Just used the Room EQ Wizard...what am I looking at?

[slickshoe62]

I just got through my first few sweeps of the Room EQ wizard. I have a fairly small room (12ft X 9ft with 8ft ceilings) with some auralex for the first reflections and a couple tube traps in the corners. I want to clean up the muddy bass and get better stereo imaging out of my monitors, so I figured I'd get a feel for whats wrong with my room through the EQ wizard software. Now that I have a graphic representation of my rooms faults...........what am I looking at?? (pic attached)

I see a peak at 93.1 Hz, which falls 15db at 105 Hz, then a bump up 20db to136Hz...
does this mean I need more bass traps? Do I need to make specific traps to tame certain bass frequencies?

Can anyone with experience on this please chime in with what my graph means, or even better, show me how to read and interpret these frequency graphs.

Also, what does the waterfall graph represent, don't really understand what those are about either.

thanks in advance

[Glenn Kuras]

Basically if you want it better you just have to keep adding bass trapping to the corners. Your room graph does not look at that bad, but there is always room for improvement.

Glenn

[slickshoe62]

any others suggestions?

[Ethan Winer]

Originally Posted by slickshoe62

does this mean I need more bass traps?

Yes.

Do I need to make specific traps to tame certain bass frequencies?

No, use broadband absorbers, as thick as possible.

please chime in with what my graph means ... what does the waterfall graph represent

This article is about the ETF software, but the principles apply to all such programs:

Using ETF

--Ethan

[slickshoe62]

thanks Ethan, I'll look into all of these things!

[slickshoe62]

just had some other quick questions for anyone out there,

should I be using 2" or 4" thick 703 fiberglass for my 2'x4' panels?
4" for just the corners and 2" for side walls to cover early reflections?

p.s 703 fiberglass is really expensive out here in the 808 state!! (hawaii)

[Glenn Kuras]

Originally Posted by slickshoe62

just had some other quick questions for anyone out there,

should I be using 2" or 4" thick 703 fiberglass for my 2'x4' panels?
4" for just the corners and 2" for side walls to cover early reflections?

p.s 703 fiberglass is really expensive out here in the 808 state!! (hawaii)

Yes for the corners use 4" (better yet 6") and for the early reflection points use 2".
Instead of 703 can you get mineral wool? That will work just as well.

Glenn

[DarkUltra]

Shouldn't you rather measure modal ringing if you have muddy bass? Peaks and dips can be improved with an EQ, but if you wanto get less muddy bass you need see the time dimension.

Bass traps improves both of course

Look at Ethan Winers density test
Rigid fiberglass density tests

[DanDan]

You are looking at Gobblydegook on a computer screen :-)

Measurement is not mandatory. I recommend that you read the Room Set Up and other articles at RealTraps and GIK. The wisdom there is true of every room. Follow that advice and you will be 90% there. If you really want to Measure, I wrote this for you. http://www.gearslutz.com/board/studi...primer-v2.html
DD

[Weasel9992]

Originally Posted by DanDan

Measurement is not mandatory.

I find myself kind of agreeing with this more and more, at least until the first round of treatment is done. The thing is, in small room the measurements will indicate the same thing every time: more bass trapping, at least up to a point.

Frank

[PaulP]

I'm slowly going in the other direction. I have no practical experience with
this (yet) but a plan that I find attractive is to first determine the problem
low frequency modes by measurement then hit them with resonator traps
tuned to those frequencies. Keep adding resonator traps until the bass is
acceptable (if it's possible). Then listen to and measure the room to see
what's up and decide what remains to be done.

The problem I have with the "add the standard absorption first" plan is that
it is broadband and will absorb a lot of energy that might not need absorbing.
But you'll never know that you lost useful energy.

For example, I see one alternative to absorption in a spot for an early
reflection (if you don't want that reflection that is) is to use a reflective
panel positioned at an angle so it sends the sound elsewhere. Why throw
all that energy away ?

Paul P

[DanDan]

Hi Paul. Two wrongs may make a right! Many aspects of acoustics are strangely counter intuitive. Absorptive reflection control panels diminish damaging reflections. I call them damaging because they cancel aspects of the wanted sound field. I would argue that the energy in the listening area is washed free of cancellation, is more coherent, and may possibly have more energy. Similarly bass traps work against the cancellations, typically mid room. They diminish energy at the boundaries, where it is not wanted anyway, this diminishes cancellations in the listen zone. Many feel the net effect is more bass. It is certainly more coherent and even.
DD

[Weasel9992]

The other thing I see happening all the time is this: we audio guys are a pretty fussy, nee' obsessive/compulsive bunch. What tends to happen is that we get all wrapped around the axle over what the plot says and we stop using our ears. Having an awesome REQ plot/waterfall is not a goal in and of itself; it's a means to achieve good translation from your monitoring chain. If you're getting that, if your clients are happy, then you're done. It doesn't matter what the plot says. Now, if there's still a nagging 70Hz thing that's bugging you, then by all means shoot it and track it down, but don't obsessively shoot the room for no purpose other than to see how flat you can get.

Frank