ETF acoustic software questions?

Discussion in 'Archived Threads 2001-2004' started by David Smith, Jan 17, 2002.

  1. David Smith

    David Smith Stunt Coordinator

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    Is there anyone here that’s familiar with ETF acoustic software that might be able to give me a little help?

    I have recently finished a new Music/HT room in part of my garage and I would like to get the very most out of my listening experience. I’ve had this software recommended to me before on this and other online forums, so I’m hoping that I can achieve very good room acoustics.

    After downloading the demo version, it seems a little confusing to me what I should do. When I read about the bass traps and diffusers that can be made to help correct some acoustic problems, I notice that it basically says if your room is over 1500 cubic feet, the bass traps will not be a very economical solution.

    I guess my question is what good does it do to know all of the measurements and see all the graphs of my system if it doesn’t give a good alternative on how to correct the problems?

    Also, what is the Q value that is talked about in the bass trap area?

    I’m sure I’ll have more questions later, but answers here would be a good start. Thanks! David

    PS Any other suggestions on how to make this software work for me would be great! It’s a little overwhelming at first glance.
     
  2. Pete Mazz

    Pete Mazz Supporting Actor

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    I just purchased ETF and still trying to get the hang of it myself. My goal is to try to tame the really bad spots with something like the BFD, if needed for the low end, and possibly some Xover mods or EQ to the main speakers for the upper end. Not sure how it'll flesh out yet but the software can tell you where the problem spots are. Can't help you with the bass traps as I've never thought of using them in my room(asthetics).

    Pete
     
  3. BruceD

    BruceD Screenwriter

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    David,

    I think you must first start with a plan. What do you expect out of your new room that you didn't have before?

    It's very hard to tell you what's wrong with your room before you actually measure it.

    There is only one fundamental procedure; setup, measure, adjust, measure, adjust, measure, adjust . . . . etc. until you get it the way you want it.

    The software will do a very good job of measuring and give you a yardstick to measure your progress towards your goal.

    Step 1 would be to spend some time with the demo room and try to understand how the demo room changes are represented in the software graphs. This helps you understand how to apply it to your situation. But you will still need to setup and measure first.

    I'll try to answer any specfic questions you have.
     
  4. Mike Dr

    Mike Dr Stunt Coordinator

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    One of the members here just recently started putting together an excellent FAQ on usage for ETF software. just search back a few days for ETF in this forum and you'll find it. It's extremely useful.
     
  5. David Smith

    David Smith Stunt Coordinator

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    Excellent. Thanks guys, for all the help.

    One more thing, I'm assumning that bass traps help eliminate the peaks in the spl. What can you do about the valleys?

    THanks again! David
     
  6. jeff peterson

    jeff peterson Supporting Actor

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    The thinking is that if you get rid of the peaks, there are no more valleys. I understand that you shouldn't try to equalize the valleys up as you'll reduce subwoofer dynamic range (don't ask me for more technical info than that).

    I think, too, that when we say flat response, that it really means all frequencies are within 3(?) db of each other; not flat as a ruler.
     
  7. BruceD

    BruceD Screenwriter

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    A procedural recommendation for using Parametric EQs for optimum bass response is to start at the lowest frequency peak, say for example 33Hz, and correct that peak first. This is based on the sub/room's bass frequency response you measured first.

    Why? Because it will effect all peaks and valleys above it as well. It will change the peaks and valleys of frequencies above it after you correct it.

    Then, after you have entered the first peak correction in the Parametric EQ, measure the room again, then proceed to correct (cut) the next higher frequency peak that shows up in this new room measurement.

    Continue this sequence up the bass frequency spectrum until you get your room's bass response within the -3dB you are looking for, or whatever sounds best to you.

    The reason I like ETF5 software for this measurement process is that you can display a real-time frequency response graph that is recalculated every 3-4 seconds. So as soon as you make the Parametric EQ adjustment another measurement automatically takes place and you're ready for the next adjustment.
     
  8. David Smith

    David Smith Stunt Coordinator

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    Thanks again for the help!

    I have another question.

    While browsing my local hi-fi shop today, I found that they had a used Audio Control Richter Scale. I went ahead and bought it with the option of returning it if it doesn't work right for me.

    Well. I realized when I got home that my receiver doesn't appear to have a tape loop. Is this correct? I have a new Marantz SR-7200.

    My question is, can I even use this piece of gear without the tape loop? If not, is there another EQ of some sort that I can use with my receiver?

    Thanks again! David
     
  9. BruceD

    BruceD Screenwriter

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    I expect you would normally connect the Richter to the sub-out of the Marantz 7200 and then the output of the Richter to your powered sub or sub amp input.
    Does the Marantz 7200 have a set of "U" shaped plugs connecting pre=outs with amp-ins?
    If the answer is yes, then you could connect the Richter to the main L&R channels if you want:
    Marantz L&R pre-out -> Richter L&R input
    Richter L&R output -> Marantz L&R amp input
    ------------------------------------------------
    You should be aware of one thing about the Richter, it only has 1/2 octave EQ controls. Generally you want finer precision than 1/2 octave, at least 1/3 or even 1/6 octave precision is preferred. The BFD 1100P we talk about in this forum uses 1/60 octave precision for it's EQ controls.
     

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