Axiom Home Page Forums General Discussion Technical Questions So, You Say You Want To Graph Your Sub's FR, HUH?

Well I downloaded the Real Traps Test Tone CD which has tones in 1Hz increments from 10 to 300 Hz. That's right, each tone is 1Hz different from the previous tone, and the next. There are 29 tracks with 10 tones on each track, i.e., Track 1 has tones from 10 to 19 Hz with each tone lasting 10 seconds. Just enough time to read the meter and write down the reading. It turned out to be a great way to discover things in my apartment that rattle. I still haven't tracked them all down yet, BUT I WILL!

I was gonna send you the bass tones CD I created last week, as well as a .PDF of the corresponding chart with track numbers and "adjustment factors" as well as two more CDs I made of bass-interesting tracks for testing.

I was going to have them delivered by a gaggle of Hooters girls, too. With a draft in each hand.

Then you made that "dumb" comment in the other thread and I canceled the whole thing. Gave him Ray's address instead 'cuz he's nice to me.

Oh, wait. He's not nice to me either.

Come to think of it, why do I hang around here?

In reply to:

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why do I hang around here

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are you a glutton for punishment?

i meant "freak" in the nicest possible way....

bigjohn

Sure.

Guys, I'm here to tell you that as an experienced photographer and Photoshop user, those grills really ARE pink. It wasn't a color cast in that photo!

Thanls for the link, Jack. I just burned the test disc. Not sure when I'll get around to using it though. I have no means of correcting my sub's response at the moment, so I'm not sure I want to find out!

You're welcome, Peter. Ignorance IS bliss. Well, as I said, even if you don't use the tones to crate a graph, you can run around the room trying to pinpoint what the heck is doing all that rattling. And with that nice SVS you have, I'd be surprised if SOMETHING wasn't rattling.

Mark, you know we love you. I NEVER pick on anybody I don't love.

Thanks also from me for the link.

Like Peter, I have no electronic solution for any wild dips and spikes. Not knowing much about such finer points of audio like this (but learning for you all), would moving the sub around relative to the fixed dimensions of the room likely change the curve much?

paul

Here's a good free tool:

http://homepage.ntlworld.com/john.mulcahy/roomeq/index.html

Curtis - thanks, I'll check it out.

>>would moving the sub around relative to the fixed dimensions of the room likely change the curve much?

Absolutely -- it's just harder to predict what the results of each move will be. There are a FEW tricks you can do that are somewhat predictable, like positioning the sub X distance from a wall so that the distance to the wall and back is 1/2 wavelength of the frequency where you have a peak, but there usually aren't enough variables to fix all your response bumps.

Hey, I wonder how well an instrumented sub crawl would work ? Put the sub in your listening position, move the mike around the room and find the spot with the best response, then place your sub in that spot and take back your listening position ?