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FR Graph

Posted: Thu Oct 12, 2006 11:46 am
by solacedagony
[ATTACH]746[/ATTACH]
I took an FR graph on a quick sweep measurement on my computer of my computer speakers using a cheap mic that I got from a guy when I bought his 8454 manual from him. I used Room EQ Wizard software that I think I got off the AVSforum ([url]http://www.avsforum.com)[/url].
That looks horrible to me, I don't have much experience reading these graphs, and I'm sure this mic isn't very accurate, but I'd imagine it should give me a rough idea of where I stand when I try it out in the car. I applied 1/3 octave smoothing, otherwise it was jagged as all get out.
I can also generate low frequency spectral delay and waterfall plots with it.

Edit: I held the mic where my head would be when I normally listen to music.

Posted: Thu Oct 12, 2006 12:31 pm
by GlassWolf
pretty normal graph for computer speakers actually.
look at it in relation to the frequencies.
you can see where the sub rolls off at about 100Hz, then you see that big dip where there's a hole between the sub and the undersized satellite speakers that kick in above the dip.
From there you can note a typical inverse bell curve on the sats, warming up the midbass range, and adding some brightness to the treble response, with that shallower dip in the midrange frequencies.
This is very typical of most peoples' listening preferences and human hearing response curves to be honest. Not that bad at all, considering what you're working with.

Posted: Thu Oct 12, 2006 1:10 pm
by solacedagony
Ah ok, that makes me feel a little better. What should a car setup sound like? Pretty flat?
I feel good that I actually recognized that the dip around 100 was where the sub was crossed over to the satellites.
Honestly, the system does sound good (Klipsche 2.1), I just figured that since it was pretty far from flat, it wasn't "good".

Posted: Thu Oct 12, 2006 1:25 pm
by GlassWolf
well, a "flat" curve with A weighting isn't that great to the ear. C weighting won't be "flat" unless the mic or RTA is weighted, but it'll be an inversebell curve, to compensate for human hearing inefficiencies.
Cars usually look pretty crappy on an RTA unless you've got a 1/3 octave or parametric EQ to shape things out. You're dealing with reflective surfaces, off axis speaker positions, off center listener position, and all sorts of things that adversely affect the sound curve.
Don't expect miracles. I spend hours with an RTA setting curves for cars to get a decent result with EQs like AC EQTs and such.. it's a lot of work.

The only shortcut I know is to use a setup like the Pioneer P9 combo that uses a pink noise generator and positional mic to set the curve, time delays, etc for you.. and use that as a starting point, and fine tune it manually from there to get your soundstage and imaging where they belong, nd not sounding overly processed.

Posted: Thu Oct 12, 2006 1:38 pm
by solacedagony
I have 5 bands parametric EQ per tweeter and mid on my 8454, and I wouldn't mind going out and getting a 1/3 octave EQ (although I have other priorities such as placement and aiming at the moment). How much is the EQ going to help out after the aiming/placement is done?
Also, I just noticed that the graph only goes to 2.5khz. I had it out to 20khz, but I guess it only saved what was on the screen at the time.