman can do it.
If a person doesn't recognize what good sounds when tweaking a sound system by
ear, then give up audio and take up fishing as a hobby. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Don't worry, you are not alone. People in home DIY are just as confused about DIY sound
design.
I never said someone should solely determine what sounds good by what the display on the RTA looks like.
But I still fail to see your point of how it is anything other than an asset while tuning, or how it wouldn't allow you to learn more (much more quickly) than sitting down fiddling with knobs.
I also wouldn't consider tuning a car "cake".
I think this is just one of those times we need to just agree to disagree //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif
But I still fail to see your point of how it is anything other than an asset while tuning, or how it wouldn't allow you to learn more (much more quickly) than sitting down fiddling with knobs.
I also wouldn't consider tuning a car "cake".
I think this is just one of those times we need to just agree to disagree //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif
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